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1

Improving Rutting Resistance of Pavement Structures Using Geosynthetics: An Overview  

PubMed Central

A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting). PMID:24526919

Karim, Mohamed Rehan; Khodaii, Ali; Almasi, Mohammad Hadi

2014-01-01

2

Improving rutting resistance of pavement structures using geosynthetics: an overview.  

PubMed

A pavement structure consists of several layers for the primary purpose of transmitting and distributing traffic loads to the subgrade. Rutting is one form of pavement distresses that may influence the performance of road pavements. Geosynthetics is one type of synthetic materials utilized for improving the performance of pavements against rutting. Various studies have been conducted on using different geosynthetic materials in pavement structures by different researchers. One of the practices is a reinforcing material in asphalt pavements. This paper intends to present and discuss the discoveries from some of the studies on utilizing geosynthetics in flexible pavements as reinforcement against permanent deformation (rutting). PMID:24526919

Mirzapour Mounes, Sina; Karim, Mohamed Rehan; Khodaii, Ali; Almasi, Mohammad Hadi

2014-01-01

3

Experimental study on properties of pervious concrete pavement materials  

Microsoft Academic Search

In this paper, a pervious concrete pavement material used for roadway is introduced. Using the common material and method, the strength of the pervious concrete is low. Using smaller sized aggregate, silica fume (SF), and superplasticizer (SP) in the pervious concrete can enhance the strength of pervious concrete greatly. The pervious pavement materials that composed of a surface layer and

Jing Yang; Guoliang Jiang

2003-01-01

4

The impact of material characteristics on tire pavement interaction noise for flexible pavements  

NASA Astrophysics Data System (ADS)

Noise pollution has recently been one of the growing problems all over the world. While there are many sources of the noise, traffic noise is the main contributor to the total environmental noise. Although there are different sources for traffic noise, the tire pavement interaction noise is the most dominant component within most city and highway limits. One of the ways to reduce the tire pavement noise is to improve the material characteristics of the pavements such that they produce less noise. In this study, the relationship between basic material characteristics (e.g., Hot Mix Asphalt (HMA) volumetrics) and sound generation and absorption characteristics of flexible pavements was investigated. In addition, the effect of linear visco-elastic properties (e.g., dynamic modulus (|E*|) and phase angle (delta)) on sound absorption was studied. In order to focus only on impact of material characteristics and overshadow the effect of surface texture, a novel laboratory tire pavement noise measurement simulator (TIPANOS) was developed. The statistical analysis results showed that although the individual material characteristics do not have appreciable influence on sound absorption, there is a significant correlation between sound pressure levels (SPL) and combination of several material and linear visco-elastic parameters.

Kocak, Salih

5

Analysis of durability of advanced cementitious materials for rigid pavement construction in California  

SciTech Connect

Caltrans specifications for the construction of rigid pavements require rapid setting, high early strength, superior workability concrete with a desired 30+ year service life. These strict specifications provide the motivations for the investigation of advanced cementitious materials for pavement construction. The cementitious materials under consideration by Caltrans may be classified into four categories: Portland cements and blends, calcium aluminate cements and blends, calcium sulfoaluminate cements, and fly ash-based cements. To achieve the desired 30+ year design life, it is essential to select materials that are expected to exhibit long-term durability. Because most of the cementitious materials under consideration have not been extensively used for pavement construction in the United States, it is essential to characterize the long-term durability of each material. This report provides general information concerning the deleterious reactions that may damage concrete pavements in California. The reactions addressed in this report are sulfate attack, aggregate reactions, corrosion of reinforcing steel, and freeze-thaw action. Specifically, the expected performance of Portland cements and blends, calcium aluminate cements and blends, calcium sulfoaluminate cements, and fly ash-based cements are examined with regard to each of the deleterious reactions listed. Additional consideration is given to any deterioration mechanism that is particular to any of these cement types. Finally, the recommended test program for assessing potential long-term durability with respect to sulfate attack is described.

Kurtis, K.E.; Monteiro, P.

1999-04-01

6

SOURCE: UNIVERSITY OF CALIFORNIA PAVEMENT RESEARCH CENTER PAVEMENT TECHNOLOGY UPDATE  

E-print Network

SOURCE: UNIVERSITY OF CALIFORNIA PAVEMENT RESEARCH CENTER PAVEMENT TECHNOLOGY UPDATE at the California Department of Transportation. Content is provided by the University of California Pavement Research Center. The University of California Pavement Research Center Using innovative research and sound

California at Berkeley, University of

7

Evaluation of pavement base and subgrade material properties and test procedures  

E-print Network

EVALUATION OF PAVEMENT BASE AND SUBGRADE MATERIAL PROPERTIES AND TEST PROCEDURES A Thesis by LESLIE TITUS-GLOVER Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1995 Major Subject. Civil Engineering EVALUATION OF PAVEMENT BASE AND SUBGRADE MATERIAL PROPERTIES AND TEST PROCEDURES A Thesis by LESLIE TITUS-GLOVER Submitted to Texas A&M University m partial fulfillment...

Titus-Glover, Leslie

1995-01-01

8

Integrated Materials and Construction Practices (IMCP) for Concrete Pavement  

E-print Network

Integrated Materials and Construction Practices (IMCP) for Concrete Pavement Workshop Participant Handbook Prepared for Prepared by Federal Highway Administration National Concrete Pavement Technology Center Office of Pavement Technology at Iowa State University 400 7th Street AW 2711 South Loop Drive

9

Advanced Characterisation of Pavement and Soil Engineering Materials Loizos, Scarpas & Al-Qadi (eds)  

E-print Network

1241 Advanced Characterisation of Pavement and Soil Engineering Materials ­ Loizos, Scarpas & Al and economical alternative for the repair of deteriorated pavements, reflective cracking continues to be major approaches have not provided a direct means for the study of crack initiation and propagation in pavements

Paulino, Glaucio H.

10

Road Materials and Pavements Design. Volume X No X/2013, pages 1 to n Review of glass fiber grid use for pavement  

E-print Network

Road Materials and Pavements Design. Volume X No X/2013, pages 1 to n Review of glass fiber grid use for pavement reinforcement and APT experiments at IFSTTAR Mai Lan Nguyen* Juliette Blanc* Jean performance, to extend service life and thus to reduce maintenance costs of road pavements. Among a large

Paris-Sud XI, Université de

11

Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material.  

PubMed

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM(10)) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, Particle Induced X-Ray Emission Analysis and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM(10), respectively. The results show that in the road simulator, where resuspension is minimized, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consist almost entirely of minerals from the pavement stone material, but also that Sulfur is enriched for the submicron particles and that Zink is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM(10) emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results imply that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties. PMID:18258284

Gustafsson, Mats; Blomqvist, Gran; Gudmundsson, Anders; Dahl, Andreas; Swietlicki, Erik; Bohgard, Mats; Lindbom, John; Ljungman, Anders

2008-04-15

12

PAVEMENT TECHNOLOGY UPDATE This Technology Transfer Program  

E-print Network

PAVEMENT TECHNOLOGY UPDATE This Technology Transfer Program publication is funded by the Division by the University of California Pavement Research Center. The University of California Pavement Research Center Using innovative research and sound engineering principles to improve pavement structures, materials

California at Berkeley, University of

13

Thermal stresses of flexible pavement with consideration of temperature-dependent material characteristics using stiffness matrix method  

NASA Astrophysics Data System (ADS)

The asphalt pavement is regarded as a multilayered elastic half space axisymmetrical body. By introducing the relationship between material characteristics and temperature into the fundamental equations of thermoelasticity and using mathematic methods of Laplace and Hankel integral transformation, the stiffness matrix for a layer is derived firstly. Then the global stiffness matrix is established for multilayered elastic half space using the finite element concepts in which layers are completely contacted. Therefore, explicit solution for thermal stresses of the asphalt pavement is obtained from the solution of the algebra equation formed by global stiffness matrix and the inverse Hankel and Laplace integral transformation. Because the elements of matrix do not include positive exponential function, the calculation is not overflowed and the shortages of transfer matrix method are overcome. This approach serves as a better model for real pavement structure as it takes into account the relationships between the material characteristics and temperature in the pavement system.

Geng, Litao; Ren, Ruibo; Zhong, Yang; Xu, Qian

2011-02-01

14

Effective pollutant retention capacity of permeable pavements for infiltrated road runoffs determined by laboratory tests.  

PubMed

The infiltration of urban runoff always implies an entrance of pollutants into the soil and ground water. Due to legal regulations in many communes there is no longer any permission needed for stormwater infiltration, if administrative regulations and the requirements of standards are observed. The results of a research project carried out under the heading "Development of an assessment procedure for permeable pavements" show, that the pollutant retention capacity of permeable pavements varies considerably, depending on the material and the specific reactive surface. The objective of the study was to work out recommendations of suitable permeable pavements for different types of urban runoff. Selected data about the quality of urban runoff was compiled into a runoff matrix, which was used for defining characteristic dilutions. In batch tests, the material of the infiltration devices is penetrated with the dilutions. A test installation in large scale is used to calibrate the sorption coefficients derived from the batch experiment. PMID:15790226

Fach, S; Geiger, W F

2005-01-01

15

23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...  

Code of Federal Regulations, 2011 CFR

...Sign Materials and Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of spectrophotometers or accurate tristimulus colorimeters for measuring the daytime color of retroreflective materials,...

2011-04-01

16

23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...  

Code of Federal Regulations, 2013 CFR

...Sign Materials and Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of spectrophotometers or accurate tristimulus colorimeters for measuring the daytime color of retroreflective materials,...

2013-04-01

17

23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...  

Code of Federal Regulations, 2010 CFR

...Sign Materials and Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of spectrophotometers or accurate tristimulus colorimeters for measuring the daytime color of retroreflective materials,...

2010-04-01

18

23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...  

Code of Federal Regulations, 2012 CFR

...Sign Materials and Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of spectrophotometers or accurate tristimulus colorimeters for measuring the daytime color of retroreflective materials,...

2012-04-01

19

23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...  

Code of Federal Regulations, 2014 CFR

...Sign Materials and Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of spectrophotometers or accurate tristimulus colorimeters for measuring the daytime color of retroreflective materials,...

2014-04-01

20

Comparison of the hydraulic behaviour and the quality of highway runoff water according to the type of pavement  

Microsoft Academic Search

This paper presents the results of an experimental investigation aimed at determining the impact of the type of pavement, whether conventional or porous, on the hydraulic behaviour and on the quality of runoff water. Data obtained from a French highway both before and after the replacement of a conventional asphalt by a porous asphalt are compared. Statistical tests have been

C Pagotto; M Legret; P Le Cloirec

2000-01-01

21

Life Cycle Assessment of Reclaimed Asphalt Pavement  

E-print Network

Life Cycle Assessment of Reclaimed Asphalt Pavement to Improve Asphalt Pavement Sustainability By-melt old binder on the RAP #12;Life Cycle Assessment (LCA) · #12;Asphalt Pavement Life Cycle Road-filled after use #12;Asphalt Pavement Life Cycle Road Construction Aggregates Additives Bitumen Down- Cycled

Minnesota, University of

22

GPR-based evaluation of strength properties of unbound pavement material from electrical characteristics  

NASA Astrophysics Data System (ADS)

It is well known that inter-particle friction and cohesion of soil particles and aggregates deeply affect the strength and deformation properties of soils, exerting critical effects on the bearing capacity of unbound pavement materials. In that respect, considering that strength characteristics of soil are highly dependent on particle interactions, and assuming a relationship between electric properties (e.g. electric permittivity) and bulk density of materials, a good correlation between mechanical and electric characteristics of soil is expected. In this work, Ground Penetrating Radar (GPR) techniques are used to investigate this topic. Two GPR equipment with same electronic characteristics and different survey configurations are used. Each radar operates with two ground-coupled antennae at 600 MHz and 1600 MHz central frequencies. Measurements are developed using 4 channels, 2 mono-static and 2 bi-static. The received signal is sampled in the time domain at dt = 7.8125 10-2 ns, and in the space domain every 2.4 10-2 m. A semi-empirical model is proposed for predicting the resilient modulus of sub-asphalt layers from GPR-derived data. Basically, the method requires to follow two steps. Firstly, laboratory tests are carried out for calibration, with the main focus to provide consistent empirical relationships between physical (e.g. bulk density) and electric properties. The second step is focused on the in-situ validation of results through soil strength measurements retrieved by CBR tests and Light Falling Weight Deflectometer (LFWD). On the basis of traditional empirical equations used for flexible pavement design, the following expression is proposed: -m Ei = ?j?hj,i j=1 where Ei [MPa] is the ith expected resilient modulus of the surveyed soil under the line of scan, hj,i [m] is the ith thickness referred to the jth layer, and ?j is a dielectric parameter calibrated as a function of the relative electric permittivity. The experimental setting requires the use of road material, typically employed for subgrade and subbase courses. Different types of soil ranging from group A1 to A4 by AASHTO soil classification system, are analyzed. As regards the laboratory experiments, material is gradually compacted in electrically and hydraulically isolated test boxes. A large metal sheet supports the experimental boxes, so that the transmitted GPR signal is totally reflected. GPR inspections are carried out for any compaction step up to the maximum density value available. Moreover, in-situ tests are carried out on targeted types of soil, with grain size distribution and texture comparable to those analyzed in laboratory environment. The results of this study confirm a promising correlation between the electric permittivities and the strength and deformation properties of the surveyed soils. Laboratory analyses show that the relationship between the relative permittivity and the bulk density is positive: the higher the density of the compacted soil sample, the higher the electric permittivity of the medium. Analogously, in-situ validation presents a good comparison between measured and predicted data. Percentage errors less than 20% demonstrate that a reliable prediction of Young Modulus using this GPR-based approach can be achieved.

Benedetto, Andrea; D'Amico, Fabrizio; Tosti, Fabio

2013-04-01

23

Road Materials and Pavements Design. Volume X No X/2009, pages 1 to n Viscoroute 2.0: a tool for the simulation of  

E-print Network

Road Materials and Pavements Design. Volume X ­ No X/2009, pages 1 to n Viscoroute 2.0: a tool for the simulation of moving load effects on asphalt pavement Chabot* A. -- Chupin* O. -- Deloffre* L. -- Duhamel** D of asphalt pavement layers. To analyze this effect, a model and a software called ViscoRoute have been

Paris-Sud XI, Université de

24

The use of marine sediments as a pavement base material.  

PubMed

The management of marine sediments after dredging has become increasingly complex. In the context of sustainable development, traditional solutions such as immersion will be increasingly regulated. More than ever, with the shortage of aggregates from quarries, dredged material could constitute a new source of materials. In this study of the potential of using dredged marine sediments in road construction, the first objective is to determine the physical and mechanical characteristics of fine sediments dredged from a harbour in the north of France. The impacts of these materials on the environment are also explored. In the second stage, the characteristics of the fine sediment are enhanced for use as a road material. At this stage, the treatment used is compatible with industrial constraints. To decrease the water content of the fine sediments, natural decantation is employed; in addition, dredged sand is added to enhance the granular distribution and to reinforce the granular skeleton. Finally, the characteristics of the mix are enhanced by incorporating binders (cement and/or lime). The mechanical characteristics measured on the mixes are compatible with their use as a base course material. Moreover, the obtained results demonstrate the effectiveness of lime in the mixes. In terms of environmental impacts, on the basis of leaching tests and according to available thresholds developed for the use of municipal solid waste incineration (MSWI) bottom ash in road construction, the designed dredged mixes satisfy the prescribed thresholds. PMID:18640020

Dubois, Vincent; Abriak, Nor Edine; Zentar, Rachid; Ballivy, Grard

2009-02-01

25

Impact of the variation in dynamic vehicle load on flexible pavement responses  

NASA Astrophysics Data System (ADS)

The purpose of this research was to evaluate the dynamic variation in asphalt pavement critical responses due to dynamic tire load variations. An attempt was also made to develop generalized regression equations to predict the dynamic response variation in flexible pavement under various dynamic load conditions. The study used an extensive database of computed pavement response histories for five different types of sites (smooth, rough, medium rough, very rough and severely rough), two different asphalt pavement structures (thin and thick) at two temperatures (70 F and 104 F), subjected to a tandem axle dual tire at three speeds 25, 37 and 50 mph (40, 60 and 80 km/h). All pavement responses were determined using the 3D-Move Analysis program (Version 1.2) developed by University of Nevada, Reno. A new term called Dynamic Response Coefficient (DRC) was introduced in this study to address the variation in critical pavement responses due to dynamic loads as traditionally measured by the Dynamic Load Coefficient (DLC). While DLC represents the additional varying component of the tire load, DRC represents the additional varying component of the response value (standard deviation divided by mean response). In this study, DRC was compared with DLC for five different sites based on the roughness condition of the sites. Previous studies showed that DLC varies with vehicle speed and suspension types, and assumes a constant value for the whole pavement structure (lateral and vertical directions). On the other hand, in this study, DRC was found to be significantly varied with the asphalt pavement and function of pavement structure, road roughness conditions, temperatures, vehicle speeds, suspension types, and locations of the point of interest in the pavement. A major contribution of the study is that the variation of pavement responses due to dynamic load in a flexible pavement system can be predicted with generalized regression equations. Fitting parameters (R2) in the rage of 0.60 to 0.87 were observed the DRC predictive equations. In addition, verification of those generalized equations was evaluated using different sets of asphalt pavement structures and pavement materials. The differences between calculated and predicted values were found to be within +/-20% for the maximum tensile strain and +/-30% for the maximum compressive strain in the asphalt layer.

Ahsanuzzaman, Md

26

Adaptive prediction of pavement performance  

E-print Network

. This adjustment is considered for each category of pavement distress separately. The computer program has been tested using field data from Long Term Pavement Performance Project (LTPP) and TxDOT Pavement Management Information System (PMIS) data collected...

Zulyaminayn, Mohammed

2012-06-07

27

Recycled materials in asphalt pavements. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the recycling of asphalt pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (Contains a minimum of 160 citations and includes a subject term index and title list.)

Not Available

1994-05-01

28

An approach to the usage of polyethylene terephthalate (PET) waste as roadway pavement material.  

PubMed

This study investigates an application area for Polyethylene Terephthalate (PET) bottle waste which has become an environmental problem in recent decades as being a considerable part of the total plastic waste bulk. Two novel additive materials, namely Thin Liquid Polyol PET (TLPP) and Viscous Polyol PET (VPP), were chemically derived from waste PET bottles and used to modify the base asphalt separately for this aim. The effects of TLPP and VPP on the asphalt and hot mix asphalt (HMA) mixture properties were detected through conventional tests (Penetration, Softening Point, Ductility, Marshall Stability, Nicholson Stripping) and Superpave methods (Rotational Viscosity, Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR)). Also, chemical structures were described by Scanning Electron Microscope (SEM) equipped with Energy Dispersive Spectrometer (EDS) and Fourier Transform Infrared (FTIR) techniques. Since TLPP and VPP were determined to improve the low temperature performance and fatigue resistance of the asphalt as well as the Marshall Stability and stripping resistance of the HMA mixtures based on the results of the applied tests, the usage of PET waste as an asphalt roadway pavement material offers an alternative and a beneficial way of disposal of this ecologically hazardous material. PMID:25080154

Gr, Metin; ubuk, M Kr?at; Arslan, Deniz; Farzanian, S Ali; Bilici, ?brahim

2014-08-30

29

78 FR 26847 - Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses  

Federal Register 2010, 2011, 2012, 2013, 2014

...three pavement types: dense-graded asphaltic concrete (DGAC), open-graded asphaltic concrete (OGAC), and Portland cement concrete (PCC). Prediction of future noise levels is based on the ``average'' pavement type, calculated as the...

2013-05-08

30

Development of Pavement Temperature Contours for India  

NASA Astrophysics Data System (ADS)

The stress-strain response of the bituminous pavements is highly sensitive to temperature. To systematically analyze the pavement performance, it is necessary that one understands the variation of pavement temperature spatially and temporally during the life time of a pavement. In this investigation, historic air temperature data for 37 locations across India was collected. Using this database, pavement temperature data was predicted by an appropriate air temperature-pavement temperature model. High and low temperature pavement temperature contours were generated for the first time for India. It was seen that the locations spanning from Srinagar to Madhya Pradesh and Rajasthan to Orissa were extremely critical. The minimum temperature in these locations was 10 C and the maximum temperature was around 68 C. Clearly such information is necessary when making choice of binder grade and bituminous layer thickness.

Nivitha, M. R.; Krishnan, J. M.

2014-06-01

31

Greenhouse gas emissions of alternative pavement designs: framework development and illustrative application.  

PubMed

Pavement rehabilitation is carbon intensive and the choice of pavement type is a critical factor in controlling greenhouse gas (GHG) emissions. The existing body of knowledge is not able to support decision-making on pavement choice due to a lack of consensus on the system boundaries, the functional units and the estimation periods. Excessive data requirements further inhibit the generalization of the existing methodologies for design evaluation at the early planning stage. This study proposes a practical life-cycle GHG estimation approach, which is arguably effective to benchmark pavement emissions given project bid tabulation. A set of case studies conducted for this study suggest that recycled asphalt pavement (e.g., foam stabilized base (FSB), and warm mix asphalt (WMA)) would prevent up to 50% of GHGs from the initial construction phase. However, from a life-cycle perspective, pavement emissions are dictated largely by the traffic characteristics and the analysis period for the use phase. The benefits from using recycled materials (e.g., FSB) are likely to diminish if the recycled products do not perform as well as those properly proportioned with less recycled materials, or if the recycled materials are locally unavailable. When the AADT reaches 10,000, use phase releases more than 97% of the life cycle emissions and the emissions difference among alternative designs will be within 1%. PMID:24333742

Liu, Xiaoyu; Cui, Qingbin; Schwartz, Charles

2014-01-01

32

Road Materials and Pavement Design. Volume 9 No. 1/2008, pages 31 to 57 Assessment of Existing Micro-mechanical  

E-print Network

Road Materials and Pavement Design. Volume 9 ­ No. 1/2008, pages 31 to 57 Assessment of Existing[UniversityofIllinoisatUrbana-Champaign]at16:0417June2014 #12;32 Road Materials and Pavement Design. Volume 9 ­ No. 1/2008 1. Introduction

Paulino, Glaucio H.

33

Compaction of asphalt pavement. Final report  

SciTech Connect

This synthesis will be of interest to construction and materials engineers, paving contractors, equipment manufacturers, and others who are involved in assessing the performance of asphalt pavements. Information is presented on various issues related to compaction of asphalt pavements. Compaction is one of the most important factors affecting the performance of asphalt pavements. The report of the Transportation Research Board describes the theory, methods, equipment, and specifications related to the compaction of asphalt pavements. A brief history of, the importance of, and factors affecting compaction are also discussed. Construction influences, density measurements, and trends are also considered.

Hughes, C.S.

1989-10-01

34

Effects of temperature and water on pavement performance  

SciTech Connect

The 12 papers in the report deal with the following areas: procedures for estimation of asphalt-concrete pavement moduli at in-situ temperatures; stress caused by temperature gradient in portland-cement concrete pavements; characterizing temperature effects for pavement analysis and design; temperature response of concrete pavements; an examination of environmental versus load effects on pavements; moisture in portland-cement concrete; effect of rainfall on the performance of continuously reinforced concrete pavements in Texas; effect of moisture on the structural performance of a crushed-limestone road base; water-induced distress in flexible pavement in a wet tropical climate; an evaluation of design high-water clearances for pavements; economic impact of pavement subsurface drainage; use of open-graded, free-draining layers in pavement systems; a national synthesis report.

Badu-Tweneboah, K.; Tia, M.; Ruth, B.E.; Richardson, J.M.; Armaghani, J.M.

1987-01-01

35

Global warming potential of pavements  

Microsoft Academic Search

Pavements comprise an essential and vast infrastructure system supporting our transportation network, yet their impact on the environment is largely unquantified. Previous life-cycle assessments have only included a limited number of the applicable life-cycle components in their analysis. This research expands the current view to include eight different components: materials extraction and production, transportation, onsite equipment, traffic delay, carbonation, lighting,

Nicholas J. Santero; Arpad Horvath

2009-01-01

36

SOURCE: UNIVERSITY OF CALIFORNIA PAVEMENT RESEARCH CENTER FIGURE 1 Moisture-induced stripping in asphalt treated base layer  

E-print Network

in asphalt treated base layer PAVEMENT TECHNOLOGY UPDATE This Technology Transfer Program publication on pavements of all types, including concrete and asphalt. It has operated facilities at UC Berkeley since 1948 the per- formance of asphalt pavements. Moisture damage is caused by a loss of adhesion, com- monly

California at Berkeley, University of

37

Functionality enhancement of industrialized optical fiber sensors and system developed for full-scale pavement monitoring.  

PubMed

Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pavement monitoring are developed, with the corresponding operational principles clarified in theory and the performance double checked by basic experiments. Furthermore, a self-healing optical fiber sensing network system is adopted to accomplish full-scale monitoring of pavements. The application of optical fiber sensors assembly and self-healing network system in pavement has been carried out to validate the feasibility. It has been proved that the research in this article provides a valuable method and meaningful guidance for the integrity monitoring of civil structures, especially pavements. PMID:24854060

Wang, Huaping; Liu, Wanqiu; He, Jianping; Xing, Xiaoying; Cao, Dandan; Gao, Xipeng; Hao, Xiaowei; Cheng, Hongwei; Zhou, Zhi

2014-01-01

38

Preliminary evaluation of the lifecycle costs and market barriers of reflective pavements  

SciTech Connect

The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher life cycle costs than conventional AC in parking lots, but several cost-saving features of porous pavements fell outside the boundaries of this study. Resin pavements were found to be only slightly more expensive than conventional AC, but the uncertainties in the cost and performance data were large. The use of light-colored additives in asphalt emulsion seal coats for parking lot pavements was found to be significantly more expensive than conventional AC, reflecting its current niche market of decorative applications. We also proposed two additional approaches to increasing the reflectivity of conventional AC, which we call the chipping and aggregate methods, and calculated their potential life cycle costs. By analyzing the potential for increased pavement durability resulting from these conceptual approaches, we then estimated the incremental costs that would allow them to be cost-effective compared to conventional AC. For our example case of Los Angeles, we found that those allowable incremental costs range from less than dollar 1 to more than dollar 11 per square yard (dollar 1 to dollar 13 per square meter) depending on street type and the condition of the original pavement. Finally, we evaluated the main actors in the pavement market and the existing and potential market barriers associated with reflective pavements. Apart from situations where lifecycle costs are high compared to conventional AC, all reflective paving technologies face a cultural barrier based on the belief that black is better. For PCC, high first costs were found to be the most significant economic barrier, particularly where agencies are cons trained by first cost. Lack of developer standards was found to be a significant institutional barrier to PCC since developers are often not held accountable for the long-term maintenance of roads after initial construction, which creates a misplaced incentive to build low first-cost pavements. PCC also faces site-specific barriers such as poorly compacted base soils and proximity to areas of frequent utility cutting.

Ting, M.; Koomey, J.G.; Pomerantz, M.

2001-11-21

39

Aquatic toxicity of airfield-pavement deicer materials and implications for airport runoff.  

PubMed

Concentrations of airfield-pavement deicer materials (PDM) in a study of airport runoff often exceeded levels of concern regarding aquatic toxicity. Toxicity tests on Vibrio fischeri, Pimephales promelas, Ceriodaphnia dubia, and Pseudokirchneriella subcapitata (commonly known as Selenastrum capricornutum) were performed with potassium acetate (K-Ac) PDM, sodium formate (Na-For) PDM, and with freezing-point depressants (K-Ac and Na-For). Results indicate that toxicity in PDM is driven by the freezing-point depressants in all tests except the Vibrio fisheri test for Na-For PDM which is influenced by an additive. Acute toxicity end points for different organisms ranged from 298 to 6560 mg/L (as acetate) for K-Ac PDM and from 1780 to 4130 mg/L (as formate) for Na-For PDM. Chronic toxicity end points ranged from 19.9 to 336 mg/L (as acetate) for K-Ac PDM and from 584 to 1670 mg/L (as formate) for Na-For PDM. Sample results from outfalls at General Mitchell International Airport in Milwaukee, WI (GMIA) indicated that 40% of samples had concentrations greater thanthe aquatic-life benchmarkfor K-Ac PDM. K-Ac has replaced urea during the 1990s as the most widely used PDM at GMIA and in the United States. Results of ammonia samples from airport outfalls during periods when urea-based PDM was used at GMIA indicated that 41% of samples had concentrations exceeding the U.S. Environmental Protection Agency (USEPA) 1-h water-quality criterion. The USEPA 1-h water-quality criterion for chloride was exceeded in 68% of samples collected in the receiving stream, a result of road-salt runoff from urban influence near the airport. Results demonstrate that PDM must be considered to comprehensively evaluate the impact of chemical deicers on aquatic toxicity in water containing airport runoff. PMID:19209582

Corsi, Steven R; Geis, Steven W; Bowman, George; Failey, Greg G; Rutter, Troy D

2009-01-01

40

Aquatic toxicity of airfield-pavement deicer materials and implications for airport runoff  

USGS Publications Warehouse

Concentrations of airfield-pavement deicer materials (PDM) in a study of airport runoff often exceeded levels of concern regarding aquatic toxicity. Toxicity tests on Vibrio fischeri, Pimephales promelas, Ceriodaphnia dubia, and Pseudokirchneriella subcapitata (commonly known as Selenastrum capricornutum) were performed with potassium acetate (K-Ac) PDM, sodium formate (Na-For) PDM, and with freezing- point depressants (K-Ac and Na-For). Results indicate that toxicity in PDM is driven by the freezing-point depressants in all tests except the Vibrio fisheri test for Na-For PDM which is influenced by an additive. Acute toxicity end points for different organisms ranged from 298 to 6560 mg/L (as acetate) for K-Ac PDM and from 1780 to 4130 mg/L (as formate) for Na- For PDM. Chronic toxicity end points ranged from 19.9 to 336 mg/L (as acetate) for K-Ac PDM and from 584 to 1670 mg/L (as formate) for Na-For PDM. Sample results from outfalls at General Mitchell International Airport in Milwaukee, Wl (GMIA) indicated that 40% of samples had concentrations greater than the aquatic-life benchmark for K-Ac PDM. K-Ac has replaced urea during the 1990s as the most widely used PDM at GMIA and in the United States. Results of ammonia samples from airport outfalls during periods when urea-based PDM was used at GMIA indicated that41% of samples had concentrations exceeding the U.S. Environmental Protection Agency (USEPA) 1 -h water-quality criterion. The USEPA 1-h water-quality criterion for chloride was exceeded in 68% of samples collected in the receiving stream, a result of road-salt runoff from urban influence near the airport. Results demonstrate that PDM must be considered to comprehensively evaluate the impact of chemical deicers on aquatic toxicity in water containing airport runoff. ?? 2009 American Chemical Society.

Corsi, S.R.; Geis, S.W.; Bowman, G.; Failey, G.G.; Rutter, T.D.

2009-01-01

41

Investigation of Self Consolidating Concrete Containing High Volume of Supplementary Cementitious Materials and Recycled Asphalt Pavement Aggregates  

NASA Astrophysics Data System (ADS)

The use of sustainable technologies such as supplementary cementitiuous materials (SCMs), and/or recycled materials is expected to positively affect the performance of concrete mixtures. However, it is important to study and qualify such mixtures and check if the required specifications of their intended application are met before they can be implemented in practice. This study presents the results of a laboratory investigation of Self Consolidating concrete (SCC) containing sustainable technologies. A total of twelve concrete mixtures were prepared with various combinations of fly ash, slag, and recycled asphalt pavement (RAP). The mixtures were divided into three groups with constant water to cementitiuous materials ratio of 0.37, and based on the RAP content; 0, 25, and 50% of coarse aggregate replaced by RAP. All mixtures were prepared to achieve a target slump flow equal to or higher than 500 mm (24in). A control mixture for each group was prepared with 100% Portland cement whereas all other mixtures were designed to have up to 70% of portland cement replaced by a combination of supplementary cementitiuous materials (SCMs) such as class C fly ash and granulated blast furnace slag. The properties of fresh concrete investigated in this study include flowability, deformability; filling capacity, and resistance to segregation. In addition, the compressive strength at 3, 14, and 28 days, the tensile strength, and the unrestrained shrinkage up to 80 days was also investigated. As expected the inclusion of the sustainable technologies affected both fresh and hardened concrete properties. Analysis of the experimental data indicated that inclusion of RAP not only reduces the ultimate strength, but it also affected the compressive strength development rate. Moreover, several mixes satisfied compressive strength requirements for pavements and bridges; those mixes included relatively high percentages of SCMs and RAP. Based on the results obtained in this study, it is not recommended to replace the coarse aggregate in SCC by more than 25% RAP.

Patibandla, Varun chowdary

42

Permeable Pavement  

NSDL National Science Digital Library

Students investigate how different riparian ground covers, such as grass or pavement, affect river flooding. They learn about permeable and impermeable materials through the measurement how much water is absorbed by several different household materials in a model river. Students use what they learn to make recommendations for engineers developing permeable pavement. Also, they consider several different limitations for design in the context of a small community.

Integrated Teaching And Learning Program

43

Recycled materials in asphalt pavements, January 1980-June 1991 (citations from the NTIS database). Rept. for Jan 80-Jun 91  

SciTech Connect

The bibliography contains citations concerning the recycling of asphalt pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (The bibliography contains 75 citations.) (Also includes title list and subject index.)

Not Available

1991-06-01

44

Analysis and design optimization of flexible pavement  

SciTech Connect

A project-level optimization approach was developed to minimize total pavement cost within an analysis period. Using this approach, the designer is able to select the optimum initial pavement thickness, overlay thickness, and overlay timing. The model in this approach is capable of predicting both pavement performance and condition in terms of roughness, fatigue cracking, and rutting. The developed model combines the American Association of State Highway and Transportation Officials (AASHTO) design procedure and the mechanistic multilayer elastic solution. The Optimization for Pavement Analysis (OPA) computer program was developed using the prescribed approach. The OPA program incorporates the AASHTO equations, the multilayer elastic system ELSYM5 model, and the nonlinear dynamic programming optimization technique. The program is PC-based and can run in either a Windows 3.1 or a Windows 95 environment. Using the OPA program, a typical pavement section was analyzed under different traffic volumes and material properties. The optimum design strategy that produces the minimum total pavement cost in each case was determined. The initial construction cost, overlay cost, highway user cost, and total pavement cost were also calculated. The methodology developed during this research should lead to more cost-effective pavements for agencies adopting the recommended analysis methods.

Mamlouk, M.S.; Zaniewski, J.P.; He, W.

2000-04-01

45

Application of Graded Finite Elements for Asphalt Pavements  

E-print Network

Application of Graded Finite Elements for Asphalt Pavements William G. Buttlar1 ; Glaucio H. Paulino2 ; and Seong Hyeok Song3 Abstract: Asphalt paving layers, particularly the surface course, exhibit: Fractures; Asphalt pavements; Finite element method; Material properties. Introduction Modern pavement

Paulino, Glaucio H.

46

Fractionation of heavy metals in pavement runoff  

Microsoft Academic Search

Abstract The transport of anthropogenic constituents by runoff from urban roadways can adversely impact the quality of adjacent receiving waters and soils. Metal elements are the most,persistent constituents found in pavement,runoff. A section of urban highway pavement in Cincinnati, Ohio, USA with an average daily traffic count of 150 000 vehicles was instrumented to sample lateral sheet flow from the

John J. Sansalone; Steven G. Buchberger; Souhail R. Al-abed

1996-01-01

47

Two-dimensional finite element analysis of flexible pavements considering non-linear materials and interface conditions  

SciTech Connect

Two-dimensional finite element analysis of a flexible pavement section was performed using a special purpose finite element method (FEM) code and a commercial general purpose FEM. Viscoelastic, plastic, and hyperbolic-elastic materials models were used in the analyses. One-dimensional interface elements were used in both analyses. The results of the analyses were compared with predictions using current evaluation/design models.

Gonzales, C.R. [Army Engineer Waterways Experiment Station, Vicksburg, MS (United States); Salami, M.R. [North Carolina A and T State Univ., Greensboro, NC (United States)

1995-06-01

48

Development of Pavement Performance Models by Combining Experimental and Field Data  

Microsoft Academic Search

The objective of this paper is to demonstrate the development of pavement performance models by combining experimental and field data. A two step approach was used. In the first step a riding quality model based on serviceability consideration is developed. The data set of the American Association of State Highways Officials~AASHO! Road Test is used to this effect. Due to

J. A. Prozzi

2004-01-01

49

MODELING PAVEMENT DETERIORATION PROCESSES BY POISSON HIDDEN MARKOV MODELS  

NASA Astrophysics Data System (ADS)

In pavement management, it is important to estimate lifecycle cost, which is composed of the expenses for repairing local damages, including potholes, and repairing and rehabilitating the surface and base layers of pavements, including overlays. In this study, a model is produced under the assumption that the deterioration process of pavement is a complex one that includes local damages, which occur frequently, and the deterioration of the surface and base layers of pavement, which progresses slowly. The variation in pavement soundness is expressed by the Markov deterioration model and the Poisson hidden Markov deterioration model, in which the frequency of local damage depends on the distribution of pavement soundness, is formulated. In addition, the authors suggest a model estimation method using the Markov Chain Monte Carlo (MCMC) method, and attempt to demonstrate the applicability of the proposed Poisson hidden Markov deterioration model by studying concrete application cases.

Nam, Le Thanh; Kaito, Kiyoyuki; Kobayashi, Kiyoshi; Okizuka, Ryosuke

50

Road Materials and Pavements Design. Volume X No X/2009, pages 1 to 16 Pavement Design for Curved Road Sections  

E-print Network

Road Materials and Pavements Design. Volume X ­ No X/2009, pages 1 to 16 Pavement Design for Curved pavements Christophe Petit* -- Malick Diakhaté* -- Anne Millien* -- Annabelle Phelipot-Mardelé* -- Bertrand@eurovia.com ABSTRACT. This paper focuses on damage processes other than the main one observed and studied in pavement

Paris-Sud XI, Université de

51

Recycled materials in asphalt pavements. (Latest citations from the NTIS bibliographic database). Published Search  

SciTech Connect

The bibliography contains citations concerning the recycling of asphalt pavement materials for road construction. Citations discuss asphalt concrete mixtures and recycling, recycled materials testing and evaluation, and pavement bases. Engineering and environmental aspects of recycled materials are examined. (Contains a minimum of 78 citations and includes a subject term index and title list.)

NONE

1995-03-01

52

Effects of Using Silica Fume and Polycarboxylate-Type Superplasticizer on Physical Properties of Cementitious Grout Mixtures for Semiflexible Pavement Surfacing  

PubMed Central

Semi-flexible pavement surfacing is a composite pavement that utilizes the porous pavement structure of the flexible bituminous pavement, which is subsequently grouted with appropriate cementitious materials. This study aims to investigate the compressive strength, flexural strength, and workability performance of cementitious grout. The grout mixtures are designed to achieve high strength and maintain flow properties in order to allow the cement slurries to infiltrate easily through unfilled compacted skeletons. A paired-sample t-test was carried out to find out whether water/cement ratio, SP percentages, and use of silica fume influence the cementitious grout performance. The findings showed that the replacement of 5% silica fume with an adequate amount of superplasticizer and water/cement ratio was beneficial in improving the properties of the cementitious grout. PMID:24526911

Karim, Mohamed Rehan; Mahmud, Hilmi; Mashaan, Nuha S.; Katman, Herdayati; Husain, Nadiah Md

2014-01-01

53

Beneficial Use of Coal Combustion By-products in the Rehabilitation of Failed Asphalt Pavements  

Microsoft Academic Search

This study demonstrates the use of Class F fly ash in combination with lime or lime kiln dust in the full depth reclamation (FDR) of asphalt pavements. FDR, in the context of this paper, is a process of pulverizing a predetermined amount of flexible pavement that is structurally deficient, blending it with chemical additives and water, and compacting it in

Tarunjit S. Butalia; William E. Wolfe

2009-01-01

54

Shakedown Analysis of Road Pavements  

Microsoft Academic Search

Shakedown behaviour of road pavements was investigated in laboratory controlled conditions using the Sydney University Pavement Testing Facility. Wheel loads lower than the shakedown load generated low permanent deformations for a larger number of load cycles in comparison with high permanent deformations for a lower number of load cycles for wheel loads higher than the shakedown load. Computer software was

P. S. Ravindra

55

Project Information Form Project Title White Paper on The application of permeable pavement with emphasis  

E-print Network

Project Information Form Project Title White Paper on The application of permeable pavement Project Depending on the type of surface pavement, permeable pavement can be termed as porous asphalt and improve water quality as well as urban heat island, the application of permeable pavement in urban areas

California at Davis, University of

56

Making "Magic" Sidewalks of Pervious Pavement  

NSDL National Science Digital Library

Students use everyday building materialssand, pea gravel, cement and waterto create and test pervious pavement. They learn what materials make up a traditional, impervious concrete mix and how pervious pavement mixes differ. Groups are challenged to create their own pervious pavement mixes, experimenting with material ratios to evaluate how infiltration rates change with different mix combinations.

Water Awareness Research and Education (WARE) Research Experience for Teachers (RET),

57

Summary of Concrete Overlays Existing concrete pavement  

E-print Network

Summary of Concrete Overlays Existing concrete pavement with surface distresses Prepared surface Monolithic pavement with new concrete surface Existing asphalt pavement with surface distresses Milled pavement with asphalt surface distresses Milled and cleaned surface New 2­5 in. (5.1­12.7 cm) bonded

58

Performance of continuously reinforced concrete pavements: Volume 6 -- CRC pavement design, construction, and performance. Final report, August 1990--December 1994  

SciTech Connect

This report is one of a series of reports prepared as part of a recent study sponsored by the Federal Highway Administration (FHWA) aimed at updating the state-of-the-art of the design, construction, maintenance, and rehabilitation of continuous reinforced concrete (CRC) pavements. The scope of work of the FHWA study included the following: (1) Conduct of a literature review and preparation of an annotated bibliography on CRC pavements and CRC overlays. (2) Conduct of a field investigation and laboratory testing related to 23 existing in-service pavement sections. This was done to evaluate the effect of various design features on CRC pavement performance, to identify any design or construction related problems, and to recommend procedures to improve CRC pavement technology. (3) Evaluation of the effectiveness of various maintenance and rehabilitation strategies for CRC pavements. (4) Preparation of a Summary Report on the current state of the practice for CRC pavements. Each of the above four items is addressed in a separate report. The following reports have been prepared under this study: Performance of CRC Pavements. Volume 1: Summary of Practice and Annotated Bibliography. Volume 2: Field Investigation of CRC Pavements. Volume 3: Analysis and Evaluation of Field Test Data. Volume 4: Resurfacing for CRC Pavements. Volume 5: Maintenance and Repair of CRC Pavements. Volume 6: CRC Pavement Design, Construction, and Performance. Volume 7: Summary. This report is Volume 6 in the series.

Zollinger, D.G.; Buch, N.; Xin, D.; Soares, J.

1999-02-01

59

Analysis of fatigue crack growth behavior in asphalt concrete material in wearing course  

Microsoft Academic Search

Fatigue crack is a main form of structural damage in flexible pavements. Under the action of repeated vehicular loading, deterioration of the asphalt concrete materials in pavements, caused by the accumulation and growth of micro and macro cracks, gradually takes place. The indirect tensile fatigue testing (ITFT) was carried out on three types of asphalt concrete materials comprising a high

Zhi Suo; Wing Gun Wong

2009-01-01

60

Geotextiles, one among the different geosynthetic products, can be used for a number of functions or applications in pavement design. Specifically, woven or nonwoven geotextiles have been used in pavements to fulfill the  

E-print Network

or applications in pavement design. Specifically, woven or nonwoven geotextiles have been used in pavements of geotextile and its location within the pavement system. The benefits of using geotextiles in pavements for more cost-effective pavements are probably being missed by not using (or by incorrectly using

Zornberg, Jorge G.

61

Reinforcement of asphalt concrete pavement by segments of exhausted fiber used for sorption of oil spill  

NASA Astrophysics Data System (ADS)

The paper is aimed at construction of the experimental road pavement made of dispersed reinforced asphalt concrete. Electronic paramagnetic resonance, infrared spectroscopy and fluorescent bitumen studies were used to prove that disperse reinforcement of asphalt concrete mixtures with fibers of exhausted sorbents reduce the selective filtration of low polymeric fractions of petroleum bitumen and improve its properties in the adsorption layer. Sesquioxides are neutralized as catalysts aging asphalt binder. This leads to improvement in the elasticity of bitumen films at low temperatures and provide better crack resistance of coatings to reduce the intensity of the aging of asphalt binder, and, therefore, to increase the durability of road pavements. The experimental road pavement made of dispersed reinforced asphalt concrete operated during 4 years and demonstrated better transport- performance properties in comparison with the analogue pavements.

Lukashevich, V. N.; Efanov, I. N.

2015-01-01

62

Evaluation of multilayered pavement structures from measurements of surface waves  

USGS Publications Warehouse

A method is presented for evaluating the thickness and stiffness of multilayered pavement structures from guided waves measured at the surface. Data is collected with a light hammer as the source and an accelerometer as receiver, generating a synthetic receiver array. The top layer properties are evaluated with a Lamb wave analysis. Multiple layers are evaluated by matching a theoretical phase velocity spectrum to the measured spectrum. So far the method has been applied to the testing of pavements, but it may also be applicable in other fields such as ultrasonic testing of coated materials. ?? 2006 American Institute of Physics.

Ryden, N.; Lowe, M.J.S.; Cawley, P.; Park, C.B.

2006-01-01

63

Field performance of geosynthetic reinforced pavements over expansive clay subgrades  

E-print Network

Field performance of geosynthetic reinforced pavements over expansive clay subgrades Zornberg, J, The University of Texas, Austin, USA 78712 Keywords: reinforced pavements; expansive soils; geogrids; geotextiles cracks on the pavement structures. Traditionally the problems related to flexible pavements over

Zornberg, Jorge G.

64

Recycled materials in asphalt pavements. October 1973-November 1989 (Citations from the NTIS data base). Report for October 1973-November 1989  

SciTech Connect

This bibliography contains citations concerning the recycling of asphalt-pavement materials, and the use of other recycled materials to manufacture asphalt pavement. Articles discuss methods used for recycling bituminous pavement including hot-mix and cold-mix. Materials used to improve recycled pavement, and recycled materials used in asphalt pavement include latexes, rubber scrap such as tires, glass shards, concretes, dusts, waste oils, roofing wastes, sulfur, and metal refining sludges. Testing and evaluation of recycled pavements both in laboratories and in test cases are considered. (Contains 110 citations fully indexed and including a title list.)

Not Available

1989-12-01

65

Simulation of cooling effect of newly-innovated urban pavements on water and heat budgets  

NASA Astrophysics Data System (ADS)

People often suffer from the intense summer heat in Japan. This trend is increasing in urban areas because of the heat island effect and global warming. The present research evaluated the effect of pavements made of traditional and new materials on water and heat budgets. We coupled the NIES Integrated Catchment-based Eco- hydrology (NICE) model (Nakayama, 2007; Nakayama and Watanabe, 2004, 2006, 2007; Nakayama et al., 2006, 2007) to an urban canopy model in order to simulate the water and heat budgets in various types of natural and artificial pavements (covered by lawn, concrete, steel plate, synthetic rubber sheet, infiltration and water-holding blocks), and to evaluate the role of a new surface material in promoting evaporation and cooling to counter the heat island phenomenon (NICE-URBAN), by comparing with the simplified empirical model. Furthermore, using the heat conductivities of natural soil, we arranged these values for artificial pavement in the model equations by including the effect of the amount of water on the heat characteristics in the material. The simulated belowground water agreed with the observed value because this model includes the processes of both interception store and soil moisture store. The NICE-URBAN simulated more correctly the cooling of water-holding pavement during the intense heat of summer in an urban area than the empirical model. Because the model estimates that the air temperature at the water-holding pavement is 2 (deg.) lower than that at the lawn and 5 (deg.) lower than that at the building rooftop, it is very powerful to use this material for positive cooling effect in combination with the lawn for passive cooling effect. The simulation of NICE-URBAN showed that the decrease of surface temperature in water-holding pavement is closely related to the promotion of evaporation from the surface, the water volume of the pavement and the surface reflectance. References; 1)Nakayama,T.,Watanabe,M.,WRR,40,doi:10.1029/2004WR003174,2004. 2)Nakayama,T.,Watanabe,M.,HESSD,3,2101-2144,2006. 3)Nakayama,T.,et al.,HP,20(16),3441-3466,doi:10.1002/hyp.6142,2006. 4)Nakayama,T.,Ecol.Model.,2007(revised). 5)Nakayama,T.,Watanabe,M.,HP,doi:10.1002/hyp.6684,2007. 6)Nakayama,T.,et al.,STOTEN,373(1),270-288,doi:10.1016/j.scitotenv.2006.11.033,2007.

Nakayam, T.; Fujita, T.

2007-12-01

66

Evaluation of bituminous materials used in pavement recycling projects at Tyndall, MacDill, and Hurlburt Air Force Bases  

NASA Astrophysics Data System (ADS)

This report presents results of a study involving bituminous materials from Tyndall and MacDill Air Force Bases and Hurlburt Field. These materials included Reclaimed Asphalt Pavement (RAP), modifiers, virgin asphalts, and new aggregates. A tentative modifier selection criterion was used to judge the quality of materials used in the recycling efforts at the respective sites. The results showed that independent adequacy of physical properties from chemical properties in selection of modifiers could not be established. However, some of the results showed that physical properties were more sensitive indicators of changes in binders due to aging. In addition, this report includes the tentative modifier selection criteria and results of an interlaboratory study from which variability limits to parameters determined using modified Clay-Gel and Heithaus procedures are established. The modified Clay-Gel and Heithaus procedures are included.

Kiggundu, B.; Martinez, R.; Humphrey, B.; Shuler, T.

1987-07-01

67

A study on issues relating to testing of soils and pavements by surface wave methods  

NASA Astrophysics Data System (ADS)

A study on the differences between testing soils and pavements using surface wave methods is presented. The differences in theoretical dispersion curves are illustrated using the transfer matrix method and the stiffness matrix method for soils and pavements, respectively. The Levenberg-Marquardt and simulated annealing methods are applied for inversion of experimental data on soils and a concrete foundation slab, and the relative merits and differences of the two inversion methods are discussed.

Lin, S.; Ashlock, J. C.

2012-05-01

68

Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods.  

PubMed

Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. PMID:23434738

Li, Hui; Kayhanian, Masoud; Harvey, John T

2013-03-30

69

211. EQUIPMENT LAYING FIRST LANE OF CONCRETE PAVEMENT NEAR THE ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

211. EQUIPMENT LAYING FIRST LANE OF CONCRETE PAVEMENT NEAR THE CAPITAL OVERLOOK, 1931. NOTE THE BEGINNING OF BITUMINOUS TYPE OF TEMPORARY PAVEMENT TO ALLOW FOR SETTLEMENT IN HYDRAULIC FILL AREAS. - George Washington Memorial Parkway, Along Potomac River from McLean to Mount Vernon, VA, Mount Vernon, Fairfax County, VA

70

CONCRETE PAVEMENT Reference Manual  

E-print Network

CONCRETE PAVEMENT Reference Manual Prepared for Federal Highway Administration Office of Pavement by National Concrete Pavement Technology Center at Iowa State University 2711 South Loop Drive, Suite 4700 No. 3. Recipient's Catalog No. 4. Title and Subtitle 5. Report Date February 2008 Concrete Pavement

71

Improving a pavement-watering method on the basis1 of pavement surface temperature measurements2  

E-print Network

Improving a pavement-watering method on the basis1 of pavement surface temperature measurements2.hendel@paris.fr)8 Abstract: Pavement-watering has been studied since the 1990's and is currently considered a9 water resource availability problems require that water consumption be optimized. Although11 pavement

Paris-Sud XI, Université de

72

ROUGH THIN PAVEMENT THICKNESS ESTIMATION BY GPR N. Pinel, L. Liu, C. Bourlier, Y. Wang  

E-print Network

ROUGH THIN PAVEMENT THICKNESS ESTIMATION BY GPR N. Pinel, L. Liu, C. Bourlier, Y. Wang IREENA pavements consider flat interfaces for simpli- fication. In this paper, the roughness of the surfaces is taken into account. First, the amplitudes of the first two echoes from the rough thin pavement

Paris-Sud XI, Université de

73

Sustainable Concrete Pavements: A Manual of Practice  

E-print Network

#12;#12;#12;Sustainable Concrete Pavements: A Manual of Practice January 2012 TECHNICAL EDITORS Dr. Peter Taylor, Associate Director National Concrete Pavement Technology Center, Iowa State and Sustainability Group, Applied Pavement Technology) CO-AUTHORS Dr. Tom Van Dam, Principal Engineer, CTLGroup

74

Road Asphalt Pavements Analyzed by Airborne Thermal Remote Sensing: Preliminary Results of the Venice Highway  

PubMed Central

This paper describes a fast procedure for evaluating asphalt pavement surface defects using airborne emissivity data. To develop this procedure, we used airborne multispectral emissivity data covering an urban test area close to Venice (Italy).For this study, we first identify and select the roads' asphalt pavements on Multispectral Infrared Visible Imaging Spectrometer (MIVIS) imagery using a segmentation procedure. Next, since in asphalt pavements the surface defects are strictly related to the decrease of oily components that cause an increase of the abundance of surfacing limestone, the diagnostic absorption emissivity peak at 11.2?m of the limestone was used for retrieving from MIVIS emissivity data the areas exhibiting defects on asphalt pavements surface.The results showed that MIVIS emissivity allows establishing a threshold that points out those asphalt road sites on which a check for a maintenance intervention is required. Therefore, this technique can supply local government authorities an efficient, rapid and repeatable road mapping procedure providing the location of the asphalt pavements to be checked.

Pascucci, Simone; Bassani, Cristiana; Palombo, Angelo; Poscolieri, Maurizio; Cavalli, Rosa

2008-01-01

75

A four-point bending test for the bonding evaluation of composite pavement  

E-print Network

A four-point bending test for the bonding evaluation of composite pavement M. Hun1 , A. Chabot1 , F investigate the crack initiation and propagation at the interface between layers of composite pavements affects the durability of composite pavements made with asphalt and cement materials. Two main problems

Paris-Sud XI, Université de

76

DETERMINATION OF ENERGY RELEASE RATE FOR A MIXED-MODE DEBONDING TEST FOR "COMPOSITE" PAVEMENTS  

E-print Network

DETERMINATION OF ENERGY RELEASE RATE FOR A MIXED-MODE DEBONDING TEST FOR "COMPOSITE" PAVEMENTS in "composite" pavement consisting of superimposed layers of processed materials (cement concrete and bituminous, mixed-mode test, multiparticle modelling, Dunder, pavement Due to the structural heterogeneity

Boyer, Edmond

77

Types of Materials  

NSDL National Science Digital Library

This webpage from Edmonds Community College provides a brief introduction to a number of core materials including ceramics, composites, concrete, electronic/optical, metals, polymers/plastics and wood.

78

Review of permeable pavement systems  

Microsoft Academic Search

The purpose of this review paper is to summarise the wide-range but diffuse literature on predominantly permeable pavement systems (PPS), highlight current trends in research and industry, and to recommend future areas of research and development. The development of PPS as an integral part of sustainable drainage systems is reviewed in the context of traditional and modern urban drainage. Particular

Miklas Scholz; Piotr Grabowiecki

2007-01-01

79

An economic based decision support system for project level pavement type selection  

NASA Astrophysics Data System (ADS)

This dissertation describes a project-level pavement type selection procedure developed for use in roadway agencies and details the overall decision framework required for making dependable pavement type selection decisions. The developed pavement type selection procedure will enable TxDOT to meet the FHWA policy guidelines, and will enable TxDOT engineers to make rational decisions that maximize benefits from expenditure of taxpayers' dollars. Salient results from the national and Texas level questionnaire surveys regarding their pavement type selection practices are documented. Three important factors: agency costs, user delay costs, and performance levels associated with candidate strategies are thoroughly evaluated and quantified for economic comparisons. Economic evaluations are primarily based on the life cycle cost analysis (LCCA) and the cost-effectiveness analysis. It also describes the requirements for and approach to generating candidate pavement strategies. The impact of miscellaneous factors on pavement type selection is also discussed. Some guidelines are suggested for the final strategy selection. A computer program TxPTS is developed to automate the economic evaluation procedures developed in this study. Finally, a few example case studies are conducted to demonstrate the use of the TxPTS computer program and to represent the economic sensitivity of candidate strategies.

Beg, Muhammad Arif

80

Statistical classification of road pavements using near field vehicle rolling noise measurements.  

PubMed

Low noise surfaces have been increasingly considered as a viable and cost-effective alternative to acoustical barriers. However, road planners and administrators frequently lack information on the correlation between the type of road surface and the resulting noise emission profile. To address this problem, a method to identify and classify different types of road pavements was developed, whereby near field road noise is analyzed using statistical learning methods. The vehicle rolling sound signal near the tires and close to the road surface was acquired by two microphones in a special arrangement which implements the Close-Proximity method. A set of features, characterizing the properties of the road pavement, was extracted from the corresponding sound profiles. A feature selection method was used to automatically select those that are most relevant in predicting the type of pavement, while reducing the computational cost. A set of different types of road pavement segments were tested and the performance of the classifier was evaluated. Results of pavement classification performed during a road journey are presented on a map, together with geographical data. This procedure leads to a considerable improvement in the quality of road pavement noise data, thereby increasing the accuracy of road traffic noise prediction models. PMID:20968348

Paulo, Joel Preto; Coelho, J L Bento; Figueiredo, Mrio A T

2010-10-01

81

Airport pavement management systems: an appraisal of existing methodologies  

Microsoft Academic Search

Airport pavement management systems (APMS) are computer-based decision support systems that can be used by the agencies running airports to determine cost-effective maintenance and rehabilitation strategies to preserve the various pavement structures (runways, taxiways, etc.) which are a critical component of these facilities. In this paper, we describe the main elements of APMS and review existing systems.

Michel Gendreau; Patrick Soriano

1998-01-01

82

Fracture resistance characterization of chemically modified crumb rubber asphalt pavement  

Microsoft Academic Search

The fracture resistance of chemically modified crumb rubber asphalt (CMCRA) pavement was evaluated based on the J-integral concept. The chemical modification process used was developed by the Federal Highway Administration and patented in 1998. The results were compared to that of crumb rubber asphalt (CRA) and control asphalt pavement. Four semi-circular core specimens (76 mm radius and 57 mm thickness)

M. A. Mull; K. Stuart; A. Yehia

2002-01-01

83

STONE PAVEMENTS IN DESERTS  

Microsoft Academic Search

Stone pavements are armored surfaces comprising intricate mosaics of coarse particles, usually only one or two stones thick, set on or in fine material. They occur widely in many unvegetated areas, and preeminently in hot deserts. Pavement studies in several deserts, and especially in Chile and California, suggest that: 1) deflation may be a relatively unimportant process of pavement formation;

RONALD U. COOKE

1970-01-01

84

INTRODUCTION Pavement preservation is an approach in enhancing pavement performance using a set of practices that extends the life  

E-print Network

INTRODUCTION Pavement preservation is an approach in enhancing pavement performance using a set of practices that extends the life of the pavement and improves safety and ride quality. According to theWorld Bank's Pavement Deterioration Model, the cost of returning a pavement to good condition after

Stephens, Jacqueline

85

The use of fluvial and marine sediments in the formulation of roller compacted concrete for use in pavements.  

PubMed

In the manufacture of Roller Compacted Concrete (RCC) used for pavement materials, various types of aggregates are used, such as crushed and rolled limestone or siliceous aggregates. The main objective is always to reach the maximum compactness to achieve higher mechanical performances. In the present work, fluvial and marine sediments, resulting from the dredging of harbours and rivers, were introduced as aggregates in the preparation of RCC for pavement construction, with a view to improving the mechanical strength of the RCC. This study included a granulometric, mineralogical and chemical characterization of the aggregates. The work also contains a mechanical characterization of the resulting material. The objective of the study was to find a resistant RCC, by developing materials such as sediments that are often classified as a waste and where their storage is harmful to the environment. The mechanical strengths obtained showed the profitability of using a Roller Compacted Concrete containing sediments. PMID:19705664

Zdiri, M; Abriakb, N E; Ben Ouezdoua, M; Neji, J

2009-07-01

86

Recycling of water-susceptible pavements  

NASA Astrophysics Data System (ADS)

Several bituminous concrete interstate pavements that experienced failures suspected to have been caused by stripping were investigated. On two projects, the degree of deterioration, potential serviceability, and possible remedial measures were studied. Cores were taken to determine the degreee of stripping and tensile strength, and dynaflect tests were performed. An emulsion mix design was developed for stripped bituminous concrete removed from another project with the expectation that it could be used as a surface mix on a highway with a low traffic volume. While this expectation was not realized, it was concluded that the material is suitable for use in a base mix. A maintenance resurfacing on a fourth project that experienced stripping failure is being monitored and the performance is being evaluated.

Maupin, G. W.

1980-05-01

87

Desert Pavement Process and Form: Modes and Scales of Landscape Stability and Instability in Arid Regions  

NASA Astrophysics Data System (ADS)

Desert pavements are recognized in arid landscapes around the world, developing via diminution of constructional/depositional landform relief and creating a 1-2 stone thick armor over a "stone free" layer. Surface exposure dating demonstrates that clasts forming the desert pavements are maintained at the land surface over hundreds of thousands of years, as aeolian fines are deposited on the land surface, transported into the underlying parent material and incorporated into accretionary soil horizons (e.g., the stone free or vesicular [Av] horizon). This surface armor provides long-term stability over extensive regions of the landscape. Over shorter time periods and at the landform-element scale, dynamic surficial processes (i.e., weathering, runoff) continue to modify the pavement form. Clast size reduction in comparison to underlying parent material, along with armoring and packing of clasts in pavements contribute to their persistence, and studies of crack orientations in pavement clasts indicate physical weathering and diminution of particle size are driven by diurnal solar insolation. Over geologic time, cracks form and propagate from tensile stresses related to temporal and spatial gradients in temperature that evolve and rotate in alignment with the sun's rays. Observed multimodal nature of crack orientations appear related to seasonally varying, latitude-dependent temperature fields resulting from solar angle and weather conditions. Surface properties and their underlying soil profiles vary across pavement surfaces, forming a landscape mosaic and controlling surface hydrology, ecosystem function and the ultimate life-cycle of arid landscapes. In areas of well-developed pavements, surface infiltration and soluble salt concentrations indicate that saturated hydraulic conductivity of Av horizons decline on progressively older alluvial fan surfaces. Field observations and measurements from well-developed desert pavement surfaces landforms also yield significantly lower infiltration rates, enhanced rates of overland flow characterized by high water:sediment ratios and reduced production of desert ecosystems. Consequently, regionally extensive pavement and significantly decreased infiltration over geologic time have resulted in widespread overland flow, elaborate drainage networks on alluvial and eolian-mantled bedrock landscapes, and channel incision and regional dissection of the pavement-mantled landforms. However, these once stable landscapes become progressively unstable with time, serving as sediment source areas for younger alluvial deposits (i.e., geologic life-cycle). Thus, regional dissection (instability) of these desert landscapes can be influenced by the intrinsic properties of pavement-mantled landscapes and not necessarily to external forces of climate change and tectonics.

Wells, Stephen G.; McFadden, Leslie D.; McDonald, Eric V.; Eppes, Martha C.; Young, Michael H.; Wood, Yvonne A.

2014-05-01

88

DEVELOPMENT OF THE WALL LABYRINTH IN PAVEMENT EPITHELIUM HAIRS OF SOME UTRICULARIA SPECIES  

Microsoft Academic Search

Sodium hypochlorite-digested material and scanning electron microscopy was used to study the morphology of wall ingrowths in pavement epithelium hairs of Utricularia species from the primitive section Pleiochasia (U. volubilis) and the advanced section Utricularia (U. stygia, U. intermedia). Wall ingrowths were reticulate-type in all examined species. Wall ingrowth development started with the formation of small papillae, which later lengthened

BARTOSZ JAN; ANDRZEJ JANKUN; JADWIGA FABER

2005-01-01

89

Performance Prediction of the NCAT Test Track Pavements Using Mechanistic Models  

NASA Astrophysics Data System (ADS)

In the pavement industry in the United States of America, there is an increasing desire to improve the pavement construction quality and life for new and rehabilitated pavements. In order to improve the quality of the pavements, the Federal Highway Administration (FHWA) has pursued a performance-related specification (PRS) for over 20 years. The goal of PRS is to provide material and construction (M/C) properties that correlate well with pavement performance. In order to improve upon the PRS projects developed in WesTrack (NCHRP 9-20) and the MEPDG-based PRS (NCHRP 9-22), a set of PRS tests and models are proposed to provide a critical link between pavement performance and M/C properties. The PRS testing is done using the asphalt mixture performance tester (AMPT). The proposed PRS focuses on rutting and fatigue cracking of asphalt mixtures. The mixtures are characterized for their stiffness, fatigue behavior, and rutting resistance using a dynamic modulus (|E*|) test, a fatigue test, and a triaxial stress sweep (TSS) test, respectively. Information from the fatigue test characterizes the simplified viscoelastic continuum damage (S-VECD) model. Once the stiffness is reduced to a certain level, the material develops macro-cracks and fails. The TSS test is used to characterize a viscoplastic (VP) model. The VP model allows the prediction of the rut depth beneath the center of the wheel. The VECD and VP models are used within a layered viscoelastic (LVE) pavement model to predict fatigue and rutting performance of pavements. The PRS is evaluated by comparing the predictions to the field performance at the NCAT pavement test track in Opelika, Alabama. The test track sections evaluated are part of the 2009 test cycle group experiment, which focused on WMA, high RAP (50%), and a combination of both. The fatigue evaluation shows that all sections would last at least 18 years at the same traffic rate. The sections do not show any cracking, suggesting the sections are well-built and a long life is possible. The rutting in the test track is also predicted. All the predicted rut depths are 2-4 mm higher than measured in the field, but the overall ranking of different pavement sections matches the ranking in the field quite well. Conclusions and recommendations for future research are drawn from the observations made from experimental results as well as performance prediction of NCAT pavement sections.

LaCroix, Andrew Thomas

90

EVALUATION OF THE INFLUENCE OF TACK COAT CONSTRUCTION FACTORS ON THE BOND STRENGTH BETWEEN PAVEMENT LAYERS  

E-print Network

EVALUATION OF THE INFLUENCE OF TACK COAT CONSTRUCTION FACTORS ON THE BOND STRENGTH BETWEEN PAVEMENT Evaluation of the Influence of Tack Coat Construction Factors on the Bond Strength between Pavement Layers 7 provided by the tack coat at the interface between pavement layers. These factors included the surface

91

Removable Urban Pavements: An innovative, sustainable technology Journal: International Journal of Pavement Engineering  

E-print Network

1 Removable Urban Pavements: An innovative, sustainable technology Journal: International Journal of Pavement Engineering URL: http://mc.manuscriptcentral.com/gpav E-mail: IJPE.editor@citg.tudelft.nl, alqadi@uiuc.edu Removable Urban Pavements: An innovative, sustainable technology François de Larrard1, Thierry Sedran2, Jean

Paris-Sud XI, Université de

92

Cathodoluminescence microscopy and petrographic image analysis of aggregates in concrete pavements affected by alkali-silica reaction  

SciTech Connect

Various microscopic techniques (cathodoluminescence, polarizing and electron microscopy) were combined with image analysis with the aim to determine a) the modal composition and degradation features within concrete, and b) the petrographic characteristics and the geological types (rocks, and their provenance) of the aggregates. Concrete samples were taken from five different portions of Highway Nos. D1, D11, and D5 (the Czech Republic). Coarse and fine aggregates were found to be primarily composed of volcanic, plutonic, metamorphic and sedimentary rocks, as well as of quartz and feldspar aggregates of variable origins. The alkali-silica reaction was observed to be the main degradation mechanism, based upon the presence of microcracks and alkali-silica gels in the concrete. Use of cathodoluminescence enabled the identification of the source materials of the quartz aggregates, based upon their CL characteristics (i.e., color, intensity, microfractures, deformation, and zoning), which is difficult to distinguish only employing polarizing and electron microscopy. - Highlights: Black-Right-Pointing-Pointer ASR in concrete pavements on the Highways Nos. D1, D5 and D11 (Czech Republic). Black-Right-Pointing-Pointer Cathodoluminescence was combined with various microscopic techniques and image analysis. Black-Right-Pointing-Pointer ASR was attributed to aggregates. Black-Right-Pointing-Pointer Source materials of aggregates were identified based on cathodoluminescence characteristics. Black-Right-Pointing-Pointer Quartz comes from different volcanic, plutonic and metamorphic parent rocks.

Stastna, A., E-mail: astastna@gmail.com [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Sachlova, S.; Pertold, Z.; Prikryl, R. [Institute of Geochemistry, Mineralogy and Mineral Resources, Faculty of Science, Charles University in Prague, Albertov 6, 128 43 Praha 2 (Czech Republic); Leichmann, J. [Department of Geological Sciences, Faculty of Science, Masaryk University in Brno, Kotlarska 267/2, 611 37 Brno (Czech Republic)

2012-03-15

93

Do et al. 1 Full Scale Tests for the Assessment of Wear of Pavement Surfaces  

E-print Network

Do et al. 1 Full Scale Tests for the Assessment of Wear of Pavement Surfaces Minh-Tan Do subjected to heavy traffic. Reports can be found in (1)(2). Evolution of pavements during its whole service shown in the figure 2. By this way, during tests on one track, pavement construction can be carried out

Boyer, Edmond

94

A review of the use of recycled solid waste materials in asphalt pavements  

Microsoft Academic Search

The construction and maintenance of UK roads consume large amounts of quarried aggregates. The use of secondary (recycled), instead of primary (virgin), materials helps easing landfill pressures and reducing demand of extraction. However, concerns over inferior road performance and additional costs have hindered the widespread use of secondary aggregates in such applications. This is especially the case in surface layers

Yue Huang; Roger N. Bird; Oliver Heidrich

2007-01-01

95

A more comprehensive life cycle cost analysis of pavement materials alternatives  

E-print Network

Life Cycle Cost Analysis (LCCA) is a commonly used tool in analyzing the economic viability of highway construction investments. The initial and life-cycle materials costs associated with highway construction involve a ...

Dunn, William Colby

2014-01-01

96

Evaluation of infiltration in layered pavements using surface GPR reflection techniques  

E-print Network

Evaluation of infiltration in layered pavements using surface GPR reflection techniques K. Grotea The bearing capacity of sub-asphalt soils, which is a critical parameter for assessing pavement conditions and guiding pavement maintenance, is greatly influenced by soil water content. In this study, ground

Hubbard, Susan

97

Nondestructive evaluation of load transfer at rigid airport pavement joints  

NASA Astrophysics Data System (ADS)

Current design criteria for rigid pavements for commercial and military airfields assume that 25% of the load applied to an edge of a slab is transferred through the joint to an adjacent unloaded slab. A nondestructive testing technique using a falling weight deflectometer (FWD) was used to conduct field testing at a number of sites. A transfer function, developed from an analytical study, was used to estimate load transfer from the measured joint efficiency as a function of the loaded area and the radius of relative stiffness of the pavement. This procedure, although analytically sound, lacks actual field verification at an instrumented pavement site. This procedure was used to estimate load transfer at a number of commercial and military airfields for a variety of joint types, climate conditions, and pavement structures. The results of these tests indicate that the assumption of load transfer as a constant value of 25% appears to be unconservative, especially during the winter months.

Hammons, Michael I.

1995-07-01

98

QUANTIFYING THE BENEFITS FOR USING GEOSYNTHETICS IN UNBOUND BASE COURSE OF PAVEMENTS IN HIGH PI CLAYS  

E-print Network

QUANTIFYING THE BENEFITS FOR USING GEOSYNTHETICS IN UNBOUND BASE COURSE OF PAVEMENTS IN HIGH PI CLAYS By: Ranjiv Gupta1 and J. G. Zornberg, Advisor2 ABSTRACT Flexible pavements over high plasticity methodology to do the same. The present study aims at constructing field test sections on actual pavements

Zornberg, Jorge G.

99

Layer coefficients for NHDOT pavement materials  

NASA Astrophysics Data System (ADS)

In 1992, the New Hampshire Department of Transportation (NHDOT) experimented with the use of reclaimed asphalt concrete as a base course material, identified by NHDOT as reclaimed stabilized base (RSB). The RSB and a control test section were placed on Interstate 93 between exits 18 and 19. The RSB test section was designed to the same structural number (SN) as the control. To evaluate the structural capacity of these test sections, the U.S. Army Cold Regions Research and Engineering Laboratory (CRREL) conducted deflection tests using a Dynatest 8000 falling weight deflectometer (FWD). Preliminary analysis of the results by NHDOT personnel showed higher deflection in the reclaimed asphalt concrete test sections. The explanation was that the layer coefficient used for the RSB layer in the design was probably incorrect. A total of 10 test sections constituting the base course materials used by NHDOT were built near Bow, New Hampshire. CRREL evaluated and estimated the layer coefficients of the base course materials. The test program was developed to characterize the material in more than one way. Tests were conducted with the heavy weight deflectometer (HWD), dynamic cone penetrometer (DCP) and the Clegg hammer. In situ California bearing ratio (CBR) tests were also conducted. The deflection from the HWD were used with the WESDEF back calculation program to determine the layer moduli. The moduli were than used with the AASHTO Design Guide to calculate the layer coefficients. The layer coefficients were also determined with the method proposed by Rohde. The CBR values from the Clegg hammer, in situ CBR and DCP tests were also used in the relationships in the HDM model to determine the layer coefficients.

Janoo, Vincent C.

1994-09-01

100

Investigation of mechanical properties of pavement through electromagnetic techniques  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) is considered as one of the most flexible geophysical tools that can be effectively and efficiently used in many different applications. In the field of pavement engineering, GPR can cover a wide range of uses, spanning from physical to geometrical inspections of pavements. Traditionally, such inferred information are integrated with mechanical measurements from other traditional (e.g. plate bearing test) or non-destructive (e.g. falling weight deflectometer) techniques, thereby resulting, respectively, in time-consuming and low-significant measurements, or in a high use of technological resources. In this regard, the new challenge of retrieving mechanical properties of road pavements and materials from electromagnetic measurements could represent a further step towards a greater saving of economic resources. As far as concerns unpaved and bound layers it is well-known that strength and deformation properties are mostly affected, respectively, by inter-particle friction and cohesion of soil particles and aggregates, and by bitumen adhesion, whose variability is expressed by the Young modulus of elasticity. In that respect, by assuming a relationship between electromagnetic response (e.g. signal amplitudes) and bulk density of materials, a reasonable correlation between mechanical and electric properties of substructure is therefore expected. In such framework, a pulse GPR system with ground-coupled antennae, 600 MHz and 1600 MHz centre frequencies was used over a 4-m30-m test site composed by a flexible pavement structure. The horizontal sampling resolution amounted to 2.410-2 m. A square regular grid mesh of 836 nodes with a 0.40-m spacing between the GPR acquisition tracks was surveyed. Accordingly, a light falling weight deflectometer (LFWD) was used for measuring the elastic modulus of pavement at each node. The setup of such instrument consisted of a 10-kg falling mass and a 100-mm loading plate so that the influence domain of the elasticity measure could be comparable to that of the radar signal. Good agreement were found between high Young modulus values and repaved zones, whereas damaged areas were characterized by lower values of E. Tomographic maps of amplitudes along the z axis were extracted up to a depth of z

Benedetto, Andrea; Tosti, Fabio; D'Amico, Fabrizio

2014-05-01

101

Evaluation of western shale-oil residue as an additive to petroleum asphalt for use as a pavement crack and joint sealant material  

SciTech Connect

The objective of this study was to perform a preliminary evaluation of using a distillation residue from Green River Formation (western) shale oil as an additive to a petroleum asphalt for use as a crack and joint filler material in portland cement concrete and asphaltic pavements. A commercially available rubberized asphalt crack and joint filler material was also tested for comparison. ASTM specification tests for sealant materials used in concrete and asphalt pavements were performed on the sealant materials. Portland cement concrete briquets prepared with an asphalt material sandwiched between two concrete wafers were tested in a stress-relaxation experiment to evaluate the relaxation and recovery properties of the sealant materials. The results show that the shale-oil modified petroleum asphalts and the neat petroleum asphalt do not pass the extension portion of the ASTM test; however, there is indication of improvement in the adhesive properties of the shale-oil modified asphalts. There is also evidence that the addition of shale-oil residue to the petroleum asphalt, especially at the 20% level, improves the relaxation and recovery properties compared with the petroleum asphalt.

Harnsberger, P.M.; Wolf, J.M.; Robertson, R.E.

1992-11-01

102

Recovery of municipal waste incineration bottom ash and water treatment sludge to water permeable pavement materials.  

PubMed

Water treatment plant sludge and municipal solid waste incinerator bottom ash are non-hazardous residues, and they can be reprocessed to produce useful materials for city public works. In this study, an effort was endeavored to investigate the properties of water permeable bricks made of water treatment sludge and bottom ash without involving an artificial aggregate step. The water treatment plant sludge was dried and ground, and the bottom ash was subjected to magnetic separation to remove ferrous metals. Both sludge and bottom ash were ground and sieved to a size of <2mm. Different contents of water treatment sludge (70-95% by weight) were mixed with bottom ash and the blocks were molded under a pressure of 110 kg/cm2. Thereafter, the molded blocks were sintered at temperatures of 900-1200 degrees C for 60-360 min. The compressive strength, permeability and water absorption rate of the sintered brick were examined and compared to relevant standards. The amount of bottom ash added in the mixture with water treatment sludge affects both the compressive strength and the permeability of the sintered bricks. The two effects are antonymous as higher bottom ash content will develop a beehive configuration and have more voids in the brick. It is concluded that a 20% weight content of bottom ash under a sintering condition of 1150 degrees C for 360 min can generate a brick with a compressive strength of 256 kg/cm2, a water absorption ratio of 2.78% and a permeability of 0.016 cm/s. PMID:16293405

Lin, Cheng-Fang; Wu, Chung-Hsin; Ho, Hsiu-Mai

2006-01-01

103

Bituminous pavement recycling Aravind K. and Animesh Das  

E-print Network

Bituminous pavement recycling Aravind K. and Animesh Das Department of Civil Engineering IIT Kanpur Introduction The bituminous pavement rehabilitation alternatives are mainly overlaying, recycling and reconstruction. In the recycling process the material from deteriorated pavement, known as reclaimed asphalt

Das, Animesh

104

A new type of low power thermoelectric micro-generator fabricated by nanowire array thermoelectric material  

Microsoft Academic Search

A new type of thermoelectric micro-generator, which is composed of n-type and p-type Bi2Te3 nanowire array thermoelectric materials, is designed to be energy source for miniaturized solid-state devices such as MEMS, micro-electrical system and even system on a chip. The nanowire arrays are fabricated by electrochemical deposition of Bi2Te3 into the nano-pores of alumina template. The measurements showed that the

Wei Wang; Falong Jia; Qinghua Huang; Jianzhong Zhang

2005-01-01

105

Structural response of LVR flexible pavements at Mn/ROAD project  

SciTech Connect

Pavement surface deflection basins provide valuable information for the structural evaluation of flexible pavements. Surface deflection measurements are rapid, inexpensive, and nondestructive and are used frequently as an indicator of pavement structural capability and performance potential. In this study, falling weight deflectometer testing results on the conventional flexible pavements (asphalt concrete surface, granular base/subbase) and aggregate-surface/surface-treated test sections in the low-volume road loop at the Minnesota Road Research Project (Mn/ROAD) were analyzed to evaluate the effect of granular material quality on the pavement structural response. Asphalt concrete (AC) modulus and subgrade ``break-point`` modulus were back-calculated using algorithms previously developed at the University of Illinois. The surface deflections were normalized to the same AC modulus and subgrade modulus. The analyses show a limited effect of granular material quality on the pavement deflection response in the case of conventional flexible pavements. Because of higher granular layer stresses, the granular material quality effects on the pavement surface deflection response of surface-treated/aggregate-surface pavements are significant. Increased AC thickness reduces the effect of granular base quality on the pavement deflection response.

Garg, N.; Thompson, M.R. [Univ. of Illinois, Urbana, IL (United States). Dept. of Civil Engineering] [Univ. of Illinois, Urbana, IL (United States). Dept. of Civil Engineering

1999-05-01

106

Guidelines and specifications for the use of reclaimed aggregates in pavement. Final report  

SciTech Connect

The project focused on evaluating the performance of recycled concrete for use as a base material under hot mix asphalt pavements and as an aggregate in Portland cement concrete pavements. In order to meet this objective, several goals were established. First, published literature on RCA was reviewed and a survey of State Highway Agencies (SHA) was performed to determine the extent of use of RCA in highway projects. Second, the RCA was tested at the FDOT Material Lab in Gainesville, Florida, to determine the material properties. Third, by using the output from the falling weight deflectometer test along with the KENSLABS and KENLAYER computer programs (Huang, 1993), a theoretical analysis was performed to predict the number of repetitions before the pavements failed in both the fatigue and permanent deformation criteria. Lastly, nine design sections involving HMA and PCC pavements were constructed at the University of Central Florida`s Circular Accelerated Test Track (UCF-CATT) to evaluate the response of the pavement sections made with RCA under actual dual-wheel loading.

Chini, S.A.; Kuo, S.S.; Duxbury, J.P.; Monteiro, F.M.B.R.; Mbwambo, W.J.

1998-08-01

107

CHECKLIST FOR INSPECTION OF POROUS PAVEMENTS Location: Inspector  

E-print Network

CHECKLIST FOR INSPECTION OF POROUS PAVEMENTS Location: Inspector: Date: Time: Site Conditions: Date minimum, Spring & Fall) Clean porous pavement to remove sediment and organic debris on the pavement surface via vacuum street sweeper. S U Adjacent non porous pavement vacuumed S U Clean catch basins (if

108

An analysis of pavement heat flux to optimize the1 water efficiency of a pavement-watering method2  

E-print Network

An analysis of pavement heat flux to optimize the1 water efficiency of a pavement-watering method2.hendel@paris.fr)8 9 Preprint version. Uploaded on May 12th , 2014.10 Abstract: Pavement-watering as a technique rarely been conducted. We propose an15 analysis of pavement heat flux at a depth of 5 cm and solar

Paris-Sud XI, Université de

109

Rehabilitation of continuously reinforced concrete pavements using overlays  

E-print Network

REHABILITATION OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS USING OVERLAYS A Thesis by SOUMYA SRIRAMAN Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... August 1993 Major Subject: Civil Engineering REHABILITATION OF CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS USING OVERLAYS A Thesis by SOUMYA SRIRAMAN Submitted to Texas A&M University in partial fulfillment of the requirements for the degree...

Sriraman, Soumya

1993-01-01

110

Life cycle assessment of concrete pavements : impacts and opportunities  

E-print Network

The concrete pavement network in the United States plays a crucial role in the economy by enabling the transport of people and goods, but it also leads to resource consumption and environmental impacts. This thesis is ...

Loijos, Alex (Alexander Nikos)

2011-01-01

111

An elastoplastic model based on the shakedown concept for flexible pavements unbound granular materials  

NASA Astrophysics Data System (ADS)

Nowadays, the problem of rutting of flexible pavements linked to permanent deformations occurring in the unbound layers is taken into account only by mechanistic empirical formulas. Finite element modelling of realistic boundary value problems with incremental rheological models will lead to unrealistic calculation time for large cycle numbers. The objective of the authors is to present a simplified model which can be used to model the flexible pavements rutting with the finite elements framework. This method is based on the shakedown theory developed by Zarka which is usually associated to materials like steels. It has been adapted for granular materials by introducing a yield surface taking into account the mean stress influence on the mechanical behaviour and a dependency of the hardening modulus with the stress state. The Drucker-Prager yield surface has been used with a non-associated flow rule. Comparisons with repeated load triaxial tests carried out on a subgrade soil have been done. These comparisons underline the capabilities of the model to take into account the cyclic behaviour of unbound materials for roads. Finally, a discussion, dealing with the use of the simplified method within a finite element modelling of a full-scale experiment, is presented.

Habiballah, Taha; Chazallon, Cyrille

2005-05-01

112

State-of-the-art guideline manual for design, quality control, and construction of sulfur-extended-asphalt (SEA) pavements  

SciTech Connect

Interest in the use of sulfur in highway pavement construction has been stimulated by unpredictable increases in cost and the relative uncertainty as to the future availability of asphalt cement (A/C) along with the potential surplus of sulfur in the near future. These events have led to the development of a new binder: a sulfur-extended-asphalt (SEA) binder. This new binder replaces some of the asphalt with sulfur in conventional asphalt paving plants. The mix material can be transported, laid, and compacted with standard paving equipment. Studies of SEA pavements indicate that their properties are comparable and in some cases may prove to be superior to those of conventional asphalt pavements. The manual presents state-of-the-art guidelines for design, quality control, safety factors, and construction of these newly developed pavements. A nonproprietary, direct mixing method and four proprietary methods of producing the SEA mixtures are described.

McBee, W.C.; Sullivan, T.A.; Izatt, J.O.

1980-01-01

113

Adaptive road crack detection system by pavement classification.  

PubMed

This paper presents a road distress detection system involving the phases needed to properly deal with fully automatic road distress assessment. A vehicle equipped with line scan cameras, laser illumination and acquisition HW-SW is used to storage the digital images that will be further processed to identify road cracks. Pre-processing is firstly carried out to both smooth the texture and enhance the linear features. Non-crack features detection is then applied to mask areas of the images with joints, sealed cracks and white painting, that usually generate false positive cracking. A seed-based approach is proposed to deal with road crack detection, combining Multiple Directional Non-Minimum Suppression (MDNMS) with a symmetry check. Seeds are linked by computing the paths with the lowest cost that meet the symmetry restrictions. The whole detection process involves the use of several parameters. A correct setting becomes essential to get optimal results without manual intervention. A fully automatic approach by means of a linear SVM-based classifier ensemble able to distinguish between up to 10 different types of pavement that appear in the Spanish roads is proposed. The optimal feature vector includes different texture-based features. The parameters are then tuned depending on the output provided by the classifier. Regarding non-crack features detection, results show that the introduction of such module reduces the impact of false positives due to non-crack features up to a factor of 2. In addition, the observed performance of the crack detection system is significantly boosted by adapting the parameters to the type of pavement. PMID:22163717

Gaviln, Miguel; Balcones, David; Marcos, Oscar; Llorca, David F; Sotelo, Miguel A; Parra, Ignacio; Ocaa, Manuel; Aliseda, Pedro; Yarza, Pedro; Amrola, Alejandro

2011-01-01

114

Hot in-place recycling of asphalt pavements. Master's thesis  

SciTech Connect

The purpose of this report is to identify factors to consider in selecting a hot in-place recycling project for asphalt pavements. This report discusses the different types of recycling processes and several selected hot in-place recycling processes that are becoming so popular today. The types of asphalt pavement distress and their causes are discussed to provide a working knowledge of possible applications for this process. Discussions on project selection, design, and construction considerations will also provide an awareness of considerations relative to this type of asphalt-pavement rehabilitation. An understanding of these topics will be helpful when selecting hot in-place recycling. The information that this report is based upon was obtained from various sources. A literature search included technical reports, periodicals, and advertisements. Personal contact was made in the form of interviews with a number of representatives in the industry and on site inspection of Cutler Repaving, Inc. and Remixer Contracting Co., Inc. operations.

Dowdy, M.L.

1987-08-04

115

A study of certain elastic and plastic strains induced in flexible pavement systems by repetitive wheel loads  

E-print Network

of Selected Test Sites VI. EVALUATION GF EQUIPMENT AHD TESTING PROCEDURES The Bankelman Beam 37 Individual Pavement Deformation Measurement Capability Effect of extrusion Minor errors Suitability for Measuring Repetitive Deflections 41 47 The Test... deflection test results 51 TABLE OF CONTENTS (CONTINUED) CHAPTER PAGE Recovery of Deformed Pavement The Overall Validity of the Data Obtained VII. CORRECTION OF IHE FIELD DATA 58 61 63 The Indicated Error The Correction Process 63 67 VIII...

Meyer, Kirby Thomas

1959-01-01

116

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional insolation  

E-print Network

Cracks in desert pavement rocks: Further insights into mechanical weathering by directional August 2010 Keywords: Desert pavements Physical weathering Desert geomorphology Insolation weathering Fractures The formation of cracks is a fundamental first step in the physical weathering of rocks in desert

Ahmad, Sajjad

117

Design of precast concrete pavement units for rapid maintenance of runways  

Microsoft Academic Search

This paper considers the use of precast cement concrete pavement units (PCPUs) as surfacing for runways in relation to slabs which have concrete to be saw cut, broken out and replaced with nondowelled, replaceable PCPUs and accept immediate overrunning by any type of aircraft in service. The finite-element analysis of the proposed replaced area shows that a considerable increase in

J. W. Bull; C. H. Woodford

1997-01-01

118

Automatic inspection of pavement cracking distress  

Microsoft Academic Search

We present an image processing algorithm customized for high-speed, real-time inspection of pavement cracking. In the algorithm, a pavement image is divided into grid cells of 88 pixels, and each cell is classified as a noncrack or crack cell using the grayscale information of the border pixels. Whether a crack cell can be regarded as a basic element (or seed)

Yaxiong Huang; Bugao Xu

2006-01-01

119

Improvements to a Transport Model of Asphalt Binder Oxidation in Pavements: Pavement Temperature Modeling, Oxygen Diffusivity in Asphalt Binders and Mastics, and Pavement Air Void Characterization  

E-print Network

Although evidence is mounting that asphalt binder oxidizes in pavements, and that oxidation and subsequent hardening of asphalt binder has a profound effect on pavement durability, important implementation issues remain to be better understood...

Han, Rongbin

2012-07-16

120

Safety considerations for the use of sulfur in sulfur-modified pavement materials  

E-print Network

of HZS Toxicity of Sulfur Dioxide Hydrogen Sulfide Emissions from Plasticization of Sulfur Mith Several Additives 30 36 37 39 47 LIST OF FIGURES Figure Effect of Temperature on the Hydrogen Sulfide Concentration Page Comparison of H2S... working distance for laboratory personnel. All mixes were prepared at temperatures below 300'F. The effect of temperature on the hydrogen sulfide concentration generated from the mix is shown in Figure 1 (6). The true peak con- centrations which occur...

Jacobs, Carolyn Yuriko

1980-01-01

121

Investigation of antenna frequency impact on assessing voids of asphalt pavements using GPR  

NASA Astrophysics Data System (ADS)

Ground Penetrating Radar (GPR) is a Non Destructive Testing (NDT) technique that has been developed and improved upon over the past 30 years. The technique is frequently utilized in order to evaluate and assess pavement structures. GPR, for pavement evaluation purposes, can be described as a remote sensing system that emits a short pulse, of electromagnetic energy, into the pavement, with a central frequency varying from 10 MHz up to 2.5GHz. The two most commonly utilized setups are air-coupled and ground-coupled antenna systems. For air-coupled systems, the antennas are suspended above the pavement surface and can operate at normal traffic speeds (up to ~ 80 Km/h). The major drawback of the air-coupled antenna is that penetration depth is limited. On the other hand, for ground-coupled systems the antennas are in direct contact with the pavement surface, providing for better signal penetration into the pavement structure; however ground coupled systems can achieve only limited operational speeds. As a generalized rule, increasing the GPR central operating frequency, increases the investigation resolution, while decreasing the overall depth of investigation In the light of the above, air-coupled systems have become increasingly popular for the evaluation of the part of the pavement structure, especially for the asphalt layers, while ground-coupled systems are utilized mostly in order to gather information from the entire pavement structure (up to ~ 3 m depth). The majority of GPR pavement studies are carried out with air-coupled horn antennas, as they can be implemented at driving speeds without need for road closures. For instance, the 1 GHz air-coupled horn antenna is commonly used for the estimation of pavement layer thickness. However signals generated by horn antenna systems must have sufficient quality to allow the performance of automated signal processing and qualitative data analysis, especially when pavement data more sensitive to the analysis parameters, such voids or moisture, is concerned. The implementation of the horn antenna method is dependent upon, amongst others, the resolution of the antenna in use. The present research work investigates the application of the GPR sensor technique to assess voids within the asphalt layers, with a focus on the air-coupled antenna penetration depth and resolution. For this purpose the dielectric properties of asphalt layer materials were estimated and related voids contents were evaluated based on data collected by an air-coupled GPR system, operating at a 1 GHz and alternatively a 2 GHz central frequency. The collected data is analyzed comparatively for the two antennas. Comparison results indicate differences between the voids determined from the 1 GHz and 2GHz antennas. These differences are further analyzed and evaluated for pavement quality control purposes. The indication of a relationship between the measured voids is also evaluated, while ground truth data is used for the validation of the GPR data analysis results. The above is presented and discussed thoroughly with the aim to assist pavement quality assurance systems

Plati, C.; Georgouli, K.; Loizos, A.

2012-04-01

122

Numerical Investigation of Design Strategies to Achieve Long-Life Pavements  

E-print Network

Increasing the HMA base thickness and modifying the HMA mixture properties to improve the resistance to fatigue cracking are among the most popular methods for achieving long-lasting pavements. Such methods are based on the idea of reducing the tensile strain at the bottom of the HMA layer below the Fatigue Endurance Limit (FEL), a level of strain below which no cumulative damage occurs to the HMA mixture. This study investigates the effectiveness of several design strategies involved in long-life, perpetual pavement design. A 3D Finite Element model of the pavement involving a linear viscoelastic constitutive model for HMA materials and non-uniform tire contact stresses is developed using ABAQUS 6.11. The effects of asphalt base course thickness and mixture type, rich binder layer, and aggregate subbase layer are examined. Four asphalt base course mixture types, namely dense graded, polymer modified, high modulus, and standard binder, are studied as a function of the asphalt base course thickness. The results underline a better performance of the high-modulus asphalt base, as compared to the other base course mixtures. The aggregate subbase layer on top of subgrade soil showed a relatively minor effect on the longitudinal and lateral strain response at the bottom of asphalt base course. The addition of a rich binder layer at the bottom of the asphalt base course showed a significant reduction in tensile strains. Tables are provided as a guideline to assess the different alternatives in design of long-life perpetual pavements.

Grace G. Abou-Jaoude; Ziad G. Ghauch

2012-03-30

123

Stochastic Modeling of Future Highway Maintenance Costs for Flexible Type Highway Pavement Construction Projects  

E-print Network

increased needs to rebuild deteriorated transportation networks. For major highway maintenance projects, a federal rule enforces to perform a life-cycle cost analysis (LCCA). The lack of analytical methods for LCCA creates many challenges of STAs to comply...

Kim, Yoo Hyun

2012-07-16

124

PCC Pavement Sustainability in New York Economy, Environment, and Society: 2 Out of 3 is Easy  

E-print Network

PCC Pavement Sustainability in New York Economy, Environment, and Society: 2 Out of 3 is Easy Bill PCC pavement sustainability strategy. NYSDOT recognizes that PCC pavements have "sustainable efforts, begging the question, "Is any pavement truly "sustainable?"" 1. PCC pavements, and pavement

125

Characterization of cementitiously stabilized subgrades for mechanistic-empirical pavement design  

NASA Astrophysics Data System (ADS)

Pavements are vulnerable to subgrade layer performance because it acts as a foundation. Due to increase in the truck traffic, pavement engineers are challenged to build more strong and long-lasting pavements. To increase the load-bearing capacity of pavements, subgrade layer is often stabilized with cementitious additives. Thus, an overall characterization of stabilized subgrade layer is important for enhanced short- and long-term pavement performance. In this study, the effect of type and amount of additive on the short-term performance in terms of material properties recommended by the new Mechanistic-Empirical Pavement Design Guide (MEPDG) is examined. A total of four soils commonly encountered as subgrades in Oklahoma are utilized. Results show that the changes in the Mr, ME and UCS values stabilized specimens depend on the soil type and properties of additives. The long-term performance (or durability) of stabilized soil specimens is investigated by conducting freeze-thaw (F-T) cycling, vacuum saturation and tube suction tests on 7-day cured P-, K- and C-soil specimens stabilized with 6% lime, 10% CFA and 10% CKD. This study is motivated by the fact that during the service life of pavement stabilized layers are subjected to F-T cycles and moisture variations. It is found that that UCS value of all the stabilized specimens decreased with increase in the number of F-T cycles. A strong correlation was observed between UCS values retained after vacuum saturation and F-T cycles indicating that vacuum saturation could be used as a time-efficient and inexpensive method for evaluating durability of stabilized soils. In this study, short- and long-term observations from stabilization of sulfate bearing soil with locally available low (CFA), moderate (CKD) and high (lime) calcium-based stabilizers are determined to evaluate and compare the effect of additive type on the phenomenon of sulfate-induced heave. The impact of different factors on the development of the ettringite, responsible for sulfate-induced heaving, is also discussed. For Level 2 design of pavements, a total of four stress-based statistical models and two feed-forward-type artificial neural network (ANN) models, are evaluated for predicting resilient modulus of 28-day cured stabilized specimens. Specifically, one semi-log stress-based, three log-log stress-based, one Multi-Layer Perceptrons Network (MLPN), and one Radial Basis Function Network (RBFN) are developed. Overall, semi-log stress-based and MLPN neural network are found to show best acceptable performance for the present evaluation and validation datasets. Further, correlations are presented for stress-based models to correlate Mr with compacted specimen characteristics and soil/additive properties. Additionally, the effect of type of additive on indirect tensile and fatigue characteristics of selected stabilized P- and V-soil is evaluated. This study is based on the fact that stabilized layer is subjected to tensile stresses under wheel loading. Thus, the resilient modulus in tension (M rt), fatigue life and strength in tension (sigmat) or flexure (represented by modulus of rupture, MOR) becomes another important design parameter within the mechanistic framework. Cylindrical specimens are prepared, cured for 28 days and subjected to different stress sequences in indirect tension to study the Mrt. On the other hand, stabilized beam specimens are compacted using a Linear Kneading Compactor and subjected to repeated cycles of reloading-unloading after 28 days of curing in a four-point beam fatigue apparatus for evaluating fatigue life and flexural stiffness. It is found that all three additives improved the Mrt, sigmat and MOR values; however, degree of improvement varied with the type of additive and soil. This study encompasses the differences in the design of semi-rigid pavements developed using AASHTO 1993 and AASHTO 2002 MEPDG methodologies. Further, the design curves for fatigue performance prediction of stabilized layers are developed for different stabilized pavement sections. Knowledge gained f

Solanki, Pranshoo

126

Fatigue properties of rubber modified pavements. Final report  

SciTech Connect

This report presents results of a study to determine the fatigue behavior of rubber modified pavements in Alaska in comparison with conventional asphalt concrete pavements. Laboratory studies were conducted on field specimens using the flexural fatigue test in the controlled-displacement mode. Tests were performed at 72 deg F and 40 deg F. Tested materials include (1) conventional HMA with AC 2.5 and AC 5; (2) PlusRide RUMAC with AC 5; (3) asphalt-rubber concrete with AC 2.5 (wet Process); and (4) rubberized asphalt-rubber concrete with AC 2.5 (wet/dry process).

Raad, L.; Saboundjian, S.; Yuan, X.

1995-05-01

127

Performance of pervious pavement parking bays storing rainwater in the north of Spain.  

PubMed

Pervious pavements are drainage techniques that improve urban water management in a sustainable manner. An experimental pervious pavement parking area has been constructed in the north of Spain (Santander), with the aim of harvesting good quality rainwater. Forty-five pervious pavement structures have been designed and constructed to measure stored water quantity and quality simultaneously. Ten of these structures are specifically constructed with different geotextile layers for improving water storage within the pavements. Following the confirmation in previous laboratory experiments that the geotextile influenced on water storage, two different geosynthetics (Inbitex and a One Way evaporation control membrane) and control pervious pavements with no geotextile layers were tested in the field. Weather conditions were monitored in order to find correlations with the water storage within the pervious pavement models tested. During one year of monitoring the three different pervious pavement types tested remained at their maximum storage capacity. The heavy rain events which occurred during the experimental period caused evaporation rates within the pervious pavements to be not significant, but allowed the researchers to observe certain trends in the water storage. Temperature was the most closely correlated weather factor with the level of the water stored within the pervious pavements tested. PMID:20706008

Gomez-Ullate, E; Bayon, J R; Coupe, S; Castro-Fresno, D

2010-01-01

128

Washington State Report Questions on NDT Testing 1. What NDT testing methods for concrete materials, concrete pavements, and overlays are you  

E-print Network

Washington State Report Questions on NDT Testing 1. What NDT testing methods for concrete materials, concrete pavements, and overlays are you trying? NDT test methods used by WSDOT include the MIT Scan, MIT the reliability of NDT testing methods compare to traditional testing methods? MIT Scan measurements were

129

Impact of Curing Methods on Curling of Concrete Pavements  

E-print Network

Impact of Curing Methods on Curling of Concrete Pavements Amir Hajibabaee Travis Ebisch Tyler Ley is Curling? Curling is when the edges of a concrete pavement (or slab) deflect up compared to the middle. Warping is the same thing only the edges deflect downward. curling warping #12;Why do pavements curl

130

Surface Distresses Detection of Pavement Based on Digital Image Processing  

Microsoft Academic Search

\\u000a Pavement crack is the main form of early diseases of pavement. The use of digital photography to record pavement images and\\u000a subsequent crack detection and classification has undergone continuous improvements over the past decade. Digital image processing\\u000a has been applied to detect the pavement crack for its advantages of large amount of information and automatic detection. The\\u000a applications of digital

Aiguo Ouyang; Chagen Luo; Chao Zhou

2010-01-01

131

Fatigue behavior of rubber modified pavements. Final report, 1994-1996  

SciTech Connect

Over the last 15 years, a number of rubberized pavement projects have been built in Alaska. Initial laboratory and field investigations sponsored by the Alaska Department of Transportation and Public Facilities (AKDOT&PF) and conducted by Raad et al. (1995) indicated improved fatigue performance of the rubberized sections in comparison with conventional asphalt concrete pavements. The report presents the results of a follow-up investigation to develop design equations for rubberized pavements in Alaska.

Raad, L.; Saboundjian, S.

1997-05-01

132

Pervious Pavement A Strategic Plan For NYC DOT  

E-print Network

Pervious Pavement A Strategic Plan For NYC DOT Presented By: Rene Brana Spring 2012 Capstone: Pervious Pavement - A Strategic Plan for NYC DOT 2 Capstone: Pervious Pavement - A Strategic Plan for NYC DOT 3 Image courtesy of

Qian, Ning

133

Evaluation of a new construction pavement section using the mechanistic-empirical pavement design guide  

NASA Astrophysics Data System (ADS)

The AASHTO Mechanistic-Empirical Design Guide (MEPDG) is one of several "next generation" pavement design approaches intended to address limitations of older empirical methods. This research investigated the capabilities and performance of the MEPDG through analyses of an empirically-designed section of NH Route 16, which the New Hampshire Department of Transportation (NHDOT) indicated may be under-designed. MEPDG distress predictions indicate that the pavement section should achieve a service life of at least 10 years. This was supported by the fatigue analysis of the base course, which also indicated that the pavement may have been damaged by traffic loads prior to the completion of the surface course. During this research, a number of limitations and model behaviors of the MEPDG were observed, some with significant importance to this analysis and to future projects within New Hampshire. Because implementation and full realization of the MEPDG requires significant investment, the results of this research should be considered before undertaking steps towards adoption of the software.

Lowe, Justin

134

Degeneration and death, by apoptosis and necrosis, of the pavement and chloride cells in the gills of the teleost Oreochromis mossambicus  

Microsoft Academic Search

Degeneration and death of branchial epithelial cells were studied in an African cichlid fish. In both freshwater and seawater fish the superficially located pavement cells are sloughed off at the end of their lifecycle. This process is preceded by degeneration via a process of cytoplasmic shrinkage and condensation related to apoptotic (physiologically controlled) cell death. The chloride cells are pleomorphic,

S. E. Wendelaar Bonga; C. J. M. van der Meij

1989-01-01

135

PARTIAL-DEPTH REPAIR OF CONCRETE PAVEMENTSCONCRETE PAVEMENTS  

E-print Network

April 2012 PARTIAL-DEPTH REPAIR OF CONCRETE PAVEMENTSCONCRETE PAVEMENTS GUIDE FOR #12;#12;Guide for Partial-Depth Repair of Concrete Pavements i Technical Report Documentation Page 1. Report No. 2 Depth Repair of Concrete Pavements April 2012 6. Performing Organization Code 7. Author(s) 8. Performing

136

RESEARCH REPORT 1250-1 EFFECT OF RECLAIMED ASPHALT PAVEMENT  

E-print Network

RESEARCH REPORT 1250-1 EFFECT OF RECLAIMED ASPHALT PAVEMENT ON BINDER PROPERTIES USING. Report Date September 1998 4. Title and Subtitle EFFECT OF RECLAIMED ASPHALT PAVEMENT ON BINDER with the Federal Highway Administration. 16. Abstract While the use of reclaimed asphalt pavement (RAP) in asphalt

Texas at Austin, University of

137

Cosmogenic 3 He surface-exposure dating of stone pavements  

E-print Network

Cosmogenic 3 He surface-exposure dating of stone pavements: Implications for landscape evolution Mexico 87545 Chad T. Olinger ABSTRACT The formation of stone pavements, a ubiquitous gravel armor at the land surface in a time-transgressive manner. A newly proposed model for pavement evolution differs from

Ahmad, Sajjad

138

Structural design of pavements with stabilized layers Animesh Das  

E-print Network

Structural design of pavements with stabilized layers Animesh Das Associate Professor, Department@iitk.ac.in The talk will primarily be divided in three parts, namely analysis of pavement structure, empirical design and composite pavements will be mentioned. The governing equations and the boundary conditions will be discussed

Das, Animesh

139

Investigation of factors affecting asphalt pavement recycling and asphalt compatibility  

SciTech Connect

Both economic and environmental factors dictate that asphalt pavement be recycled. Many recycling projects have been completed using a variety of recycling additives, but little work has been done on the physiochemical aspects of pavement recycling. The present exploratory study was undertaken to better define the physiochemical variables of recycling. Objectives of the present study include: (1) to determine if molecular structuring in the asphalt binder could be observed in oxidized (air-aged) asphalt-aggregate briquets, and if so, how was structuring affected during briquits, and if so, how was structuring affected during briquet recycling and (2) to determine if recycling agents penetrate the strongly adsorbed asphalt layer on the aggregate surface. Differences were seen in asphalt component compatibility as judged by the state of peptization parameters. In extreme cases the values of the parameters correlated with properties of asphalts of known compatibility; however, a relationship between the parameters determined on a series of asphalts in pavements was not established. The parameters might be useful in evaluating additives for pavement recycling; however, more systems need to be studied to fully assess their potential usefulness. Finally, the parameters need to be correlated with performance-related measurements such as asphalt rheological and mix properties. Examination of the parameters and their changes on asphalt oxidative aging may also be informative with regard to asphalt durability inasmuch as oxidation-induced changes are a major cause of asphalt pavement failure.

Venable, R.L.; Petersen, J.C.; Robertson, R.E.; Plancher, H.

1983-03-01

140

Pavement recycling. Executive summary and report  

SciTech Connect

The Federal Highway Administration (FHWA) initiated Demonstration Project 39 (DP 39) Recycling Asphalt Pavements in June 1976. The project showed that asphalt pavement recycling was a technically viable rehabitation technique, and it was estimated that the use of reclaimed asphalt pavement (RAP) would amount to approximately 15 percent of the total hot-mix asphalt (HMA) production by the mid-1980s. It was expected that most of the asphalt pavement removed would be reused in new pavement construction or overlays.

NONE

1995-10-01

141

Early-life study of the FA409 full-depth asphalt-concrete pavement sections  

SciTech Connect

The Illinois Department of Transportation (IDOT) is currently implementing a mechanistic thickness-design procedure for full-depth asphalt-concrete pavements. This thesis is an early design-life investigation of full-depth asphalt-concrete pavements, constructed on FA409 near Carlyle, Illinois in 1986. Included in the study are: sampling and testing of paving and subgrade materials; extensive non-destructive testing (NDT) using the Falling Weight Deflectometer (FWD); development of techniques for interpreting NDT data; determination of as-built structural characteristics of the various pavement sections; evaluation of subsurface drainage and lime-treated soil behavior; and examination of the validity of the ILLI-PAVE computer model. The simplicity of a full-depth asphalt-concrete pavement allows useful information regarding pavement structure to be determined from FWD surface-deflection data. The ILLI-PAVE model was used in conjunction with statistical methods to quantify, in the form of regression equations or algorithms, the relationship between pavement structure (Tac, Eac, and Eri) and pavement response to FWD loading. Testing of pavement and subgrade material samples as used to validate these algorithms.

Hill, H.J.

1988-01-01

142

Quantifying mobile and immobile zones during simulated stormwater infiltration through a new permeable pavement material.  

PubMed

We have designed a new eco-material for use in permeable pavements in view to ensuring the sustainable management of stormwater in urban areas. The specific characteristic of this material is that it allows the infiltration of rainfall, storing the infiltrated water and trapping the pollutants carried by runoff such as engine oil and heavy metals. This new material is composed of a mixture of crushed concrete , resulting from inert construction waste, and organic material (compost). We performed tracing experiments in view to monitor the flow of the water within this material in order to study its hydrodynamics under heavy rainfall (rain with a return period of 10 years). The experimental results revealed preferential flows due to the heterogeneity of the material and liable to act as a major vector for the mobility of the pollutants transported within the material by stormwater. The work presented in this article consists in quantifying these preferential flows by determining their water contents in mobile (?m) and immobile (?im) water during infiltration. To do this, we used the (NON-EQUILIBRIUM Convection-Dispersion Equation) model, in order to evaluate mobile and stagnant zones in the framework of tracing experiments. PMID:25230252

Bentarzi, Y; Ghenaim, A; Terfous, A; Wanko, A; Poulet, J B

2015-03-01

143

Asphalt in Pavement Maintenance.  

ERIC Educational Resources Information Center

Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many

Asphalt Inst., College Park, MD.

144

Road Materials and Pavement Design. Volume X No. X/2001, pages 1 to n Towards a novel framework for handling  

E-print Network

Road Materials and Pavement Design. Volume X ­ No. X/2001, pages 1 to n Towards a novel framework and Pavement Design. Volume X ­ No. X/2001 1. Introduction Nowadays, enterprises are outsourcing their business

Paris-Sud XI, Université de

145

Investigation of Primary Causes of Load-Related Cracking in Asphalt Concrete Pavement in North Carolina  

NASA Astrophysics Data System (ADS)

This dissertation presents causes of cracking in asphalt concrete pavement in North Carolina through field investigation and laboratory experiments with field extracted material. North Carolina is experiencing higher than anticipated rates of fatigue cracking compared to other state. These higher than expected rates could be reflective of the national trends in mix design practice or could be caused by structural pavement failures. The problems associated with premature cracking in North Carolina pavements point to the need to evaluate the North Carolina Department of Transportation (NCDOT) mixes, processes, and measures to ensure that these factors properly balance the goals of preventing cracking and minimizing permanent deformation. Without solid data from in-service pavements, any conclusions regarding the causes of these failures might be pure conjecture. Accordingly, this research examines material properties through laboratory experiments using field-extracted materials and investigates in situ pavements and pavement structure. In order to assess condition of existing pavement, alligator cracking index (ACI) was developed. The asphalt content in the top layer that exhibits top-down cracking or bottom-up cracking has a proportional relationship to ACI values. The air void content in a bottom layer that exhibits top-down cracking or bottom-up cracking shows an inverse proportional relationship to ACI values. These observations reflect reasonable results. A comparison between ACI and asphalt film thickness values does not produce noteworthy findings, but somewhat reasonable results are evident once the range of comparison is narrowed down. Thicker film thicknesses show higher ACI values. From field core visual observations, road widening is identified as a major cause of longitudinal cracking. Regions with observed layer interface separation tend to have low ACI values. Through tensile strain simulation based on actual field conditions, it is observed that sites with observed bottom-up cracking have higher tensile strain levels at the bottom of the asphalt layer than sites with observed top-down cracking. Extracted binder fatigue test results indicate that binder properties between good and poor sections of a given site are not the result of differences in the binder properties. Hence, other mixture design factors are at work in controlling the site variability in terms of fatigue resistance.

Park, Hong Joon

146

A comprehensive approach for the assessment of in-situ pavement density using GPR technique  

NASA Astrophysics Data System (ADS)

Proper construction of the asphalt pavement is a prerequisite to developing a long lasting roadway that does not require extensive future maintenance. This goal is achieved by verifying that design specifications are met through the use of quality assurance (QA) practices. The in-situ density is regarded as one of the most important controls used to ensure that a pavement being placed is of high quality because it is a good indicator of future performance. In-situ density is frequently assessed utilizing one or more of the following three methods: cores, nuclear density gauge measurements or non-nuclear density gauge measurements. Each of the above mentioned methods, however, have their distinct disadvantages. Cores, for example, are generally considered to be the most accurate means of measuring in-situ density, however, they are a time consuming and destructive test that introduces a defect into asphalt pavements. Because of the destructive nature associated with coring, contractors and agencies have alternatively used non-destructive nuclear and non-nuclear density gauges for quality control purposes. These instruments allow for a more rapid assessment of the in-situ density, allowing measurements to be taken even during the pavement's construction. The disadvantage of these gauges are that they provide density readings only at discrete locations of the asphalt pavement mat, while no consensus exists among pavement researchers on the proper correlation between the gauges and core density. In recent years, numerous alternative methods have been introduced for the assessment of in-situ density, both during asphalt pavement construction and afterwards. These methods include, amongst others, intelligent compaction, thermal imaging and ground penetrating radar (GPR). Among these methods, GPR has been defined as both a technically feasible and promising method for the nondestructive, rapid, and continuous evaluation of in-situ asphalt pavement density based on electromagnetic mixing (EM) theory, through the utilization of proper models. These models enable the prediction of asphalt mixture density dependent on its bulk dielectric constant as measured by the GPR, the dielectric properties of the asphalt mix materials, as well as other material information. The goal of the present study is to attempt to verify the prediction performance of various density models. To accomplish this goal GPR surveys were carried out in the field during asphalt pavement construction to evaluate the density results due to different compaction modes. The GPR data was analyzed to calculate the appropriate asphalt mix dielectric properties needed for the activation of the considered density prediction models. Predicted densities were compared with densities of the field cores extracted from the as-built asphalt pavement prior to trafficking. It was found that the predicted density values were significantly lower when compared to the ground truth data. A further investigation of the effect of temperature on GPR readings showed that GPR seems to overestimate the in-situ density. However, this approach could be used effectively to evaluate the performance of different compaction methods and set up the compaction pattern that is needed to achieve the desired asphalt pavement density.

Plati, Christina; Georgiou, Panos; Loizos, Andreas

2013-04-01

147

COLLINS, KELLY ALYSSA. A Field Evaluation of Four Types of Permeable Pavement with Respect to Water Quality Improvement and Flood Control. (Under the direction of  

E-print Network

to Water Quality Improvement and Flood Control. (Under the direction of Dr.William F. Hunt.) In North capabilities in reducing runoff, but are not credited for improving water quality. To further test the hydrologic and water quality responses of various permeable pavement designs, a 20-stall parking lot

Hunt, William F.

148

Assessing the potential for restoration of surface permeability for permeable pavements through maintenance.  

PubMed

Permeable pavements (PPs) have been in use as stormwater management systems in Canada and the United States for over 20 years. After years of exposure to sediment and debris build-up, surface clogging reduces the infiltration of stormwater and inhibits the hydraulic and environmental functions of the pavement. Removal of surface material has been shown to restore infiltration but the majority of studies have been limited to small-scale testing. This paper presents the results of small- and full-sized equipment testing aimed at restoring surface permeability, including the first testing of regenerative-air and vacuum-sweeping streetsweepers in Ontario. Maintenance achieved partial restoration of PP surface permeability. Post-treatment surface infiltration rates displayed large spatial variability, highlighting that localized conditions throughout the pavement have a confounding influence on the overall effectiveness of maintenance. The impact of maintenance may be improved by establishing regular cleaning intervals and developing instructional guidelines for pavement owners and equipment operators. PMID:24225094

Drake, Jennifer; Bradford, Andrea

2013-01-01

149

Mairepav 6 : the Sixth International Conference on maintenance and rehabilitation of pavements and technological control, At Torino, Italy, July 8-10, 2009  

E-print Network

Mairepav 6 : the Sixth International Conference on maintenance and rehabilitation of pavements as the basics (Cormier & Thébeau 2003) for choosing types of pavement. In that context, many studies have been of pavements. LCPC has performed several studies based on LCA, with the aim of developing a method suitable

Paris-Sud XI, Université de

150

Recycling of portland cement concrete pavement, Johnson County. Final report, 1986-1995  

SciTech Connect

In recent years there has been increasing interest in recycling construction materials. Surface courses of bituminous pavements are currently being actively recycled all over Kansas. The recycling of portland cement concrete pavements (PCCP) can help alleviate any material disposal problems during construction, especially in urban areas and reduce the consumption or importation of virgin aggregate into aggregate poor areas. Two test sections using the coarser fraction from the original crushed portland cement concrete pavement were placed on K-7 in 1985. One section incorporated a recycled base and standard PCCP construction, another section was designed as a recycled base and recycled PCCP. Two other sections were control sections constructed with regular aggregate.

Wojakowski, J.B.; Fager, G.A.; Catron, M.A.

1995-08-01

151

Energy equivalents for selected pavement materials: Their production and placement  

NASA Astrophysics Data System (ADS)

Energy requirements for selected pavement surfaces are discussed. Energy requirements for hot-mixed bituminous recycling and portland cement concrete recycling projects are presented along with conventional pavement methods. Energy requirements for conventional thin surface treatments are also discussed. Environmental analyses involving both air and noise quality measurement are included for various recycling and conventional paving options.

Lane, K. R.

1981-03-01

152

Reconstruction of a pavement geothermal deicing system  

SciTech Connect

In 1948, US 97 in Klamath Falls, Oregon was routed over Esplanade Street to Main Street and through the downtown area. In order to widen the bridge across the US Bureau of Reclamation A Canal and to have the road cross under the Southern Pacific Railroad main north-south line, a new bridge and roadway were constructed at the beginning of this urban route. Because the approach and stop where this roadway intersected Alameda Ave (now Hwy 50 -- Eastside Bypass) caused problems with traffic getting traction in the winter on an adverse 8% grade, a geothermal experiment in pavement de-icing was incorporated into the project. A grid system within the pavement was connected to a nearby geothermal well using a downhole heat exchanger (DHE). The 419-foot well provided heat to a 50-50 ethylene glycol-water solution that ran through the grid system at about 50 gpm. This energy could provide a relatively snow free pavement at an outside temperature of {minus}10 F and snowfall up to 3 inches per hour, at a heat requirement of 41 Btu/hr/ft{sup 2}. Over time, the well temperature dropped from 143 to 98 F at the surface. The bridge and surface pavement, geothermal well, and associated equipment were modified. This paper describes the modifications.

Lund, J.W. [Geo-Heat Center, Klamath Falls, OR (United States)

1999-03-01

153

Application of a New Decision Method in Expressway Pavement Management System  

Microsoft Academic Search

We have proposed the decision-making model of maintenance for cement concrete pavement, by analyzing the formation and evolution characteristics of cement concrete pavement diseases and considering the actual maintenance of Hunan Province, under the thought of preventive maintenance, According to the requirement of preventive maintenance, during the schedule making, we should firstly choose the preventive maintenance measures, such as replace

Jiang-hong Zeng; Jia Xu

2009-01-01

154

AREA UNDER TREES BETWEEN HOUSES AND EDGE OF PAVEMENT ON ...  

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

AREA UNDER TREES BETWEEN HOUSES AND EDGE OF PAVEMENT ON THE EAST SIDE OF SOUTH JEFFERSON STREET FROM SOUTHEAST CORNER OF INTERSECTION OF SOUTH JEFFERSON STREET AND HIGHLAND AVENUE - South Albany Historic District, Bounded by South Jefferson Street, Highland Avenue & Whitney Avenue, Albany, Dougherty County, GA

155

Cosmogenic 3He surface-exposure dating of stone pavements: Implications for landscape evolution in deserts  

Microsoft Academic Search

The formation of stone pavements, a ubiquitous gravel armor mantling landforms in arid regions of the world, has been previously attributed to erosion by wind and water or alternating shrinking and swelling of soil horizons, implying that gravel is concentrated at the land surface in a time-transgressive manner. A newly proposed model for pavement evolution differs from these models in

Stephen G. Wells; Leslie D. McFadden; Jane Poths; Chad T. Olinger

1995-01-01

156

Measurement of visibility loss due to splash and spray: porous, SMA and conventional asphalt pavements  

Microsoft Academic Search

Road traffic accidents are a major problem for the safety, well-being and economies of Southeast Asian countries. In Thailand, many accidents are caused by environmental or road conditions. Poor visibility on wet pavement is a major cause of accidents. Accumulated water on wet pavement surfaces creates the splash and spray effect, resulting in visibility loss. The main objective of this

Pichaya Rungruangvirojn; Kunnawee Kanitpong

2010-01-01

157

Optimal scheduling of rehabilitation activities for multiple pavement facilities: exact and approximate solutions  

Microsoft Academic Search

This paper presents a mathematical programming model for optimal highway pavement rehabilitation planning which minimizes the life-cycle cost for a finite horizon. It extends previous researches in this area by solving the problem of multiple rehabilitation activities on multiple facilities, with realistic empirical models of deterioration and rehabilitation effectiveness. The formulation is based on discrete control theory. A nonlinear pavement

Yanfeng Ouyang; Samer Madanat

2004-01-01

158

A review on using crumb rubber in reinforcement of asphalt pavement.  

PubMed

An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction. PMID:24688369

Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

2014-01-01

159

A Review on Using Crumb Rubber in Reinforcement of Asphalt Pavement  

PubMed Central

An immense problem affecting environmental pollution is the increase of waste tyre vehicles. In an attempt to decrease the magnitude of this issue, crumb rubber modifier (CRM) obtained from waste tyre rubber has gained interest in asphalt reinforcement. The use of crumb rubber in the reinforcement of asphalt is considered as a smart solution for sustainable development by reusing waste materials, and it is believed that crumb rubber modifier (CRM) could be an alternative polymer material in improving hot mix asphalt performance properties. In this paper, a critical review on the use of crumb rubber in reinforcement of asphalt pavement will be presented and discussed. It will also include a review on the effects of CRM on the stiffness, rutting, and fatigue resistance of road pavement construction. PMID:24688369

Mashaan, Nuha Salim; Ali, Asim Hassan; Karim, Mohamed Rehan; Abdelaziz, Mahrez

2014-01-01

160

Millimeter-wave nondestructive evaluation of pavement conditions  

NASA Astrophysics Data System (ADS)

The United States is suffering from an aging civil infrastructure crisis. Key to recovery are rapid inspection technologies like that being investigated by the VOTERS project (Versatile Onboard Traffic Embedded Roaming Sensors), which aims to outfit ordinary road vehicles with compact low-cost hardware that enables them to rapidly assess and report the condition of roadways and bridge decks free of driver interaction. A key piece of hardware, and the focus of this paper, is a 24 GHz millimeter-wave radar system that measures the reflectivity of pavement surfaces. To account for the variability of real-world driving, such as changes in height, angle, speed, and temperature, a sensor fusion approach is used that corrects MWR measurements based on data from four additional sensors. The corrected MWR measurements are expected to be useful for various characterization applications, including: material type; deterioration such as cracks and potholes; and surface coverage conditions such as dry, wet, oil, water, and ice. Success at each of these applications is an important step towards achieving the VOTERS objective, however, this paper focuses on surface coverage, as whatever covers the driving surface will be most apparent to the MWR sensor and if not accounted for could significantly limit the accuracy of other applications. Contributions of the paper include findings from static lab tests, which validate the approach and show the effects of height and angle. Further contributions come from lab and in-field dynamic tests, which show the effects of speed and demonstrate that the MWR approach is accurate under city driving conditions.

Vines-Cavanau, David; Busuioc, Dan; Birken, Ralf; Wang, Ming

2012-04-01

161

Surface runoff from full-scale coal combustion product pavements during accelerated loading  

Microsoft Academic Search

In this study, the release of metals and metalloids from full-scale portland cement concrete pavements containing coal combustion products (CCPs) was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections under well-controlled conditions. An equivalent of 20 years of highway traffic loading was simulated at the OSU\\/OU Accelerated Pavement Load Facility (APLF). Three types of portland cement

Chin-Min Cheng; Panuwat Taerakul; Wei Tu; Behrad Zand; Tarunjit Butalia; William Wolfe; Harold Walker

2008-01-01

162

Numerical Investigation of Design Strategies to Achieve Long-Life Pavements  

E-print Network

Increasing the HMA base thickness and modifying the HMA mixture properties to improve the resistance to fatigue cracking are among the most popular methods for achieving long-lasting pavements. Such methods are based on the idea of reducing the tensile strain at the bottom of the HMA layer below the Fatigue Endurance Limit (FEL), a level of strain below which no cumulative damage occurs to the HMA mixture. This study investigates the effectiveness of several design strategies involved in long-life, perpetual pavement design. A 3D Finite Element model of the pavement involving a linear viscoelastic constitutive model for HMA materials and non-uniform tire contact stresses is developed using ABAQUS 6.11. The effects of asphalt base course thickness and mixture type, rich binder layer, and aggregate subbase layer are examined. Four asphalt base course mixture types, namely dense graded, polymer modified, high modulus, and standard binder, are studied as a function of the asphalt base course thickness. The result...

Ghauch, Ziad G

2011-01-01

163

Contributions of performance-graded asphalt to low temperature cracking resistance of pavements. Final report  

SciTech Connect

The purpose of this research was to study and evaluate the role that asphalt cracking. As part of the Strategic Highway Research Program (SHRP) new specifications for asphalt binders were developed that are based on the performance of the material. The asphalt binder graded and specified according to these new performance-based specifications is called PG binder. These new specifications are commonly referred to as Superpave (Superior Performing Asphalt Pavement) binder specifications. A section of Interstate 64 in southern Indiana was experiencing severe low temperature cracking before it was reconstructed over the summers of 1995 and 1996. The binder used in the new pavement mixes was PG material. Dynamic Shear Rheometer (DSR) tests, Bending Beam Rheometer (BBR) tests, and viscosity tests were performed on this binder. Comparisons were made between test results obtained from the binders in the old pavement and the new pavement. All tests and comparisons were based on the Superpave binder specifications.

Loh, S.W.; Olek, J.

1999-05-01

164

Thermal cracking of rubber modified pavements, May 1995. Final report  

SciTech Connect

In accordance with the original ISTEA mandate (1991) to use crumb tire rubber in pavements, Alaska would be required to use about 250 tons of used tire rubber starting in 1994 and increasing to about 1,000 tons of rubber in 1997 and each year thereafter. A number of pavements using crumb rubber modifiers have been built in the state and have been in service for periods of 8 to 15 years. Knowledge of the behavior of these rubber-modified pavements under extreme climate conditions, particularly in relation to their low temperature cracking resistance, is necessary for future design and construction of rubberized pavements in Alaska. This report presents results of a study to determine the low temperature cracking resistance of rubber modified pavements in Alaska in comparison with conventional asphalt concrete pavements.

Raad, L.; Yuan, X.; Saboundjian, S.

1995-05-01

165

[ ]April 2013 Thickness is currently a pay item for portland cement concrete (PCC) pavements  

E-print Network

) pavements and a quality control item for both PCC and hot mix asphalt (HMA) pavements. A change in pavement are performed by destructively coring the finished pavement and measuring the thickness of the core are collected for each lot. Today, multiple non- destructive pavement evaluation tools are available

Harms, Kyle E.

166

Advancement of Erosion Testing, Modeling, and Design of Concrete Pavement Subbase Layers  

E-print Network

Department of Transportation. The author is grateful for their supports. vi D NOMENCLATURE AASHTO American Association of State Highway and Transportation Officials AASHO American Association of State Highway Officials AC Asphalt concrete... ACP Asphaltic concrete pavement ADT Average daily traffic ADTT Average daily truck traffic ASB Asphalt stabilized base ASTM American Society of Testing Materials CoTE Coefficient of thermal expansion COPES Concrete Pavement Evaluation...

Jung, Youn Su

2010-10-12

167

Pavement performance modelling with an auto-regression approach  

Microsoft Academic Search

In this paper, an auto-regression method is applied to pavement performance modelling to improve the predictive accuracy of predictions when there are only limited or incomplete data available. Using age and past measured conditions as independent variables, the average trend within a pavement group is captured by a global function shared by all pavements, while any pavement-specific effects are reflected

Z. Luo

2011-01-01

168

New structural systems for zero-maintenance pavements. Volume 3: Anchored pavement system designed for Edens Expressway  

NASA Astrophysics Data System (ADS)

The response of the Edens Expressway subjected to mechanical and environmental loads using the anchored pavement concept is discussed. The mechanical and thermal properties of materials that could be encountered in future reconstruction of Edens Expressway are presented in a consistent form for computer programming. These properties are viewed as typical design values during investigation of pavement response. The behavior of the anchored pavement under induced temperature loads and weakening of subgrade (by thawing action) is clearly demonstrated. The example problem provides the input parameters of materials and loads for the analysis, the generation of finite element mesh, and the results of the analysis.

Saxena, S. K.; Militsopoulos, S. G.

1980-08-01

169

Road Materials and Pavement Design, 2013 Vol. 14, No. S2, 5778, http://dx.doi.org/10.1080/14680629.2013.812838  

E-print Network

Road Materials and Pavement Design, 2013 Vol. 14, No. S2, 57­78, http://dx.doi.org/10.1080/14680629.2013.812838 IlliTC ­ low-temperature cracking model for asphalt pavements Eshan V. Davea *, William G. Buttlarb for asphalt pavements located in regions with cold climate; however, most pavement design methods do

Paulino, Glaucio H.

170

Hot in-place recycling of asphalt pavements. Final report, 1988-1989  

SciTech Connect

This report contains the results of a literature search concerning hot in-place asphalt pavement recycling. Current methods and procedures for hot in-place recycling were reviewed and the advantages and disadvantages of each presented. Four construction sites were visited. Each site used a different procedure to recycle the pavement. These procedures along with the equipment used are discussed in regard to selecting a recycling method, material controls, and available cost data.

Shoenberger, J.E.; Vollor, T.W.

1990-09-01

171

Study of the durability of demolition aggregates on pavements  

NASA Astrophysics Data System (ADS)

This work is an experimental contribution to the study of durability of various materials coming from the demolition of buildings for their use in the flexible infrastructures of pavements. However, these pavements undergo traffic loading which causes, in the long time permanent deformations and settlements thus generating significant degradations of materials. Various recent works aim at characterizing these materials. This work falls under this scope and gives an approach of the mechanical behavior and the response of these last to repetitive loadings. After identification of materials and the determination of the characteristics of hardness and durability, we studied their mechanical behavior with cyclic shearing on these three materials (aggregates of concrete, brick and concrete block). These tests enabled us to analyze the mechanisms which occur through the various parameters related to loading (the amplitude and the repetition of loading, the parameters related to materials (the water content, the density and the grain size distribution). The study of the durability of these materials consists on quantifying the degradation rate of the grains after the various tests and the grain size distribution which governs the amplitude of crushing.

Bachir, Melbouci; Fazia, Boudjemia

2009-06-01

172

LRRB Pavement Management Systems Pavement Management Systems  

E-print Network

LRRB Pavement Management Systems Pavement Management Systems Presented by: Michael Marti SRF for implementing and monitoring research results (RIC) #12;LRRB Pavement Management Systems LRRB Structure LRRB and counties in implementing Pavement Management and/or using better §Project produced several deliverables

Minnesota, University of

173

Joint application of GPR and electrostatic resistivity to assess mixed pavement condition  

NASA Astrophysics Data System (ADS)

In planning maintenance and rehabilitation of paved streets it is of first importance to gather internal structure information to establish a diagnostic. We investigate the potential of the GPR and of the capacitively-coupled resistivity array profiling techniques to map the geometry and the defects present at various depths in streets with mixed pavement. GPR is excellent at delineating boundaries of material with contrasting electrical properties whereas the resistivity array is needed to determine the nature and quality of the imaged material. Thicknesses of asphalt and concrete can be continuously determined. Defects such as cracks, delaminations, voids and former repairs can be mapped. Quality of the concrete slab can be assessed by resistivity. The performances of the two techniques are demonstrated first using numerical modeling and imaging of typical pavement defects. Resistivity and GPR data were collected along a few streets in Montreal using a 1GHz GPR smart cart and a compact 2-receiver dipole resistivity system. Streets were selected to demonstrate the responses to different pavement defects. The results allow to show the performance and limitations of present systems. In particular, it is shown that multiple configuration arrays and real-time imaging for the resistivity pulled array are needed. For the arrays we investigate some designs and for the real-time imaging a technique based on Kalman filtering was developed.

Chouteau, M.; Camerlynck, C.; Kaouane, C.

2009-05-01

174

Sensitivity Analysis of Heavy Pavement Design for a Container Terminal Area, Case Study: Port of Gaza, Palestine  

NASA Astrophysics Data System (ADS)

This study focuses on the sensitivity analysis of various design parameters for heavy-duty pavement for container terminal areas using Airport Pavement Structural Design System (APSDS) to yield an optimal design solution. APSDS is based on layered elastic theory, which was introduced into airfield design practice with the release of the computer program LEDFAA (Layered Elastic Design, Federal Aviation Administration). In this study, the pavement structure was found very sensitive to design parameters, where 15-60 mm more in base thickness was increased the design life twice. A reduction of base thickness was 27% by changing the handling system from rubber tyred gantry crane system to straddle carrier system and a reduction of 42-76% of base thickness by changing the interface condition at the bottom of base layer from smooth to rough. Other effects of design parameters such as lateral wandering distribution, container weight frequency, variation of elastic modulus for concrete block pavers and sub-grade are discussed. Also various construction materials were used and several combinations of base and sub-base materials were analysed to be able to select the most economical pavement structures.

Abualtayef, Mazen; de Heer, Ronald; Kuroiwa, Masamitsu; Matsubara, Yuhei; Khaled Seif, Ahmed

175

Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material  

Microsoft Academic Search

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic are the main reason for high particle mass concentrations in busy street and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM10) is exceeded due to

Mats Gustafsson; Gran Blomqvist; Anders Gudmundsson; Andreas Dahl; Erik Swietlicki; Mats Bohgard; John Lindbom; Anders Ljungman

2008-01-01

176

Lower bound shakedown analysis of layered pavements using discontinuous stress fields  

Microsoft Academic Search

Pavements and railways are subjected to repeated wheel loads of different magnitudes. Both load magnitudes and number of repetitions of load need to be considered in order to avoid significant damages to a pavement. A conventional finite element technique is convenient for calculating static pavement responses, but the prediction of pavement performance under repeated loading is much more difficult as

H. S. Yu; M. Z. Hossain

1998-01-01

177

Measurements of the stiffness and thickness of the pavement asphalt layer using the enhanced resonance search method.  

PubMed

Enhanced resonance search (ERS) is a nondestructive testing method that has been created to evaluate the quality of a pavement by means of a special instrument called the pavement integrity scanner (PiScanner). This technique can be used to assess the thickness of the road pavement structure and the profile of shear wave velocity by using the principle of surface wave and body wave propagation. In this study, the ERS technique was used to determine the actual thickness of the asphaltic pavement surface layer, while the shear wave velocities obtained were used to determine its dynamic elastic modulus. A total of fifteen locations were identified and the results were then compared with the specifications of the Malaysian PWD, MDD UKM, and IKRAM. It was found that the value of the elastic modulus of materials is between 3929 MPa and 17726 MPa. A comparison of the average thickness of the samples with the design thickness of MDD UKM showed a difference of 20 to 60%. Thickness of the asphalt surface layer followed the specifications of Malaysian PWD and MDD UKM, while some of the values of stiffness obtained are higher than the standard. PMID:25276854

Zakaria, Nur Mustakiza; Yusoff, Nur Izzi Md; Hardwiyono, Sentot; Nayan, Khairul Anuar Mohd; El-Shafie, Ahmed

2014-01-01

178

Pollutant load removal efficiency of pervious pavements: is clogging an issue?  

PubMed

Pervious pavements in car parks and driveways reduce the peak runoff rate and the quantity of runoff discharged into urban drains as well as improve the stormwater quality by trapping the sediments in the infiltrated water. The paper focuses on presenting results from the laboratory tests carried out to evaluate water quality improvements and effects of long-term decrease in infiltration rates with time due to sediments trapping (clogging) within the pavement pores. Clogging was not found to be a major factor affecting pervious pavement performance after simulating 17 years of stormwater quality samples. PMID:19809141

Kadurupokune, N; Jayasuriya, N

2009-01-01

179

Rutting Performance of Airport Hot-Mix Asphalt Characterized by Laboratory Performance Testing, Full-Scale Accelerated Pavement Testing, and Finite Element Modeling  

E-print Network

potential laboratory tests, (b) comparisons of laboratory tests results to full-scale accelerated pavement test results, and (c) analyses of results from finite element simulations. The laboratory study evaluated of the repeated load test, the static creep...

Rushing, John Ford

2014-04-25

180

Do sediment type and test durations affect results of laboratory-based, accelerated testing studies of permeable pavement clogging?  

PubMed

Previous studies have attempted to quantify the clogging processes of Permeable Interlocking Concrete Pavers (PICPs) using accelerated testing methods. However, the results have been variable. This study investigated the effects that three different sediment types (natural and silica), and different simulated rainfall intensities, and testing durations had on the observed clogging processes (and measured surface infiltration rates) of laboratory-based, accelerated PICP testing studies. Results showed that accelerated simulated laboratory testing results are highly dependent on the type, and size of sediment used in the experiments. For example, when using real stormwater sediment up to 1.18mm in size, the results showed that neither testing duration, nor stormwater application rate had any significant effect on PICP clogging. However, the study clearly showed that shorter testing durations generally increased clogging and reduced the surface infiltration rates of the models when artificial silica sediment was used. Longer testing durations also generally increased clogging of the models when using fine sediment (<300?m). Results from this study will help researchers and designers better anticipate when and why PICPs are susceptible to clogging, reduce maintenance and extend the useful life of these increasingly common stormwater best management practices. PMID:25618819

Nichols, Peter W B; White, Richard; Lucke, Terry

2015-04-01

181

A utility evaluation of nondestructive testing devices used on asphalt concrete pavements  

E-print Network

A UTILITY EVALUATION OF NONDESTRUCTIVE TESTING DEVICES USED ON ASPHALT CONCRETE PAVEMENTS A Thesis by SHELLEY MARIE STOFFELS Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE August 1986 Major Subject: Civil Engineering A UTILITY EVALUATION OF NONDESTRUCTIVE TESTING DEVICES USED ON ASPHALT CONCRETE PAVEMENTS A Thesis by SHELLEY MARIE STOFFELS Approved as to style and content by: Robe L. Lytt red...

Stoffels, Shelley Marie

1986-01-01

182

Permeable Pavement Monitoring at the Edison Environmental Center Demonstration Site - presentation  

EPA Science Inventory

The EPA?s Urban Watershed Management Branch has been monitoring an instrumented 110-space pervious pavement parking lot. The lot is used by EPA personnel and visitors to the Edison Environmental Center. The design includes 28-space rows of three permeable pavement types: asphal...

183

Clogging evaluation of open graded friction course pavements tested under rainfall and heavy vehicle simulators.  

PubMed

In this study a new procedure is developed to obtain core samples from field sections to assess clogging mechanisms of open graded friction course (OGFC) pavements using X-ray computed tomography (CT) imaging. The approach compared X-ray computed tomography (CT) images taken before and after: (1) rainfall simulations without trafficking to investigate particle-related clogging and (2) full-scale accelerated pavement rutting tests (APT) to investigate deformation related clogging of OGFC layers. Rainfall simulations were performed with runoff water of known total suspended solids (TSS) and particle size distributions (PSDs). Full-scale accelerated rutting tests were performed under controlled temperature and loads. Both investigations were performed for three different OGFC pavements with different layer thicknesses and mix types. The clogging of rutting test sections were also evaluated by comparing the surface permeability measurements performed before and after APT testing. The results of X-ray CT image processing revealed a significant reduction in air-void content of core samples after APT rutting tests. The highest air-void reduction was concentrated at the bottom of the OGFC layers. Permeability measurements also showed a 40%-90% reduction in permeability after APT trafficking. X-ray CT image processing of core samples tested under simulated rainfall showed that air void content reduction is concentrated in the lower part (2-6mm from the bottom) of the OGFC layers as a result of particle accumulation. Small changes in air void contents were observed in the upper part of the OGFC layers (10-15mm) while these reductions in air void contents were not significant to cause surface overflow and hence it is expected that the tested OGFC pavements will have sufficient permeability to infiltrate water during most average storm events. PMID:23920417

Coleri, Erdem; Kayhanian, Masoud; Harvey, John T; Yang, Kai; Boone, John M

2013-11-15

184

Striated boulder pavements within glaciomarine diamicts of the Yakataga Formation, Middleton Island, Alaska  

SciTech Connect

The presence of striated boulder pavements in glacial sequences is often cited as evidence of transport and deposition by grounded glacier ice. However, recent reports show that striated pavements also form in non-glacial environments by the abrasion of boulder lag surfaces by floating glacier and seasonal ice. Several striated boulder pavements are identified within Early Pleistocene upper Yakataga Formation sediments exposed on Middleton Island close to the southern edge of the Gulf of Alaska continental shelf. The sequence is dominated by thick stratiform units of massive and stratified diamict formed by the settling of fine-grained sands and muds from suspension together with ice-rafted debris. Boulder pavements outcrop as extensive planar horizons within the diamicts, can be traced for several kilometers along strike and consist of single lines of clasts with faceted upper surfaces showing consistently oriented striation directions. Clasts are not preferentially aligned, however, and do not have the characteristic bullet shape of boulders transported at a glacier base and deposited by lodgement processes. Striated boulder pavements on Middleton Island appear to have formed as boulder lag surfaces generated by wave and tidal current reworking of diamict on relatively shallow banks. Lags were then overridden and abraded by a grounding ice shelf. The glacially-abraded boulder pavements on Middleton Island record the repeated expansion of a continuous ice shelf to the edge of the Gulf of Alaska continental shelf during the Early Pleistocene.

Eyles, C.H.

1985-01-01

185

Recycling seal-coat pavements with self-cementing fly ash. Phase 2, progress report No. 1  

SciTech Connect

The purpose of the proposed research is to evaluate the feasibility of recycling existing seal-coat pavements through stabilization with self-cementing fly ash. It is proposed that existing pavements can be pulverized in-place, sufficient quantities of Class C fly ash and water added, and the resulting mixture be compacted. The stabilized section could then be utilized as a base course section having greater support capacity than the original pavement section. The recycling process is intended primarily for existing pavements having up to 4 inches of asphaltic bound material underlain by a granular-base section of variable composition. The intent of the Phase II research is to establish more definitive criteria relevant to mix design and pavement thickness design for the proposed recycling process. The criteria is to be formulated through both laboratory and field tests on recycled pavements in a multistate area.

Ferguson, E.G.

1987-04-01

186

Research on the Maintenance Decision-Making of Cement Concrete Pavement Based on Preventive Maintenance  

Microsoft Academic Search

The cement concrete pavement maintenance decision-making model has been proposed, by analyzing the formation and development characteristics of pavement diseases and considering the actual maintenance in Hunan Expressway. The maintenance decision-making tree and the decision-making progress have been established in order to realize the purpose of rational distribution of maintenance funds and improve maintenance quality, under the thought of preventive

Jian Zhao; Jia Xu

2009-01-01

187

Investigation and application of fractured slab techniques for PCC pavements. Final report, May 1996--April 1999  

SciTech Connect

Slab fracture techniques, including break and seat, crack and seat, and rubblization have in recent years gained widespread recognition among pavement engineers as means for eliminating or substantially reducing the potential for reflective cracking in hot mix asphalt (HMA) overlays over portland cement concrete (PCC) pavements. Guidelines for the use of these techniques in Wisconsin, however, have not been clearly established. This reports examines the PCC rehabilitation techniques of rubblization and crack and seat used in Wisconsin and their performance. The report examines the literature and evaluates the critical issues associated with the use of PCC fracture techniques by various agencies. Several elements pertinent to fracture techniques are also identified and incorporated in a database for in-service fractured overlaid PCC pavements in Wisconsin. In addition, the in-service performance of cracked and seated and rubblized pavements in Wisconsin is evaluated.

Owusu-Ababio, S.; Nelson, T.

1999-04-01

188

Identification of frost susceptible aggregates and their use in concrete or bituminous pavements  

SciTech Connect

Coarse aggregates have been recognized as potential sources of deterioration of concrete exposed to freezing and thawing action. Whenever coarse aggregates are involved, deterioration of pavement structures can take place as pitting, pop-outs, and varying extents of D-cracking. Recently, serious damage of bituminous pavements was observed where the coarse aggregate fraction played an important role. In some concrete and bituminous pavements, a typical pattern of surface damage was also found associated to the application of deicers. In order to prevent damage to concrete and bituminous pavements by frost susceptible aggregates, they must be identified by reliable testing procedures. The present study was designed to investigate the significance of the details of the pore structure on the frost resistance of concrete aggregates. Likewise, the surface failure taking place in concrete and bituminous pavements exposed to deicers was closely analyzed. Based on field data, a discriminating function was obtained to differentiate between aggregates of varying frost resistance. This function was derived by taking into consideration the details of the pore structure of coarse aggregates in concrete pavements.

Salcedo, M.A.

1984-01-01

189

Integration and road tests of a self-sensing CNT concrete pavement system for traffic detection  

NASA Astrophysics Data System (ADS)

In this paper, a self-sensing carbon nanotube (CNT) concrete pavement system for traffic detection is proposed and tested in a roadway. Pre-cast and cast-in-place self-sensing CNT concrete sensors were simultaneously integrated into a controlled pavement test section at the Minnesota Road Research Facility (MnROAD), USA. Road tests of the system were conducted by using an MnROAD five-axle semi-trailer tractor truck and a van, respectively, both in the winter and summer. Test results show that the proposed self-sensing pavement system can accurately detect the passing of different vehicles under different vehicular speeds and test environments. These findings indicate that the developed self-sensing CNT concrete pavement system can achieve real-time vehicle flow detection with a high detection rate and a low false-alarm rate.

Han, Baoguo; Zhang, Kun; Burnham, Tom; Kwon, Eil; Yu, Xun

2013-01-01

190

Effects of pavement surface characteristics and textures on skid resistance  

E-print Network

to the pavement suriace between parallel lines of nmsking tape and then worked into the surface voids with an aluminum squeeoee faced neith a rubber pad having a hardness approxi- mately equivalent to that of a tire tread rubber. An average tex- ture depth... particles m?ch like a tire tread element. Hater is poured into the cylinder, and the time required for a known volume of water to es- cape through any pores in the pavement and between the rubber ring and the pavement surface is measured. The water...

Tomita, Hisao

1970-01-01

191

GPR in Nondestructive Quality Assurance of New Asphalt Pavements  

NASA Astrophysics Data System (ADS)

Mara Nord is an international cooperation project financed by Interreg IVA Nord funding program with partners from Finland, Sweden and Norway. One of the objectives in Mara Nord project has been to research the quality assurance of new asphalt pavement. Ground penetrating radar (GPR) survey is used as an alternative method for coring in quality assurance. There exist numerous advantages for the use of GPR. For example, the fluent measuring arrangements without closing the traffic on the road and the extensive continuous profile that can be constructed from the measuring data. Within the framework of Mara Nord Project field tests were organized in Seinjoki region in Finland on August 2011. The tests were done by four consulting companies from Finland and Rovaniemi University of Applied Sciences. The aim of these tests was to compare the measured dielectric value profiles and the calculated void content profiles of the equipment. The tested equipment was GSSI manufactured SIR-20 and 1 GHz horn antennas. Void content values were calculated using the model presented by Mr. Roimela (1997). All core samples were taken from the right wheel path. The same reference core samples were used when analyzing the data of each GPR equipment. Some samples were taken right after the pavement work was completed with the rest three weeks after during the test measurements. The tests indicated that GPRs have very good repeatability in measuring dielectric changes on top surface layers of asphalt pavements. Furthermore, different GPRs locate the same detectable longitudinal dielectric changes with high accuracy. Some differences were found in the dielectric value levels, yet reproducibility of the calculated void content values was quite good. The test data was also used to evaluate the reliability of the regression model between the dielectric values measured through GPR and the void content of the pavement determined from reference cores. Test data indicated that accurate regression model could not be validated by using test data because of too wide variation. The variation of void content in core sample results was not always registered by GPR with corresponding variation in dielectric value. There was some moisture present in test conditions and this might have influenced the GPR results. There are some reference data from dry conditions which will be used later on for analyzing the influence of moisture. There was also quite wide variation in void content determined from core samples taken close to each other during field tests. However, wide variation was not seen in core samples taken right after the pavement work. It is possible that traffic load had its effect on the asphalt pavement compaction. The results indicate that when using only one survey line it should be located between wheel paths. Another option is GPR void content measurements should be done right after the pavement work.

Poikajrvi, J.; Peisa, K.; Narbro, A.

2012-04-01

192

Estimation of in-situ density and moisture content in HMA pavements based on GPR trace reflection amplitude using different frequencies  

NASA Astrophysics Data System (ADS)

The basic goal of the present research is to investigate the estimation of both the in-situ density and moisture content within the Hot Mix Asphalt (HMA) pavement layer(s) in a non-destructive way using Ground Penetrating Radar (GPR) trace reflection amplitude. For this purpose, an extensive pavement survey was conducted using an air-coupled GPR system, operating at 1 GHz or alternatively with a 2 GHz central frequency. The collected data were analyzed comparatively for the two antennae. The variability of electric permittivity caused by variations in HMA material is discussed, while the effect of the different frequencies is compared on the ability to retrieve permittivity, in-situ density and moisture content of the compacted HMA material using relationships suggested in reviewed international literature. The main finding of the present research is that for the same type of HMA material, the assessment of the material properties appears to be independent from the two central frequencies of investigation. However, there is evidence concerning the variations between the GPR wave data for the two different frequencies. The

Plati, Christina; Loizos, Andreas

2013-10-01

193

Effects of conductive fillers on temperature distribution of asphalt pavements  

NASA Astrophysics Data System (ADS)

The sun provides a cheap and abundant source of clean and renewable energy. Solar cells have been used to capture this energy and generate electricity. A more useful form of the solar cell would be asphalt pavements, which get heated up by solar radiation. Graphite powders are utilized as thermal conductive fillers to make an asphalt collector conductive so as to improve the efficiency of the asphalt collector. Accounting for the important application conditions and evaluating the effects of the heat conductive materials and the solar energy absorbability of the conductive asphalt collector, a finite element model has been developed to predict temperature distributions in the conductive asphalt solar collector. In this study, an experimental validation exercise was conducted using the measured data taken from full-depth asphalt slabs. Validation results showed that the model can satisfactorily predict the temperature distributions in asphalt concrete slabs. The optimal depth is 25-50 mm for placing pipes that serve as the heat exchanger. Meanwhile, the effect of the surroundings on the solar energy potential of the asphalt collector was noticeable.

Mingyu, Chen; Shaopeng, Wu; Yuan, Zhang; Hong, Wang

2010-05-01

194

Manufacturing technology of the composite materials: nanocrystalline material - polymer type  

Microsoft Academic Search

Purpose: This paper presents the material and technological solution which makes it possible to obtain the nanocrystalline, ferromagnetic powder material of Fe73.5Cu1Nb3Si13.5B9 alloy after its thermal nanocrystallization with the succeeding high-energy milling. Another aspect was to develop the technology to obtain the nanocrystalline composite materials made by binding the obtained powder material with the high density low- pressures polyethylene (PEHD)

B. Zi?bowicz; D. Szewieczek; L. A. Dobrza?ski

195

Exploration of Pavement Oxidation Model Applications and Field Validation  

E-print Network

Asphalt paved road is one of the building blocks of the modem world. Flexibility is one of its major advantages; however, this flexibility suffers from asphalt oxidation since the first day of pavement service life. Several elements of binder...

Cui, Yuanchen

2014-08-11

196

Pavement conference..............2 Eno award ...............................3  

E-print Network

· Pavement conference..............2 · Eno award ...............................3 · ITSO conference work with intelligent pavement, which elimi- nates the need for external sensors by enabling the pavement itself to detect vehicles. Yu cre- ates the pavement by incorporating carbon nanotubes

Minnesota, University of

197

Permeable pavement is a system that allows rainwater and runoff to move through the pavement's porous surface to a storage layer below.  

E-print Network

Permeable pavement is a system that allows rainwater and runoff to move through the pavement. It has been shown by decades of scientific research that permeable pavements reduce runoff volumes. Research has also shown that the stormwater that flows through the layers of a permeable pavement system

Goodman, Robert M.

198

Saw-Cutting Guidelines for Concrete Pavements: Examining the Requirements for Time and Depth of Saw-Cutting  

Microsoft Academic Search

Joints are placed in Portland cement concrete pavements (PCCP) to control random cracking. These joints provide a weakened plane that enables a crack to form in a controlled manner, relieving residual stresses that develop when thermal, hygral, or hydration movements are resisted by sub grade and adjoining pavement. While the concept of creating a weakened plane through saw-cutting is straightforward,

Kambiz Raoufi; Tony Their; W. Jason Weiss; Jan Olek; Tommy E. Nantung

2009-01-01

199

4/28/2010 1Porous Pavements Porous Pavements  

E-print Network

4/28/2010 1Porous Pavements Porous Pavements for Stormwater Restoration in Urban Environments Cliff Aichinger Ramsey-Washington Metro Watershed District #12;4/28/2010 2Porous Pavements Porous Pavements Why am new volume reduction rules. Porous pavement is one of a relative few BMPs that address stormwater

Minnesota, University of

200

Fabrication of high-efficiency Fresnel-type lenses by pinhole diffraction imaging of sol-gel hybrid materials  

SciTech Connect

Sol-gel hybrid materials containing a large quantity of photoactive molecules exhibited large changes in both refractive index and volume on UV exposure. The materials were used for fabrication of Fresnel-type lenses using a simple method: pinhole diffraction imaging. With this technique, problems associated with the contact method could be overcome and Fresnel-type lenses with good focusing performance could be fabricated easily. Importantly, a high diffraction efficiency approaching 85% could be obtained.

Kang, Dong Jun; Phong, Phan Viet; Bae, Byeong-Soo [Laboratory of Optical Materials and Coating (LOMC), Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of)

2004-11-08

201

Recycling and use of waste materials and by-products in highway construction: A synthesis of highway practice. Final report  

Microsoft Academic Search

The report on recycling and use of waste materials and by-products in highway construction will be of interest to administrators and policy makers; pavements, materials, geotechnical, and environmental engineers; and other professionals involved with highway design, construction, and maintenance. Information is provided on the technical, economic, and environmental aspects (including legislative and regulatory considerations) of recycling and on the specific

R. J. Collins; S. K. Ciesielski; L. S. Mason

1994-01-01

202

GPR abilities in investigation of the pavement transversal cracks  

NASA Astrophysics Data System (ADS)

This paper describes the results of an investigation into the capabilities of the GPR technique within the field of pavement crack diagnostics. Initially, laboratory tests were performed on prototypes simulating idealized cracks. Next, long-term visual observation and repeated GPR scanning were performed, on three roads of semi-rigid construction, several hundreds of meters long and subjected to heavy traffic. Furthermore, a road of rigid construction was tested, having a more than 70-year history of use. In several cases the cracks were probed by drillings, in order to recognize structures responsible for signal generation, or to explain reasons of signal lacking. The main result of this work is a list of GPR indications of cracks, which can be noticed on echograms. It was created through a correlation of the visually-observed cracks with the corresponding echograms, with decimeter accuracy. Several types of GPR responses were classified and linked to possible categories of crack structures, or to processes associated with the presence of cracks (as crumbling, erosion, and lithological alterations). The poor visibility of cracks was also studied, due to small crack size, or to the blurred character of the damaged area, or else to masking effects related to coarse grains in the asphalt mixture. The efficiency of the proposed method for the identification and localization of cracks is higher when a long-term GPR observation is performed.

Krysi?ski, Lech; Sudyka, Jacek

2013-10-01

203

Incorporating uncertainty in the Life Cycle Cost Analysis of pavements  

E-print Network

Life Cycle Cost Analysis (LCCA) is an important tool to evaluate the economic performance of alternative investments for a given project. It considers the total cost to construct, maintain, and operate a pavement over its ...

Swei, Omar Abdullah

2012-01-01

204

Quantitative expression analysis of selected transcription factors in pavement, basal and trichome cells of mature leaves from Arabidopsis thaliana  

Microsoft Academic Search

Gene expression levels of several transcription factors from Arabidopsis thaliana that were described previously to be involved in leaf development and trichome formation were analysed in trichome, basal\\u000a and pavement cells of mature leaves. Single cell samples of these three cells types were collected by glass micro-capillaries.\\u000a Real-time reverse transcription (RT)-PCR was used to analyse expression patterns of the following

Martin Schliep; Berit Ebert; Ulrike Simon-Rosin; Daniela Zoeller; Joachim Fisahn

2010-01-01

205

Preventive Maintenance Condition Standards of Expressway Asphalt Pavement  

Microsoft Academic Search

There isn't a unified pavement preventive maintenance road condition standard both at home and abroad till now, in view of that, macro and micro road condition standard for expressway asphalt pavement preventive maintenance is established, among which macro standard is under the promise of PSSIges83, and is under the control standard of 82lesPCI<88, 88lesRQI<93, 85lesSRI<90. Its determinative process, the usage

Hu Guoxiang; Li Jie

2009-01-01

206

Comparative Occupational Survey of Civilian and Military Members in the Pavements Maintenance and Construction Equipment Operator Specialties. Final Report for Period 1 October 1975-30 October 1977.  

ERIC Educational Resources Information Center

A study was conducted to analyze and compare the job performance of civil service and military pavements maintenance workers and construction equipment operators. A military sample of 2,675 and a civilian sample of 1,974 were surveyed by means of a job inventory checklist and relative time spent rating method. Of the three job types that were

Cowan, Douglas K.

207

Water quality and quantity assessment of pervious pavements performance in experimental car park areas.  

PubMed

Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates and basic oxygen furnace slag). This study therefore encompasses the majority of the materials used as permeable surfaces and sub-base layers all over the world. Effluent from the test bays was monitored for dissolved oxygen, pH, electric conductivity, total suspended solids, turbidity and total petroleum hydrocarbons in order to analyze the behaviour shown by each combination of surface and sub-base materials. In addition, permeability tests were undertaken in all car parks using the 'Laboratorio Caminos Santander' permeameter and the Cantabrian Portable Infiltrometer. All results are presented together with the influence of surface and sub-base materials on water quality indicators using bivariate correlation statistical analysis at a confidence level of 95%. The polymer-modified porous concrete surface course in combination with limestone aggregate sub-base presented the best performance. PMID:24718346

Saudo-Fontaneda, Luis A; Charlesworth, Susanne M; Castro-Fresno, Daniel; Andres-Valeri, Valerio C A; Rodriguez-Hernandez, Jorge

2014-01-01

208

Electrical resistance tomography for imaging the spatial distribution of moisture in pavement sections  

SciTech Connect

Electrical Resistance Tomography (ERT) was used to image spatial moisture distribution and movement in pavement sections during an infiltration test. ERT is a technique for determining the electrical resistivity distribution within a volume from measurement of injected currents and the resulting electrical potential distribution on the surface. The transfer resistance (ratio of potential to injected current) data are inverted using an algorithm based on a finite element forward solution which is iteratively adjusted in a least squares sense until the measured and calculated transfer resistances agree to within some predetermined value. Four arrays of ERT electrodes were installed in vertical drill holes 1.22 m (4 ft) placed at the comers of a square 61 cm (2 ft) on a side into a pavement section which is used for a truck scale ramp on U.S. Highway 99 just north of Sacramento, CA. Water was introduced slowly into the pavement through a shallow hole in the center of this pattern and ERT data were collected in various planes as the water infiltrated into the pavement and subgrade materials over a period of several hours. The ERT data were inverted, and the resulting images show (1) the basic structure of the pavement section and (2) the movement of water through the image planes as a function of time during infiltration. An interesting result is that the water does not appear to drain from the section toward the shoulder as had been expected based on the design.

Buettner, M.; Ramirez, A.; Daily, W.

1995-11-08

209

12th Annual Minnesota Pavement  

E-print Network

12th Annual Minnesota Pavement Conference: Session Summaries Conference Sponsors: Minnesota Research Alliance (TERRA) Pavement Research Institute (PRI) Hosted by: Center for Transportation Studies provides information to practitioners and others in pavement design, construction, and maintenance

Minnesota, University of

210

Research on tensile strength characteristics of bridge deck pavement bonding layers  

NASA Astrophysics Data System (ADS)

As the development of the traffic in the world, the bridge deck pavement is playing a more and more important role in the whole traffic system. Big span bridge has become more and more especially cement concrete bridge, therefore the bridge deck pavement bonding layers are emphasized as an important part of bridge traffic system, which can mitigate travel impact to bridge and magnify stationary or traffic amenity. The quality and durability of deck pavement bonding layer has directly effect on traffic safety, comfort, durability and investment of bridge. It represents the first line of defence against the ingress of water, road de-icing salts and aggressive chemicals. In real project, many early age damage of bridge deck pavement has become serious disease that affecting the function of bridge. During the construction of the bridge deck, many types of asphalt binders were used, such as styrene-butadiene-styrene (SBS) modified asphalt, styrene-butadiene rubber (SBR) modified asphalt, neoprene latex asphalt, etc. In this paper UTM-25 was used to test the tensile strength of different bridge deck pavement bonding layers with the different treatment methods to inter-surface.

Wu, Shaopeng; Han, Jun

2009-12-01

211

Research on tensile strength characteristics of bridge deck pavement bonding layers  

NASA Astrophysics Data System (ADS)

As the development of the traffic in the world, the bridge deck pavement is playing a more and more important role in the whole traffic system. Big span bridge has become more and more especially cement concrete bridge, therefore the bridge deck pavement bonding layers are emphasized as an important part of bridge traffic system, which can mitigate travel impact to bridge and magnify stationary or traffic amenity. The quality and durability of deck pavement bonding layer has directly effect on traffic safety, comfort, durability and investment of bridge. It represents the first line of defence against the ingress of water, road de-icing salts and aggressive chemicals. In real project, many early age damage of bridge deck pavement has become serious disease that affecting the function of bridge. During the construction of the bridge deck, many types of asphalt binders were used, such as styrene-butadiene-styrene (SBS) modified asphalt, styrene-butadiene rubber (SBR) modified asphalt, neoprene latex asphalt, etc. In this paper UTM-25 was used to test the tensile strength of different bridge deck pavement bonding layers with the different treatment methods to inter-surface.

Wu, Shaopeng; Han, Jun

2010-03-01

212

Determination of the Presence Conditions of Pavement Markings using Image Processing  

E-print Network

Pavement markings, as a form of traffic control devices, play a crucial role in safely guiding drivers. Restriping pavement markings is an important task in the maintenance of traffic control devices. Every year state agencies spend a lot of money...

Ge, Hancheng

2012-10-19

213

Evaluation of non-metallic fiber reinforced concrete in new full depth pcc pavements. Final report  

SciTech Connect

This final report presents the construction and performance evaluation of a new full depth pavement, constructed with a new type non-metallic fiber reinforced concrete (NMFRC). The mixture proportions used, the quality control tests conducted for the evaluation of the fresh and hardened concrete properties, the procedure used for mixing, transporting, placing, consolidating, finishing, and curing of the concrete are described. Periodic inspection of the full depth pavement was done and this report includes the results of these inspections. The feasibility of using this NMFRC in the construction of highway structures has been discussed. The new NMFRC with enhanced fatigue, impact resistance, modulus of rupture, ductility and toughness properties is suitable for the construction of full depth pavements. However, a life-cycle cost analysis shows that NMFRC is not a favorable choice, because of it`s high initial cost.

Ramakrishnan, V.; Tolmare, N.S.

1998-12-30

214

Improvement of etch selectivity and process latitude in ArF lithography by spin coating type hard masking material  

NASA Astrophysics Data System (ADS)

The role of photoresist masking is greatly increased for 193 nm (ArF) lithography, which was no problem for 248 nm (KrF) DUV lithography. Main reason for this masking is poor etch resistance for currently developed ArF resist. The methacrylate (MA) back-bone type used for 193 nm resist shows poor etch resistance compared to the poly-hydroxy-stylene (PHS) back-bone type used for 248 nm resist. Acrylate type back-bone has high transmittance, so that better contrast and resolution can be obtained, although the etch resistance and the mechanical hardness is dropped. The radical polymerization method is mainly used for methacrylate resin synthesis, which is different from the anionic polymerization or blending system for 248 nm resist. In case of radical polymerization, the resultant resin has bad uniformity (or homogeneity) across the resist and has wide degree of poly-dispersion (1.8~2.0) which is about 2 times larger than that of 248 nm resist. This nonuniformity and wide dispersion makes notable line edge roughness for 193 nm resist compared to 248 nm resist. It is necessary to use organic (such as amorphous carbon) and/or inorganic (PE-SiON) masking layer due to weak etch resistance of 193 nm resist. So we need another spin coating material that can function as a mask and the anti-reflection film. Also we need to control this masking layer due to the alignment failure by absorption characteristics of high carbon density, the reduction of the throughput, the additional CVD equipment cost, and the increased particle during the additional layer deposition process. Thus we developed spin type dual hard masking material, including silicon contained materials. We tried to maximize the carbon density of base resin and to control many additive materials (cross-linker or catalyst) in order to optimize the optical factor such as the refractive index and the absorption coefficient. Also we could improve the surface roughness and could control the hydrogen characteristics for wider process margin with maximize etch selectivity between the resist and sub-layer. And we controlled silicon content portion and acidity, optical performance through the change of chromorphore's ratio or specious for the lithography performance. We could obtain good etch selectivity and process latitude, and reduce the cost for the mass production of sub-70 nm devices by using the suggested masking material.

Lee, Chang Ho; Lee, Jung Hoon; Park, Kyoung Sil; Han, Seok; Kim, Do-hyeon; Kang, KyongRim; Kim, Youngho; Kim, Tae Sung; Kang, Hye-Young; Oh, Hye-Keun

2006-03-01

215

Assessment of porous asphalt pavement performance: hydraulics and water quality  

NASA Astrophysics Data System (ADS)

The objective of this study is to focus on the water quality treatment and hydraulic performance of a porous asphalt pavement parking lot in Durham, New Hampshire. The site was constructed in October 2004 to assess the suitability of porous asphalt pavement for stormwater management in cold climates. The facility consists of a 4-inch asphalt open-graded friction course layer overlying a high porosity sand and gravel base. This base serves as a storage reservoir in-between storms that can slowly infiltrate groundwater. Details on the design, construction, and cost of the facility will be presented. The porous asphalt pavements is qualitatively monitored for signs of distress, especially those due to cold climate stresses like plowing, sanding, salting, and freeze-thaw cycles. Life cycle predictions are discussed. Surface infiltration rates are measured with a constant head device built specifically to test high infiltration capacity pavements. The test measures infiltration rates in a single 4-inch diameter column temporarily sealed to the pavement at its base. A surface inundation test, as described by Bean, is also conducted as a basis for comparison of results (Bean, 2004). These tests assess infiltration rates soon after installation, throughout the winter, during snowmelt, after a winter of salting, sanding, and plowing, and after vacuuming in the spring. Frost penetration into the subsurface reservoir is monitored with a frost gauge. Hydrologic effects of the system are evaluated. Water levels are monitored in the facility and in surrounding wells with continuously logging pressure transducers. The 6-inch underdrain pipe that conveys excess water in the subsurface reservoir to a riprap pad is also continuously monitored for flow. Since porous asphalt pavement systems infiltrate surface water into the subsurface, it is important to assess whether water quality treatment performance in the subsurface reservoir is adequate. The assumed influent water quality is derived from that which is entering the stormwater treatment system in the adjacent parking lot. Since the facility is new, parking has been less intensive here, and influent concentrations will be adjusted down accordingly. Several wells have been installed in and around the facility. Screened intervals are at two levels; in the reservoir and beneath the facility. One well in the facility is continually monitored for basic water quality parameters (temperature, specific conductivity, pH, dissolved oxygen) and level, and is also sampled with an automated refrigerated sampler. Grab samples are collected from the other wells as a basis for comparison. Water samples are collected during several storm events and during interstorm periods to assess water quality treatment performance. The samples are analyzed for nutrients, metals, petroleum hydrocarbons, and pathogens. The potential for leaching of pollutants from the asphalt binder will also be assessed during these storm events. Water quality treatment performance is compared to those of several other studies. Updates on spring 2005 data are also included in the presentation.

Briggs, J. F.; Ballestero, T. P.; Roseen, R. M.; Houle, J. J.

2005-05-01

216

Evaluation of clay content in soils for pavement engineering applications using GPR  

NASA Astrophysics Data System (ADS)

Clay content significantly influences the mechanical behavior of soils, thereby playing an important role in many fields of applications such as civil engineering, geology and agriculture. In the area of pavement engineering, clay content in structural bearing courses of pavement frequently causes damages and defects, such as transversal and longitudinal cracks, or other faults. The main consequence is a lowering of both the road safety and operability, with the number of expected accidents increasing. In this study, ground-penetrating radar (GPR) laboratory tests were carried out to predict the clay amount in pavement structural layers under different clay and moisture conditions. GPR data processing is performed using two different methods. The first method is based on the Fresnel theory and focuses on the Rayleigh scattering of the radar waves. The approach is based on a different scattering of the various components of the frequency spectrum, mostly depending on both the soil texture and variation in soil moisture content. For the application of this method, we used a pulse radar with ground-coupled, 500 MHz centre-frequency antennas in a common offset, bistatic configuration. The transmitter and receiver were linked by optic fiber electronic modules. The second method is based on full-waveform inversion of the ultra wideband radar data. In particular, a specific radar-antenna electromagnetic model is used to filter out antenna effects and antenna-medium interactions from the raw radar data and retrieve the response of the soil only, expressed in terms of a layered medium Green's function. To estimate the medium geometrical and electrical values, an optimization inverse problem is formulated. For the application of that second method, we used a vector network analyzer (VNA) as continuous-wave stepped-frequency radar system to acquire data in the 500-3000 MHz frequency range. A doubled-ridged broadband horn antenna operating in far-field conditions was used as transmitter and receiver, and was connected to the radar using a high-quality coaxial cable. Typical road materials for subgrade and sub-base courses were used. In particular, three types of soils classified, respectively, as A1,A2,A3 by AASHTO were used and adequately compacted in electrically and hydraulically isolated boxes. A copper sheet was laid at the bottom of the experimental boxes to control the bottom boundary conditions in the electromagnetic model. Basically, two significant cases were considered for each soil type, taking into account the 0% and the 25% by weight of bentonite clay, respectively. Water was gradually added and GPR measurements were carried out for all moisture steps until the maximum saturation level was reached. Concerning the Rayleigh scattering method, analyses show a high consistency of the results with respect to our expectations. A negative correlation between the shift of the frequency spectrum peaks and the clay amount was demonstrated, by virtue of its strong hygroscopic properties. Similarly, the full-waveform inversion technique allowed to measure reliable electric parameters. Generally, different responses (e.g. electric conductivity and permittivity) of the 0% clay-member cases compared to those of the analogous clayey soil samples highlight the large potentiality of both methods for the detection of clay.

Tosti, Fabio; Patriarca, Claudio; Benedetto, Andrea; Slob, Evert C.; Lambot, Sbastien

2013-04-01

217

Contact based analysis of asphalt pavement with the effect of aggregate angularity  

Microsoft Academic Search

Relating the performance behavior of asphalt pavement with its design parameters may provide the insight information of how to control and improve the quality of asphalt pavement. The relation must be developed in a functional form so the effect of design parameters on the overall stressstrain response of asphalt pavement then can be quantified based on a single-variable perturbation. This

Han Zhu; Julie E. Nodes

2000-01-01

218

Automated pavement crack detection  

E-print Network

of the number and orientation of the edges detected in the windows yields a classification of the crack type. The extent of the cracking is calculated by the total number of cracks found in the pavement section. To my parents. ACKNOWLEDGMENTS I wish... and Unimodal III IMAGE ANALYSIS . . A. Projection Histogram B. Error Analysis on Window Size and Shape Factor 1. Shape Factor 2. Window Size C. Classification Rule 1. Two-Direction Algorithm 2. Four-Direction Algorithm 3. Eight-Direction Algorithm . D...

Rao, Ashok Madhava

2012-06-07

219

Influences of eolian and pedogenic processes on the origin and evolution of desert pavements  

E-print Network

Influences of eolian and pedogenic processes on the origin and evolution of desert pavements Leslie in the evolution of these pavements. Eolian dust (I) I=leroles mechanical mogmentatloa oIliow rock, providing the source materiaJ for pavements., and (2) accumulates slowly below basaIdc colluvium in Row depressions

Ahmad, Sajjad

220

Evolution of desert pavements and the vesicular layer in soils of the Transantarctic Mountains  

E-print Network

Evolution of desert pavements and the vesicular layer in soils of the Transantarctic Mountains: Desert soils Soil chronosequences Pavement development index Ventifaction Desert varnish Compared to mid-latitude deserts, the properties, formation and evolution of desert pavements and the underlying vesicular layer

Ahmad, Sajjad

221

Cloud Impacts on Pavement Temperature in Energy Balance Models  

NASA Astrophysics Data System (ADS)

Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with road safety. Pavement temperature is an important variable when considering vehicle response to various weather conditions. A complex, yet direct relationship exists between tire and pavement temperatures. Literature has shown that as tire temperature increases, friction decreases which affects vehicle performance. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from the inability to model different types of clouds and their influence on radiation. This research focused on forecast improvement by determining how cloud type impacts the amount of shortwave radiation reaching the surface and subsequent pavement temperatures. The study region was the Great Plains where surface solar radiation data were obtained from the High Plains Regional Climate Center's Automated Weather Data Network stations. Road pavement temperature data were obtained from the Meteorological Assimilation Data Ingest System. Cloud properties and radiative transfer quantities were obtained from the Clouds and Earth's Radiant Energy System mission via Aqua and Terra Moderate Resolution Imaging Spectroradiometer satellite products. An additional cloud data set was incorporated from the Naval Research Laboratory Cloud Classification algorithm. Statistical analyses using a modified nearest neighbor approach were first performed relating shortwave radiation variability with road pavement temperature fluctuations. Then statistical associations were determined between the shortwave radiation and cloud property data sets. Preliminary results suggest that substantial pavement forecasting improvement is possible with the inclusion of cloud-specific information. Future model sensitivity testing seeks to quantify the magnitude of forecast improvement.

Walker, C. L.

2013-12-01

222

Use of Falling Weight Deflectometer Data to Quantify the Relative Performance of Reinforced Pavement Sections  

E-print Network

Pavement Sections Joshi, R.V.1 , S.M. ASCE and Zornberg J.G.2 , PhD., P.E, A.M. ASCE 1 Research Assistant in Grimes County, Texas. The pavement involves eight different experimental cross sections including control the flexible pavement to environmental loading. The objective of this paper is to characterize the possible

Zornberg, Jorge G.

223

Equations for predicting the layer stiffness moduli in pavement systems containing lime-flyash stabilized materials  

E-print Network

in a restricted time frame are especially appreciated. vili TABLE OF CONTENTS CHAPTER I. INTRODUCTION Significance and Objectives of Research . . . . . . . . . . . . . . . Scope Test site 1 located on FM 3378 in Bowie County . . . . Test site 2... for Multi-layered Pavements . . . . . . . . . . . Statistical Analysis Procedure Pattern Search Technique . Regression Analysis Number 1 Regression Analysis Number 2 Regression Analysis Number 3 CHAPTER IV. ANALYSIS AND RESULTS Deflection Basin...

Alam, Shah Manzoor

1984-01-01

224

Analysis of aggregate imaging system (AIMS) measurements and their relationship to asphalt pavement skid resistance  

E-print Network

) ........................................................9 2.3 Schematic of Hysteresis and Adhesive Forces Acting on Tire-Pavement Interface (Bazlamit and Reza 2005)..............................................................10 2.4 Aggregate Methods for Providing Pavement Texture (Dahir 1979... forces combine to give a pavement its skid resistance, hysteresis and adhesion. These forces are the result of interaction between the different texture scales on the pavement surface and the tire. Figure 2.3, from Bazlamit and Reza (2005), shows...

Luce, Anthony David

2009-05-15

225

Evaluation of the Structure-induced Rolling Resistance (SRR) for pavements including  

E-print Network

Evaluation of the Structure-induced Rolling Resistance (SRR) for pavements including viscoelastic.chupin@ifsttar.fr Abstract: This article addresses the question of whether the viscoelastic behavior of asphalt pavements consumption of road traffic, as compared to non-dissipative pavements. In the context of sustainable

Paris-Sud XI, Université de

226

of Transportation Rigid Pavement Design and Analysis Web-Based Training Site  

E-print Network

Texas Department of Transportation Rigid Pavement Design and Analysis Web-Based Training Site Highway Administration Texas Department of Transportation, 2004 Rigid Pavement Design and Analysis Web for six computer programs pertaining mainly to the design and analysis of rigid pavements. The programs

Texas at Austin, University of

227

Response of desert pavement to seismic shaking, Hector Mine earthquake, California, 1999  

E-print Network

Response of desert pavement to seismic shaking, Hector Mine earthquake, California, 1999 P. K. Haff characteristic surface disturbances on nearby desert pavements. These disturbances included (1) zones of wholesale gravel displacement interspersed with zones of intact pavement, (2) displaced and rotated cobbles

Ahmad, Sajjad

228

EVALUATION OF THE PAVEMENT STRUCTURAL CONDITION AT NETWORK LEVEL USING FALLING WEIGHT  

E-print Network

EVALUATION OF THE PAVEMENT STRUCTURAL CONDITION AT NETWORK LEVEL USING FALLING WEIGHT DEFLECTOMETER agencies to improve the surface condition of pavements, but these measures have not successfully prevented the problem from reoccurring. As a result, the overall pavement condition keeps deteriorating because

Manuel, Lance

229

Obscuration of supersoft X-ray sources by circumbinary material. A way to hide Type Ia supernova progenitors?  

NASA Astrophysics Data System (ADS)

Context. The progenitors of Type Ia supernovae are usually assumed to be either a single white dwarf accreting from a non-degenerate companion (the single-degenerate channel) or the result of two merging white dwarfs (the double degenerate channel). However, no consensus currently exists as to which progenitor scenario is the correct one, or whether the observed Type Ia supernovae rate is produced by a combination of both channels. Unlike a double degenerate progenitor, a single-degenerate progenitor is expected to emit supersoft X-rays for a prolonged period of time (~1 Myr) as a result of the burning of accreted matter on the surface of the white dwarf. An argument against the single-degenerate channel as a significant producer of Type Ia supernovae has been the lack of observed supersoft X-ray sources and the lower-than-expected integrated soft X-ray flux from elliptical galaxies. Aims: We wish to determine whether it is possible to obscure the supersoft X-ray emission from a nuclear-burning white dwarf in an accreting single-degenerate binary system. In the case of obscured systems we wish to determine their general observational characteristics. Methods: We examine the emergent X-ray emission from a canonical supersoft X-ray system surrounded by a spherically symmetric configuration of material, assuming a black-body spectrum with Tbb = 50 eV and L = 1038 erg s-1. The circumbinary material is assumed to be of solar chemical abundances, and we leave the mechanism behind the mass-loss into the circumbinary region unspecified. Results: We find that relatively low circumstellar mass-loss rates, ? = 10-9-10-8 M? yr-1, at binary separations of ~1 AU or less, will cause significant attenuation of the X-rays from the supersoft X-ray source. These circumstellar mass-loss rates are sufficient to make a canonical supersoft X-ray source in typical external galaxies unobservable in Chandra. Conclusions: If steadily accreting, nuclear-burning white dwarfs are canonical supersoft X-ray sources our analysis suggests that they can be obscured by relatively modest circumbinary mass-loss rates. This may explain the discrepancy of supersoft sources relative to the Type Ia supernova rate inferred from observations if the single-degenerate progenitor scenario contributes significantly to the Type Ia supernova rate. Recycled emissions from obscured systems may be visible in wavebands other than X-rays. It may also explain the lack of observed supersoft sources in symbiotic binary systems.

Nielsen, M. T. B.; Dominik, C.; Nelemans, G.; Voss, R.

2013-01-01

230

Relating tensile, bending, and shear test data of asphalt binders to pavement performance  

Microsoft Academic Search

Eight different asphalt binders representing a wide range of applications for pavement construction were tested in uniaxial tension, bending, and shear stresses. Theoretical analyses were performed in this study to convert the data from the three engineering tests to stiffness moduli for predicting pavement performance. At low temperatures, high asphalt stiffness may induce pavement thermal cracking; thus, the allowable maximum

J.-S. Chen; C.-J. Tsai

1998-01-01

231

FIELD AND COMPUTER SIMULATION EXPERIMENTS ON THE FORMATION OF DESERT PAVEMENT  

E-print Network

FIELD AND COMPUTER SIMULATION EXPERIMENTS ON THE FORMATION OF DESERT PAVEMENT JOHN WAINWRIGHT1), to observe the speed at which desert pavement surfaces could be re-established following disturbance erosion processes. Copyright # 1999 John Wiley & Sons, Ltd. KEY WORDS: raindrop erosion; desert pavement

Ahmad, Sajjad

232

FILTERING OF ARTIFACTS AND PAVEMENT SEGMENTATION FROM MOBILE Jorge Hernandez and Beatriz Marcotegui  

E-print Network

FILTERING OF ARTIFACTS AND PAVEMENT SEGMENTATION FROM MOBILE LIDAR DATA Jorge Hern the contour between pavements and roads. The method uses a quasi-flat zone algorithm and a region adjacency boundary. Finally, edges with a value compatible with the pavement/road difference (about 14[cm

Cord, Aurélien

233

TRANSPORTATION RESEARCH RECORD 1574 Paper No. 971071 89 Performance of Rigid Pavements  

E-print Network

TRANSPORTATION RESEARCH RECORD 1574 Paper No. 971071 89 Performance of Rigid Pavements Containing designed and constructed rigid pavements containing recycled concrete aggregate (RCA). Success has been project did exhibit significantly more slab cracking in the recycled pavement than in the corresponding

Vandenbossche, Julie M.

234

Dynamical Processes on Desert Pavements and the Healing of Surficial Disturbances  

E-print Network

Dynamical Processes on Desert Pavements and the Healing of Surficial Disturbances PETER K. HAFF, California, 92093-0225 Received June 16, 1994 Mature desert pavements are traditionally regarded as hall period on small cleared patches, or plats, on pavement sur- faces in Panamint Valley, California

Ahmad, Sajjad

235

Friction evaluation of concrete paver blocks for airport pavement applications  

NASA Technical Reports Server (NTRS)

The development and use of concrete paver blocks is reviewed and some general specifications for application of this type of pavement surface at airport facilities are given. Two different shapes of interlocking concrete paver blocks installed in the track surface at NASA Langley's Aircraft Landing Dynamics Facility (ALDF) are described. Preliminary cornering performance results from testing of 40 x 14 radial-belted and bias-ply aircraft tires are reviewed. These tire tests are part of a larger, ongoing joint NASA/FAA/Industry Surface Traction and Radial Tire (START) Program involving several different tire sizes. Both dry and wet surface conditions were evaluated on the two concrete paver block test surfaces and a conventional, nongrooved Portland cement concrete surface. Future test plans involving evaluation of other concrete paver block designs at the ALDF are indicated.

Yager, Thomas J.

1992-01-01

236

Cosmogenic {sup 3}He surface-exposure dating of stone pavements. Implications for landscape evolution in deserts  

SciTech Connect

The formation of stone pavements, a ubiquitous gravel armor mantling landforms in arid regions of the world, has been previously attributed to erosion by wind and water or alternating shrinking and swelling of soil horizons, implying that gravel is concentrated at the land surface in a time-transgressive manner. A newly proposed model for pavement evolution differs from these models in that pavement clasts are continuously maintained at the land surface in response to deposition and pedogenic modification of windblown dust. In-situ cosmogenic {sup 3}He surface-exposure ages on volcanic and alluvial landforms in the Mojave Desert of California are used to understand pavement evolution over geologic time scales and to test this new model. These exposure ages are stratigraphically consistent, show internal consistency at each site, and, for stone pavements adjacent to pristine, continuously exposed volcanic bedrock, are indistinguishable at the 1{sigma} level. We conclude that stone pavements are born at the surface and that pavements may provide one of the longest-term records of geologic, hydrologic, and climatic processes operating on desert surfaces. 23 refs., 3 figs., 1 tab.

Wells, S.G. [Univ. of California, Riverside, CA (United States)] [Univ. of California, Riverside, CA (United States); McFadden, L.D. [Univ. of New Mexico, Albuquerque, NM (United States)] [Univ. of New Mexico, Albuquerque, NM (United States); Poths, J.; Olinger, C.T. [Los Alamos National Lab., NM (United States)] [Los Alamos National Lab., NM (United States)

1995-07-01

237

Development on preventive maintenance management system for expressway asphalt pavements  

Microsoft Academic Search

In view of the status that there was no expressway pavement preventive maintenance management system at home and abroad at present, based on the technology theory obtained by the author and the demands and process of expressway asphalt pavement preventive maintenance management, preventive maintenance management system for expressway asphalt pavement (EPMMS (V1.0)) was developed. The work or functions of expressway

Hu Guoxiang; Li Jie

2010-01-01

238

Viscoroute 2.0: a tool for the simulation of moving load effects on asphalt pavement  

E-print Network

As shown by strains measured on full scale experimental aircraft structures, traffic of slow-moving multiple loads leads to asymmetric transverse strains that can be higher than longitudinal strains at the bottom of asphalt pavement layers. To analyze this effect, a model and a software called ViscoRoute have been developed. In these tools, the structure is represented by a multilayered half-space, the thermo-viscoelastic behaviour of asphalt layers is accounted by the Huet-Sayegh rheological law and loads are assumed to move at constant speed. First, the paper presents a comparison of results obtained with ViscoRoute to results stemming from the specialized literature. For thick asphalt pavement and several configurations of moving loads, other ViscoRoute simulations confirm that it is necessary to incorporate viscoelastic effects in the modelling to well predict the pavement behaviour and to anticipate possible damages in the structure.

Chabot, Armelle; Deloffre, Lydie; Duhamel, Denis

2010-01-01

239

Production variability analysis of hot-mixed asphalt concrete containing reclaimed asphalt pavement. Final research report  

SciTech Connect

A research project was undertaken to evaluate the production and construction variability of Hot Mix Asphalt Concrete (HMAC) containing high quantities of reclaimed asphalt pavement (RAP) material. Four construction projects were selected for this purpose. Two of the projects used 35 percent RAP material (both type-C mixes), while the other two used 40 percent (a type-B mix) and 50 percent (a type-D mix) of the RAP material, respectively. The projects differed in sizes, with total construction tonnage ranging from 10.9 million kg to 27.2 million kg (12,000 to 30,000 tons). In all cases, dedicated stockpiles of RAP material were used. Analysis was performed on the results obtained from the tests. The gradation and asphalt content deviations, air voids, penetration and viscosities, and stabilities, were included in the analysis. Pay adjustment factors were determined for gradation and asphalt content deviation, as well as for air voids (based on TxDOT Specification 3007). In general, these high-percent RAP projects indicated a variability higher than that of a typical HMAC without RAP. The pay adjustment factors for gradation and asphalt content deviation were lower than typical values. The construction gradations were finer than the job-mix formula target gradations, possibly a result of aggregate crushing during the milling operation.

Solaimanian, M.; Kennedy, T.W.

1995-02-01

240

Pervious Pavement System Evaluation-Paper  

EPA Science Inventory

The use of a pervious pavement can be effective as a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete paver systems as a type of porous pavement. Although the pavers are impermeable, the spaces between the pave...

241

Enhancing the resolution of gpr spectra for pavement engineering applications  

NASA Astrophysics Data System (ADS)

Ground Penetrating Radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non-destructive method uses electromagnetic radiation and detects the reflected signals from subsurface structures. It can detect objects, changes in material, and voids and cracks. GPR has many applications in a number of fields. In the field of civil engineering one of the most advanced technologies used for road pavement monitoring is based on the deployment of advanced GPR systems. One of the most relevant causes of road pavement damage is often referable to water intrusion in structural layers. In this context, GPR has been recently proposed as a method to estimate moisture content in a porous medium without preventive calibration. Hence, the development of methods to obtain an estimate of the moisture content is a crucial research field involving economic, social and strategic aspects in road safety for a great number of public and private Agencies. In particular, a recent new approach was proposed to estimate moisture content in a porous medium basing on the theory of Rayleigh scattering, showing a shift of the frequency peak of the GPR spectrum towards lower frequencies as the moisture content increases in the soil. The weakness characterizing this approach is represented by the needs of high resolution signals, whereas GPR spectra are affected by low resolution. Hence, the rising requirement for high resolution leads to specific demands for improved prediction methods. Recently, a new technique combining the response of the conventional fast Fourier transform (FFT, well known for its high-precision receiving signal level) with that of the MUSIC (multiple signal classification) algorithm, well known for its super-resolution capacity has been proposed. This combined method has been proved to obtain a high precision level in quantifying the shift of the frequency peak of the GPR spectrum. This combined method can perform a reliable coarse estimate of the (abscissa of the) frequency peak. Unfortunately, whereas resolution affecting the GPR spectra has been enhanced, we still need a sensible increasing of the moisture content to appreciate a visible frequency shift. Hence, sub-sample resolution techniques are needed to obtain a resolution better than the sample period. Addressing some of these issues, this work proposes a sub-sample resolution technique exploiting a fast parabolic interpolator, running on three samples of the GPR spectrum in the neighborhood of the frequency peak (i.e. the coarse estimation). More in details, the new detector searches for the (abscissa of the) vertex of the parabola fitted over three GPR samples: the coarse estimate of the frequency peak, and one sample before and after this estimation. The rationale behind the new fast parabolic approach is as follows. We expect the method to obtain a finer estimation of the (abscissa of the) frequency peak because we are now interpolating a parabola in the neighborhood of the same maximum (i.e the coarse estimate), but with a narrow variance thus increasing the estimation accuracy. No noteworthy increase of computational complexity and processing throughput is required to implement the new approach. In fact, near the totality of the amount of the required computation is due to the former stage (i.e. FFT and/or MUSIC implementation to evaluate the coarse estimate of the frequency peak), and the latter logic (i.e. the interpolation function) is negligible from implementation and computational point of view. Experimental results confirm the effectiveness of the proposed approach to evidence and quantify moisture content in soil. In fact, the proposed sub-sample super resolution technique can resolve a frequency shift in the GPR spectrum even for a corresponding amount of moisture less than 2-3%.

Benedetto, F.; Benedetto, A.

2012-04-01

242

Impact of compressed natural gas fueled buses on street pavements  

SciTech Connect

Capital Metro, the Ausin, Texas transit authority, is currently evaluating a number of CNG fueled buses. As part of the U.S. DOT Region Six University Transportation Centers Program (UTCP), a study was instigated into the scale of incremental pavement consumption associated with the operation of these buses. The study suggests that replacing current vehicles with CNG powered models utilizing aluminum storage tanks would raise average network equivalent single rehabilitation costs across the network of over four percent. Finally, it recommends that full cost study be undertaken with evaluation of the adoption of alternative bus fuels - which includes pavement and environmental impacts.

Yang, D.; Harrison, R.

1995-07-01

243

Thin, applied surfacing for improving skid resistance of concrete pavements  

NASA Astrophysics Data System (ADS)

The use of select aggregate in a thin wearing surface of portland cement mortar to prolone or restore a concrete pavement's ability to develop high friction was accomplished. Two fine aggregates, blast furnace slag and lightweight expanded shale were found to exhibit skid resistance greater than the other aggregates evaluated. The British polishing wheel was used in the laboratory evaluation of aggregate to simulate wear. The need for a method of restoring friction to a worn, but otherwise sound concrete pavement led to a field evaluation of several different techniques for placing a very thin overlay. The successful method was a broomed, very thin layer of mortar, 3 mm thick.

Scholer, C. F.

1980-12-01

244

Desert pavement study at Amboy, California  

NASA Technical Reports Server (NTRS)

Desert pavement is a general term describing a surface that typically consists of a thin layer of cm-sized rock fragments set on top of a layer of finer material in which no fragments are found. An understanding of desert pavement is important to planetary geology because they may play a major role in the formation and visibility of various aeolian features such as wind streaks, which are important on Mars and may be important on Venus. A field study was conducted in Amboy, California to determine the formation mechanism of desert pavements. The probable sequence of events for the formation and evolution of a typical desert pavement surface, based on this experiment and the work of others, is as follows. Starting with a layer of surface material consisting of both fine particles and rock fragments, aeolian deflation will rapidly erode the surface until an armored lag is developed, after which aeolian processes become less important. The concentration of fragments then slowly increases as new fragments are brought to the surface from the subsurface and as fragments move downslope by sheet wash. Sheet wash would be responsible for removing very fine particles from the surface and for moving the fragments relative to one another, forming interlocks.

Williams, S.; Greeley, R.

1984-01-01

245

Fast simulated annealing inversion of surface waves on pavement using phase-velocity spectra  

USGS Publications Warehouse

The conventional inversion of surface waves depends on modal identification of measured dispersion curves, which can be ambiguous. It is possible to avoid mode-number identification and extraction by inverting the complete phase-velocity spectrum obtained from a multichannel record. We use the fast simulated annealing (FSA) global search algorithm to minimize the difference between the measured phase-velocity spectrum and that calculated from a theoretical layer model, including the field setup geometry. Results show that this algorithm can help one avoid getting trapped in local minima while searching for the best-matching layer model. The entire procedure is demonstrated on synthetic and field data for asphalt pavement. The viscoelastic properties of the top asphalt layer are taken into account, and the inverted asphalt stiffness as a function of frequency compares well with laboratory tests on core samples. The thickness and shear-wave velocity of the deeper embedded layers are resolved within 10% deviation from those values measured separately during pavement construction. The proposed method may be equally applicable to normal soil site investigation and in the field of ultrasonic testing of materials. ?? 2006 Society of Exploration Geophysicists.

Ryden, N.; Park, C.B.

2006-01-01

246

Electrical resistance tomography for monitoring the infiltration of water into a pavement section  

SciTech Connect

Electrical resistance tomography (ERT) was used to follow the infiltration of water into pavement section at the UC Berkeley Richmond Field Station. A volume of pavement 1m square and 1.29 m deep was sampled by an ERT array consisting of electrodes in 9 drilled holes plus 8 surface electrodes. The data were collected using a computer controlled data acquisition system capable of collecting a full data set in under 1 hour, allowing for nearly real time sampling of the infiltration. The infiltration was conducted in two phases. During the first phase, water was introduced into the asphalt-concrete (AC) layers at a slow rate of about 8 ml per hour for a period of about 6 days. In the second phase, water was introduced into the asphalt-treated-permeable base (ATPB) layer at a more rapid rate of about 100 ml/h for about 2 days. The ERT images show that water introduced into the upper AC layers shows up as a decrease in resistivity which grows with time. The images also appear to show that when water moves into the layers below the ATPB, the resistivity increases; an unexpected result. There are some indications that the water moved laterally as well as down into the deeper ATPB and the aggregate base. The images also show that when water is introduced directly into the ATPB and aggregate layer, the water moves into the the underlying materials much more quickly.

Buettner, M.; Daily, B.; Ramirez, A.

1997-07-03

247

Experimental pavement using household waste slag  

SciTech Connect

Municipal wastes used to be simply landfilled, but because of increasing difficulty in finding disposal sites, it became common practice to incinerate wastes and landfill the ash. In view of rapidly dwindling landfill sites, the author thought that the landfill site problem might be solved by finding a way to utilize slag made from incinerator ash. In this paper, a method for utilizing water-granulated slag as an asphalt pavement material is discussed. On the basis of laboratory test results, trial paving using base course materials consisting of crushed stone and 25 or 50% slag was carried out, paying attention primarily to bearing capacity. Marshall tests and fatigue resistance tests were conducted to determine the optimum content of water-granulated slag, and it was concluded that quality comparable to that of conventional asphalt concrete was attained at the slag content of 25% or less and that no problem would arise if the slag content was kept at 60% or less of the fine aggregate content. The mix proportions thus determined were also tested through experimental paving. A follow-up study to evaluate the durability of the experimental pavements confirmed that the experimental pavements were comparable in performance with conventional asphalt concrete pavements. This paper also reports on some problems encountered that need to be solved before utilizing water-granulated slag.

Kouda, Masahiro [Nippon Hodo Co., Ltd., Kasugai, Aichi (Japan). Nagoya Research Inst.] [Nippon Hodo Co., Ltd., Kasugai, Aichi (Japan). Nagoya Research Inst.

1996-12-31

248

Reducing greenhouse gas emissions through strategic management of highway pavement roughness  

NASA Astrophysics Data System (ADS)

On-road vehicle use is responsible for about a quarter of US annual greenhouse gas (GHG) emissions. Changes in vehicles, travel behavior and fuel are likely required to meet long-term climate change mitigation goals, but may require a long time horizon to deploy. This research examines a near-term opportunity: management of pavement network roughness. Maintenance and rehabilitation treatments can make pavements smoother and reduce vehicle rolling resistance. However, these treatments require material production and equipment operation, thus requiring a life cycle perspective for benefits analysis. They must also be considered in terms of their cost-effectiveness in comparison with other alternatives for affecting climate change. This letter describes a life cycle approach to assess changes in total GHG (measured in CO2-e) emissions from strategic management of highway pavement roughness. Roughness values for triggering treatments are developed to minimize GHG considering both treatment and use phase vehicle emission. With optimal triggering for GHG minimization, annualized reductions on the California state highway network over a 10-year analysis period are calculated to be 0.82, 0.57 and 1.38 million metric tons compared with historical trigger values, recently implemented values and no strategic intervention (reactive maintenance), respectively. Abatement costs calculated using /metric-ton CO2-e are higher than those reported for other transportation sector abatement measures, however, without considering all benefits associated with pavement smoothness, such as vehicle life and maintenance, or the time needed for deployment.

Wang, Ting; Harvey, John; Kendall, Alissa

2014-03-01

249

Nondestructive testing, evaluation, and rehabilitation for roadway pavement: Warren County, Mississippi, Cincinnati, Ohio, and Berkeley, California  

NASA Astrophysics Data System (ADS)

This report documents the results of one FIS technology transfer initiative: the demonstration of nondestructive pavement evaluation technology (NDT) to cooperating Federal and non-federal partners. The demonstrations utilized Falling Weight Deflectometer (FWD) technology, a commercially available nondestructive procedure for determining the structural adequacy of a pavement system. Data obtained from FWD tests were combined with pavement material properties and estimated future traffic volumes to design rehabilitation strategies for the existing streets and roadways of three communities. The specific objectives of the study were to: (1) Evaluate and develop improvements to the initial guide specification used for contracting FWD technology; (2) Evaluate the three analytical methods used by each contractor to develop the pavement repair strategies; (3) Document and explain the differences in the results of the pavement evaluation methods; (4) Document the benefits of FWD technology over other conventional techniques; and (5) Transfer nondestructive testing of pavements technology to non-federal partners, and demonstrate how analysis of the test results can be used to develop rehabilitation strategies for roadway pavements.

Grau, Richard H.; Alexander, Don R.

1994-07-01

250

Assessment of an Impulse GPR Antenna Abilities in Investigation of Transversal Cracks of the Bituminous Pavement  

NASA Astrophysics Data System (ADS)

Ground Penetrating Radar (GPR) technique is commonly used for detection of internal singularities of construction structure. The method is particularly efficient in the case of linear horizontal objects when profile scanning is being performed in the direction perpendicular to object elongation and polarization of the electric field is parallel to the elongation. Then the singular object manifests itself in the echogram as a scattering hyperbola. Similar response is generated by an object having shape close to a vertical half plane with horizontal edge, when the edge acts like the scattering linear object. The use of GPR technique for investigation of transversal cracks in the bituminous pavement would seem to be promising, but numerous paradoxes occur just at the beginning tests. Even well visible cracks of more than ten millimeters thickness doesn't generate noticeable GPR response, while thinner ones sometimes can produce strong response but in the deeper interior of the pavement. Thus arise a more general question: what the GPR technique can tell us about the cracks? Trying to study this problem some laboratory tests were performed to estimate efficiency of signal generation by structures simulating idealized cracks' shapes. Next long-term (several years) visual observation and repeated GPR scanning was performed on the three road sections (each one of several hundred meters length) with heavy traffic, where ongoing cracking process occurs. The preliminary measurements were directed to obtain the proper way of scanning. The main aim of the analysis was to find GPR characteristics of cracks that can be noticed on echograms. It was performed by detailed correlation of the visually observed cracks position with echograms using decimeter precision. These efforts provided a list of diagnostic GPR characteristics of cracks and some provisional scale of their intensity. In several cases the cracks were probed by drillings to recognize structures responsible for signal generation or to explain reasons of lacking signal. The three field cases represent different types of bituminous pavement and different degrees of cracking process progress, what showed first of all a large diversity GPR responses types and existence of specific masking effect related possibly to large-size granulation of the asphalt mixture. These examples show that the strong signals are frequently related to advanced deterioration in lower, older layers and confirm difficulty of cracks detection in a new cover. But on other hand long term observation showed that numerous new cracks appear on the surface in places, where some structural singularities were noticed earlier inside the new construction.

Krysi?ski, L.; Sudyka, J.

2012-04-01

251

Cooler reflective pavements give benefits beyond energy savings: durability and illumination  

SciTech Connect

City streets are usually paved with asphalt concrete because this material gives good service and is relatively inexpensive to construct and maintain. We show that making asphalt pavements cooler, by increasing their reflection of sunlight, may lead to longer lifetime of the pavement, lower initial costs of the asphalt binder, and savings on street lighting and signs. Excessive glare due to the whiter surface is not likely to be a problem.

Pomerantz, Melvin; Akbari, Hashem; Harvey, John T.

2000-06-01

252

Breaking/cracking and seating concrete pavements. Final report  

SciTech Connect

This synthesis will be of interest to pavement designers, maintenance engineers, and others interested in reducing reflection cracking of asphalt overlays on portland cement concrete (PCC) pavement. Information is presented on the technique of breaking or cracking of the concrete pavement into small segments before overlaying with asphalt concrete. Asphalt concrete overlays on existing PCC pavements are subject to reflection cracking induced by thermal movements of PCC pavement. The report of the Transportation Research Board discusses the technique of breaking/cracking and seating of the existing PCC before an overlay as a means to reduce or eliminate reflection cracking.

Thompson, M.R.

1989-03-01

253

Pavement management practices. Final report  

SciTech Connect

This synthesis will be of interest to pavement designers, maintenance engineers, and others responsible for the management of highway pavements. Information is presented on pavement management systems - the established, documented procedures used to treat all activities involved in providing and sustaining pavements in an acceptable condition. As highway agencies focus more attention on maintenance and rehabilitation of highway networks, the use of some form of a pavement management system becomes increasingly important. This report of the Transportation Research Board describes the features, applicability, and used of a pavement management system and recommends five general steps for implementing a new pavement management system or improving an existing system.

Peterson, D.E.

1987-11-01

254

Nondestructive evaluation of load transfer at rigid airport pavement joints  

Microsoft Academic Search

Current design criteria for rigid pavements for commercial and military airfields assume that 25% of the load applied to an edge of a slab is transferred through the joint to an adjacent unloaded slab. A nondestructive testing technique using a falling weight deflectometer (FWD) was used to conduct field testing at a number of sites. A transfer function, developed from

Michael I. Hammons

1995-01-01

255

EVALUATION AND MITIGATION OF ASPHALT PAVEMENT TOP-DOWN CRACKING  

Microsoft Academic Search

Top-down cracking has become an asphalt surface course distress of growing concern that must be dealt with during the design, construction, maintenance, and resurfacing of long-life asphalt pavements. The surface course is designed for heavy vehicle loadings and general traffic conditions in terms of rutting, resistance, durability, noise levels, smoothness, and frictional characteristics. The surface course must be properly maintained

John J. Emery

256

By-Products Utilization  

E-print Network

-products. Use of fly ash in cement-based materials provides not only economic, but also technical, ecological be consumed. Because of these reasons, a substantial amount of #12;research has been carried out by Naik-volume fly ash concretes in pavement construction. Phase I Investigation Material A Type I cement obtained

Wisconsin-Milwaukee, University of

257

DEVELOPMENT OF A HYDROPHOBIC SUBSTANCE TO MITIGATE PAVEMENT ICE ADHESION  

EPA Science Inventory

The specific problem to which this report is addressed is the development of a hydrophobic substance to mitigate the adhesion of ice to pavement as an alternative to deicing chemicals. The factors involved in evaluating this concept are the following: Economics; safety; environme...

258

Winter Performance and Maintenance of Porous Asphalt Pavements  

E-print Network

Winter Performance and Maintenance of Porous Asphalt Pavements Robert M. Roseen, Ph.D., P.E., D impacts for new development and reverse impacts in areas with redevelopment. #12;Porous Asphalt Design impacts for new development and reverse impacts in areas with redevelopment. Porous asphalt systems

259

Thickness and air voids measurement on asphalt concrete pavements using ground-penetrating radar  

NASA Astrophysics Data System (ADS)

Layer thickness and air voids are important parameters in quality assurance of newly paved hot mix asphalt (HMA) pavements. A non-destructive testing (NDT) technique was used to collect layer thickness information. The thicknesses estimated by the technique were compared with core thicknesses. Ground penetrating radar (GPR) system with air coupled antennas was used for on-site pavement data collection. Two application softwares - RADAN and ROAD DOCTOR - were used to process the field data for estimating layer thicknesses and air voids along the scanned pavements. 150 mm diameter cores taken from random locations on the pavements were tested in the laboratory to determine layer thickness and air voids. Statistical analyses were conducted to compare thicknesses and generate a regression equation relating air voids and dielectric constant of the pavement material. No significant differences were found between thickness estimates from RADAN and ROAD DOCTOR softwares when compared to the core measurements. However, RADAN and ROAD DOCTOR results are marginally significantly different from each other. ROAD DOCTOR software was used to generate air voids for the pavements scanned. Laboratory results from cores were utilized to determine calibration factors for the air voids -- dielectric equation. A relationship between air voids and dielectric constant is presented. It is concluded that GPR system with air coupled antennas used alongside a reduced core testing has a potential for quality control of newly paved hot mixed asphalt pavements.

Dhakal, Sharad Raj

260

Acute pavement burns: a unique subset of burn injuries: a five-year review of resource use and cost impact.  

PubMed

This study focuses on the hospital care of a rare subset of burn injuries caused by contact with environmentally heated pavement, to further understand the required use of resources. This article aims to show that pavement burns are typically more severe than their flame/scald counterparts. A retrospective review of patients admitted to the burn center with injuries suffered from contact with hot pavement was performed. Patients were stratified on the presence or absence of altered mental status (AMS) and additional inciting factors. A representative sample of similarly sized flame and scald wounds treated in the same time period was compiled for comparison. Those with pavement burns had a significantly greater requirement for operative intervention, repetitive debridements, overall cost/percent burned, and lengthier hospital stays than those with flame/scald burns. Pavement burn victims with AMS were significantly more likely to require an operation, a greater cost/percent burned, and longer hospital stays than those without AMS. Pavement burns are significantly worse than similarly sized scald/flame burns with regards to length of stay and total hospital costs, and the necessity of initial and repetitive operative intervention. These discrepancies are even greater in patients with AMS as a concomitant inciting factor. It is apparent that these wounds often continue to deepen during a patient's stay, likely because of continued pressure on the wounds while recumbent. As such, this article highly recommends pressure off-loading beds and more aggressive debridement in the treatment of these unique injuries. PMID:25207798

Silver, Andrew G; Dunford, Gerrit M; Zamboni, William A; Baynosa, Richard C

2015-01-01

261

Lichen colonization of the Roman pavement at Baelo Claudia (Cadiz, Spain): biodeterioration vs. bioprotection  

Microsoft Academic Search

This paper describes the effect of lichen colonization on the first century A.D. pavement of the forum at Baelo Claudia, a Roman city located in southern Spain. Lichen colonization is scarce, covering only 13% of the total surface. The rest of the flagstones are mostly uncovered but show strong physico-chemical weathering. The flagstones colonized by lichens do not show weathering.

X. Ario; J. J. Ortega-Calvo; A. Gomez-Bolea; C. Saiz-Jimenez

1995-01-01

262

Hydraulic and treatment performance of pervious pavements under variable drying and wetting regimes.  

PubMed

Pervious pavements are an effective stormwater treatment technology. However, their performance under variable drying and wetting conditions have yet to be tested, particularly under a continuous time scale. This paper reports on the clogging behaviour and pollutant removal efficiency of three pervious pavement types over 26 accelerated years. These pavements were monolithic porous asphalt (PA), Permapave (PP) and modular Hydrapave (HP). Over a cycle of 13 days, the period of which was equivalent to the average annual Brisbane, Australia rainfall (1,200 mm), the pavements were randomly dosed with four different flows. Drying events of 3 h duration were simulated during each flow. Inflow and outflow samples were collected and analysed for Total Suspended Solids (TSS), Total Phosphorus (TP) and Total Nitrogen (TN). To evaluate the rate of clogging, a 1 in 5 year Brisbane storm event was simulated in the 6th, 8th, 12th, 16th, 20th and 24th week. Under normal dosing conditions, none of the pavements showed signs of clogging even after 15 years. However, under storm conditions, both PA and HP started to clog after 12 years, while PP showed no signs of clogging after 26 years. The drying and various flow events showed no effects in TSS removal, with all systems achieving a removal of approximately 100%. The average TP removal was 20% for all flows except for low flow, which had a significant amount of leaching over time. Leaching from TN was also observed during all flows except high flow. The TSS, TP and TN results observed during storm events were similar to that of high flow. PMID:22335113

Yong, C F; Deletic, A; Fletcher, T D; Grace, M R

2011-01-01

263

Heat storage of pavement and its effect on the lower atmosphere  

Microsoft Academic Search

Heat flux at the air\\/ground interface was observed and analyzed for various pavement materials on summer days. The surface temperature, heat storage and its subsequent emission to the atmosphere were significantly greater for asphalt than for concrete or bare soil. At the maximum, asphalt pavement emitted an additional 150 W m?2 in infrared radiation and 200 W m?2 in sensible

Akio Wake

1996-01-01

264

AUTOMATED REAL TIME PAVEMENT MARKING RETROREFLECTIVITY MEASUREMENTS Norbert H. Maerz, University of Missouri-Rolla, 1006 Kingshighway, Rolla MO, 65409-0660, USA. Tel: (573) 341-  

E-print Network

LASERLUX® : AUTOMATED REAL TIME PAVEMENT MARKING RETROREFLECTIVITY MEASUREMENTS Norbert H. Maerz retroreflectometer is being used to measure the retroreflectivity of pavement lane markings. This vehicle-mounted retroreflectometer provides the measurements needed for proper highway pavement marking management. Quick, simple

Maerz, Norbert H.

265

Traffic-generated emissions of ultrafine particles from pavement-tire interface  

NASA Astrophysics Data System (ADS)

In a road simulator study, a significant source of sub-micrometer fine particles produced by the road-tire interface was observed. Since the particle size distribution and source strength is dependent on the type of tire used, it is likely that these particles largely originate from the tires, and not the road pavement. The particles consisted most likely of mineral oils from the softening filler and fragments of the carbon-reinforcing filler material (soot agglomerates). This identification was based on transmission electron microscopy studies of collected ultrafine wear particles and on-line thermal treatment using a thermodesorber. The mean particle number diameters were between 15-50 nm, similar to those found in light duty vehicle (LDV) tail-pipe exhaust. A simple box model approach was used to estimate emission factors in the size interval 15-700 nm. The emission factors increased with increasing vehicle speed, and varied between 3.710 11 and 3.210 12 particles vehicle -1 km -1 at speeds of 50 and 70 km h -1. This corresponds to between 0.1-1% of tail-pipe emissions in real-world emission studies at similar speeds from a fleet of LDV with 95% gasoline and 5% diesel-fueled cars. The emission factors for particles originating from the road-tire interface were, however, similar in magnitude to particle number emission factors from liquefied petroleum gas-powered vehicles derived in test bench studies in Australia 2005. Thus the road-tire interface may be a significant contributor to particle emissions from ultraclean vehicles.

Dahl, Andreas; Gharibi, Arash; Swietlicki, Erik; Gudmundsson, Anders; Bohgard, Mats; Ljungman, Anders; Blomqvist, Gran; Gustafsson, Mats

266

Nondestructive testing of pavements and pavement bases. 1964-June, 1981 (citations from the NTIS Data Base). Report for 1964-Jun 81  

SciTech Connect

Nondestructive methods for quality assurance of pavements and pavement bases are investigated in these Government-sponsored research reports. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed. (This updated bibliography contains 167 citations, 16 of which are new entries to the previous edition.)

Not Available

1981-07-01

267

Nondestructive testing of pavements and pavement bases. 1964-March 1980 (citations from the NTIS Data Base). Report for 1964-March 1980  

SciTech Connect

Nondestructive methods for quality assurance of pavements and pavement bases are investigated in these Government-sponsored research reports. Vibration, nuclear activation, radiometry, and acoustic detection are among the various techniques employed. (This updated bibliography contains 151 abstracts, 17 of which are new entries to the previous edition.)

Habercom, G.E. Jr.

1980-04-01

268

Long-term stormwater quantity and quality performance of permeable pavement systems.  

PubMed

This study examined the long-term effectiveness of permeable pavement as an alternative to traditional impervious asphalt pavement in a parking area. Four commercially available permeable pavement systems were evaluated after 6 years of daily parking usage for structural durability, ability to infiltrate precipitation, and impacts on infiltrate water quality. All four permeable pavement systems showed no major signs of wear. Virtually all rainwater infiltrated through the permeable pavements, with almost no surface runoff. The infiltrated water had significantly lower levels of copper and zinc than the direct surface runoff from the asphalt area. Motor oil was detected in 89% of samples from the asphalt runoff but not in any water sample infiltrated through the permeable pavement. Neither lead nor diesel fuel were detected in any sample. Infiltrate measured 5 years earlier displayed significantly higher concentrations of zinc and significantly lower concentrations of copper and lead. PMID:14511707

Brattebo, Benjamin O; Booth, Derek B

2003-11-01

269

Exploratory study of hot in-place recycling of asphalt pavements. Volume 1. Final report, September 1992-September 1994  

SciTech Connect

Hot in-place recyling (HIR) is a method for rehabilitation of asphalt pavements. Potential for cost savings and resource preservation are high because existing pavement materials are processed on-site, with only the addition of small amounts of recycling agent. The Oregon Department of Transportation (ODOT) constructed HIR projects in 1992 and 1993. In September 1992, ODOT contracted with Oregon State University (OSU) to evaluate the HIR projects, synthesize existing information on HIR, and develop guidelines for HIR use. This report is in two volumes. Volume I includes the body of the report, Volume II includes the appendices.

Rogge, D.F.; Hislop, W.P.; Dominick, D.

1994-11-01

270

Runoff and infiltration characteristics of pavement structures--review of an extensive monitoring program.  

PubMed

The stormwater runoff and infiltration performance of permeable pavements has been systematically evaluated within an intensive monitoring program. The primary objective of the investigation was to generate a broad database, which enables the development of an advanced simulation module for urban drainage modelling. Over 160 field and lab scale experiments have been completed and analyzed for surface runoff and infiltration characteristics. The test series include several pavement types under various boundary conditions such as diverse precipitation impacts, varying surface slope and layer construction as well as different stages of surface clogging and several base and subgrade layer characteristics. The results represent a reliable and comprehensive database that allows profound conclusions and substantial recommendations. PMID:18048986

Illgen, M; Harting, K; Schmitt, T G; Welker, A

2007-01-01

271

Relating tensile, bending, and shear test data of asphalt binders to pavement performance  

Microsoft Academic Search

Eight different asphalt binders representing a wide range of applications for pavement construction were tested in uniaxial\\u000a tension, bending, and shear stresses. Theoretical analyses were performed in this study to convert the data from the three\\u000a engineering tests to stiffness moduli for predicting pavement performance. At low temperatures, high asphalt stiffness may\\u000a induce pavement thermal cracking; thus, the allowable maximum

J.-S. Chen; C.-J. Tsai

1998-01-01

272

Full scale demonstration of air-purifying pavement.  

PubMed

Experiments concerning a full-scale demonstration of air purifying pavement in Hengelo, The Netherlands, are reported. The full width of the street was provided with concrete pavement containing TiO? over a length of 150 m ("DeNOx street"). Another part of the street, about 100 m, was paved with normal paving blocks ("Control street"). The outdoor monitoring was done during 26 days for a period exceeding one year, and measured parameters included traffic intensity, NO, NO? and ozone concentrations, temperature, relative humidity, wind speed and direction, and the visible and UV light irradiance. Prior and parallel to these field measurements, the used blocks were also measured in the lab to assess their performance. The NOx concentration was, on average, 19% (considering the whole day) and 28% (considering only afternoons) lower than the obtained values in the Control street. Under ideal weather conditions (high radiation and low relative humidity) a NOx concentration decrease of 45% could be observed. PMID:23731840

Ballari, M M; Brouwers, H J H

2013-06-15

273

Abrasion resistance of concrete containing nano-particles for pavement  

Microsoft Academic Search

The abrasion resistance of concrete containing nano-particles for pavement is experimentally studied. Both nano-TiO2 and nano-SiO2 are, respectively, employed to be as the additives. For comparison, the abrasion resistance of plain concrete and the concrete containing polypropylene (PP) fibers is also experimentally studied in this work. The test results indicate that the abrasion resistance of concretes containing nano-particles and PP

Hui Li; Mao-hua Zhang; Jin-ping Ou

2006-01-01

274

POROUS PAVEMENT: RESEARCH; DEVELOPMENT; AND DEMONSTRATION  

EPA Science Inventory

This paper discusses the U.S. Environmental Protection Agency's porous pavement research program along with the economics, advantages, potential applications, and status and future research needs of porous pavements. Porous pavements are an available stormwater management techniq...

275

The vesicular layer and carbonate collars of desert soils and pavements: formation, age and relation to climate change  

Microsoft Academic Search

The vesicular, fine-grained A horizon (Av) is the widespread, ubiquitous surficial horizon of desert soils in diverse landforms and parent materials of varying ages. Now known to form mostly through accumulation of eolian dust, recent studies show that dust accumulation and concomitant soil development are genetically linked to stone pavement formation. Changes in the magnitude of eolian activity and effective

Leslie D McFadden; Eric V McDonald; Stephen G Wells; Kirk Anderson; Jay Quade; Steven L Forman

1998-01-01

276

Design Methodologies of Asphalt Pavement Used in China and Mozambique  

NASA Astrophysics Data System (ADS)

This study discusses and compares Asphalt Concrete (AC) pavement design methodologies used in China and Mozambique (based on South African Transportation and Communication Commission (SATCC) methodologies). The SATCC design methodologies use California Bearing Ratio (CBR) and catalogues methods. The South African catalogues are basically used for roads with traffic less than 30 million ESAs. The design catalogues method give small thickness than CBR and Chinese methods. The Chinese and the South African design methods give nearly the same thickness; this study concludes that these methods can be used in both countries; China and Mozambique. The results also show that the strong point of Chinese method is verifying the tensile stress and allowable displacement on the pavement calculated from computer program APDS.

Francisco Rufino Diogo, Jose; Shubber, Ammar Abbas Mohammed; Lin, Mu Han

277

On-site inspections of pavement damages evolution using GPR  

NASA Astrophysics Data System (ADS)

Ground-penetrating radar (GPR) is being increasingly used for pavements maintenance due to the wide range of applications spanning from physical to geometrical inspections, thereby allowing for a reliable diagnosis of the main causes of road structural damages. In this work, an off-ground GPR system was used to investigate a large-scale rural road network. Two sets of surveys were carried out in different time periods, with the main goals to i) localize the most critical sections; ii) monitor the evolution of previous damages and localize newborn deep faults, although not revealed at the pavement surface level; iii) analyze the causes of both evolution and emergence of faults by considering environmental and human factors. A 1-GHz GPR air-launched antenna was linked to an instrumented van for collecting data at traffic speed. Other support techniques (e.g. GPS data logger, odometer, HD video camera) were used for cross-checking,. Such centre frequency of investigation along with a 25-ns time window allow for a signal penetration of 900 mm, consistent with the deepest layer interfaces. The bottom of the array was 400 mm over the surface, with a minimum distance of 1200 mm from the van body. Scan length of maximum 10 km were provided for avoiding heavy computational loads. The rural road network was located in the District of Rieti, 100 km north from Rome, Italy, and mostly develops in a hilly and mountainous landscape. In most of the investigated roads, the carriageway consists in two lanes of 3.75 meters wide and two shoulders of 0.50 meters wide. A typical road section includes a HMA layer (65 mm average thickness), a base layer (100 mm average thickness), and a subbase layer (300 mm average thickness), as described by pavement design charts. The first set of surveys was carried out in two days at the beginning of spring in moderately dry conditions. Overall, 320-km-long inspections were performed in both travel directions, thereby showing a productivity of approximately 160 km/day at 40 km/h speed, on the average. After processing and first-checking, GPR profiles were divided into homogeneous sections according to the combination of different parameters (e.g. route analyzed, long distance conditions of regularity/irregularity in layers arrangement). In such context, a high consistency between surface damages, mismatches from the GPR scans, and boundary environmental conditions was demonstrated. In addition, deep mismatches were detected even for early-stage or unrevealed faults. The second set of surveys was carried out in autumn in high humidity conditions, due to recent rainfalls. 160 km of relevant routes from the same road network were investigated. Results showed a high consistency with those collected during the first-stage of surveys. Minor changes were found in those sections with low traffic loads (e.g. farther away from the biggest town of Rieti), whereas major mismatches were detected in wetlands (e.g. close to rivers), work zones, and nearby those sections already deeply damaged in the past. This work benefited from networking activities carried out within the EU funded COST Action TU1208 'Civil Engineering Applications of Ground Penetrating Radar'.

Tosti, Fabio; D'Amico, Fabrizio; Calvi, Alessandro; Benedetto, Andrea

2014-05-01

278

Contributions to an Improved Oxygen and Thermal Transport Model and Development of Fatigue Analysis Software for Asphalt Pavements  

E-print Network

Fatigue cracking is one primary distress in asphalt pavements, dominant especially in later years of service. Prediction of mixture fatigue resistance is critical for various applications, e.g., pavement design and preventative maintenance. The goal...

Jin, Xin

2012-02-14

279

International Symposium on Pavement LCA (Pavement LCA 2014) TRB Co-Sponsored  

E-print Network

International Symposium on Pavement LCA (Pavement LCA 2014) TRB Co-Sponsored (Sustainable Pavements AFD00(1)) FHWA Co-Sponsored (Sustainable Pavement Task Group) Location: UC Davis Campus Conference Assessment (LCA) for pavements. The workshop will be coordinated with activities of the FWHA Sustainable

California at Davis, University of

280

Anisotropic Characterization and Performance Prediction of Chemically and Hydraulically Bounded Pavement Foundations  

E-print Network

ANISOTROPIC CHARACTERIZATION AND PERFORMANCE PREDICTION OF CHEMICALLY AND HYDRAULICALLY BOUNDED PAVEMENT FOUNDATIONS A Dissertation by REZA SALEHI ASHTIANI Submitted to the Office of Graduate Studies of Texas A&M University... FOUNDATIONS A Dissertation by REZA SALEHI ASHTIANI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Chair of Committee...

Salehi Ashtiani, Reza

2010-10-12

281

Effect of pavement temperature on the macrotexture of a semidense asphalt surface  

E-print Network

Effect of pavement temperature on the macrotexture of a semidense asphalt surface J. Luong, M the influence of the surface temperature on the macrotexture of a semidense asphalt pavement located in an urban area and a semidense asphalt sample in laboratory. The superficial macrotexture profiles at different

Boyer, Edmond

282

Oxidative reactions and their impact on the properties of asphalt as a pavement binder  

E-print Network

OXIDATIVE REACTIONS AND THEIR IMPACT ON THE PROPERTIES OF ASPHALT AS A PAVE~ BINDER A Thesis by CHEE KEUNG LAU Submitted to the Office of Graduate Studies of Texas A & M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1991 Major Subject: Chemical Engineering OXIDATIVE REACTIONS AND THEIR IMPACT ON THE PROPERTIES OF ASPHALT AS A PAVEMENT BINDER A Thesis by CHEE KEUNG LAU Approved as to style and content by: Charles J. over (Chair...

Lau, Chee Keung

2012-06-07

283

A new technology of preventive reinforcement for the semi-rigid base of asphalt pavement expressway  

Microsoft Academic Search

As for the existing treated methods for the base layer of asphalt pavement, there were at least two main shortages: the one was the lagged technology, the other one was the unseasonable choosing of treated time. In order to develop a new preventive maintenance technologies for the asphalt pavement, in this paper, the authors propose that, before the damages happen

Guo-xiang Hu; Jie Li; Bai-lin Sun

2011-01-01

284

Leaching of heavy metals and polycyclic aromatic hydrocarbons from reclaimed asphalt pavement.  

PubMed

The work presented herein displays the results of a study addressing environmental concerns related to the possible leaching of pollutants from reclaimed asphalt pavement. Samples from an experimental site were tested in both static batch tests and column leaching tests. Selected heavy metals and polycyclic aromatic hydrocarbons (PAHs) were analysed in leachates. The results have allowed us to consider the leaching of pollutants to be rather weak for most of the parameters studied. Concentrations in solutions from batch leaching tests were generally below the EC limit values for drinking water. Pollutant concentrations from column experiments were higher in solutions as of the initial leaching stages, but then decreased rapidly and wound up at values below the detection limits. The factors influencing results proved to be the material grain size and the percolation water flow rate. Results from leaching experiments performed on core samples taken on two rebuilt road section pavements, containing 10% and 20% of reclaimed asphalt pavement, respectively, confirmed the results obtained from the batch and column experiments. PMID:16083938

Legret, M; Odie, L; Demare, D; Jullien, A

2005-09-01

285

New structural systems for zero-maintenance pavements. Volume 3: Anchored pavement system designed for Edens Expressway  

Microsoft Academic Search

The response of the Edens Expressway subjected to mechanical and environmental loads using the anchored pavement concept is discussed. The mechanical and thermal properties of materials that could be encountered in future reconstruction of Edens Expressway are presented in a consistent form for computer programming. These properties are viewed as typical design values during investigation of pavement response. The behavior

S. K. Saxena; S. G. Militsopoulos

1980-01-01

286

Performance Based Mechanistic-Empirical Approach to Assess Joint Sealant Effectiveness on Sustainability of Concrete Pavement Infrastructure  

E-print Network

The primary purpose of sealing joints in rigid pavement is to prevent or reduce the amount of water infiltrating into pavement structure. It is well accepted that the presence of moisture in a pavement structure is a contributor to a variety...

Neshvadian Bakhsh, Keivan

2014-08-11

287

Full Depth Reclamation of Asphalt Pavements Using Class F Fly Ash  

Microsoft Academic Search

This study demonstrates the use of Class F fly ash in combination with lime or lime kiln dust in the full depth reclamation (FDR) of asphalt pavements. FDR is a process of pulverizing a predetermined amount of flexible pavement that is structurally deficient, blending it with chemical additives and water, and compacting it in place to construct a new stabilized

Jeffryes Chapman; Wei Tu; Behrad Zand; Tarunjit Butalia

288

Utilize Cementitious High Carbon Fly Ash (CHCFA) to Stabilize Cold In-Place Recycled (CIR) Asphalt Pavement as Base Coarse  

SciTech Connect

The purpose of this study was to evaluate the performance of cementitious high carbon fly ash (CHCFA) stabilized recycled asphalt pavement as a base course material in a real world setting. Three test road cells were built at MnROAD facility in Minnesota. These cells have the same asphalt surface layers, subbases, and subgrades, but three different base courses: conventional crushed aggregates, untreated recycled pavement materials (RPM), and CHCFA stabilized RPM materials. During and after the construction of the three cells, laboratory and field tests were carried out to characterize the material properties. The test results were used in the mechanistic-empirical pavement design guide (MEPDG) to predict the pavement performance. Based on the performance prediction, the life cycle analyses of cost, energy consumption, and greenhouse gasses were performed. The leaching impacts of these three types of base materials were compared. The laboratory and field tests showed that fly ash stabilized RPM had higher modulus than crushed aggregate and RPM did. Based on the MEPDG performance prediction, the service life of the Cell 79 containing fly ash stabilized RPM, is 23.5 years, which is about twice the service life (11 years) of the Cell 77 with RPM base, and about three times the service life (7.5 years) of the Cell 78 with crushed aggregate base. The life cycle analysis indicated that the usage of the fly ash stabilized RPM as the base of the flexible pavement can significantly reduce the life cycle cost, the energy consumption, the greenhouse gases emission. Concentrations of many trace elements, particularly those with relatively low water quality standards, diminish over time as water flows through the pavement profile. For many elements, concentrations below US water drinking water quality standards are attained at the bottom of the pavement profile within 2-4 pore volumes of flow.

Wen, Haifang; Li, Xiaojun; Edil, Tuncer; O'Donnell, Jonathan; Danda, Swapna

2011-02-05

289

AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT  

E-print Network

-destructive tests (NDT) have become increasingly popular, for allowing pave- ment overlay designs to be based on the in situ conditions of a pavement structure. Among the array of NDT tests, standard methods are limited Weight De- ectometer (FWD) is the most popular for the NDT testing of exible pavements. The FWD (see Fig

Avignon et des Pays de Vaucluse, Université de

290

Mechanical analysis of a mixed mode debonding test for "composite" pavements A. Chabot*, M. Hun, F. Hammoum  

E-print Network

Mechanical analysis of a mixed mode debonding test for "composite" pavements A. Chabot*, M. Hun, F" pavements, a four-point bending test on bi-layer structures is performed. Before mixed mode failure debonding, modeling, composite pavement, four-point bending test. 1. Introduction To ensure a long lasting

Paris-Sud XI, Université de

291

MONITORING OF ARTIFICIAL DEFECTS WITHIN A PAVEMENT STRUCTURE WITH A NDT METHOD BASED ON A MECHANICAL IMPACT  

E-print Network

MONITORING OF ARTIFICIAL DEFECTS WITHIN A PAVEMENT STRUCTURE WITH A NDT METHOD BASED-destructive testing (NDT) method used to monitor a pavement structure which contains artificial defects. A 25 m long-destructive testing method (NDT) used to monitor a pavement structure which contains artificial defects. The method

Boyer, Edmond

292

Discussion on the Prediction Method of the Pavement Performance for Expressway  

Microsoft Academic Search

The empirical regression model was selected for forecasting the preventive maintenance time; the grey system theory was used to determine if pavements were fit for preventive maintenance. Combined with the instance, on the forecasting of the pavement performance for an expressway, the application of the grey system theory was introduced.

He Xiao-ming; Guan Peng; Hu Guo-xiang; Zhou Lin

2009-01-01

293

Simultaneous detection of lane and pavement boundaries using model-based multisensor fusion  

Microsoft Academic Search

This paper treats a problem arising in the design of intelligent vehicles: automated detection of lane and pavement boundaries using forward-looking optical and radar imaging sensors mounted on an automobile. In previous work, lane and pavement boundaries have always been located separately. This separate detection strategy is problematic in situations when either the optical or the radar image is too

Bing Ma; Sridhar Lakshmanan; Alfred O. Hero III

2000-01-01

294

Smart Road Pavement Research HomePage  

NSDL National Science Digital Library

Dubbed "the Smart Road" by Virginia's Department of Transportation, this full-scale facility for pavement research and evaluation of high-tech transportation systems uses computers, electronics, and satellites to create a realistic environment for collecting traffic and environmental data under controlled conditions, "and should advance the general understanding of the engineering behavior of pavement systems." This site, from the Virginia Tech Civil Engineering Materials Program, provides information from the researchers who have designed the Smart Road. The page contains a description of the project's current status, an explanation of objectives, construction photos, a detailed description of the instrumentation used, and data. Note, the research plan and testing links are still under construction. This site introduces an interesting project for highway and transportation engineers.

295

A comparison of the micromagnetic and microstructural properties of four NdFeB-type materials processed by the HDDR route  

Microsoft Academic Search

Transmission electron microscopy has been used to study the physical and magnetic microstructures of thinned sections of four different NdFeB-type alloys. Three of the materials were prepared by the solid-HDDR process and differed in that one was a simple ternary alloy, another contained Co & Ga additions and a third was appreciably richer in Nd than stoichiometric Nd2Fe14B1. For the

P. Thompson; O. Gutfleisch; J. N. Chapman; I. R. Harris

1999-01-01

296

Recycling of plastic and rubber tire waste in asphalt pavements  

SciTech Connect

This paper discusses some important issues related to the use of recycled thermoplastics and rubber tire waste in asphalt binders for hot-mix pavements. Both high temperature rheological and low temperature fracture studies are presented on recycled polyethylene, devulcanized and crumb rubber-modified asphalt binders. The results are compared to unmodified and commercially available modified binders. This research is especially timely in light of the US Intermodal Surface Transportation Efficiency Act of 1991, Section 1038 which, starting in 1995, will force state and local governments to use significant amounts of recycled rubber tire or plastic waste in federally funded highway projects. High temperature rheological measurements of the loss modulus, loss tangent and complex modulus show a significant improvement when only small quantities of crumb rubber, devulcanized crumb rubber or waste polyethylene are added to the asphalt binders. The low temperature fracture performance of the modified asphalts is greatly influenced by the interfacial strength between the dispersed and continuous phase. The fracture toughness increases dramatically, only when low molecular weight polymers are grafted in-situ onto the rubber and polymer dispersed phases in order to strength the interface. This points to a crack-pinning mechanism as being responsible for the dramatic increase in fracture toughness that is observed in this work. Single phase, devulcanized crumb rubber-asphalt systems perform quite poorly at low temperatures.

Morrison, G.R.; Lee, N.K.; Hesp, S.A.M. [Queen`s Univ., Kingston, Ontario (Canada). Dept. of Chemistry

1994-12-31

297

Accuracy of Ground Penetrating Radar Horn-Antenna Technique for Sensing Pavement Subsurface  

Microsoft Academic Search

Ground penetrating radar (GPR) is an intelligent sensor technique that has led to a powerful nondestructive testing (NDT) method for road pavement evaluation. Recent improvements in hardware and, in particular, software processing have contributed to the rapidly expanding popularity and usability of this technique in the pavement engineers community. In the present work, a GPR sensor system mounted on a

Andreas Loizos; Christina Plati

2007-01-01

298

Thermal stability analysis under embankment with asphalt pavement and cement pavement in permafrost regions.  

PubMed

The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8?m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results. PMID:24027444

Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

2013-01-01

299

Thermal Stability Analysis under Embankment with Asphalt Pavement and Cement Pavement in Permafrost Regions  

PubMed Central

The permafrost degradation is the fundamental cause generating embankment diseases and pavement diseases in permafrost region while the permafrost degradation is related with temperature. Based on the field monitoring results of ground temperature along G214 Highway in high temperature permafrost regions, both the ground temperatures in superficial layer and the annual average temperatures under the embankment were discussed, respectively, for concrete pavements and asphalt pavements. The maximum depth of temperature field under the embankment for concrete pavements and asphalt pavements was also studied by using the finite element method. The results of numerical analysis indicate that there were remarkable seasonal differences of the ground temperatures in superficial layer between asphalt pavement and concrete pavement. The maximum influencing depth of temperature field under the permafrost embankment for every pavement was under the depth of 8?m. The thawed cores under both embankments have close relation with the maximum thawed depth, the embankment height, and the service time. The effective measurements will be proposed to keep the thermal stabilities of highway embankment by the results. PMID:24027444

Jinping, Li; Xiaojuan, Quan

2013-01-01

300

Feasibility of crumb rubber use for asphalt pavement construction in Rhode Island. Final research report  

SciTech Connect

This is the final report of the research project, entitled `Viable Use of Crumb Rubber for Highway Construction in Rhode Island.` This study dealt with the investigation of the means by which the State of Rhode Island can effectively comply with the mandate of the Section 1038 of the 1991 Intermodal Surface Transportation Efficiency Act (ISTEA) to use recycled rubber in asphalt pavements. More specifically, this laboratory investigation characterized Hot Mix Asphalt (HMA) with Crumb Rubber Modifiers (CRM).

Lee, K.W.; Kovacs, W.D.; Marcus, A.S.; Madapati, R.R.

1995-12-15

301

FRP Dowels for Concrete Pavements Darren Eddie, Junior Structural Engineer, Reid Crowther & Partners;  

E-print Network

= L FRP Dowels for Concrete Pavements By Darren Eddie, Junior Structural Engineer, Reid Crowther - Introduction Joints are used in concrete pavements in order to control cracking due to thermal pavements due to the expansion of steel during the corrosion process. This expansion can create large

302

An algorithm for pavement crack detection based on multiscale space  

NASA Astrophysics Data System (ADS)

Conventional human-visual and manual field pavement crack detection method and approaches are very costly, time-consuming, dangerous, labor-intensive and subjective. They possess various drawbacks such as having a high degree of variability of the measure results, being unable to provide meaningful quantitative information and almost always leading to inconsistencies in crack details over space and across evaluation, and with long-periodic measurement. With the development of the public transportation and the growth of the Material Flow System, the conventional method can far from meet the demands of it, thereby, the automatic pavement state data gathering and data analyzing system come to the focus of the vocation's attention, and developments in computer technology, digital image acquisition, image processing and multi-sensors technology made the system possible, but the complexity of the image processing always made the data processing and data analyzing come to the bottle-neck of the whole system. According to the above description, a robust and high-efficient parallel pavement crack detection algorithm based on Multi-Scale Space is proposed in this paper. The proposed method is based on the facts that: (1) the crack pixels in pavement images are darker than their surroundings and continuous; (2) the threshold values of gray-level pavement images are strongly related with the mean value and standard deviation of the pixel-grey intensities. The Multi-Scale Space method is used to improve the data processing speed and minimize the effectiveness caused by image noise. Experiment results demonstrate that the advantages are remarkable: (1) it can correctly discover tiny cracks, even from very noise pavement image; (2) the efficiency and accuracy of the proposed algorithm are superior; (3) its application-dependent nature can simplify the design of the entire system.

Liu, Xiang-long; Li, Qing-quan

2006-10-01

303

Evaluation of various surface-sealing techniques for the preventative maintenance of flexible pavements. Research report(Final)  

SciTech Connect

The selection of an appropriate surface-seal technique for the preventative maintenance of flexible pavements has been a major concern among the various highway agencies for a number of years. In an effort to better equip the engineer in making decisions concerning the selection of the most cost-effective method of pavement maintenance, seven of the different surface-sealing techniques currently available in Florida were constructed in the fall of 1984 for evaluation. The only major problems encountered at the time of construction was the loss of cover material in the sand seal, mineral seal, and surface-treatment sections and raveling in the slurry seal section. These problems are believed to have been caused by traffic on the roadway before adequate curing had occurred. The test sections were evaluated immediately after construction and at 6 months, 1 year, 2 years, and 3 years, with the evaluation consisting of rut-depth measurements, crack survey, dynamic deflection measurements, rideability, and friction testing. At the conclusion of 3 years, the cost-effectiveness of each section was determined.

Musselman, J.A.; Leitner, E.B.; Murphy, K.H.; Page, G.C.

1989-02-01

304

JOINT DETERIORATION MONITORING FOR SELECTION OF PROPER PRESERVATION TYPE AND TIMING  

E-print Network

JOINT DETERIORATION MONITORING FOR SELECTION OF PROPER PRESERVATION TYPE AND TIMING Research Problem Statement Premature deterioration at concrete pavement joints reduces concrete pavement life Roadmap that has resulted in multiple studies dealing with mechanisms that cause joint deterioration

305

Cost-benefit analysis of low-noise pavements: dust into the calculations  

Microsoft Academic Search

This paper presents a cost-benefit analysis (CBA) of roads noise measures in Norway. Low-noise pavement alternatives were compared to stone mastic asphalt with a maximum aggregate size of 11mm. The low-noise alternatives were expected to reduce the noise levels by 14.5dB over their lifetime, compared to the reference, but had shorter lifetime and, mostly, higher investment cost. A new element

Knut Veisten; Juned Akhtar

2011-01-01

306

Example of using small falling weight deflectomer (FWD) for Earth structures and low cost road pavement in Japan  

NASA Astrophysics Data System (ADS)

The FWD (Falling Weight Deflectometer) is an instrument which makes the weight fall freely on its loading plate to apply impact load and measures the displacement caused by the fall at the center of impact load and also at the points in radial direction from the center of impact load. A kind of instrument which is mounted on or drawn by a vehicle used for construction of concrete pavement or asphalt pavement of a runway is usually called FWD. The impact load of FWD is 49KN to 196kN and it can obtain the modulus of elasticity of each pavement layer by back analysis based on the theory of multi-layer elasticity using 6 to 8 of extemal displacement sensors. On the other hand, the small FWD is an FWD which is constructed small and easy and is applicable for hand carry. It makes the weight fall freely on the loading plate to apply impact load and measures the load and displacement caused by the fall. It was developed for mainly assessing the rigidity and bearing capacity of the subgrade easily and promptly. It can measure many points in short term and obtain coefficient of subgrade reaction and modulus of subgrade elasticity without using reaction facilities like as plate bearing test or CBR test. It has also been tried to apply the small FWD to low cost asphalt road pavement (later called as low cost road pavement). Application examples of small FWD test for earth structure and low cost load pavement in Japan are shown and the methods and test results are stated in this report.

Shibata, Hideaki; Tanaka, Yasutomo; Ono, Isamu; Okano, Tsuyoshi

2007-01-01

307

Spouses' materialism: Effects of parenthood status, personality type, and sex  

Microsoft Academic Search

This study responds to a call for broadened conceptualizations of materialism and its role in self-definition (Richins & Dawson, 1992). Data from 202 spouses were analyzed for relationships among materialism, parenthood status, and personality type, defined as spousal warmness or coolness (Csikszentmihalyi & Rochberg-Halton, 1981). Testable hypotheses were based on the concept of object-subject interchangeability (Claxton & Murray, 1994) as

Reid P. Claxton; Jeff B. Murray; Swinder Janda

1995-01-01

308

Finite Element Investigation of the Deterioration of Doweled Rigid Pavements  

E-print Network

The purpose of this study is to describe the failure of concrete around dowel bars in jointed rigid pavements, and the resulting effect on the pavement performance. In fact, under repetitive vehicle loading, concrete in contact with the dowel bar deteriorates, particularly at the joint face. The degradation of concrete around the dowel negatively affects the latter's performance in terms of transferring wheel loads through vertical shear action. In this context, a nonlinear 3D Finite Element analysis was performed using the commercial FE code Abaqus (v-6.11). The FE model was validated with classical analytical solutions of shear and moment along the dowel. A concrete damaged plasticity model was used for the PCC slab to model the degradation of concrete matrix around the dowels under incremental loading. Results obtained show, among other things, that the degradation of concrete matrix around the dowel was found to initiate at the face of the joint and propagate towards the interior of the dowel. Also, results obtained confirmed the decrease in load transfer capability of the dowels as the PCC matrix deteriorates. The central dowels under the wheel load lost a significant portion of their load-transfer capacity as the PCC matrix around them deteriorated, while dowels farther away from the wheel load became more engaged in load transfer.

Ziad G. Ghauch

2013-06-23

309

Finite Element Investigation of the Deterioration of Doweled Rigid Pavements  

E-print Network

The purpose of this study is to describe the failure of concrete around dowel bars in jointed rigid pavements, and the resulting effect on the pavement performance. In fact, under repetitive vehicle loading, concrete in contact with the dowel bar deteriorates, particularly at the joint face. The degradation of concrete around the dowel negatively affects the latter's performance in terms of transferring wheel loads through vertical shear action. In this context, a nonlinear 3D Finite Element analysis was performed using the commercial FE code Abaqus (v-6.11). The FE model was validated with classical analytical solutions of shear and moment along the dowel. A concrete damaged plasticity model was used for the PCC slab to model the degradation of concrete matrix around the dowels under incremental loading. Results obtained show, among other things, that the degradation of concrete matrix around the dowel was found to initiate at the face of the joint and propagate towards the interior of the dowel. Also, resul...

Ghauch, Ziad G

2011-01-01

310

NEW LOW CONCENTRATION CPC TYPE COLLECTOR WITH CONVECTION CONTROLED BY A HONEYCOMB TIM MATERIAL: A COMPROMISE WITH STAGNATION TEMPERATURE CONTROL AND SURVIVAL OF CHEAP FABRICATION MATERIALS  

Microsoft Academic Search

Stationary non evacuated CPC collectors have the potential to perform close to evacuated tubular collectors at high temperatures, yet they can be manufactured with the simplicity and low cost of good flat plate collectors. However taking full advantage of the concentration factor achievable with CPCs without the use of more expensive materials is a real challenge, as there is always

Manuel Collares Pereira; Maria Joo Carvalho; Joo Correia de Oliveira

311

Effectiveness of low impact development practices in two urbanized watersheds: retrofitting with rain barrel/cistern and porous pavement.  

PubMed

The impacts of urbanization on hydrology and water quality can be minimized with the use of low impact development (LID) practices in urban areas. This study assessed the performance of rain barrel/cistern and porous pavement as retrofitting technologies in two urbanized watersheds of 70 and 40km(2) near Indianapolis, Indiana. Six scenarios consisting of the watershed existing condition, 25% and 50% implementation of rain barrel/cistern and porous pavement, and 25% rain barrel/cistern combined with 25% porous pavement were evaluated using a proposed LID modeling framework and the Long-Term Hydrologic Impact Assessment (L-THIA)-LID model. The model was calibrated for annual runoff from 1991 to 2000, and validated from 2001 to 2010 for the two watersheds. For the calibration period, R(2) and NSE values were greater than 0.60 and 0.50 for annual runoff and streamflow. Baseflow was not calibrated in this study. During the validation period, R(2) and NSE values were greater than 0.50 for runoff and streamflow, and 0.30 for baseflow in the two watersheds. The various application levels of barrel/cistern and porous pavement resulted in 2-12% reduction in runoff and pollutant loads for the two watersheds. Baseflow loads slightly increased with increase in baseflow by more than 1%. However, reduction in runoff led to reduction in total streamflow and associated pollutant loads by 1-9% in the watersheds. The results also indicate that the application of 50% rain barrel/cistern, 50% porous pavement and 25% rain barrel/cistern combined with 25% porous pavement are good retrofitting options in these watersheds. The L-THIA-LID model can be used to inform management and decision-making for implementation of LID practices at the watershed scale. PMID:23474339

Ahiablame, Laurent M; Engel, Bernard A; Chaubey, Indrajeet

2013-04-15

312

Recent advances in the characterization of transportation geo-materials. Geotechnical special publication No. 89  

SciTech Connect

This special publication, sponsored by the Pavements Committee of the Geo-Institute, contains five papers from sessions of the Third National Conference of the Geo-Institute. The goal of the project was to encourage the application of geotechnical fundamentals in pavement design, and help the transfer of new developments in dealing with other earth-supported structures subjected to static, dynamic, and cyclic loads. Papers focus on recent advances in field and laboratory characterization of transportation geo-materials, including the use of various nondestructive testing techniques (falling weight deflecometer, spectral analysis of surface waves, ground penetrating radar, seismic pavement analyzer, Humbold stiffness gauge) and cone penetration testing for field characterization, application of a new Tube Suction test method for characterizing durability of pavement foundation core samples, and laboratory stress path testing of granular materials under dynamic confinement conditions using a new advanced triaxial test device.

Tutumluer, E.; Papagiannakis, A.T. [eds.

1999-07-01

313

Pavement Thickness Design Parameter  

E-print Network

consuming · Several methods available, but design information generally the same · Terminology: #12;Pavement Thickness Design · Good design uses these parameters: ­ Soil characteristics (subgrade) ­ Soil compaction Distribution ­ HMA ­ PCC #12;Pavement Thickness Design · Soil Resilient Modulus MR ­ Property of the soil

314

Rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems in the presence of trees.  

PubMed

The retrofitting of sustainable drainage systems (SuDS) such as permeable pavements is currently undertaken ad hoc using expert experience supported by minimal guidance based predominantly on hard engineering variables. There is a lack of practical decision support tools useful for a rapid assessment of the potential of ecosystem services when retrofitting permeable pavements in urban areas that either feature existing trees or should be planted with trees in the near future. Thus the aim of this paper is to develop an innovative rapid decision support tool based on novel ecosystem service variables for retrofitting of permeable pavement systems close to trees. This unique tool proposes the retrofitting of permeable pavements that obtained the highest ecosystem service score for a specific urban site enhanced by the presence of trees. This approach is based on a novel ecosystem service philosophy adapted to permeable pavements rather than on traditional engineering judgement associated with variables based on quick community and environment assessments. For an example case study area such as Greater Manchester, which was dominated by Sycamore and Common Lime, a comparison with the traditional approach of determining community and environment variables indicates that permeable pavements are generally a preferred SuDS option. Permeable pavements combined with urban trees received relatively high scores, because of their great potential impact in terms of water and air quality improvement, and flood control, respectively. The outcomes of this paper are likely to lead to more combined permeable pavement and tree systems in the urban landscape, which are beneficial for humans and the environment. PMID:23697848

Scholz, Miklas; Uzomah, Vincent C

2013-08-01

315

Desert pavements and associated rock varnish in the Mojave Desert: How old can they be?  

NASA Astrophysics Data System (ADS)

Desert pavements are common features of arid landscapes and have been widely used as a relative age indicator of the geomorphic surfaces upon which they are developed. In this study I examined the patterns of pavement development as a function of elevation in the Mojave Desert as well as the causes for the gradual disappearance of pavement at high elevations. Pavement density, as measured by percentage of pebble coverage, decreases systematically with elevation gain by 3% per 100 m, from 95% coverage below 500 m to less than 60% at 1700 m. Plants appear to be the main agent of pavement disruption; plant density decreases as pavement density increases. Burrowing by rodents and crusting by cryptobiota also disrupt pavement development at higher elevation. During the last glacial maximum, plant communities were displaced 1000 1400 m downward in the Mojave Desert. Pavements today generally do not survive above the blackbush (Coleogyne ramossisma)-sagebrush (Artemisia tridentata) zone. Evidence from packrat middens shows that these and other plants typical of high elevations today grew as low as 300 400 m during the last glacial maximum. I suggest that during the last glacial maximum, desert pavements were confined to the lowest alluvial fans of Death Valley and adjoining low valleys. No alluvial desert pavements above 400 m in the region are older than the latest Pleistocene. By the same reasoning, desert varnish on desert pavements above 400 m may all be Holocene in age, except where developed on stable boulders.

Quade, Jay

2001-09-01

316

Use of recycled materials in highway construction. Final report  

SciTech Connect

The major objectives of this study were to examine: (1) the types of recycled materials that are appropriate and feasible as alternative paving materials, such as glass and tires; and (2) the types of recycled materials, such as mixed-plastics and compost, that can be utilized in all types of transportation applications other than pavements. Seven key products are investigated: (1) tires, (2) glass, (3) asphalt concrete, (4) fly ash, (5) compost, (6) mixed plastics, and (7) aluminum sign stock. Performance and cost data for rubber-asphalt pavements is documented for both in-state and nationwide applications. The national experience with the use of waste glass as an additive to asphalt concrete and its use in unbound base materials is also highlighted. Programs for experimental use of recycled materials are outlined. Recommendations for staffing and program changes to deal with recycling issues are also discussed.

Swearingen, D.L.; Jackson, N.C.; Anderson, K.W.

1992-02-01

317

Pavement macrotexture estimation using principal component analysis of tire/road noise  

NASA Astrophysics Data System (ADS)

An investigation on the prediction of macrotexture Mean Texture Depth (MTD) of pavement from a moving vehicle is conducted. The MTD was predicted by using the tire/road noise measured from a microphone mounted underneath a moving vehicle. Principal Component Analysis (PCA) is used to filter noise from microphone data prioer to estimating its energy over an optimally selected bandwidth. Energy obtained using this method is named PCA energy, hence the developed method for MTD estimation is termed as PCA Energy Method. The acoustic energy is assumed to have positive linear correlation with MTD of pavement. Moreover, PCA was used to differentiate important information about the road surface from noisy data while vehicle is moving, yielding a set of principal component vectors representing the conditions of each road section. This principal component vector was used to compute the PCA energy that is to be used for MTD prediction. The frequency band most relative to pavement macrotexture was determined to be 140 to 700 Hz through theoretical and statistical research. Then, a MTD prediction model was built based on a Taylor series expansion with two variables, PCA energy and the driving speed of the vehicle. The model parameters were obtained from an engineered track (interstate highway) with known MTD, and then applied to urban roads for the feasibility test. The accuracy of the model is 83.61% for the engineered track, which is 10% higher than the previous energy-based methods without PCA treatment. Moreover, applicability of the model is increased by the extended MTD prediction range between 0.2 and 3 mm compared to that of the engineered track having 0.4 to 1.5 mm. In addition, the MTD could be predicted every 7.8 meters and with good repeatability in the urban road test, which proves the feasibility of the proposed approach. Therefore, the PCA Energy Method is a reliable, efficient, and cost effective way to predict MTD for engineering applications as an important index for pavement friction prediction and pavement segregation identification.

Zhang, Yiying; McDaniel, J. Gregory; Wang, Ming L.

2014-04-01

318

The effect of carbonation after demolition on the life cycle assessment of pavements  

E-print Network

The high contribution of CO? emissions associated with pavements has driven research to assess the life cycle of concrete versus asphalt structures and to develop a strategy to reduce the carbon footprint. The life cycle ...

Rossick, Katelyn M

2014-01-01

319

Automated crack control analysis for concrete pavement construction  

E-print Network

probabilistic approach to determine the optimum time and depth of sawcutting for newly constructed portland cement concrete pavements. Variability in climate conditions and material characteristics during the hardening process affects the potential of cracking...

Jang, Se Hoon

2005-11-01

320

Performance of concrete pavements containing recycled concrete aggregate. Interim report, October 1993-October 1996  

SciTech Connect

This interim report documents the field performance of nine concrete pavement projects that incorporate recycled concrete aggregate (RCA) in the construction of the pavement. Multiple sections were evaluated on many of the nine projects, due to perceived differences in performance levels or variations in pavement design (such as the use of virgin aggregate or the inclusion of dowel bars). All told, a total of 17 sections (of which 12 contain RCA) were subjected to an extensive field testing program, consisting of pavement condition surveys, drainage surveys, falling weight deflectometer (FWD) testing, coring, and serviceability assessments. A minimum of eight cores were retrieved from each section for laboratory evaluation of compressive strength, split tensile strength, dynamic elastic modulus, static elastic modulus, and thermal coefficient of expansion, as well as for volumetric surface testing and petrographic analyses.

Wade, M.J.; Cuttell, G.D.; Vandenbossche, J.M.; Yu, H.T.; Smith, K.D.

1997-03-01

321

Reactor Material Program Fracture Toughness of Type 304 Stainless Steel  

SciTech Connect

This report describes the experimental procedure for Type 304 Stainless Steel fracture toughness measurements and the application of results. Typical toughness values are given based on the completed test program for the Reactor Materials Program (RMP). Test specimen size effects and limitations of the applicability in the fracture mechanics methodology are outlined as well as a brief discussion on irradiation effects.

Awadalla, N.G.

2001-03-28

322

Validation and development of guidelines to select MRR strategies for rigid pavements  

E-print Network

Maintenance, rehabilitation and reconstruction (MRR) work to rigid pavement roadways requires a great demand of time, effort, and money. The nature of this work not only affects state highway agencies (SHAs) but also, roadway users and local...

Herrera, Edgar Efren

2001-01-01

323

Surface runoff from full-scale coal combustion product pavements during accelerated loading  

SciTech Connect

In this study, the release of metals and metalloids from full-scale portland cement concrete pavements containing coal combustion products (CCPs) was evaluated by laboratory leaching tests and accelerated loading of full-scale pavement sections under well-controlled conditions. An equivalent of 20 years of highway traffic loading was simulated at the OSU/OU Accelerated Pavement Load Facility (APLF). Three types of portland cement concrete driving surface layers were tested, including a control section (i.e., ordinary portland cement (PC) concrete) containing no fly ash and two sections in which fly ash was substituted for a fraction of the cement; i.e., 30% fly ash (FA30) and 50% fly ash (FA50). In general, the concentrations of minor and trace elements were higher in the toxicity characteristic leaching procedure (TCLP) leachates than in the leachates obtained from synthetic precipitation leaching procedure and ASTM leaching procedures. Importantly, none of the leachate concentrations exceeded the TCLP limits or primary drinking water standards. Surface runoff monitoring results showed the highest release rates of inorganic elements from the FA50 concrete pavement, whereas there were little differences in release rates between PC and FA30 concretes. The release of elements generally decreased with increasing pavement loading. Except for Cr, elements were released as particulates (>0.45 {mu} m) rather than dissolved constituents. The incorporation of fly ash in the PC cement concrete pavements examined in this study resulted in little or no deleterious environmental impact from the leaching of inorganic elements over the lifetime of the pavement system.

Cheng, C.M.; Taerakul, P.; Tu, W.; Zand, B.; Butalia, T.; Wolfe, W.; Walker, H. [Western Kentucky University, Bowling Green, KY (United States)

2008-08-15

324

Performance of a movable flexible pipe-encapsulated FBG sensor developed for shape monitoring of multi-layered pavement structure  

NASA Astrophysics Data System (ADS)

The large span and heterogeneous components of multi-layered pavement structure usually bring about stochastic damage, and many modern approaches, such as ground penetrating radar, integral imaging and optical fiber sensing technology, have been employed to detect the degeneration mechanism. Restricted by the cost and universality, novel elements for pavement monitoring are in high demand. Optical fiber sensing technology for high sensitivity, long stability, anti-corrosion and resistance to water erosion then is considered. Therefore, a movable FBG sensor located in flexible pipe is developed, which has long stroke inside inner wall of the hollow pipe, and a full-scale shape of the structure could be sketched just with one FBG. Theoretical and experimental methods about establishing the relationship between wavelength variable and curvature have been provided, and function about reconfiguring the coordinate is converted to a mathematic question. Move over, transfer error modification has been taken into account for modify related error. Multi-layered pavement model embedded with this sensor will be accomplished to inspect its performance in later work. The work in the paper affords a feasible method for shape monitoring and would be potentially valuable for the maintenance and inverse design of pavement structure.

Wang, Huaping; Liu, Wanqiu; Zhou, Zhi

2014-03-01

325

An integrated life cycle assessment and life cycle analysis model for pavement overlay systems  

Microsoft Academic Search

Pavement systems have significant impacts on the environment and economy due to large material consumption, energy input, and capital investment. To evaluate the sustainability of rigid pavement overlay designs, an integrated life cycle assessment and life cycle cost analysis model was developed to calculate the environmental impacts and costs of overlay systems resulting from material production and distribution, overlay construction

H. Zhang; G. A. Keoleian; M. D. Lepech

326

Fracture behavior of geosynthetic interlayers in road pavements  

SciTech Connect

For different overlay systems currently used in practice (PGM 14, PGM-G, and TENSAR grid) the fracture behavior of the interface between interlayer and asphalt overlay as well as of the entire system is characterized and analyzed. A simple and easy-to-use wedge splitting test according to Tschegg is carried out in order to evaluate both the interface and reflective cracking behavior. The specimens used in this test consist of modified cores taken from road pavements. This investigation demonstrates that the overlay systems show considerable variation in their fracture mechanism parameters (such as resistance to crack propagation of the interface or propagation of reflection cracks), but only minor differences with regard to the other properties (such as bonding tensile strength of the interlayer compound system or the notch tensile strength of the reflective crack). The effectiveness of the interlayer system is diminished when the resistance against crack propagation in the interface is reduced.

Tschegg, E.K.; Ehart, R.J.A. [Technical Univ., Vienna (Austria). Inst. of Applied and Technical Physics; Ingruber, M.M. [Univ. of Agriculture, Vienna (Austria). Inst. of Meteorology and Physics

1998-09-01

327

A method for assessing the physical recovery of Antarctic desert pavements following human-induced disturbances: a case study in the Ross Sea region of Antarctica.  

PubMed

With increasing visitor numbers an understanding of the impacts of human activities in Antarctic terrestrial environments has become important. The objective of this study was to develop a means for assessing recovery of the ground surface desert pavement following physical disturbance. A set of 11 criteria were identified to assess desert pavement recovery. Assessed criteria were: embeddedness of surface clasts; impressions of removed clasts; degree of clast surface weathering; % overturned clasts; salt on underside of clasts; development of salt coatings; armouring per m(2); colour contrast; evidence of subsidence/melt out; accumulation of salt on cut surfaces; and evidence of patterned ground development. Recovery criteria were assigned a severity/extent rating on a scale from zero to four, zero being highly disturbed, and four being undisturbed. A relative % recovery for each criteria was calculated for each site by comparison with a nearby undisturbed control area, and an overall Mean Recovery Index (MRI) was assigned to each pavement surface. To test the method, 54 sites in the Ross Sea region of Antarctica were investigated including areas disturbed by: bulldozer scraping for road-fill, contouring for infrastructure, geotechnical investigations, and experimental treading trial sites. Disturbances had occurred at timescales ranging from one week to 50 years prior to assessment. The extent of desert pavement recovery at the sites investigated in this study was higher than anticipated. Fifty of the 54 sites investigated were in an intermediate, or higher, stage of desert pavement recovery, 30 sites were in an advanced stage of recovery, and four sites were indistinguishable from adjacent control sites (MRI = 100%). It was found that active surfaces, such as the gravel beach deposits at the Greenpeace World Park Base site at Cape Evans, the aeolian sand deposits at Bull Pass, and the alluvial fan deposits of the Loop Moraine field campsite, recovered relatively quickly, whereas less active sites, such as the bulldozed tracks at Marble Point, and Williams Field to McMurdo Station pipeline site on Ross Island, showed only intermediate recovery 20-30 years after disturbance. The slabby grano-diorite surface material at the former Vanda Station site, meant that the impacts that had occurred were hard to detect following decommissioning of the station and site remediation. Desert pavements disturbed by randomly dispersed footprints, temporary field campsites at the Loop Moraine and VXE6 Pond in the Wright Valley, recovered to be undetectable (MRI = 100%) within five years, whereas track formation from repeated trampling, particularly the concentration of larger clasts along the margin of a confined track, persisted for over 15 years (MRI = 82%). The recovery assessment method developed in this study has environmental management applications and potential to advance our ability to predict the recovery of desert pavement following human impacts from activities in Antarctica. PMID:23000478

O'Neill, Tanya A; Balks, Megan R; Lpez-Martnez, Jernimo; McWhirter, Judi L

2012-12-15

328

Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement.  

PubMed

Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5h to 111d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35?g/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-hcuring time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement. PMID:24556229

Mahler, Barbara J; Van Metre, Peter C; Foreman, William T

2014-05-01

329

Concentrations of polycyclic aromatic hydrocarbons (PAHs) and azaarenes in runoff from coal-tar- and asphalt-sealcoated pavement  

USGS Publications Warehouse

Coal-tar-based sealcoat, used extensively on parking lots and driveways in North America, is a potent source of PAHs. We investigated how concentrations and assemblages of PAHs and azaarenes in runoff from pavement newly sealed with coal-tar-based (CT) or asphalt-based (AS) sealcoat changed over time. Samples of simulated runoff were collected from pavement 5 h to 111 d following application of AS or CT sealcoat. Concentrations of the sum of 16 PAHs (median concentrations of 328 and 35 ?g/L for CT and AS runoff, respectively) in runoff varied relatively little, but rapid decreases in concentrations of azaarenes and low molecular weight PAHs were offset by increases in high molecular weight PAHs. The results demonstrate that runoff from CT-sealcoated pavement, in particular, continues to contain elevated concentrations of PAHs long after a 24-h curing time, with implications for the fate, transport, and ecotoxicological effects of contaminants in runoff from CT-sealcoated pavement.

Mahler, Barbara J.; Van Metre, Peter C.; Foreman, William T.

2014-01-01

330

Relating tensile, bending, and shear test data of asphalt binders to pavement performance  

SciTech Connect

Eight different asphalt binders representing a wide range of applications for pavement construction were tested in uniaxial tension, bending, and shear stresses. Theoretical analyses were performed in this study to covert the data from the three engineering tests to stiffness moduli for predicting pavement performance. At low temperatures, high asphalt stiffness may induce pavement thermal cracking; thus, the allowable maximum stiffness was set at 1,000 MPa. At high temperatures, low asphalt stiffness may lead to pavement rutting (ruts in the road); master curves were constructed to rank the potential for rutting in the asphalts. All three viscoelastic functions were shown to be interchangeable within the linear viscoelastic region. When subjected to large deformation in the direct tension test, asphalt binders behaved nonlinear viscoelastic in which the data under bending, shear and tension modes were not comparable. The asphalts were, however, found toe exhibit linear viscoelasticity up to the failure point in the steady-state strain region.

Chen, J.S.; Tsai, C.J. [National Cheng-Kung Univ., Tainan (Taiwan, Province of China). Dept. of Civil Engineering] [National Cheng-Kung Univ., Tainan (Taiwan, Province of China). Dept. of Civil Engineering

1998-12-01

331

Waxing and waning of dreissenid pavements as a possible result of astronomical forcing  

NASA Astrophysics Data System (ADS)

Human induced range expansions of invasive dreissenid bivalves are of great concern. However, the underlying biological processes are only poorly understood, partly due to the lack of information on natural expansion events. Here we use the extinct bivalve species Sinucongeria primiformis as a model organism for testing natural (i.e. pre-Anthropocene) blooms of dreissenid species in a lacustrine system of Lake Pannon during the Tortonian (~10.5 Myr; Late Miocene). 600 samples from a consecutive core were evaluated for the relative abundance of this pavement-forming mollusc, which cover about 8 millennia of Late Miocene time with a decadal resolution. The formation of these pavements occurred in repetitive cycles, which were also documented for carious other geophysical and geochemical and biotic proxies. The investigated bivalve was among the most successful species settling in offshore environments of Lake Pannon, where it formed vast pavements. The tolerance for poorly oxygenated lake bottoms close to the epilimnion/hypolimnion boundary was probably the key adaptation to outcompete other species in this lacustrine offshore environment. We document that solar forcing might have played an important role for lake hydrology, which in turn allowed population blooms during phases of improved ecological conditions. The repeated establishment of dysoxic conditions was lethal for the populations and is reflected by pyrite incrustations in the shell cavities. The cyclicities might be expressions of the Gleissberg cycles and the 500 yr cycle, indicating that bottom water oxygenation was strongly influenced by these solar cycles. This example shows that dreissenid bivalves may be pioneers, which quickly dominate aquatic ecosystems even in pre-Anthropocene records. The surprisingly strong influence of solar forcing on the success of the Miocene dreissenids is an overlooked aspect for predicting the population dynamics of extant dreissenids. This study was supported by the Austrian Science Fund (FWF grants P21414-B16 and P25365-B25).

Harzhauser, Mathias; Mandic, Oleg; Kern, Andrea K.; Piller, Werner E.; Neubauer, Thomas A.; Albrecht, Christian; Wilke, Tom

2014-05-01

332

Different types of radiation can be shielded by different materials Space Math http://spacemath.gsfc.nasa.gov  

E-print Network

Rem. Most low- intensity forms of 'EM' radiation can be shielded by using clothing or skin creams. In high dosages, X-rays and gamma-rays require shielding to reduce their health effects, otherwise of the differences in Q, different forms of radiation produce different levels of tissue damage. Beyond this

333

Incestuous paternity detected by STR-typing of chorionic villi isolated from archival formalin-fixed paraffin-embedded abortion material using laser microdissection.  

PubMed

Microscopic examination of a blood clot expelled by a physically and mentally disabled woman taken to the emergency room because of genital bleeding revealed the presence of chorionic villi encircled by decidua, hemorrhage, and necrosis. In order to identify the father of the product of conception, sections of formalin-fixed, paraffin-embedded abortion material were subjected to laser microdissection: DNA extraction from chorionic villi selectively isolated from the surrounding tissues allowed successful STR-typing of fetal cells, which was otherwise prevented by excess maternal DNA. The large number of homozygous genotypes in the fetal profile suggested incestuous paternity. Analysis of reference DNA samples from male relatives excluded the woman's father, paternal grandfather, and maternal grandfather, whereas the obligate paternal alleles of the fetus were constantly present in the genotypes of the woman's brother, clearly demonstrating brother-sister incest (probability of paternity > 99.99999%). PMID:16423229

Robino, Carlo; Barilaro, Maria Rosa; Gino, Sarah; Chiarle, Roberto; Palestro, Giorgio; Torre, Carlo

2006-01-01

334

Road-runoff metal concentrations in Toledo, Ohio, and their relation to average daily traffic and age of pavement overlay.  

PubMed

Road runoff can contain metal concentrations and sampling of it can be expensive if auto-samplers are used. In this study, an inexpensive storm water sampling apparatus was developed and used for collecting the road runoff at eleven different sites in Toledo area. Sites were selected with the purpose of evaluating the effects of average daily traffic (ADT) and the age of pavement overlay on road runoff metal concentrations. Ag, As, Cd, and Mo concentrations were primarily below detection limit. Ba, Mn, Ni, Cu, Pb, and Zn were observed in higher concentrations but lower than <800 mug/L. Mg, Al, Fe, K, Na, and Ca were observed in mg/L levels, much higher concentrations. ADT was positively correlated with runoff concentrations of K, Mn, Pb and Zn. The source of Ca, Mg, and Mn appeared to be the asphalt pavement surface; with time, as the pavement aged, these sources appeared to be depleted as observed by lower runoff concentrations in older pavements. PMID:20371930

Apul, D S; Miller, E; Jain, V

2010-01-01

335

Laboratory analysis of the infiltration capacity of interlocking concrete block pavements in car parks.  

PubMed

Interlocking concrete block pavements (ICBPs) have been widely used in car parks to reduce runoff. Researches have demonstrated that clogging is the most influential factor in the reduction of the infiltration capacity of this type of permeable pavement. Nevertheless, there is no laboratory study of the infiltration performance of ICBPs that combines clogging levels with variables related with the topography of car parks such as runoff surface length (R(SL)) and surface slope (S(S)). This paper studies the infiltration behaviour of ICBP during their operational life in a car park using an improved version of the Cantabrian Fixed (CF) Infiltrometer. This laboratory device simulates direct rainfall and runoff from adjacent impervious areas over an ICBPs surface of 0.25 m(2) for different slopes (0, 3, 5, 7 and 10%) and three scenarios of clogging (surface newly built, surface clogged and surface clogged with maintenance). This paper presents the results of the tests and a statistical analysis based on three regression models (corresponding to each clogging scenario) depending on the R(SL) and S(S) variables. All models passed a confidence level of 95%, presenting high R(2) values and showing that R(SL) is a more influential variable than the S(S) for all clogging scenarios. PMID:23202575

Saudo-Fontaneda, Luis A; Rodriguez-Hernandez, Jorge; Vega-Zamanillo, Angel; Castro-Fresno, Daniel

2013-01-01

336

Combined Effect of Moving Wheel Loading and Three-Dimensional Contact Stresses on Perpetual Pavement Responses  

Microsoft Academic Search

Tirepavement interaction was analyzed with measured three-dimensional (3-D) tire contact stresses at various load levels (35, 44, and 53 kN) and constant tire pressure (720 kPa). The combined effect of moving wheel load and 3-D contact stresses on flexible pavement response was evaluated with a developed 3-D finite element (FE) model, which incorporated the measured 3-D tire contact stresses, hot-mix

Hao Wang; Imad L. Al-Qadi

2009-01-01

337

Consolidation of continuously reinforced concrete pavements  

E-print Network

to determine the effects of coarse aggregate factor, maximum aggregate size, vibrator spacing, and the method of vibrator mounting on the achieved consolidation of C R C P were performed. Also studied were variations in consolidation throughout the depth...-l/2 in. , and a maximum vibrator spacing of 24 in. should be specified when slip-form paving C R C P. M ounting vibrators perpendicular to the direction of travel was not found to be as effective as a parallel mounting method. The slabs were found...

Winn, Dan Parker

2012-06-07

338

A test of porous pavement effectiveness on clay soils during natural storm events.  

PubMed

Porous pavements allow precipitation to infiltrate through the pavement to the soil, reducing the volume of stormwater runoff produced at a site. However, porous pavements are not widely used on fine-grained soils due to concerns about their performance. Our objective was to investigate the efficacy of porous pavements in controlling stormwater runoff on clay soils. We compared the performance of an asphalt parking lot and a porous pavement parking lot of grass pavers in Athens, Georgia, USA, over relatively small and low-intensity rain events. The porous lot produced 93% less runoff than the asphalt lot. The total volume of runoff at the porous lot was significantly less than the asphalt lot (t = 2.96, p = 0.009). Turbidity was significantly greater at the asphalt lot (t = 6.18, p < 0.001) whereas conductivity was significantly higher at the porous lot (t = 2.31, p = 0.03). Metal and nutrient concentrations were below detection limits at both lots during seven of nine small storm events. During events in which we could detect pollutants, calcium, zinc, silica, and total phosphorus concentrations were higher at the asphalt lot whereas total nitrogen concentrations were greater at the porous lot. Our results suggest porous pavements are a viable option for reducing stormwater runoff and some pollutants from small storms or the first flush from large storms on clay soils. PMID:16426659

Dreelin, Erin A; Fowler, Laurie; Ronald Carroll, C

2006-02-01

339

Asphalt pavement surfaces and asphalt mixtures. Transportation research record  

SciTech Connect

The papers in this volume, which deal with asphalt pavement surfaces and asphalt mixtures, should be of interest to state and local construction, design, materials, and research engineers as well as contractors and material producers. The papers in Part 1 include discussions of pavement smoothness specifications and skidding characteristics. The first four papers in Part 2 were submitted in response to a call for papers for a session at the 75th Annual Meeting of the Transportation Research Board on low-temperature properties of hot-mix asphalt. The next eight are on the influence of volumetric and strength properties on the performance of hot-mix asphalt. In the following three papers, the topics covered are the complex modulus of asphalt concrete, cold in-place asphalt recycling, and polymer modification of asphalt pavements in Ontario. The last two papers were presented in a session on relationship of materials characterization to accelerated pavement performance testing.

NONE

1996-12-31

340

Complex Modulus Prediction of Asphalt Concrete Pavement Cores  

E-print Network

. For field cores complex modulus measuring methods, except some expensive pavement field testers, empirical and semiempirical models are widely used, but an accurate mechanical test method is more desired. In this research, Arizona, Yellowstone National Park...

Ling, Meng

2013-12-02

341

Use of stabilized bottom ash for bound layers of road pavements.  

PubMed

This paper reports about the lab scale results obtained by using stabilized bottom ash (SBA) from an Italian municipal solid waste incinerator as aggregates in cement-bound mixes and asphalt concretes for road pavements. The investigation focused on SBA content. From the road construction point of view, performance related to compaction, volumetric and mechanical properties were assessed. The environmental aspects were investigated performing leaching tests. The results suggested that SBA satisfied the environmental Italian law for reuse of non-hazardous waste but affected significantly the stress-strain behavior of the final products. Therefore a maximum percentage of 10% was suggested. PMID:23535513

Toraldo, Emanuele; Saponaro, Sabrina; Careghini, Alessandro; Mariani, Edoardo

2013-05-30

342

Wearability of Portland Cement Concrete Pavement Finishes  

E-print Network

Affecting Skid Resistance. . 2. 3. 1 Surface Texture. 2. 3. 2 Surface Temperature 2. 3. 3 Aggregate Properties 2. 3. 4 Other Factors. 11 13 15 17 2. 4 Nethods of Improving and Restoring Surface Texture. 18 2. 4. 1 Surface Treatments 2. 4. 2... 4. 3. 4. 6 Test Set 5 3. 4. 7 Test Set 6. 39 41 42 42 43 43 44 3. 5 Testing Methods and Procedures. . IV RESULTS AND DISCUSSION. 44 46 4. 1 Results 46 4. 1. 1 General. 4. 1. 2 Control Tests. 4. 1. 3 ATD and BPN Relationships. . . 46...

McKeen, William Rew

1971-01-01

343

Experimental Study on Geocell-Reinforced Flexible Pavements with Recycled Asphalt Pavement (RAP) Bases under Cyclic Loading  

E-print Network

, it is estimated that U. S. production of asphalt pavement materials is around 500 million tons per years, including about 60 million tons of RAP - which transportation agencies reuse or recycle directly into pavements. In addition, agencies reuse or recycle... efforts to recover and reuse old asphalt paving materials in road construction were made in Nevada and Texas in 1974. RAP has been mostly used in hot or cold mix asphalt with virgin asphalt binder and aggregate. In addition, RAP has been used...

Acharya, Bhagaban

2011-12-31

344

Thermal conductance of and heat generation in tire-pavement interface and effect on aircraft braking  

NASA Technical Reports Server (NTRS)

A finite-difference analysis was performed on temperature records obtained from a free rolling automotive tire and from pavement surface. A high thermal contact conductance between tire and asphalt was found on a statistical basis. Average slip due to squirming between tire and asphalt was about 1.5 mm. Consequent friction heat was estimated as 64 percent of total power absorbed by bias-ply, belted tire. Extrapolation of results to aircraft tire indicates potential braking improvement by even moderate increase of heat absorbing capacity of runway surface.

Miller, C. D.

1976-01-01

345

On-site infiltration of road runoff using pervious pavements with subjacent infiltration trenches as source control strategy.  

PubMed

The focus in this work was on subsoil infiltration of stormwater from parking lots. With regard to operation, reduced infiltration performance due to clogging and pollutants in seepage, which may contribute to contaminate groundwater, are of interest. The experimental investigation covered a pervious pavement with a subjacent infiltration trench draining an impervious area of 2 ha. In order to consider seasonal effects on the infiltration performance, the hydraulic conductivity was measured tri-monthly during monitoring with a mobile sprinkling unit. To assess natural deposits jointing, road bed, gravel of infiltration trenches and subsoil were analysed prior to commencement of monitoring for heavy metals, polycyclic aromatic and mineral oil type hydrocarbons. Furthermore, from 22 storm events, water samples of rainfall, surface runoff, seepage and ground water were analysed with regard to the above mentioned pollutants. The study showed that the material used for the joints had a major impact on the initial as well as the final infiltration rates. Due to its poor hydraulic conductivity, limestone gravel should not be used as jointing. Furthermore, it is recommended that materials for the infiltration facilities are ensured free of any contaminants prior to construction. Polycyclic aromatic and mineral oil type hydrocarbons were, with the exception of surface runoff, below detection limits. Heavy metal concentrations of groundwater were with the exception of lead (because of high background concentrations), below the permissible limits. PMID:22179634

Fach, S; Dierkes, C

2011-01-01

346

Fusing complementary images for pavement cracking measurements  

NASA Astrophysics Data System (ADS)

Cracking is a major pavement distress that jeopardizes road serviceability and traffic safety. Automated pavement distress survey (APDS) systems have been developed using digital imaging technology to replace human surveys for more timely and accurate inspections. Most APDS systems require special lighting devices to illuminate pavements and prevent shadows of roadside objects that distort cracks in the image. Most artificial lighting devices are laser based, and are either hazardous to unprotected people or require dedicated power supplies on the vehicle. This study was aimed to develop a new imaging system that can scan pavement surface at highway speed and determine the level of severity of pavement cracking without using any artificial lighting. The new system consists of dual line-scan cameras that are installed side by side to scan the same pavement area as the vehicle moves. Cameras are controlled with different exposure settings so that both sunlit and shadowed areas can be visible in two separate images. The paired images contain complementary details useful for reconstructing an image in which the shadows are eliminated. This paper intends to present (1) the design of the dual line-scan camera system, (2) a new calibration method for line-scan cameras to rectify and register paired images, (3) a customized image-fusion algorithm that merges the multi-exposure images into one shadow-free image for crack detection, and (4) the results of the field tests on a selected road over a long period.

Yao, Ming; Zhao, Zuyun; Yao, Xun; Xu, Bugao

2015-02-01

347

Types and Distribution of Bright Materials in 4 Vesta  

NASA Technical Reports Server (NTRS)

A strong case can be made that Vesta is the parent asteroid of the howardite, eucrite and diogenite (HED) meteorites [1]. As such, we have over a century of detailed sample analysis experience to call upon when formulating hypotheses regarding plausible lithologic diversity on Vesta. It thus came as a surprise when Dawn s Framing Camera (FC) first revealed distinctly localized materials of exceptionally low and high albedos, often closely associated. To understand the nature and origin of these materials, and how they inform us of the geological evolution of Vesta, task forces began their study. An initial step of the scientific endeavor is to develop a descriptive, non-genetic classification of objects to use as a basis for developing hypotheses and observational campaigns. Here we present a catalog of the types of light-toned deposits and their distribution across Vesta. A companion abstract [2] discusses possible origins of bright materials and the constraints they suggest for vestan geology.

Mittlefehldt, D. W.; Li, Jian-Yang; Pieters, C. M.; De Sanctis, M. C.; Schroder, S. E.; Hiesinger, H.; Blewett, D. T.; Russell, C. T.; Raymond, C. A.; Yingst, R. A.

2012-01-01

348

Biological threats can frequently be controlled by screening materials and by following the procedures listed below.Emergency response agencies have plans in place to deal with these types of threats.  

E-print Network

Biological threats can frequently be controlled by screening materials and by following the procedures listed below.Emergency response agencies have plans in place to deal with these types of threats Biological Threats Received by Mail For questions, contact School of Medicine Health & Safety at 3-0110 #12;

Ford, James

349

THERMAL UPGRADING OF 9977 RADIOACTIVE MATERIAL (RAM) TYPE B PACKAGE  

SciTech Connect

The 9977 package is a radioactive material package that was originally certified to ship Heat Sources and RTG contents up to 19 watts and it is now being reviewed to significantly expand its contents in support of additional DOE missions. Thermal upgrading will be accomplished by employing stacked 3013 containers, a 3013 aluminum spacer and an external aluminum sleeve for enhanced heat transfer. The 7th Addendum to the original 9977 package Safety Basis Report describing these modifications is under review for the DOE certification. The analyses described in this paper show that this well-designed and conservatively analyzed package can be upgraded to carry contents with decay heat up to 38 watts with some simple design modifications. The Model 9977 package has been designed as a replacement for the Department of Transportation (DOT) Fissile Specification 6M package. The 9977 package is a very versatile Type B package which is certified to transport and store a wide spectrum of radioactive materials. The package was analyzed quite conservatively to increase its usefulness and store different payload configurations. Its versatility is evident from several daughter packages such as the 9978 and H1700, and several addendums where the payloads have been modified to suit the Shipper's needs without additional testing.

Gupta, N.; Abramczyk, G.

2012-03-26

350

Pavement recycling guidelines for state and local governments: Participant`s reference book. Final report, September 1995--December 1997  

SciTech Connect

Recycling or reuse of existing asphalt pavement materials to produce new pavement materials has the following advantages: (1) reduced costs of construction, (2) conservation of aggregate and binder, (3) preservation of the existing pavement geometrics, (4) preservation of the environment, and (5) conservation of energy. This document was prepared to provide the following information on recycling of asphalt pavements: (1) performance data, (2) legislation/specification limits, (3) selection of pavement for recycling and recycling strategies, (4) economics of recycling, and (5) structural design of recycled pavements. The following recycling methods have been included: hot-mix asphalt recycling (both batch and drum plants), asphalt surface recycling, hot-in-place recycling, cold-mix asphalt recycling, and full depth reclamation. Materials and mix design, construction methods and equipment, case histories and quality control/quality assurance have been discussed for all recycling methods.

Kandhal, P.S.; Mallick, R.B.

1997-12-01

351

PAH volatilization following application of coal-tar-based pavement sealant  

USGS Publications Warehouse

Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, have recently been identified as a source of volatile PAHs to the atmosphere. We tracked the volatilization of PAHs for 1 year after application of a coal-tar-based pavement sealant by measuring gas-phase PAH concentrations above the pavement surface and solid-phase PAH concentrations in sealant scraped from the surface. Gas-phase concentrations at two heights (0.03 and 1.28 m) and wind speed were used to estimate volatilization flux. The sum of the concentrations of eight frequently detected PAHs (?PAH8) in the 0.03-m sample 1.6 h after application (297,000 ng m-3) was about 5000 times greater than that previously reported for the same height above unsealed parking lots (66 ng m-3). Flux at 1.6 h after application was estimated at 45,000 ?g m-2 h-1 and decreased rapidly during the 45 days after application to 160 ?g m-2 h-1. Loss of PAHs from the adhered sealant also was rapid, with about a 50% decrease in solid-phase ?PAH8 concentration over the 45 days after application. There was general agreement, given the uncertainties, in the estimated mass of ?PAH8 lost to the atmosphere on the basis of air sampling (23 g m-2) and adhered sealant sampling (6 g m-2) during the first 16 days after application, translating to a loss to the atmosphere of one-quarter to one-half of the PAHs in the sealcoat product. Combining the estimated mass of ?PAH8 released to the atmosphere with a national-use estimate of coal-tar-based sealant suggests that PAH emissions from new coal-tar-based sealcoat applications each year (~1000 Mg) are larger than annual vehicle emissions of PAHs for the United States.

Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

2012-01-01

352

The status of the type material of Pycnostigmus rostratus Cameron (Hymenoptera, Figitidae, Pycnostigminae)  

Technology Transfer Automated Retrieval System (TEKTRAN)

A recent paper by Buffington and van Noort (2007) revising world Pycnostigminae prompted a more detailed investigation of the type material of Pycnostigmus rostratus Cameron, in order to clarify which specimens are actually types and their type status. Cameron described P. rostratus in 1905 basing ...

353

A COMPARISON OF TWO THERMAL INSULATION AND STRUCTURAL MATERIALS; FOR USE IN TYPE B PACKAGINGS  

Microsoft Academic Search

This paper presents the summary of design features and test results of two Type B Shipping Package prototype configurations comprising different insulating materials developed by the Savannah River National Laboratory (SRNL) for the Department of Energy. The materials evaluated, a closed-cell polyurethane foam and a vacuformed ceramic fiber material, were selected to provide adequate structural protection to the package containment

P. Blanton; K. Eberl

2010-01-01

354

Properties of Extruded PS-212 Type Self-Lubricating Materials  

NASA Technical Reports Server (NTRS)

Research has been underway at the NASA Lewis Research Center since the 1960's to develop high temperature, self-lubricating materials. The bulk of the research has been done in-house by a team of researchers from the Materials Division. A series of self-lubricating solid material systems has been developed over the years. One of the most promising is the composite material system referred to as PS-212 or PM-212. This material is a powder metallurgy product composed of metal bonded chromium carbide and two solid lubricating materials known to be self-lubricating over a wide temperature range. NASA feels this material has a wide potential in industrial applications. Simplified processing of this material would enhance its commercial potential. Processing changes have the potential to reduce processing costs, but tribological and physical properties must not be adversely affected. Extrusion processing has been employed in this investigation as a consolidation process for PM-212/PS-212. It has been successful in that high density bars of EX-212 (extruded PM-212) can readily be fabricated. Friction and strength data indicate these properties have been maintained or improved over the P.M. version. A range of extrusion temperatures have been investigated and tensile, friction, wear, and microstructural data have been obtained. Results indicate extrusion temperatures are not critical from a densification standpoint, but other properties are temperature dependent.

Waters, W. J.; Sliney, H. E.; Soltis, R. F.

1993-01-01

355

The falling weight deflectometer (FWD) test is one of the most com-monly used tools for nondestructive evaluation of flexible pavements.  

E-print Network

for nondestructive evaluation of flexible pavements. Although the test is intrinsically dynamic, the state that the fore- going discrepancy may lead to systematic errors in the estimation of pavement moduli and extract the static pavement response from transient FWD records. With the filtered (i.e., zero

Guzina, Bojan

356

Binzhou Perpetual Pavement Test Road  

Microsoft Academic Search

Expressway construction has been carried out on a large-scale in China. Vigorous economical development has caused rapid growth in traffic volume and truck axle loads creating a severe challenge for the pavement structure design. Therefore, the high-performance and low- maintenance cost of a long-life perpetual pavement structure is gaining attention. This paper discusses the first perpetual asphalt pavement test road

Yongshun Yang; Jincheng Wei; Wang Lin; David Timm; Gerald Huber

2009-01-01

357

OPTIMIZATION AND TESTING OF HIGHWAY MATERIALS TO MITIGATE ICE ADHESION  

EPA Science Inventory

Field tests at the WSU Pavement Test Facility augment BBRC laboratory tests with comparative results. Factors of concern included pavement type, tire type, environment and toxicity, wear, ice/snow adhesion and asphalt overlays which included the substances as a component of the m...

358

The synergy of permeable pavements and geothermal heat pumps for stormwater treatment and reuse.  

PubMed

The use of permeable pavement systems with integrated geothermal heat pumps for the treatment and recycling of urban runoff is novel and timely. This study assesses the efficiency of the combined technology for controlled indoor and uncontrolled outdoor experimental rigs. Water quality parameters such as biochemical oxygen demand, nutrients, total viable heterotrophic bacteria and total coliforms were tested before and after treatment in both rigs. The water borne bacterial community genomic deoxyribonucleic acid (DNA) was analyzed by polymerase chain reaction (PCR) amplification followed by denaturing gradient gel electrophoresis (DGGE) and was further confirmed by DNA sequencing techniques. Despite the relatively high temperatures in the indirectly heated sub-base of the pavement, potentially pathogenic organisms such as Salmonella spp., Escherichia coli, faecal Streptococci and Legionella were not detected. Moreover, mean removal rates of 99% for biochemical oxygen demand, 97% for ammonia-nitrogen and 95% for orthophosphate-phosphates were recorded. This research also supports decision-makers in assessing public health risks based on qualitative molecular microbiological data associated with the recycling of treated urban runoff. PMID:21275249

Tota-Maharaj, K; Scholz, M; Ahmed, T; French, C; Pagaling, E

2010-12-14

359

Volatilization of polycyclic aromatic hydrocarbons from coal-tar-sealed pavement  

USGS Publications Warehouse

Coal-tar-based pavement sealants, a major source of PAHs to urban water bodies, are a potential source of volatile PAHs to the atmosphere. An initial assessment of volatilization of PAHs from coal-tar-sealed pavement is presented here in which we measured summertime gas-phase PAH concentrations 0.03 m and 1.28 m above the pavement surface of seven sealed (six with coal-tar-based sealant and one with asphalt-based sealant) and three unsealed (two asphalt and one concrete) parking lots in central Texas. PAHs also were measured in parking lot dust. The geometric mean concentration of the sum of eight frequently detected PAHs (?PAH8) in the 0.03-m samples above sealed lots (1320 ng m-3) during the hottest part of the day was 20 times greater than that above unsealed lots (66.5 ng m-3). The geometric mean concentration in the 1.28-m samples above sealed lots (138 ng m-3) was five times greater than above unsealed lots (26.0 ng m-3). Estimated PAH flux from the sealed lots was 60 times greater than that from unsealed lots (geometric means of 88 and 1.4 ?g m-2 h-1, respectively). Although the data set presented here is small, the much higher estimated fluxes from sealed pavement than from unsealed pavement indicate that coal-tar-based sealants are emitting PAHs to urban air at high rates compared to other paved surfaces.

Van Metre, Peter C.; Majewski, Michael S.; Mahler, Barbara J.; Foreman, William T.; Braun, Christopher L.; Wilson, Jennifer T.; Burbank, Teresa L.

2012-01-01

360

Quality of osmotically pre-treated and vacuum dried pineapple cubes on storage as influenced by type of solutes and packaging materials.  

PubMed

The quality and stability of osmotically pre-treated and subsequently vacuum dried pineapple cubes using three different solutes and packed in three different types of packaging materials on storage was evaluated. The experiment was laid out in completely randomized block design with two factors and three replications for each treatment. Treatment combinations were considered as one factor and storage interval as another factor. Pineapple cubes stored in glass bottle showed very little percentage variation in moisture content due to its high moisture barrier properties. In all treatment combination, acidity values were invariably found to increase as the storage progressed. For all three different osmotic treatments, HDPE pouch packet always showed highest acidity followed by PVDC pouch. Again among three solutes under consideration, invert sugar recorded a rapid increase in acidity than other solutes. In pineapple cubes osmotically treated with sucrose solution, the rates of decrease of total sugar content were lower than that of invert sugar and sorbitol treated pineapple cubes. The percentage decrease of total sugar content was highest when the osmotically dehydrated pineapple cubes were packed in HDPE pouch and it was least in glass bottles. There was a gradual decrease in ascorbic acid content with the extension of storage period and this decrease was statistically significant at all storage intervals up to six-month. Lowest value of ascorbic acid content (15.210mg per 100g initial solid) was recorded in invert sugar treated pineapple cube packed in HDPE pouch after 6months of storage. PMID:25114348

Paul, Prodyut Kumar; Ghosh, Swapan Kumar; Singh, Dhananjay Kumar; Bhowmick, Nilesh

2014-08-01

361

Preliminary evaluation of LTPP continuously reinforced concrete (CRC) pavement test sections. Final report, February 1995--October 1998  

SciTech Connect

As part of the study reported here, analysis of data from the LTPP GPS-5 test sections was conducted to identify factors that influence long-term crack spacing in continuously reinforced concrete (CRC) pavements and to determine that effect of crack spacing on pavement performance. Data from the 85 test sections from the GPS-5 experiment were analyzed.

Tayabji, S.D.; Selezneva, O.; Jiang, Y.J.

1999-07-01

362

The value of a Pavement Management System (PMS) and the planning and cost-benefit tools it provides for decision making have long been recognized  

E-print Network

The value of a Pavement Management System (PMS) and the planning and cost-benefit tools it provides this scenario: as a DOT pavement and main- tenance engineer, you are faced with budgeting the maintenance to the Rutgers' Center for Advanced Infrastructure and Transportation (CAIT) for help. Teams from CAIT's Pavement

Neimark, Alexander V.

363

Dynamic Hydraulic Conductivity (Permeability) of Asphalt Pavements M. Emin Kutay1, Ahmet H. Aydilek2 and Tom Harman3  

E-print Network

1 Dynamic Hydraulic Conductivity (Permeability) of Asphalt Pavements M. Emin Kutay1, Ahmet H's permeability. To investigate the unsteady (dynamic) fluid flow in asphalt pavements, a 3D fluid flow model the dynamic permeabilities of different asphalt specimens exposed to pulsatile pressures. It was shown

Aydilek, Ahmet

364

TOLLWAY LCCA PROCESS FOR ADDAMS MEMORIAL TOLLWAY ADDAMS EXPRESSWAY PAVEMENT RECONSTRUCTION --  

E-print Network

TOLLWAY LCCA PROCESS FOR ADDAMS MEMORIAL TOLLWAY Page 1 ADDAMS EXPRESSWAY PAVEMENT RECONSTRUCTION and expand capacity along the Jane Addams Memorial Tollway between I-39 and the Kennedy Expressway and for the maintenance activities anticipated over a 50-year life span for each of the pavement types under consideration

365

Life cycle assessment of representative swiss road pavements for national roads with an accompanying life cycle cost analysis.  

PubMed

The subject of this paper is an environmental life cycle assessment (LCA) and life cycle cost analysis (LCCA) of processes needed to construct and maintain representative Swiss asphalt, concrete, and composite pavements (including subbase layers) applicable for the Swiss national road network over a period of 75 years. The environmental indicators analyzed are the global warming potential indicator, the nonrenewable cumulative energy demand, and the Swiss ecological scarcity indicator. Processes of the use phase of the road (fuel consumption, noise, etc.) have been evaluated qualitatively based on intensive research. The study shows that the global warming potential of concrete and asphalt pavements equilibrates over the analysis period and that concrete pavements compared to asphalt and composite pavements offer advantages in regards to the nonrenewable cumulative energy demand, the ecological scarcity indicator, and life cycle costs. The qualitative evaluation of the processes of the use phase shows for example the positive qualities of concrete pavements regarding fuel consumption and permanent noise properties. PMID:23865779

Gschsser, Florian; Wallbaum, Holger

2013-08-01

366

Reducing conflicts between motor vehicles and pedestrians: the separate and combined effects of pavement markings and a sign prompt.  

PubMed Central

The effects of a symbolic "yield here to pedestrians" sign and advance yield pavement markings on pedestrian/motor vehicle conflicts, motorists' yielding behavior, and the distance motorists' yield in advance of crosswalks were evaluated at multilane crosswalks at uncontrolled T intersections. In Experiment 1, the sign, when used alone, reduced pedestrian/motor vehicle conflicts and increased motorist yielding distance. The use of fluorescent yellow-green sheeting as the background of the sign did not increase the effectiveness of the sign. Further reductions in pedestrian/motor vehicle conflicts and further increases in yielding distance were associated with the addition of advance yield pavement markings. In Experiment 2, advance yield pavement markings, when used alone, were as effective in reducing pedestrian/motor vehicle conflicts and increasing yielding distance as the sign combined with pavement markings. These data suggest that the pavement markings were the essential component for reducing conflicts and increasing yielding distance. PMID:15669404

Huybers, Sherry; Van Houten, Ron; Malenfant, J E Louis

2004-01-01

367

Pavement thickness evaluation using ground penetrating radar  

Microsoft Academic Search

Accurate knowledge of pavement thickness is important information to have both at a network and project level. This information aids in pavement management and design. Much of the time this information is missing, out of date, or unknown for highway sections. Current technologies for determining pavement thickness are core drilling, falling weight deflectometer (FWD), and ground penetrating radar (GPR). Core

Dwayne Arthur Harris

2006-01-01

368

User's guide: Cold-mix recycling of asphalt concrete pavements. Final report  

SciTech Connect

This guide provides the technical information required to implement the application of cold-mix recycling of asphalt concrete pavements. Included are details on areas on application, benefits/advantages, limitations/disadvantages, and costs associated with this technology. Information is provided on two demonstration sites at Fort Gillem, Georgia, and Fort Leavenworth, Kansas. Also provided is information concerning funding, procurement, maintenance, and performance monitoring. A fact sheet on recycling, contract specification example, and references are provided in the appendixes.... Asphalt pavement recycling, Emulsified asphalt cement, Cold milling, In-place cold-mix asphalt recycling, Cold-mix asphalt recycling, Recycling of asphalt.

Shoenberger, J.E.

1992-09-01

369

SORPTIVITY-BASED SERVICE LIFE PREDICTIONS FOR CONCRETE PAVEMENTS  

E-print Network

SORPTIVITY-BASED SERVICE LIFE PREDICTIONS FOR CONCRETE PAVEMENTS by Dale P. Bentz, Mark A. Ehlen Pavements. Proceedings, Volume 1. International Society for Concrete Pavements. September 9-13, 2001 Pavements ­ Orlando, Florida, USA ­ September 9-13, 2001. 181 SORPTIVITY-BASED SERVICE LIFE PREDICTIONS

Bentz, Dale P.

370

Pavement Sealcoat, PAHs, and the Environment  

NASA Astrophysics Data System (ADS)

Recent research by the USGS has identified coal-tar-based pavement sealants as a major source of polycyclic aromatic hydrocarbons (PAHs) to the environment. Coal-tar-based sealcoat is commonly used to coat parking lots and driveways and is typically is 20-35 percent coal tar pitch, a known human carcinogen. Several PAHs are suspected mutagens, carcinogens, and (or) teratogens. In the central and eastern U.S. where the coal-tar-based sealants dominate use, sum-PAH concentration in dust particles from sealcoated pavement is about 1,000 times higher than in the western U.S. where the asphalt-based formulation is prevalent. Source apportionment modeling indicates that particles from sealcoated pavement are contributing the majority of the PAHs to recent lake sediment in 35 U.S. urban lakes and are the primary cause of upward trends in PAHs in many of these lakes. Mobile particles from parking lots with coal-tar-based sealcoat are tracked indoors, resulting in elevated PAH concentrations in house dust. In a recently completed study, volatilization fluxes of PAHs from sealcoated pavement were estimated to be about 60 times fluxes from unsealed pavement. Using a wide variety of methods, the author and colleagues have shown that coal-tar-based sealcoat is a major source of PAHs to the urban environment and might pose risks to aquatic life and human health.

Van Metre, P. C.; Mahler, B. J.

2011-12-01

371

Asphalt Pavement Design using Results of Laboratory Fatigue Tests of Asphalt Mixtures  

Microsoft Academic Search

Fatigue tests with use of 4 Point Bending test were performed on conventional and innovative asphalt mixtures: typical asphalt concrete, high stiffness modulus asphalt concrete and stone mastic asphalt with conventional and special binders, multigrade or elastomer-bitumen. The results of fatigue testing were applied for development of fatigue characteristics of particular asphalt mixtures. Pavement design analysis was performed with design

Dariusz Sybilski; Wojciech Ba?kowski

2002-01-01

372

Evaluation of ASTM test method D 4867, effect of moisture on asphalt concrete paving mixtures. Final report, May 1995--May 1997  

SciTech Connect

The moisture sensitivities of 21 dense-graded asphalt pavements were predicted in 1987 using American Society for Testing and Materials (ASTM) Test Method D 4867, Effect of Moisture on Asphalt Concrete Paving Mixtures. Tests were performed on cores taken from the pavements. The air-void levels of the cores varied from pavement to pavement. In 1995 and 1996, cores were again taken from the pavements to ascertain whether the test method correctly predicted performance. Pavement distress surveys were also performed.

Stuart, K.D.

1998-09-01

373

Contributing to the sustainable use of stormwater: the role of pervious pavements.  

PubMed

The city of Melbourne, Australia is experiencing a water crisis with potable water storage reservoirs at an all time low. With increasing urbanisation there is an ever increasing need to research and explore sustainable water management initiatives. There is potential to minimise the negative impacts of stormwater runoff and augment dwindling supplies of potable water through adoption of pervious paving technology. The traditional approach to stormwater management has focused on constructing drainage networks to carry stormwater away from developed areas as quickly as possible to avoid the risk of flooding. The main aim of this research project was to establish relationships between rainfall intensity, infiltration rate and pervious pavement runoff and to examine the improvement to stormwater quality after infiltrating through pervious pavements. This paper describes the laboratory experiment set-up to determine the infiltration patterns and stormwater quality improvement for simulated storms precipitating on pervious pavements. Next, the scaling-up of the experimental rig to a field-based trial is explained. Preliminary results from this work are presented to demonstrate the potential benefits of pervious pavements in the Australian landscape. PMID:18075181

Jayasuriya, L N N; Kadurupokune, N; Othman, M; Jesse, K

2007-01-01

374

Project Information Form Project Title Evaluation of the Combined Effect of Recycled Asphalt Pavement (RAP),  

E-print Network

Project Information Form Project Title Evaluation of the Combined Effect of Recycled Asphalt Pavement (RAP), Recycled Asphalt Shingles (RAS), and Different Virgin Binder Sources on Performance the allowable RAP content to 25 percent in asphalt mixes. Caltrans-industry-academia task group has proposed

California at Davis, University of

375

Development of a Prediction Model for Skid Resistance of Asphalt Pavements  

E-print Network

Page FIGURE 1 Schematic plot of hysteresis and adhesion. ................................................ 7 FIGURE 2 Pavement wavelength and surface characteristics. ................................... 10 FIGURE 3 Schematic plot... Page TABLE 1 Comparison between Different Skid Resistance and Texture Measuring Techniques................................................................. 19 TABLE 2 Comparison of Different Polishing...

Rezaei, Arash

2012-02-14

376

New Developments in the Debate on Pavement-Vehicle  

E-print Network

New Developments in the Debate on Pavement-Vehicle Interaction: The Impact of Pavement Design aerodynamics Improve energy efficiency Reduce rolling resistance, including pavement-vehicle interaction #12 standards for big trucks" February 18, 2014 What about fuel efficiency standards for pavements? #12;Slide 5

de Weck, Olivier L.

377

Durability of Saw-Cut Joints in Plain Cement Concrete Pavements  

Microsoft Academic Search

The objective of this project was to evaluate factors influencing the durability of the joints in portland cement concrete pavement in the state of Indiana. Specifically this work evaluated the absorption of water, the absorption of deicing solutions, the relationship between the degree of saturation and concrete deterioration, and the role of Soy Mehyl Esters as a potential concrete sealant.

Javier Castro; Wenting Li; Mohammad Pour-Ghaz; Mike Golias; Bernie Tao; Hongfang Sun; William Jason Weiss

2011-01-01

378

Presence of Host ICAM-1 in Human Immunodeficiency Virus Type 1 Virions Increases Productive Infection of CD4+ T Lymphocytes by Favoring Cytosolic Delivery of Viral Material  

Microsoft Academic Search

Although there is now convincing evidence that the infectivity of human immunodeficiency virus type 1 (HIV-1) is increased by incorporation of host intercellular adhesion molecule 1 (ICAM-1) in budding virions, the exact mechanism(s) through which ICAM-1 can so significantly affect HIV-1 biology remains obscure. To address this question, we focused our attention on the most proximal events in the virus

Melanie R. Tardif; Michel J. Tremblay

2003-01-01

379

Beyond the Beaten Track: Resettlement Initiatives of Pavement Dwellers and Slum Dwellers in Bombay.  

ERIC Educational Resources Information Center

The Society for Promotion of Adult Resource Centres was created to alleviate the problem of railway settlement families and pavement dwellers in Bombay, India. The area resource center provides information, analysis of available resources, discussion of problems, and sharing of experiences. (JOW)

Patel, Sheela

1988-01-01

380

Wear mechanism of disc-brake block material for new type of drilling rig  

Microsoft Academic Search

To improve friction and wear performance and service life of the disc-brake pair material of a drilling rig, a new type of\\u000a asbestos-free frictional material with better performance for disc-brake blocks is developed, and its wear mechanism is investigated\\u000a by friction and wear experiments. Topography and elementary components of the brake blocks wear surface are analyzed by employing\\u000a SEM and

Xinhua Wang; Simin Wang; Siwei Zhang; Deguo Wang

2008-01-01

381

Desert pavement development on the lake shorelines of Lake Eyre (South), South Australia  

NASA Astrophysics Data System (ADS)

To the southwest of Lake Eyre (South), South Australia, silcrete boulders exposed by the erosion of the surrounding fine sediments undergo mechanical weathering to form desert pavement. Successive palaeoshorelines of Lake Eyre have exposed an age-related sequence of different stages in the weathering of the boulders. This study investigates desert pavement development in this saline environment. In addition, it attempts to develop a model for the development of desert pavement following exposure of the silcrete boulders, based on palaeo-lake shorelines dated from previous studies. Seven stages can be recognised corresponding to stages of soil and pavement development. Prior to stage one is the actual exposure of the boulder as the result of erosion by wave action at the lake shoreline or by erosion as the lake level falls during desiccation. At stage-1 the upper surface of the boulder breaks up through mechanical weathering (salt weathering), while the rest of the boulder is still buried. At stage-2 the surface fragments fall to the edge of the stone and expose more of the stone, which continues to break-up. There is no soil development in stages 1 and 2. By stage-3 most of the stone is exposed and broken up, making a mini-hill. At this stage soil development begins with the accumulation of sandy soil between the rock fragments. At stage-4 the stones form small cones and the soil is more developed. It is sandy with a typical of colour 10 YR 6/6. At stage-5 the stones forming the small cone are completely fragmented. Stone fragments at the centre are very angular but smoother at the edges of the mini-hill as the result of weathering (etching by chemical processes?). Soil texture is silty/sand and soil colour is 7.5 YR 6/6. At stage-6 the surface is nearly flat. The soil is sandy/silt and soil colour is between 7.5 YR 5/6 and 7.5 YR 5/8. Stage-7a is the gibber plain phase, composed of small well rounded stones, as a result of continued etching of the edges of the fragmented stones. The soil is silty, and the soil colour is between 5 YR 5/6 and 5 YR 5/8. Stage-7b is also gibber plain, with small well rounded stone fragments but where the soil has been replaced by crystalline gypsum. This sequence differs from sequences described in other areas, especially on alluvial fan or terrace surfaces. This may be partly due to the different origin of the clasts, as "pre-weathered" silcrete boulders, and partly due to the importance of chemical weathering by "etching" in this salt-rich environment.

Al-Farraj, Asma

2008-08-01

382

The development and geometry of shape change in Arabidopsis thaliana cotyledon pavement cells  

PubMed Central

Background The leaf epidermis is an important architectural control element that influences the growth properties of underlying tissues and the overall form of the organ. In dicots, interdigitated pavement cells are the building blocks of the tissue, and their morphogenesis includes the assembly of specialized cell walls that surround the apical, basal, and lateral (anticlinal) cell surfaces. The microtubule and actin cytoskeletons are highly polarized along the cortex of the anticlinal wall; however, the relationships between these arrays and cell morphogenesis are unclear. Results We developed new quantitative tools to compare population-level growth statistics with time-lapse imaging of cotyledon pavement cells in an intact tissue. The analysis revealed alternating waves of lobe initiation and a phase of lateral isotropic expansion that persisted for days. During lateral isotropic diffuse growth, microtubule organization varied greatly between cell surfaces. Parallel microtubule bundles were distributed unevenly along the anticlinal surface, with subsets marking stable cortical domains at cell indentations and others clearly populating the cortex within convex cell protrusions. Conclusions Pavement cell morphogenesis is discontinuous, and includes punctuated phases of lobe initiation and lateral isotropic expansion. In the epidermis, lateral isotropic growth is independent of pavement cell size and shape. Cortical microtubules along the upper cell surface and stable cortical patches of anticlinal microtubules may coordinate the growth behaviors of orthogonal cell walls. This work illustrates the importance of directly linking protein localization data to the growth behavior of leaf epidermal cells. PMID:21284861

2011-01-01

383

Surface control of desert pavement pedologic process and landscape function, Cima Volcanic field,  

E-print Network

Surface control of desert pavement pedologic process and landscape function, Cima Volcanic field, Mojave Desert, California Y.A. Wooda,*, R.C. Grahama , S.G. Wellsb a Soil and Water Sciences Program, Department of Environmental Sciences, University of California, Riverside, CA 92521-0424, USA b Desert

Ahmad, Sajjad

384

Hydrological impacts evaluation of pervious pavement based on a storm water management model  

Microsoft Academic Search

Hydrological performances of pervious pavement were examined at a site within Little Mill Creek watershed in Lenexa, Kansas, USA using three hydrological indicators of peak flow rate, total runoff volume and runoff coefficient based on the 2-yr, 10-yr and 100-yr design rainfall events and a continuous ten year hourly rainfall record. Three scenarios of undeveloped, developed with no runoff control

Yan-wei Sun; Xiao-mei Wei; Christine A. Pomeroy

2011-01-01

385

Optimization of p-type segmented FeSi 2\\/Bi 2Te 3 thermoelectric material prepared by spark plasma sintering  

Microsoft Academic Search

A p-type segmented FeSi2\\/Bi2Te3 thermoelectric material has been optimized and the optimal junction temperature has been determined based on estimation and measurement. It was observed that the optimal junction temperature is about 195 C, which corresponds to the segment length ratio 10:1 and the hot-side temperature 510 C for the segmented material FeSi2\\/Bi2Te3. The maximum power outputs are about 800

J. L. Cui

2003-01-01

386

Field monitoring and modeling of pavement response and service life consumption due to overweight truck traffic  

E-print Network

performance with respect to both rutting and fatigue cracking. Charts to evaluate the service life of the existing pavement subjected to OTTs are established in terms of the unit service life consumed due to the rutting and fatigue cracking with the various...

Oh, Jeong-Ho

2004-11-15

387

Hydrologic and Pollutant Removal Performance of a Full-Scale, Fully Functional Permeable Pavement Parking Lot  

EPA Science Inventory

In accordance with the need for full-scale, replicated studies of permeable pavement systems used in their intended application (parking lot, roadway, etc.) across a range of climatic events, daily usage conditions, and maintenance regimes to evaluate these systems, the EPA?s Urb...

388

Leaching of heavy metals and polycyclic aromatic hydrocarbons from reclaimed asphalt pavement  

Microsoft Academic Search

The work presented herein displays the results of a study addressing environmental concerns related to the possible leaching of pollutants from reclaimed asphalt pavement. Samples from an experimental site were tested in both static batch tests and column leaching tests. Selected heavy metals and polycyclic aromatic hydrocarbons (PAHs) were analysed in leachates. The results have allowed us to consider the

M. Legret; L. Odie; D. Demare; A. Jullien

2005-01-01

389

A source mixing model to apportion PAHs from coal tar and asphalt binders in street pavements and urban aquatic sediments.  

PubMed

Present-day and more than 30 years old road and footpath pavements from Auckland, New Zealand were analysed for PAHs to test the hypothesis that coal tar based pavement binders contribute to unusually high PAH concentrations in adjacent stream and estuarine sediments. Total PAH (?(28)PAH) concentrations in the dichloromethane-soluble fraction ("binder"), comprising 5-10% of pavement mass, were as high as 200,000 mgkg(-1) (10,000 mgkg(-1) in binder+aggregate). Older and deeper pavement layers were strongly pyrogenic, whereas pavement layers from recently sealed roads had a more petrogenic composition and more than 1000 times lower ?(28)PAH concentrations. Source identification analysis using three PAH isomer ratio pairs (benz(a)anthracene/(benz(a)anthracene+chrysene); benzo(a)pyrene/(benzo(a)pyrene+benzo(e)pyrene); and indeno(1,2,3-cd)pyrene/(indeno(1,2,3-cd)pyrene+benzo(g,h,i)perylene) revealed low PAH (bitumen) pavements to have consistently lower isomer ratios than high PAH (coal tar) samples. Moreover, pavement data for one isomer ratio (e.g. benzo(a)pyrene/(benzo(a)pyrene+benzo(e)pyrene) were highly correlated with those of another isomer ratio (e.g. benz(a)anthracene/(benz(a)anthracene+chrysene) and were bounded at their lower and higher extremes by the characteristics of pure bitumen and coal tar, respectively, suggesting that PAH composition of a given pavement sample could be accounted for by conservative mixing between coal tar and bitumen as source materials. A concentration-weighted mixing model, with coal tar and bitumen as source materials, explained more than 80% of the variance in isomer ratios and enveloped the entire PAH compositional and concentration range encountered. PAH composition and concentrations in adjacent stream sediments (> 15 mgkg(-1) dry weight) were consistent with diluted coal tar material as a principal PAH source. Due to the very high PAH concentrations of coal tar, a coal tar content of as little as 0.01% of total sediment mass can account for more than 90% of PAH concentrations in adjacent stream sediments. PMID:20843538

Ahrens, Michael J; Depree, Craig V

2010-12-01

390

High performance p-type thermoelectric materials and methods of preparation  

NASA Technical Reports Server (NTRS)

The present invention is embodied in high performance p-type thermoelectric materials having enhanced thermoelectric properties and the methods of preparing such materials. In one aspect of the invention, p-type semiconductors of formula Zn4-xAxSb3-yBy wherein 0?x?4, A is a transition metal, B is a pnicogen, and 0?y?3 are formed for use in manufacturing thermoelectric devices with substantially enhanced operating characteristics and improved efficiency. Two methods of preparing p-type Zn4Sb3 and related alloys of the present invention include a crystal growth method and a powder metallurgy method.

Caillat, Thierry (Inventor); Borshchevsky, Alexander (Inventor); Fleurial, Jean-Pierre (Inventor)

2005-01-01

391

Evaluation of tire pressure, tire construction, axle configuration, and axle load on flexible pavement performance  

E-print Network

loading among axles, and high tire pressures. The tire is represented as a uniformly loaded circular area with contact pressure assumed as 9OX, of inflation pressure. A modified Chevron N-layer model was used to calculate pavement stresses and strains...

Jamy, Ahmad Najeeb

1991-01-01

392

Monitoring of the permeable pavement demonstration site at Edison Environmental Center  

EPA Science Inventory

The EPA?s Urban Watershed Management Branch has installed an instrumented, working full-scale 110-space pervious pavement parking lot and has been monitoring several environmental stressors and runoff. This parking lot demonstration site has allowed the investigation of differenc...

393

Model based pavement-vehicle interaction simulation for life cycle assessment of pavements  

E-print Network

Responsible for about a third of the annual energy consumption and greenhouse gas (GHG) emissions, the U.S. transportation Network needs to attain a higher level of sustainability. This is particularly true for the roadway ...

Akbarian, Mehdi

2012-01-01

394

On-machine laser triangulation sensor for precise surface displacement measurement of various material types  

NASA Astrophysics Data System (ADS)

The paper presents a custom-designed laser triangulation based metrology system, which enables high precision surface displacement measurement of various material types with a single sensor configuration. Laser structuring applications require material surface alignment relative to the laser focus position where fabrication conditions are optimal. The measurement system utilizes a high-quality UV wavelength laser beam (primarily used for structuring purposes) with automatic control of its intensity. The laser source operates in a continuous wave (CW) mode during the measurement process, whereas the UV wavelength enables measurement of transparent materials. Robust displacement measurement of various material types was solved by introducing a new approach of structured light projection and its centroid detection. A high resolution 2D galvanometric scanning system is used for dynamic symmetrical pattern projection, which is proven to reduce the effects of material surface related errors and speckle noise. Furthermore, a "double curve fitting" (DCF) centroid detection algorithm, where Gaussian curves are fitted to radial cross sections of the acquired pattern, and an ellipse is fitted to their peak positions, was introduced. The method includes subsurface scattering compensation, which proves crucial for translucent material measurement, where incident light penetrates into the material surface and causes uneven light intensity distribution of the acquired pattern. Experimental results have shown that the metrology system is robust to laser intensity variation and material type, with measurement bias lower than 50 ?m and standard deviation lower than +/-6.3 ?m for all materials. The developed probe has been integrated into commercial LPKF laser structuring systems.

bontar, Klemen; Podobnik, Botjan; Pove, Franc; Mihelj, Matja

2013-09-01

395

[Technology transfer of building materials by ECOMAT  

SciTech Connect

This report discusses the plan for technology transfer of building materials developed by ECOMAT to the commercial private sector. Some of the materials are briefly discussed like foams, fiber reinforcement, fly ash development, and polymer fillers.

NONE

1996-01-01

396

Materials design of p-type transparent conducting oxides of delafossite CuAlO 2 by super-cell FLAPW method  

Microsoft Academic Search

We propose a new crystal growth method and a new valence control method to fabricate a low-resistive p-type and transparent conducting oxides of Delafossite CuAlO2 based on ab initio electronic structure calculation using a super-cell FLAPW method. We propose a Cu-vacancy-acceptor doping method by decreasing a Cu-vapor pressure in order to increase a Cu-vacancy concentration. We also propose the Mg-

T. Koyanagi; H. Harima; A. Yanase; H. Katayama-yoshida

2003-01-01

397

DETERIORATION FORECASTING IN FLEXIBLE PAVEMENTS DUE TO FLOODS AND SNOW STORMS  

E-print Network

DETERIORATION FORECASTING IN FLEXIBLE PAVEMENTS DUE TO FLOODS AND SNOW STORMS Salar Shahini.birken@neu.edu, 4 mi.wang@neu.edu ABSTRACT Roadway agencies and state DOTs utilize Pavement Management Systems (PMS process of pavements is an integral part of any Pavement Management System. As pavement condition grows

Boyer, Edmond

398

About the sizes of elastomer particles in the asphalt concrete binder providing the maximum service life of pavements  

NASA Astrophysics Data System (ADS)

It is noted that the durability of asphalt concrete pavements is determined by the time of the trunk cracks formation in the polymer-containing composites - in the modified by elastomers (e.g., by rubber) bitumenous binder of asphalt. Developed by the authors previously the theory of the cracks propagation in heterosystems [1] has allowed to investigate the problem of the cracks propagation in the rubber-bitumen composite. This investigations show that most effectively to prevente the trunk cracks formation in asphalt concrete can ultrafine rubber particles (150-750 nm) in a bitumenos binder of asphalt.

Kaplan, A. M.; Chekunaev, N. I.

2014-05-01

399

Tolerable Strains for HMA Overlays over Concrete Pavements  

E-print Network

Tolerable Strains for HMA Overlays over Concrete Pavements By Ashwani Gautam Submitted to the graduate degree program in Civil Engineering and the Graduate Faculty of the University of Kansas School of Engineering in partial fulfillment.../23/09 ii The Thesis Committee for Ashwani Gautam certifies That this is the approved version of the following thesis: Tolerable Strains for HMA Overlays over Concrete Pavements Committee: _______________________ Dr. Jie Han, Chairperson...

Gautam, Ashwani

2009-06-10

400

Minimizing Distress on Flexible Pavements Using Variable Tire Pressure  

Microsoft Academic Search

The potential of variable tire pressure technology to minimize distress on flexible pavements with thin asphalt surfacing layers and peat soil subgrade was evaluated using in-situ stress-strain data. Pavement interfacial strains and corresponding subgrade stresses imposed by a three-axle truck were measured and used to estimate the fatigue life of the surfacing layer. Three levels of truck wheel loads in

Philip M. O. Owende; Anton M. Hartman; Shane M. Ward; Michael D. Gilchrist; Michael J. O'Mahony

2001-01-01

401

Development of a mult-objective strategic management approach to improve decisions for pavement management practices in local agencies  

E-print Network

and the flow of knowledge across management levels can contribute to making better informed decisions. Hence, the adoption of the multi-objective strategic pavement management approach developed in this dissertation should lead to identifying more efficient...

Chang Albitres, Carlos Martin

2009-05-15

402

Multitarget detection\\/tracking for monostatic ground penetrating radar: application to pavement profiling  

Microsoft Academic Search

Monostatic ground penetrating radar (GPR) has proven to be a useful technique in pavement profiling. In road and highway pavements, layer thickness and permittivity of asphalt and concrete can be estimated by using an inverse scattering approach. Layer-stripping inversion refers to the iterative estimation of layer properties from amplitude and time of delay (TOD) of echoes after their detection. This

Umberto Spagnolini; Vittorio Rampa

1999-01-01

403

The type-material of Arctiinae (Lepidoptera, Erebidae) described by Burmeister and Berg in the collection of the Museo Argentino de Ciencias Naturales Bernardino Rivadavia (Buenos Aires, Argentina)  

PubMed Central

Abstract Carlos G. Burmeister and Carlos Berg were among the most important and influential naturalists and zoologists in Argentina and South America and described 241 species and 34 genera of Lepidoptera. The Museo Argentino de Ciencias Naturales Bernardino Rivadavia (MACN) housed some of the Lepidoptera type specimens of these authors. In this study we present a catalogue with complete information and photographs of 11 Burmeister type specimens and 10 Berg type specimens of Phaegopterina, Arctiina and Pericopina (Lepidoptera, Erebidae, Arctiinae, Arctiini) housed in the MACN. Lectotypes or holotypes were designated where primary type specimens could be recognized; in some cases we were not able to recognize types. The catalogue also proposes nomenclatural changes and new synonymies: Opharus picturata (Burmeister, 1878), comb. n.; Opharus brunnea Gaede, 1923: 7, syn. n.; Hypocrisias jonesi (Schaus, 1894), syn. n.; Leucanopsis infucata (Berg, 1882), stat. rev.; Paracles argentina (Berg, 1877), sp. rev.; Paracles uruguayensis (Berg, 1886), sp. rev. PMID:25061380

Beccacece, Hernn M.; Vincent, Benoit; Navarro, Fernando R.

2014-01-01

404

Severity effects of dual-tandem and dual-tridem repeated heavier aircraft gear loading on pavement rutting performance  

Microsoft Academic Search

In this paper, the rutting behaviour of flexible test pavements subjected to multiple-wheel heavy aircraft gear loading at the National Airport Pavement Test Facility (NAPTF) are characterized. Two series of traffic tests were conducted. During the first series, a Boeing 777 (B777) aircraft gear and a Boeing 747 (B747) gear were trafficked on two low-strength subgrade and two medium-strength subgrade

Kasthurirangan Gopalakrishnan; Marshall R. Thompson

2006-01-01

405

Use of shredded tires in the subbase layer of asphalt pavements  

SciTech Connect

Research was conducted on the use of shredded scrap tires for use in the subbase layer of asphalt pavements. Mixtures of shredded scrap tires with virgin soil provide a means of recycling unwanted tires and conserving a finite supply of virgin soil. The mechanistic procedure for the design of pavement systems requires resilient modulus values. Plastic and elastic strains were measured using external LVDT`s and internal proximity sensors. Resilient modulus measurements were conducted on cohesionless soils mixed with various amounts of shredded tire chips. The performance f the shredded tire mixture is compared to that of the naturally occurring virgin soil used in subbase applications in New Jersey. A number of experimental issues are discussed such as: method of compaction, optimum ratio of shredded tire chips to soil, optimum size and gradation of shredded tire chips, and strength testing using California Bearing Ratio.

Papp, W.J. Jr.; Maher, M.H. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Civil and Environmental Engineering; Baker, R.F. [New Jersey Dept. of Transportation, Trenton, NJ (United States)

1997-12-31

406

Exploratory study of hot in-place recycling of asphalt pavements. Volume 2. Appendices. Final report, September 1992-September 1994  

SciTech Connect

Hot-in-place recycling (HIR) is a method for rehabilitation of asphalt pavements. Potential for cost savings and resource preservation are high because existing pavement materials are processed on-site, with only the addition of small amounts of recycling agent. The Oregon Department of Transportation (ODOT) constructed HIR projects in 1992 and 1993. In September 1992, ODOT contracted with Oregon State University (OSU) to evaluate the HIR projects, synthesize existing information on HIR, and develop guidelines for HIR use. This report summarizes the information developed during the study: Construction equipment used on ODOT HIR projects is discussed; Field data from six HIR projects are presented; Results of a limited laboratory investigation of HIR are presented; Proper project selection was found to be extremely critical to HIR success. A selection procedure is presented; Based on information from the field studies and a limited laboratory testing program, a recommended mix design procedure is presented. This report is in two volumes. Volume I includes the body of the report, Volume II includes the appendices.

Rogge, D.F.; Hislop, W.P.; Dominick, D.

1994-11-01

407

Experimental and Numerical Studies of the Effects of Water Sprinkling on Urban Pavement on Heat Island Mitigation  

NASA Astrophysics Data System (ADS)

One of the main causes of 'heat island phenomeno' is thought to be the artificial covers of the ground surface with asphalt or concrete which reduce greatly inherent cooling effect of water evaporation from soil surface. In this study, as a candidate method of mitigating the heat island the effects of the 'water sprinkling' on the pavements are discussed from field experiments and numerical studies. Three field experiments of water sprinkling on the asphalt/concrete pavements were performed in hot summer days in 2004-2006. For detecting the change in temperatures, the authors developed and used a 3-D measurements system which consists of two vertical planes with 6m high and 16m wide, and has network arrays of 102 thermistors distributed spatially in the planes. The temperatures measured in and around the water sprinkled area indicated that the ground surface temperature decreased 5 to 15 degrees uniformly in the water sprinkled area compared with those in the un-sprinkled area, while the relative decrease of atmospheric temperature was approximately up to 1 degree. The subsurface temperature at a depth of 14cm under the pavement decreased significantly and kept lower than that at the same depth in un-sprinkled area over the next morning. A numerical model was developed and applied to interpret the experimental results. It deals with the heat balance of radiation, sensible/latent heat transfer at the ground surface and heat conduction through the artificial and natural soil layer under ground. temperature and vapor conditions changes at and near ground surface were modeled by using the bulk formula.Good agreements between the calculated time-temperature profiles and the experimental ones were obtained by assuming adequate physical parameters and meteorological conditions. The model could be improved in order to evaluate the changes of temperature and vapor contents in atmosphere near the ground surface caused by aerodynamic turbulent diffusion.

Yoshioka, M.; Tosaka, H.; Nakagawa, K.

2007-12-01

408

Effects of electrical conductivity of substrate materials on microstructure of diamond-like carbon films prepared by bipolar-type plasma based ion implantation  

NASA Astrophysics Data System (ADS)

Diamond-like carbon (DLC) films are prepared by a bipolar-type plasma based ion implantation, and the structural differences between DLC films deposited on different electrical conductive substrates, i.e., conductive Si wafers and insulating glass plates are examined by Raman spectroscopy and x-ray photo emission spectroscopy (XPS). In the Raman measurements, graphite (G) and disorder (D) peaks are observed for both samples. However, the additional photo luminescence is overlapped on the spectra in the case of on-glass sample. To elucidate the structural difference, the intensity ratio of D to G peak (I(D)/I(G)), G peak position and full width at half maximum (FWHM) are obtained by curve fitting using Gaussian function and linear baseline. It is found that the I(D)/I(G) is lower, G peak position is higher and FWHM of G peak is narrower for on-glass sample than for on-Si sample. According to Robertson [1], lower I(D)/I(G) seems more sp3 C-C bonding in amount for on-glass sample. In contrast, higher G peak position and narrower FWHM of G peak suggest less sp3 C-C bonding in amount for on-glass sample. The results of XPS analysis with C1s spectra reveal that sp3 ratio, i.e., the intensity ratio of sp3/(sp3+sp2) is smaller for on-glass sample than for on-Si sample. The inconsistency of the trend between I(D)/I(G) and other parameters (G peak position and FWHM of G peak) might be caused by the overlap of photo luminescence signal on Raman spectrum as to on-glass sample. From these results, it is considered that sp3 C-C bonding is reduced in amount when using insulating substrate in comparison with conductive substrate.

Nakao, S.; Sonoda, T.

2013-03-01

409

Pavement-management system for concrete roadways in Virginia. Phase 1. Condition ratings. Final report  

SciTech Connect

The report traces the development of a rating system for evaluating the service condition of Virginia's portland-cement concrete pavements. The service condition is assessed in terms of distress roughness, i.e., that portion of a pavement's poor-ride characteristics directly attributable to the occurrence of certain key distress types. Field surveys of the occurrence of these distresses provide the necessary data for estimating distress roughness through the use of prediction equations that have been established from the standard statistical analysis of pavement-section distress data and roughness measurements. Distress measurements and their corresponding ratings and a condition survey rating procedure are appended.

Long, R.R.

1988-04-01

410

Fore and aft elastic response characteristics of 34 x 9.9, type 7, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. M.S. Thesis - George Washington Univ., May 1973; [static and rolling tests on dry concrete pavements  

NASA Technical Reports Server (NTRS)

An investigation was conducted to determine the fore-and-aft elastic response characteristics of 34 x 9.9, type VII, 14 ply-rating aircraft tires of bias-ply, bias-belted, and radial-belted design. The investigation consisted of static and rolling tests on dry concrete pavements at the Langley aircraft landing loads and traction facility; statistical techniques which related the measured tire elastic characteristics to variations in the vertical load, inflation pressure, braking force and/or tire vertical deflection; and a semiempirical analysis which related the tire elastic behavior to measured wheel slippage during steady-state braking. The bias-belted tire developed the largest spring constant value for most loading conditions; the radial-belted tire, the smallest. The elastic response of the tire free periphery to static braking included both tread stretch and carcass torsional wind-up about the axle for the bias-ply and bias-belted tires and carcass wind-up alone for the radial-belted tire.

Tanner, J. A.

1974-01-01

411

The impact of geology on the performance of a bituminous surfaced pavementa case study from southeastern Nigeria  

NASA Astrophysics Data System (ADS)

One of the multi-million Naira dual carriageways in Nigeria, the Enugu-Port Harcourt expressway, has continued to experience failure at some sections, namely the stretches covering Lokpaukwu, Lokpanta, and Leru. This road section which, unlike others, does not respond to regular and routine maintenance, is concentrated on one geologic formation, the Eze Aku Shale which has been intruded by a dolerite sill. The emplacement of the dolerite sill had resulted in intense fracturing of the shales in the vicinity of the intrusions which includes portions of where the express road crosses. The road problem is most severe where the dolerite sill is traced right under and across the road. There is evidence from the study that the road problem is linked to the geological/hydrogeological conditions of the area. For example, the problematic section of the road is built on a considerably jointed, fractured and weathered shale formation as a subgrade. The subgrade ultimately has low bearing capacity. The road is almost at the foot of an escarpment where there is a concentration of natural groundwater discharge. Most of the discharge zones including natural water courses are now almost blocked resulting in increased groundwater storage and rise in water table under the highway pavement. This leads to fast deterioration of the base course materials. The dolerite sill, where it crosses the road, is less than 2 m below the grade level. It impedes vertical infiltration as well as lateral groundwater flow. Thus its position with respect to the highway grade elevation leads to an almost perpetual wetting of the base and sub-base materials.

Okagbue, C. O.; Uma, K. O.

412

A novel, compact, low-cost, impulse ground-penetrating radar for nondestructive evaluation of pavements  

Microsoft Academic Search

This paper reports on the development of a novel, compact, low-cost, impulse ground-penetrating radar (GPR) and demonstrate its use for nondestructive evaluation of pavement structures. This GPR consists of an ultrashort-monocycle-pulse transmitter (330 ps), an ultrawide-band (UWB) sampling receiver (0-6 GHz), and two UWB antennas (0.2-20 GHz)-completely designed using microwave-integrated circuits with seamless electrical connections between them. An approximate analysis

Jeong Soo Lee; Cam Nguyen; Thomas Scullion

2004-01-01

413

Characterization of elastic-plastic fracture behavior of type 347 stainless steel piping materials  

SciTech Connect

Type 347 austenitic stainless steel is a stabilized grade selected for improved resistance to sensitization and higher allowable stress levels than other standard grades of austenitic stainless steel in the operating temperature range up to 800 F. Columbium additions to Type 347 stainless steel result in the formation of columbium carbides at high temperature during the processing of the material. The presence of the columbium carbides prevents the formation of chromium carbides at grain boundaries. Formation of chromium carbides at grain boundaries causes sensitization of stainless steels with a corresponding loss of corrosion resistance of the stainless steel in certain aqueous environments. Elastic-plastic fracture toughness testing has been performed on several heats of stabilized Type 347 austenitic stainless steel piping material. J-R curve tests were performed at 315 C (600 F). The testing was performed with the specimen cracks oriented in the circumferential (LC) and longitudinal (CL) directions. The J-R curves for the Type 347 stainless steels were compared with similar data on other austenitic stainless steels. Metallographic and fractographic evaluations were performed on the material and the fracture surfaces of the broken test specimens. The columbium carbide distribution affects the fracture behavior of the material by creating sites for the nucleation of voids resulting in the ductile dimpled fracture appearance. This observation is evidenced by the difference in J-R curve behavior and by differences in the fracture appearance between the LC and CL oriented specimens. Microstructural features associated with the carbides and EDS X-ray analysis of the material and fracture surfaces are utilized to rationalize the observed behavior.

Magee, T.P.; Hoffmann, C.L. [Combustion Engineering, Incorporated, Windsor, CT (United States). ABB Combustion Engineering Nuclear Operations

1995-11-01

414

Pattern recognition algorithms for density estimation of asphalt pavement during compaction: a simulation study  

NASA Astrophysics Data System (ADS)

This paper presents the application of artificial neural network (ANN) based pattern recognition to extract the density information of asphalt pavement from simulated ground penetrating radar (GPR) signals. This study is part of research efforts into the application of GPR to monitor asphalt pavement density during compaction. The main challenge is to eliminate the effect of roller-sprayed water on GPR signals during compaction and to extract density information accurately. A calibration of the excitation function was conducted to provide an accurate match between the simulated signal and the real signal. A modified electromagnetic mixing model was then used to calculate the dielectric constant of asphalt mixture with water. A large database of GPR responses was generated from pavement models having different air void contents and various surface moisture contents using finite-difference time-domain simulation. Feature extraction was performed to extract density-related features from the simulated GPR responses. Air void contents were divided into five classes representing different compaction statuses. An ANN-based pattern recognition system was trained using the extracted features as inputs and air void content classes as target outputs. Accuracy of the system was tested using test data set. Classification of air void contents using the developed algorithm is found to be highly accurate, which indicates effectiveness of this method to predict asphalt concrete density.

Shangguan, Pengcheng; Al-Qadi, Imad L.; Lahouar, Samer

2014-08-01

415

Pavement Design TTP Orientation Seminar  

E-print Network

? Reuse?) · Goal at all stages is greater efficiency ­how is efficiency defined? #12;Where Are We Now Materials ReUse, Vehicle/Pavement Interaction, New Materials, Information Technology Integration #12;Is Variables Highways - it's the trucks · Loads · Tire pressures · Speeds · Dynamics (interaction

Handy, Susan L.

416

Pavement Design TTP Orientation Seminar  

E-print Network

(Abandonment? Reuse?) · Goal at all stages is greater efficiency ­ how is efficiency defined? #12;Where Are We-2050 Sustainability Materials ReUse, Vehicle/Pavement Interaction, New Materials, Information Technology Integration the "good old" days? #12;Traffic Variables Highways - it's the trucks · Loads · Tire pressures · Speeds

Handy, Susan L.

417

Evaluation and prediction of moisture-induced damage in asphaltic concrete pavements  

SciTech Connect

The indirect tensile strength (ITS) test using Tunnicliff and Root moisture conditioning procedures, and boiling test was evaluated to determine the moisture susceptibility of asphaltic concrete specimens. A procedure was developed for inventorying stripping in asphaltic concrete pavements. Cores were obtained from existing pavements and then tested in the laboratory for moisture susceptibility. ITS testing and visual strip ratings were used to evaluate moisture-induced damage in the flexible pavements. Moisture susceptibility of asphaltic concrete mixtures was evaluated in the laboratory using various destructive test methods. A procedure was developed to compare the results of the field-sampling program with the laboratory test results. It was shown, through a laboratory testing procedure, that various asphalt cement sources of the same grade (AC-20), when used with different aggregates and antistrip additives, yielded different ITS values and visual strip ratings. Using the laboratory results, the ACMODAS (Asphalt Concrete Moisture Damage Analysis System) computer program was used to predict consequences of moisture-induced damage in asphaltic concrete mixtures.

Amirkhanian, S.N.

1987-01-01

418

Application of positron annihilation and Raman spectroscopies to the study of perovskite type materials  

Microsoft Academic Search

Defect properties of perovskite type materials, Ba3B'Nb2O9 (where B'=Mg, Zn, or Co), with near-stoichiometric compositions were studied by positron annihilation and Raman spectroscopies. Theoretical simulations of stoichiometric perovskites revealed a dependence of the positron bulk lifetime on the degree of ordering. In Ba3MgNb2O9 (BMN) the positron bulk lifetime for a completely disordered structure is 195 ps versus 237 ps for

D. Grebennikov; O. Ovchar; A. Belous; P. Mascher

2010-01-01

419

Joining of advanced materials by superplastic deformation  

DOEpatents

A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.

Goretta, Kenneth C. (Downers Grove, IL); Routbort, Jules L. (Hinsdale, IL); Gutierrez-Mora, Felipe (Woodridge, IL)

2008-08-19

420

Recycling asphalt pavements. January 1975-January 1990 (a Bibliography from the COMPENDEX data base). Report for January 1975-January 1990  

SciTech Connect

This bibliography contains citations concerning the recycling of asphalt-containing pavement materials. Articles include examples of recycling asphalt pavements; performance testing of recycled paving; methods including cold in-place, cold off-site, and hot-mix recycling; additives in recycled pavement for better performance; use of scrap roofing asphalt in conjunction with recycled paving; economics of recycling; process design; and process variables. Recycling of other materials is considered in related bibliographies. (Contains 130 citations fully indexed and including a title list.)

Not Available

1990-03-01

421

Desert pavement morphology and dynamics, Big Bend National Park, Texas  

E-print Network

Desert pavements consist of a one- to two-layer thick surface armory of stones overlying finer, virtually stone-free material which often adopts the appearance of a meticulously tiled mosaic. They cover half of the arid land surface in North America...

Harmon, Courtney Michelle

2009-05-15

422

DEVELOPMENT OF A NEW TYPE A(F)RADIOACTIVE MATERIAL PACKAGING FOR THE DEPARTMENT OF ENERGY  

SciTech Connect

In a coordinated effort, the Department of Transportation (DOT) and Nuclear Regulatory Commission (NRC) proposed the elimination of the Specification Packaging from 49 CFR 173.[1] In accordance with the Federal Register, issued on October 1, 2004, new fabrication of Specification Packages would no longer be authorized. In accordance with the NRC final rulemaking published January 26, 2004, Specification Packagings are mandated by law to be removed from service no later than October 1, 2008. This coordinated effort and resulting rulemaking initiated a planned phase out of Specification Type B and Type A fissile (F) material transportation packages within the Department of Energy (DOE) and its subcontractors. One of the Specification Packages affected by this regulatory change is the UN1A2 Specification Package, per DOT 49 CFR 173.417(a)(6). To maintain continuing shipments of DOE materials currently transported in UN1A2 Specification Package after the existing authorization expires, a replacement Type A(F) material packaging design is under development by the Savannah River National Laboratory. This paper presents a summary of the prototype design effort and testing of the new Type A(F) Package development for the DOE. This paper discusses the progress made in the development of a Type A Fissile Packaging to replace the expiring 49 CFR UN1A2 Specification Fissile Package. The Specification Package was mostly a single-use waste disposal container. The design requirements and authorized radioactive material contents of the UN1A2 Specification Package were defined in 49 CFR. A UN1A2 Specification Package was authorized to ship up to 350 grams of U-235 in any enrichment and in any non-pyrophoric form. The design was specified as a 55-gallon 1A2 drum overpack with a body constructed from 18 gauge steel with a 16 gauge drum lid. Drum closure was specified as a standard 12-gauge ring closure. The inner product container size was not specified but was listed as any container that met Specification 7A requirements per 49 CFR 178.350. Specification 7A containers were required to withstand Type A packaging tests required by 49CFR173.465 with compliance demonstrated through testing, analysis or similarity to other containers. The maximum weight of the 7A product container, the radioactive content, and any internal packaging was limited to 200 lbs. The total gross weight for the UN1A2 Specification Package was limited to 350 lbs. No additional restrictions were applied. Authorization for use did not require the UN1A2 Specification Package to be tested to the Normal Conditions of Transport (NCT) and Hypothetical Accident Conditions (HAC) required for performance based, Type A(F) packages certified by the NRC or DOE. The Type A(F) Packaging design discussed in this paper is required to be in compliance with the regulatory safety requirements defined in Code of Federal Regulations (CFR) 10 CFR 71.41 through 71.47 and 10 CFR71.71. Sub-criticality of content must be maintained under the Hypothetical Accident Conditions specified under 10 CFR71.73. These federal regulations, and other applicable DOE Orders and Guides, govern design requirements for a Type A(F) package. Type A(F) packages with less than an A2 quantity of radioactive material are not required to have a leak testable boundary. With this exception a Type A(F) package design is subject to the same test requirements set forth for the design of a performance based Type B packaging.

Blanton, P.; Eberl, K.

2008-09-14

423

A numerical model for flexible pavements rut depth evolution with time  

NASA Astrophysics Data System (ADS)

A simplified method has been developed for the finite elements modelling of flexible pavements rut depth evolution with time. This method is based on the shakedown theory established by Zarka for metallic structures. The yield surface of Drucker-Prager and the plastic potential of Von Mises have been used. The simplified method determines straightforwardly the purely elastic state or the elastic shakedown state or the plastic shakedown state. The calibration of the simplified method with two unbound granular materials for roads under repeated loads triaxial tests, is explained. Then, a finite elements modelling of a flexible pavement has been carried out. Calculations of 2D and 3D have been performed and rut depth evolutions with time are shown, which underline the capabilities of the model to take into account the accumulation of plastic strains along the loading cycles. Copyright

Allou, Fatima; Chazallon, Cyrille; Hornych, Pierre

2007-01-01

424

Piezoelectric characterization and thermal stability of a high-performance ?-quartz-type material, gallium arsenate  

NASA Astrophysics Data System (ADS)

Piezoelectric measurements were performed on large single crystals (8 mm along the c direction) of an ?-quartz-type piezoelectric material, gallium arsenate, GaAsO4, which allow us to extend the structure-property relationships in the ?-quartz-type materials. These first measurements on Y-rotated-cut plates have shown that gallium arsenate is the highest-performance piezoelectric material of this group. As compared to the coupling coefficients of the other materials with the same structure (kSiO_2=8%, kAlPO_4=11%, and kGaPO_4=16%), gallium arsenate exhibits the highest piezoelectric coupling coefficient of about 22%, as has been predicted by the structure-property relationships. Moreover, from these piezoelectric measurements, the C66' elastic constant was determined and compared with elastic constants in quartz-type materials. The proposed value for the cut angle of the AT plane in GaAsO4 is -6.3. In order to extend the previous thermal stability results, thermal gravimetric analysis (TGA) and x-ray diffraction have been carried out on GaAsO4 powder at high temperatures. It has been shown that GaAsO4 is stable up to 1030 C. The thermal-expansion coefficient of GaAsO4 is 4.010-5K-1. The thermal expansion of the predicted AT plane (Y-6.3) in GaAsO4 is shown to be similar to that of the other materials. Finally, it is demonstrated that the intertetrahedral bridging angle ? (A-O-B) of GaAsO4 is the most stable in ?-quartz materials, which enables one to predict that GaAsO4 should retain high piezoelectric performances up to 925 C.

Cambon, Olivier; Haines, Julien; Fraysse, Guillaume; Dtaint, Jacques; Capelle, Bernard; Van der Lee, Arie

2005-04-01

425

Enhancement of concrete properties for pavement slabs using waste metal drillings and silica fume.  

PubMed

This paper presents a comparative study on the effects of steel fibres and waste metal drillings on the mechanical/physical behaviour of conventional and silica fume concrete. The amount of silica fume used was 10% of cement by mass and the amount of steel fibres and metal drillings used in both concrete mixtures was 0.5% by concrete volume for steel fibres and 0.0, 0.25, 0.50 and 0.75% for metal drillings, respectively. In total, 10 different mixtures were made and tested for compressive strength, modulus of elasticity, flexural strength and toughness. Our data reveal the significant impact of the effect of silica fume, steel fibres and industrial waste metal drillings on the mechanical and physical characteristics of concrete mixtures. The results also show that mixtures with steel fibres and waste metal drillings have comparable behaviour. Hence, there is a potential for use of waste metal drillings as an alternative to steel fibres for specific cases such as concrete pavement slabs. PMID:19542098

Hassani, Abolfazl; Arjmandi, Mohsen

2010-01-01

426

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...  

Code of Federal Regulations, 2012 CFR

...ability of Type B and fissile materials packagings to withstand accident conditions in...SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials...ability of Type B and fissile materials packagings to withstand accident conditions...

2012-10-01

427

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...  

Code of Federal Regulations, 2013 CFR

...ability of Type B and fissile materials packagings to withstand accident conditions in...SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials...ability of Type B and fissile materials packagings to withstand accident conditions...

2013-10-01

428

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...  

Code of Federal Regulations, 2014 CFR

...ability of Type B and fissile materials packagings to withstand accident conditions in...SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials...ability of Type B and fissile materials packagings to withstand accident conditions...

2014-10-01

429

49 CFR 173.467 - Tests for demonstrating the ability of Type B and fissile materials packagings to withstand...  

Code of Federal Regulations, 2011 CFR

...ability of Type B and fissile materials packagings to withstand accident conditions in...SHIPPERS-GENERAL REQUIREMENTS FOR SHIPMENTS AND PACKAGINGS Class 7 (Radioactive) Materials...ability of Type B and fissile materials packagings to withstand accident conditions...

2011-10-01

430

Effect of counterface material type and its topography on the tribological properties of polyimide composites  

NASA Technical Reports Server (NTRS)

Graphite fiber reinforced polyimide composite pins were slid against seven different counterfaces to determine the effect of material type on the tribological properties of polymer composites. In addition, the effect of sliding a new pin on a pre-established transfer film was investigated. The results indicated that almost a five order of magnitude difference in composite wear rate can occur just by varying the counterface material. An attempt to make all surfaces as smooth as possible was made, but due to differences in material composition this was not possible and a range of surface roughnesses were obtained. The results indicate that the smoother the surface, the lower the composite wear rate; but that small protrusions (not discernible with arithmetic surface roughness measurements) can markedly increase wear rates. A pre-established transfer film improved both run in and steady state wear rates.

Fusaro, R. L.

1985-01-01

431

POROUS PAVEMENT. PHASE I. DESIGN AND OPERATIONAL CRITERIA  

EPA Science Inventory

Design and operational criteria, utilization concepts, benefits and disadvantages, as well as other characteristics of porous pavements are presented in this report. Particular emphasis is placed on porous asphalt pavements, but the criteria and design approach are applicable to ...

432

Pavement Design TTP Orientation Seminar  

E-print Network

­Maintenance ­Rehabilitation ­Reconstruction (Abandonment? Reuse?) · Goal at all stages is greater efficiency, Traffic Considerations, ReDesign 2010-2050 Sustainability Materials ReUse, Vehicle/Pavement Interaction;Traffic Variables Highways - it's the trucks · Loads · Tire pressures · Speeds · Dynamics (interaction

Handy, Susan L.

433

Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes  

USGS Publications Warehouse

Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) has increased in the United States during the past 40 years. We evaluated sources of PAHs in post-1990 sediments in cores from 40 lakes in urban areas across the United States using a contaminant mass-balance receptor model and including as a potential source coal-tar-based (CT) sealcoat, a recently recognized source of urban PAH. Other PAH sources considered included several coal- and vehicle-related sources, wood combustion, and fuel-oil combustion. The four best modeling scenarios all indicate CT sealcoat is the largest PAH source when averaged across all 40 lakes, contributing about one-half of PAH in sediment, followed by vehicle-related sources and coal combustion. PAH concentrations in the lakes were highly correlated with PAH loading from CT sealcoat (Spearman's rho=0.98), and the mean proportional PAH profile for the 40 lakes was highly correlated with the PAH profile for dust from CT-sealed pavement (r=0.95). PAH concentrations and mass and fractional loading from CT sealcoat were significantly greater in the central and eastern United States than in the western United States, reflecting regional differences in use of different sealcoat product types. The model was used to calculate temporal trends in PAH source contributions during the last 40 to 100 years to eight of the 40 lakes. In seven of the lakes, CT sealcoat has been the largest source of PAHs since the 1960s, and in six of those lakes PAH trends are upward. Traffic is the largest source to the eighth lake, located in southern California where use of CT sealcoat is rare.

Van Metre, Peter C.; Mahler, Barbara J.

2010-01-01

434

Contribution of PAHs from coal-tar pavement sealcoat and other sources to 40 U.S. lakes.  

PubMed

Contamination of urban lakes and streams by polycyclic aromatic hydrocarbons (PAHs) has increased in the United States during the past 40 years. We evaluated sources of PAHs in post-1990 sediments in cores from 40 lakes in urban areas across the United States using a contaminant mass-balance receptor model and including as a potential source coal-tar-based (CT) sealcoat, a recently recognized source of urban PAH. Other PAH sources considered included several coal- and vehicle-related sources, wood combustion, and fuel-oil combustion. The four best modeling scenarios all indicate CT sealcoat is the largest PAH source when averaged across all 40 lakes, contributing about one-half of PAH in sediment, followed by vehicle-related sources and coal combustion. PAH concentrations in the lakes were highly correlated with PAH loading from CT sealcoat (Spearman's rho=0.98), and the mean proportional PAH profile for the 40 lakes was highly correlated with the