These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Recycling of pavement materials  

E-print Network

materials. A comparison was made between the recycled pavements and typical conventional asphalt concrete pavements. An economic asse?sment of thc recycled pavements was made to determine thc economic feasibility of recycling. Results of laboratory... evaluations show that: recycled pavement mixtures possess properties equivalent to conventional asphalt concrete mixtures; and rccvcl inI' con ho accom- plished with conventional ertuapment. kyar po I'lotion associated with hot-mix recycling of asphalt...

O'Neal, Randy Jim

2012-06-07

2

Enhancement of Pavement Maintenance Decision Making by Evaluating the Effectiveness of Pavement Maintenance Treatments.  

E-print Network

??The performance of different pavement maintenance treatments were evaluated by investigating practical projects collected from Tennessee Pavement Management System (PMS) and Long Term Pavement Performance… (more)

Dong, Qiao

2011-01-01

3

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

4

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

5

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

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

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

8

Micro-thermal stress analysis of cement based pavement composite  

SciTech Connect

A four-layer sphere model for microscopic thermal analysis was proposed based upon the structural form of cement based pavement composites. Using temperature induced stresses of pavement structure as the external field, the micro-thermal stresses of two types of cement based pavement composite were calculated. The results showed that, by introducing the low stiffness rubberized asphalt in the interphase of coarse aggregate phase and cement mortar phase of Portland cement concrete, the interfacial thermal stresses could be reduced significantly, thus improving crack resistance of the pavement material under low temperature environment. Factors affecting micro-thermal stress of cement based pavement composite were discussed.

Li, G.; Zhao, Y.; Pang, S.S. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Mechanical Engineering; Huang, W. [Southeast Univ., Nanjing (China). Coll. of Transportation

1998-12-31

9

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

10

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.

11

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

12

Overview of the Arizona Quiet Pavement Program  

Microsoft Academic Search

The Arizona Quiet Pavement Pilot Program (QP3) was initially implemented to reduce highway related traffic noise by overlaying most of the Phoenix metropolitan area Portland cement concrete pavement with a one inch thick asphalt rubber friction coarse. With FHWA support, this program represents the first time that pavement surface type has been allowed as a noise mitigation strategy on federally

Paul Donavan; Larry Scofield

2005-01-01

13

Layer by layer evaluation of a PCC pavement as it was constructed: Comparison of backcalculated values to lab material values. Research investigation (final)  

SciTech Connect

This study was conducted to observe the background layer strengths of a pavement structure as each layer was constructed and compare these layer strengths to laboratory tested sample strengths. The objective was carried out by gathering Falling Weight Deflectometer deflection data on each sequential layer. The laboratory samples included bulk samples of the base, shelby tube samples of the subgrade, and concrete core samples from the pavement`s structure. Laboratory tests were performed on these extracted samples to estimate the resilient modulus testing on the base samples was not performed because the backcalculated base results were inconclusive and no comparison could be made.

Netemeyer, R.; Munsell, S.

1999-02-01

14

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

15

Evaluation of base widening methods on flexible pavements in Wyoming  

NASA Astrophysics Data System (ADS)

The surface transportation system forms the biggest infrastructure investment in the United States of which the roadway pavement is an integral part. Maintaining the roadways can involve rehabilitation in the form of widening, which requires a longitudinal joint between the existing and new pavement sections to accommodate wider travel lanes, additional travel lanes or modification to shoulder widths. Several methods are utilized for the joint construction between the existing and new pavement sections including vertical, tapered and stepped joints. The objective of this research is to develop a formal recommendation for the preferred joint construction method that provides the best base layer support for the state of Wyoming. Field collection of Dynamic Cone Penetrometer (DCP) data, Falling Weight Deflectometer (FWD) data, base samples for gradation and moisture content were conducted on 28 existing and 4 newly constructed pavement widening projects. A survey of constructability issues on widening projects as experienced by WYDOT engineers was undertaken. Costs of each joint type were compared as well. Results of the analyses indicate that the tapered joint type showed relatively better pavement strength compared to the vertical joint type and could be the preferred joint construction method. The tapered joint type also showed significant base material savings than the vertical joint type. The vertical joint has an 18% increase in cost compared to the tapered joint. This research is intended to provide information and/or recommendation to state policy makers as to which of the base widening joint techniques (vertical, tapered, stepped) for flexible pavement provides better pavement performance.

Offei, Edward

16

Pore-system characteristics of pavement seam materials of urban sites  

Microsoft Academic Search

Summary The original light-brown sandy seam filling of pavements in urban areas turns dark and changes its properties by the time due to various inputs of urban dust. Deposited Corg inputs do mostly not have natural characteristics but are man-made, e.g., diesel dust. Thus, properties of the seam material are not predictable from experiences with forest or agricultural soils. Semiperviously

Thomas Nehls; Grzegorz Jozefaciuk; Zofia Soko?owska; Mieczyslaw Hajnos; Gerd Wessolek

2006-01-01

17

Rut Resistance Behavior of Pavement Structures Combined by the Different Asphalt Mixtures  

Microsoft Academic Search

In this paper rut resistance behavior of pavement structures combined by the different asphalt mixtures is presented. Nine types of Hot Mix Asphalt (HMA) and ten types of their different combinations are experienced with China's wheel tracking tester in this study. They are composed of three types of aggregate gradation including a coarse, a middle and a fine gradation of

Fan Tong-jiang

2010-01-01

18

General outlook of pavement and vehicle dynamics  

SciTech Connect

The interaction between vehicle and pavement is complex since pavement roughness excites the dynamic forces generated by vehicles, while these dynamic forces simultaneously increase the pavement roughness. The objective of this paper is to provide an overview of the results of recent research related to pavement and vehicle dynamics and their interaction and to evaluate their potential use in the design and management of pavements. Pavement dynamic models are capable of determining stresses, strains, and deflections in various directions when harmonic, pulse, or transient loads are applied. Vehicle dynamic models simulate the effect of pavement roughness on the inertia of various vehicle components. These models can predict the dynamic forces produced by different axles and wheels of traveling vehicles at different locations along the pavement. Pavement response computed using dynamic models matches field measurements closer than those computed using static models. The concept of vehicle-pavement interaction can be applied to weigh-in-motion, pavement design and performance, and vehicle regulations.

Mamlouk, M.S. [Arizona State Univ., Tempe, AZ (United States). Dept. of Civil and Environmental Engineering

1997-11-01

19

Mix Type Selection for Perpetual Pavements  

Microsoft Academic Search

The notion of long-life asphalt pavements or Perpetual Pavements came about in the 1960s, although they were not recognized as such at that time. Using thick layers of HMA was seen as a way of reducing the total section thickness of the pavement. Since then, it has become apparent that this approach to design can lead to asphalt pavements that

David E. Newcomb; Kent R. Hansen

20

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

21

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

22

Assessment of secondary materials for pavement construction: Technical and environmental aspects  

SciTech Connect

Current research at the University of Nottingham to enable the use of secondary materials in road construction covers technical aspects, mechanical properties of waste materials and the environmental implications of their use. Materials studied are minestone, china clay sand, slate waste, pulverized fuel ash and furnace bottom ash. The laboratory program set up for this research and the methodologies suggested for the study of the properties of these materials are presented. The test methods currently used to select pavement aggregates are presented along with current methods for the assessment of the environmental impact of secondary aggregates. The potential of the secondary aggregates is assessed within the current technical and environmental procedures previously presented. Two new methodologies are presented, one for the mechanical examination of secondary aggregates and one for the environmental assessment. The mechanical assessment encompasses conventional characterization and classification tests on both unbound and lightly treated pavement materials, and fundamental tests such as repeated load triaxial tests (RLTT) and repeated load indirect tensile tests (RLITT). Some sample results are presented, suggesting the feasibility and adequacy of this methodology for material discrimination, and evaluation of mechanical properties for design purposes. The environmental assessment indicates how the leaching concentration of contaminants from intensive testing can be used as the first step in assessing the environmental acceptability of a secondary material, and the means of determining a more realistic measure of in situ performance is discussed. The advantages and advancements of the presented methodologies over the basic and inappropriate techniques currently used to assess the suitability of secondary aggregates for use as pavement construction materials are discussed.

Nunes, M.C.M. [Univ. of Nottingham (United Kingdom). Dept. of Civil Engineering] [Univ. of Nottingham (United Kingdom). Dept. of Civil Engineering; [National Lab. of Civil Engineering, Lisbon (Portugal); Bridges, M.G.; Dawson, A.R. [Univ. of Nottingham (United Kingdom). Dept. of Civil Engineering] [Univ. of Nottingham (United Kingdom). Dept. of Civil Engineering

1996-12-31

23

Study on thin-layer antiskid and flame retardant colored pavement material for tunnels  

Microsoft Academic Search

???? Abstract-In order to improve the antiskid ability of tunnel pavement and reduce fire loss for tunnels, a kind of thin-layer antiskid and flame retardant colored pavement material was prepared. This material was composed of adhesive base material and colored antiskid aggregate. Firstly film forming substance was prepared by polyurethane\\/epoxy resin IPN composite. Secondly, adhesive base material was composed of

Liu Hengquan; Zhang Zhiyong; Guo Donghua; Peng Lei; Bao Zuojun; Han Wenyuan

2011-01-01

24

Impact of pavement conditions on crash severity.  

PubMed

Pavement condition has been known as a key factor related to ride quality, but it is less clear how exactly pavement conditions are related to traffic crashes. The researchers used Geographic Information System (GIS) to link Texas Department of Transportation (TxDOT) Crash Record Information System (CRIS) data and Pavement Management Information System (PMIS) data, which provided an opportunity to examine the impact of pavement conditions on traffic crashes in depth. The study analyzed the correlation between several key pavement condition ratings or scores and crash severity based on a large number of crashes in Texas between 2008 and 2009. The results in general suggested that poor pavement condition scores and ratings were associated with proportionally more severe crashes, but very poor pavement conditions were actually associated with less severe crashes. Very good pavement conditions might induce speeding behaviors and therefore could have caused more severe crashes, especially on non-freeway arterials and during favorable driving conditions. In addition, the results showed that the effects of pavement conditions on crash severity were more evident for passenger vehicles than for commercial vehicles. These results provide insights on how pavement conditions may have contributed to crashes, which may be valuable for safety improvement during pavement design and maintenance. Readers should notice that, although the study found statistically significant effects of pavement variables on crash severity, the effects were rather minor in reality as suggested by frequency analyses. PMID:23892046

Li, Yingfeng; Liu, Chunxiao; Ding, Liang

2013-10-01

25

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

26

The Impact of Cloud Type on Surface Radiation and Road Pavement Temperature  

NASA Astrophysics Data System (ADS)

Forecast systems provide decision support for end-users ranging from the solar energy industry to municipalities concerned with winter road maintenance. The racing community also relies on racetrack pavement temperature forecast systems because tire friction decreases as temperature increases, affecting vehicle performance. Race crews perform vehicle maintenance (e.g., tire pressure and suspension adjustments) to maximize traction given a forecasted racetrack temperature. Many forecast systems suffer from inaccurate radiation forecasts resulting in part from a lack of information relating radiation to cloud types. This research seeks to improve the forecasts by determining how cloud type impacts the amount of solar radiation reaching the surface. Cloud type information was obtained from the Naval Research Laboratory Cloud Classifier algorithm and radiation data were obtained from a Davis Weather Station. A theoretical maximum solar radiation distribution was calculated. Cloud type-radiation distribution analyses from Salisbury, North Carolina during May-June 2012 indicated that low clouds allowed approximately 20% of the maximum possible radiation to reach the surface, mid level clouds 32%, high clouds 40% and cumuliform types 34%. A categorical regression analysis revealed 33% of the variation in solar radiation on cloudy case days can be explained by cloud type. Inclusion of clear case days with apparent variability lowered this to 7% suggesting another influence on radiation. A similar bulk statistical analysis is in progress on a much larger data set obtained from the Oklahoma Mesonet. This work lays the foundation for use of satellite cloud type information in order to improve the output of forecast systems. Distribution of mean solar radiation measured at the surface for all nine case studies, sorted by cloud type height characteristics, where n represents the sample size.

Walker, C. L.; Anderson, A.; Chapman, M.; Drobot, S.

2012-12-01

27

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

Gürü, Metin; Cubuk, M Kür?at; Arslan, Deniz; Farzanian, S Ali; Bilici, Ibrahim

2014-08-30

28

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

29

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.

30

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

31

Functionality Enhancement of Industrialized Optical Fiber Sensors and System Developed for Full-Scale Pavement Monitoring  

PubMed Central

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

32

Auto-synchronized laser scanning range sensor for thermoplastic pavement marking material thickness measurement  

NASA Astrophysics Data System (ADS)

Pavement marking materials provide delineation on highways around the world. The condition of the marking materials is very important for the driver's safety as well as the comfort and the driving expenses. Currently thermoplastic pavement marking materials (TPMM) are widely used in states. Measuring the thickness of TPMM on pavement is an essential index to monitor the contractors, calculate durability of marking materials, and provide better information for the pavement marking evaluation. In recent years to measure the thickness of TPMM, a procedure involving pre-embedded plates sprayed with the marking materials has been widely accepted. This method is labor intensive, and cannot obtain a continuous-thickness profile. Therefore there are demands to develop a high-speed automatic measuring system for determining the thickness and uniformity of marking materials. In this paper, a laser range sensor based on auto-synchronized laser scanning is proposed for the thermoplastic pavement marking material thickness measurement. Compare to classical triangulation method, this approach doesn't scarify the system resolution for large field of view and it is more suitable for highway speed measurement. To achieve high speed measurement, PSD (Position Sensitive Detector) is used in the prototype system instead of CCD (Charge Couple Device) in traditional auto-synchronized system. The standoff distance and transverse scan range of the prototype system both are 1 foot. The lab test results show that the prototype system can measure the thermoplastic type thickness with error in 5mil at laser scanning rate up to 50Hz.

Sun, Wei; Chen, Xuemin; Chen, Yuanhang; Ekbote, Aditya; Liu, Richard Ce

2006-03-01

33

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

34

Pavement management  

SciTech Connect

The 11 papers in this report deal with the following areas: effect of pavement roughness on vehicle fuel consumption; rational seasonal load restrictions and overload permits; state-level pavement monitoring program; data requirements for long-term monitoring of pavements as a basis for development of multiple regression relations; simplified pavement management at the network level; combined priority programming of maintenance and rehabilitation for pavement networks; Arizona pavement management system: Phase 2-verification of performance prediction models and development of data base; overview of paver pavement management system; economic analysis of field implementation of paver pavement management system; development of a statewide pavement maintenance management system; and, prediction of pavement maintenance expenditure by using a statistical cost function.

Ross, F.R.; Connor, B.; Lytton, R.L.; Darter, M.I.; Shahin, M.Y.

1982-01-01

35

Vibration of vehicle-pavement coupled system based on a Timoshenko beam on a nonlinear foundation  

NASA Astrophysics Data System (ADS)

This paper focuses on the coupled nonlinear vibration of vehicle-pavement system. The pavement is modeled as a Timoshenko beam resting on a six-parameter foundation. The vehicle is simplified as a spring-mass-damper oscillator. For the first time, the dynamic response of vehicle-pavement coupled system is studied by modeling the pavement as a Timoshenko beam resting on a nonlinear foundation. Consequently, the shear effects and the rotational inertia of the pavement are included in the modeling process. The pavement model is assumed to be a linear-plus-cubic Pasternak-type foundation. Furthermore, the convergent Galerkin truncation is used to obtain approximate solutions to the coupled vibratory response of the vehicle-pavement coupled system. The dynamic responses of the vehicle-pavement system with the asphalt pavement on soft soil foundation are investigated via the numerical examples. The numerical results show that the calculation for the coupled vibratory response needs high-order modes. Moreover, the coupling effects between the pavement and the vehicle are numerically examined by using the convergent modal truncation. The physical parameters of the vehicle-pavement system such as the shear modulus are compared for determining their influences on the coupled vibratory response.

Ding, Hu; Yang, Yan; Chen, Li-Qun; Yang, Shao-Pu

2014-12-01

36

Contribution of lateral processes to stone pavement formation in deserts inferred from clast orientation patterns  

NASA Astrophysics Data System (ADS)

Stone pavements are widespread landforms of arid environments. They typically develop by accretionary rise above a thickening aeolian mantle which usually contains a surficial vesicular unit. Hence, stone pavements are regarded as stable landforms and, thus, are often used as surface-age indicators. We studied orientation patterns of pavement clasts and depict their geometrical properties. We introduce a new statistical approach for quantitative description of circular data. From four study regions in a wide variety of environmental settings we show that preferred, non-random orientation of clast length axes is a recurrent feature of modern stone pavements. Orientation is primarily determined by no other relief parameter than slope aspect. In 40 out of 52 measured plots an angle of 72 ± 9° separates two angle maxima. The same patterns are present in stone lines buried under a cover of aeolian dust. We interpret these features as fossil stone pavements, accordingly. Furthermore, on artificially cleared plots disturbed stone pavements begin to recover within few months by a process which creates essentially the same orientation pattern. We suggest that lateral surficial processes such as unconcentrated overland flow and creep contribute to the formation and maintenance of stone pavements as well as to this preferred clast orientation. They arrange clasts symmetrical to slope aspect with an angle determined by the axes ratio of the transported object. This results in the frequent bimodal pattern of stone length axes. This special type of transport requires previous accumulation of aeolian material forming a fine grained, even vesicular layer. Thus, there is close relationship between stone pavement and vesicular layer. We conclude that lateral processes take part in stone pavement formation. The commonly accepted model of dust accretion, which is not rendered obsolete by our findings, has to be complemented by this lateral component. This has implications for the stability of stone pavement-covered surfaces and for their applicability as age indicators. Quickly resealing disturbances as well as fossilised stone pavements imply this prominent desert surface feature may become fragile and transient.

Dietze, Michael; Kleber, Arno

2012-02-01

37

Possible environmental impacts of recycled glass used as a pavement base material.  

PubMed

In theory, glass diverted or recovered from the municipal solid waste (MSW) stream can be used as feedstock (glass cullet) in the production of new glass containers. However, post-consumer glass typically contains a mixture of clear and coloured material and is often contaminated with other wastes; characteristics that are impediments to the production of new containers. Sorting and cleaning of glass diverted from MSW to make it feasible for use in bottle industries are also time consuming and costly tasks. There is, however, the potential to use recycled glass as a sub-base material for road pavement construction. Geotechnical investigations to date suggest that use of recycled glass as a roadway sub-base could be cost-effective, and thus preclude the need for expensive sorting. There is, however, the necessessity to further investigate the potential short- and long-term toxicity, health hazards, and/or environmental pollution associated with use of mixed glass cullet as an aggregate, considering conditions during stockpiled storage and after placement. The results of laboratory tests on recycled glass regarding its potential to release pollutants to the environment via leaching are presented herein. Five random samples of crushed glasses were collected from a recycling company in Melbourne, Australia. The parameters tested for each sample were total organic matter, heavy metals, sulfates, chlorides, conductivity, pH and surfactant levels. It wais found that in most cases, the contamination levels were within the State of Victoria's Environmental Protection Agency-specified limits for manual handling, thus indicating that recycled glass could probably be safely used in pavement sub-bases. PMID:22627644

Imteaz, Monzur Alam; Ali, M M Younus; Arulrajah, Arul

2012-09-01

38

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

39

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

40

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

41

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

42

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

43

Unintended Impacts of Increased Truck Loads on Pavement Supply-Chain Emissions  

E-print Network

Unintended Impacts of Increased Truck Loads on Pavement Supply-Chain Emissions Nakul Sathaye, Arpad by pavements. The supply chain associated with pavement maintenance and construction releases significant air tailpipe versus pavement supplychain emissions. In some cases, unintended emissions from the pavement

California at Berkeley, University of

44

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

45

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

46

An evaluation of the flexible pavement design system FPS19  

E-print Network

The flexible pavement design program used by the Texas Department of Transportation (TXDOT) for the past 20 years, FPS1 1 , uses the Stiffness Coefficient, based on Dynaflect deflections, to characterize pavement strength. The difficulty...

Carmona, Gerardo M

2012-06-07

47

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

48

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

49

A study of load transfer capacities of four types of transverse contraction joints in concrete pavements  

E-print Network

the averages of all measurements that the corrugated metal point should. place first, then the crimp contraotion point, the plain dummy )oint, and the staring point. Xt must be yointed out that all 4efleotion measuremento were obtained in April, 19...) starlug Joint, ($) plain Joint and (4) corrugated metal Joint. These Joints were contained in separate oavements ha~ing different widths& this)encases? and Joint spacing. Also some of the pavements oonta1ned expansion and. ?arp1ng Joints in addition...

McDonald, James Newton

2012-06-07

50

Principles of bituminous pavement design and the recent trends Animesh Das1  

E-print Network

Principles of bituminous pavement design and the recent trends Animesh Das1 Introduction Understanding pavement behaviour is a complex task. This complexity is due to the complex response of the individual pavement materials which is very difficult to predict. In a typical pavement a number

Das, Animesh

51

Pavement condition data analysis  

SciTech Connect

This paper describes a computer methodology for analyzing pavement condition data to define inputs for pavement management systems. This system of programs was developed during a Federal Highway Administration research project. In the project, eight state highway departments were studied to determine the types of pavement condition data collected, procedures used for collecting data, the inputs to the states' pavement management systems, and computer programs used by the states to analyze raw pavement condition data. Several of the programs were assembled into the Method for Analyzing Pavement Condition, MAPCON, during a project performed at Pennsylvania State University. These and other existing or new programs (a total of 18) were identified, tested, modified, and incorporated onto a MS/DOS microcomputer system. MAPCON guides the user through selection of analysis method, raw data entry, and data analysis.

Zaniewski, J.P.; Hudson, S.W.; Hudson, W.R.

1987-07-01

52

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

53

The evaluation of airfield pavements  

E-print Network

for the multiple-wheel assembly, because the stress patterns do not over- lap appreciably at shallow depths, ? Wheel Load -- ? ? Pavement Base Pressure Distribution ? Subgrade Figure 2. Distribution of Pressure Produced by a Single Wheel Load ? Thin... loading conditions. It is an accepted theorem of the engineering profession that the value and accuracy of a test procedure is directly related to how well the test corresponds to field conditions. It is easily seen that bearing values obtained...

Poor, Arthur Reginald

2012-06-07

54

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

55

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

56

Long Term Monitoring of Moisture Under Pavements.  

National Technical Information Service (NTIS)

Monitoring of the environmental instrumentation installed under select pavement sections constructed by the Ohio Department of Transportation (ODOT) in 1995 on US 23 in Delaware County, Ohio was continued. The measurements made consisted of soil moisture,...

J. Howdyshell, T. Butalia, W. Wolfe

2010-01-01

57

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

E-print Network

considerations include a description of hazards en- countered in handling liquid sulfur. These hazards are the emission of toxic gases above 320'F (160'C), fires, explosions, and burns. Symptoms of exposure to these hazards are described and first aid... evaluated for exposure to noxious and obnox1ous emiss1ons due to the presence of sulfur in the pavement. Included in this study are methods of monitoring the potent1ally hazardous products as deter- mined from laboratory data and simulated field tests...

Jacobs, Carolyn Yuriko

2012-06-07

58

Evaluation of flexible pavement performance life in Florida. Final research report, October 1993--June 1998  

SciTech Connect

The pavement performance life provides information on how long a particular pavement type will typically last before it needs rehabilitation. This study presents the research effort to estimate the average flexible pavement performance life in Florida. Two data files of Pavement Condition Survey (PCS) and Work Program Administration (WPA) were used for this study. SAS programs were applied to analyze and manipulate these two data files. The pavement performance condition curves were developed for a large sample size of pavement sections based on the polynomial model. The average pavement performance lives were evaluated for each pavement group based on the performance curves. The results of the evaluation showed that the primary system had longer average performance life than the interstate system. Generally, the polynomial model performed well in fitting the data. The pavement performance curve indicates that if M and R are performed while the pavement is still in the `slow rate of deterioration` phase, life cycle cost may be reduced.

Ping, W.V.; He, Y.

1998-06-01

59

Directory of certified insulation material. Sorted by type and manufacturer  

SciTech Connect

Insulation materials that have been certified as complying with the regulations that became effective September 22, 1981 are identified in the directory. Six physical forms of insulation are covered: board; foil; foam and spray; blanket; loose fill; and water heater kits, duct, and pipe wrap. Information on the manufacturer and brand name; material, type, facings; primary use, usage exposure, vapor barrier; labeled product thickness, and labeled thermal performance is given. (MCW)

Not Available

1982-03-01

60

Influence of vehicular positions and thermal effects on structural behaviour of concrete pavement  

Microsoft Academic Search

Structural response of concrete pavements is influenced by the position of the axle loads and if critical load positions are not considered in concrete pavement analysis, the design may be inadequate and lead to early failure of the pavement. Whilst there has been a great deal of research conducted on concrete pavement performance and deterioration under vehicular loads and environmental

David P. Thambiratnam; Andreas Nataatmadja; Daksh Baweja

61

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

62

Surface Loading of a Multilayered Viscoelastic Pavement: Semianalytical Solution  

E-print Network

response of a linear viscoelastic pavement. The material parameters of the asphalt concrete are characterized by the relaxation modulus and creep compliance, which are further represented by the Prony series modulus and creep compliance are used simultaneously, instead of only one parameter in the conventional

Pan, Ernie

63

Evaluation of the existing performance models used for pavement management by the Texas Department of Transportation  

E-print Network

68 70 70 70 77 80 81 85 tx CHAPTER COMPARISON OF PERFORMANCE PERIODS EFFECT OF POISSON'S RATIO IV DEVELOPMENT OF RESEARCH DATABASE GENERAL LONG TERM PAVEMENT PERFORMANCE DATA Background . LTPP Experiments . Structure of the LTPP IMS... 68 70 70 70 77 80 81 85 tx CHAPTER COMPARISON OF PERFORMANCE PERIODS EFFECT OF POISSON'S RATIO IV DEVELOPMENT OF RESEARCH DATABASE GENERAL LONG TERM PAVEMENT PERFORMANCE DATA Background . LTPP Experiments . Structure of the LTPP IMS...

Mukherjee, Biswajit

2012-06-07

64

The impact of fine aggregate characteristics on asphalt concrete pavement design life  

Microsoft Academic Search

The development of the Mechanistic–Empirical Pavement Design Guide (MEPDG) provides an opportunity to simulate the performance of pavements. This paper considers the impact of fine aggregate on the predicted performances of pavements by simulating the performance differences between pavement mixes prepared with different sources of fine aggregate with different gradations using the MEPDG. A natural and four manufactured sands from

Tamer M. Breakah; Jason P. Bausano; R. Christopher Williams; Stan Vitton

2011-01-01

65

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

Microsoft Academic Search

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

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

1992-01-01

66

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

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

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

69

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

70

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

71

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

72

of Concrete Pavements Joint PerformanCe  

E-print Network

practitioners under- stand how to optimize concrete pavement joint perfor- mance through the identificationof Concrete Pavements Joint PerformanCe interim Guide for optimum JUNE 2012 #12;#12;Interim Guide for Optimum Joint Performance of Concrete Pavements i Technical Report Documentation Page 1. Report No. 2

73

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

E-print Network

to the human environment, causing noise, air pollution and traffic congestion; moreover, they exert of the RUP concept in decreasing the public nuisance caused by pavement and road network maintenance work

Paris-Sud XI, Université de

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

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

Federal Register 2010, 2011, 2012, 2013

...DEPARTMENT OF TRANSPORTATION Federal Highway Administration [FHWA Docket No. FHWA-2013-0014...Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses AGENCY: Federal Highway Administration (FHWA), DOT. ACTION:...

2013-05-08

76

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

77

PRECAST REPLACEMENT OF CONCRETE PAVEMENT SLABS (Tollway) Effective: March 30, 2009  

E-print Network

PRECAST REPLACEMENT OF CONCRETE PAVEMENT SLABS (Tollway) Effective: March 30, 2009 Revised: October 19, 2012 DESCRIPTION. This work shall consist of the removal of existing concrete pavement, restoration of the subbase material, the installation of precast concrete pavement slabs in accordance

78

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

79

Nondestructive Evaluation of Pavements Ultrasonic  

E-print Network

Nondestructive Evaluation of Pavements Ð Ultrasonic Tomography Kyle Hoegh, Graduate Student Dr. Lev:// pavementndt.weebly.com #12;Outline ·! Ultrasonic Tomography Overview ·! Georgia Example ·! MnROAD ­!Joint.weebly.com #12;Ultrasonic Methods: Pros and Cons ·! Advantages ­! Multiple applications ·! Thickness

Minnesota, University of

80

AUTOMATIC DETECTION AND CLASSIFICATION OF DEFECT ON ROAD PAVEMENT USING ANISOTROPY MEASURE  

E-print Network

AUTOMATIC DETECTION AND CLASSIFICATION OF DEFECT ON ROAD PAVEMENT USING ANISOTROPY MEASURE Tien Sy-sy.nguyen@etu.univ-orleans.fr ABSTRACT Existing systems for automated pavement defect detection can only identify cracking type defects for the inspectors and road users [1]. In the last few years, several automated pavement inspecting systems which use

Paris-Sud XI, Université de

81

Optimum mix design of enhanced permeable concrete – An experimental investigation  

Microsoft Academic Search

Permeable pavement, due to its high porosity and permeability, is considered as an alternative to traditional impervious hard pavements for controlling stormwater in an economical and friendly environmental way. Permeable concrete normally made of single-sized aggregate bound together by Portland cement, using restrictedly as a pavement material, because of its insufficient structural strength. Aimed at developing a new type of

C. Lian; Y. Zhuge

2010-01-01

82

Analysis of engineering characteristics of pavement deflection trends  

SciTech Connect

This paper describes analysis of pavement deflection data collected by the Transport Research Laboratory at two experimental road sites in England during 1960--1985. Measurements of Benkelman beam deflections together with records of traffic loading were taken at 6 to 12 month intervals. The analysis investigates the deflection trend as a function of road base material and thickness. The deflection trend was represented by a negative exponential curve form. Engineering aspects of the curve form were extracted and statistically analyzed. The results obtained focus on the dependency of deflection progression on both road base material and thickness, which are shown to act either jointly or singly, depending on the engineering characteristic of the pavement deflection trend.

Kerali, H.R.; Lawrance, A.J. [Univ. of Birmingham (United Kingdom)] [Univ. of Birmingham (United Kingdom)

1999-05-01

83

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

84

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

85

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

86

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

E-print Network

SOURCE: UNIVERSITY OF CALIFORNIA PAVEMENT RESEARCH CENTER FIGURE 1 Moisture-induced stripping in asphalt treated base layer PAVEMENT TECHNOLOGY UPDATE This Technology Transfer Program publication is provided by the University of California Pavement Research Center. The University of California Pavement

California at Berkeley, University of

87

Use of scrap rubber in asphalt pavement surfaces. Special report  

SciTech Connect

Scrap tire rubber was mixed into an asphalt concrete wearing course to study the effect of ice disbonding from the pavement surface under traffic. Rubber contents of 0, 3, 6, and 12% by weight were studied. Initial laboratory ice disbonding test results led to the development of a new paving material, Chunk Rubber Asphalt Concrete (CRAC), that uses larger pieces of rubber in a much denser asphalt concrete mix. Strength values doubled and ice disbonding performance was enhanced.

Eaton, R.A.; Roberts, R.J.; Blackburn, R.R.

1991-12-01

88

Adaptive prediction of pavement performance  

E-print Network

Zulyaminayn, B. S, Bangladesh University of Engineering and Technology Chair of Advisory Committee Dr Roger E. Smith A Visual Basic 60 computer program for adjusting family performance curves in TM making reasonable predictions of individual pavement..., in years, and alpha, a horizontal asymptote factor that controls the maximum range of distress growth or ride loss, base of the natural logarithms (e = 2. 71828. . . ), chi, a weighting factor that controls performance, epsilon, a climate weightmg...

Zulyaminayn, Mohammed

2012-06-07

89

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

90

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

91

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

92

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

93

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

94

Experimental Study on Geocell-Reinforced Recycled Asphalt Pavement (RAP) Bases under Static and Cyclic Loading  

E-print Network

Recycled Asphalt Pavement (RAP) is a removed and reprocessed pavement material containing asphalt and aggregates which can be used as a base course material for pavement applications. Geocells are a three-dimensional interconnected honeycomb type...

Thakur, Jitendra Kumar

2011-01-13

95

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

96

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

97

Field performance of geosynthetic reinforced pavements over expansive clay subgrades  

E-print Network

cracks on the pavement structures. Traditionally the problems related to flexible pavements over flexible pavements. 1 INTRODUCTION Basal reinforcement of pavement systems has been used for the purposes of the soil in the vicinity of the pave- ment shoulders (Figure 1a). This leads to settlements in the shoulder

Zornberg, Jorge G.

98

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-m×30-m test site composed by a flexible pavement structure. The horizontal sampling resolution amounted to 2.4×10-2 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

99

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

100

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

101

Mechanistic modeling of roughness on continuously reinforced concrete pavement  

E-print Network

MECHANISTIC MODELING OF ROUGHNESS ON CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS A Thesis by SUPRIYA SRIRAMAN Submitted to the OAice of graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1996 Major Subject: Civil Engineering MECHANISTIC MODELING OF ROUGHNESS ON CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS A Thesis by SUPRIYA SRI~ Submitted to Texas A&M University in partial fulfillment of the requirements...

Sriraman, Supriya

2012-06-07

102

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

2012-06-07

103

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

104

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

105

Development of equations to determine the increase in pavement condition due to treatment and the rate of decrease in condition after treatment for a local agency pavement network.  

E-print Network

DEVELOPMENT OF EQUATIONS TO DETERMINE THE INCREASE IN PAVEMENT CONDITION DUE TO TREATMENT AND THE RATE OF DECREASE IN CONDITION AFTER TREATMENT FOR A LOCAL AGENCY PAVEMENT NETWORK A Thesis by MAITHILEE MUKUND DESHMUKH Submitted... CONDITION DUE TO TREATMENT AND THE RATE OF DECREASE IN CONDITION AFTER TREATMENT FOR A LOCAL AGENCY PAVEMENT NETWORK A Thesis by MAITHILEE MUKUND DESHMUKH Submitted to the Office of Graduate Studies of Texas A&M University in partial...

Deshmukh, Maithilee Mukund.

2010-07-14

106

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

107

Adaptive Road Crack Detection System by Pavement Classification  

PubMed Central

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

Gavilan, Miguel; Balcones, David; Marcos, Oscar; Llorca, David F.; Sotelo, Miguel A.; Parra, Ignacio; Ocana, Manuel; Aliseda, Pedro; Yarza, Pedro; Amirola, Alejandro

2011-01-01

108

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

109

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 8×8 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

110

Reflectance of interurban-road pavements from radar-based measurements  

NASA Astrophysics Data System (ADS)

Reflectance measurements in interurban-road typical pavements are essential for traffic security. The reflectance of interurban-road pavements presents high variability due to such variables as climatic and atmospheric conditions and the presence of foreign materials on the road (e.g. dirt, fuel or oil). For this reason, the recording of real-time measurements for these kinds of pavements is a complex task. However, its critical importance in traffic safety demands precise measurements under all the possible conditions. In this context, the use of remote-sensing systems working in the radar spectral range is of great interest. With active sensors that receive their own radar signal, the reflectance measurements made by the remote-sensing system are not influenced by the atmospheric conditions. In this work, we present a radar-based methodology to develop real-time measurements of the reflectance in typical interurban-road pavements. We are engaged in extending this new method to study the reflectance of interurban-road pavements within the visible spectrum.

Fernandez, Paz; Peña-García, Antonio; Poyatos-Martínez, David; Escot-Bocanegra, David; Fernández-Oliveras, Alicia

2013-11-01

111

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

112

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

113

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

in pavements. In this model, oxygen transport and reaction were described mathematically as two interlinked steps: 1) diffusion and/or flow of oxygen from the atmosphere above the pavement into the interconnected air voids in the pavement; and 2) diffusion...

Han, Rongbin

2012-07-16

114

Influence of Recycled Asphalt Pavement on Fatigue Performance of Asphalt Concrete Base Courses  

Microsoft Academic Search

This paper presents the physical properties of recycled asphalt pavement RAP and its influence on the mechanical perfor- mance of a binder course asphalt pavement mix. A series of binder course mixes were designed containing varying percentages of RAP. A mix made from only virgin material was selected as the control mix for the investigation. The effect of introducing RAP

Amir Tabakovic?; Amanda Gibney; Ciaran McNally; Michael D. Gilchrist

2010-01-01

115

International Journal of Road Materials and Pavement Design. V.5., 4, pp. 435-452, 2004.  

E-print Network

or field observations. There is not enough mechanistic interpretation is available in the literature performed to evaluate the intermediate- and low-temperature fatigue cracking parameters of typical ARM repetition before developing fatigue cracking. Most of the current studies are based on empirical relations

Mobasher, Barzin

116

Evaluation of pavement base and subgrade material properties and test procedures  

E-print Network

was essential for accomplishing this work and especially that of Mr. Charles Shlieker. The author also wishes to thank his parents Dr. and Mrs. J. C Titus-Glover, his sister and brother in law Dr, and Mrs. P. A. Hagan, his brothers Andrew and Cyril, Dr... changes from granular to fme grained, the K, value approach's zero. The model is flexible and is capable of a resilient modulus decrease as the octahedral shear stress increases and a resilient modulus increase as the first stress invariant increases...

Titus-Glover, Leslie

2012-06-07

117

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

Microsoft Academic Search

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

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

2001-01-01

118

Effects of overlay designs on reliability of flexible pavements  

Microsoft Academic Search

Management of flexible pavements requires timely application of preventive maintenance and rehabilitation actions such as overlays. These actions are an integral part of a design strategy that minimises the use of recourses over the pavement's life-cycle. The objective of this paper is to develop a reliability model for flexible pavements that accounts for the effects of overlay designs. In this

Vighnesh P. Deshpande; Ivan D. Damnjanovic; Paolo Gardoni

2010-01-01

119

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

120

The environmental influence of asphalt pavement and countermeasures  

Microsoft Academic Search

To asphalt pavement, because asphalt is polymer materials, the aging of asphalt cannot be ignored; bituminous mixture is made up of asphalt and aggregate, meanwhile it contains interior pore space. Because of the rheology behaviour of bituminous, bituminous mixture will emerge viscous-plastic deformation under traffic load, and because of the porous in it, the water which enters the pore will

Qingguo Yang; Jincheng Ning

2011-01-01

121

Truck fleet model for design and assessment of flexible pavements  

Microsoft Academic Search

The mechanistic empirical method of flexible pavement design\\/assessment uses a large number of numerical truck model runs to predict a history of dynamic load. The pattern of dynamic load distribution along the pavement is a key factor in the design\\/assessment of flexible pavement. While this can be measured in particular cases, there are no reliable methods of predicting the mean

Abraham Belay; Eugene Obrien; Dirk Kroese

2008-01-01

122

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

123

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

124

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

125

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

126

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

127

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.

128

The Concrete and Pavement Challenge  

ERIC Educational Resources Information Center

The modern world is characterized by the extensive use of concrete and asphalt pavement. Periodically, these materials are replaced and the old materials disposed of. In this challenge, students will be asked to develop ways to reuse the old materials. It is important for students to understand how concrete and asphalt are made and applied, as…

Roman, Harry T.

2012-01-01

129

Research of infrared laser based pavement imaging and crack detection  

NASA Astrophysics Data System (ADS)

Road crack detection is seriously affected by many factors in actual applications, such as some shadows, road signs, oil stains, high frequency noise and so on. Due to these factors, the current crack detection methods can not distinguish the cracks in complex scenes. In order to solve this problem, a novel method based on infrared laser pavement imaging is proposed. Firstly, single sensor laser pavement imaging system is adopted to obtain pavement images, high power laser line projector is well used to resist various shadows. Secondly, the crack extraction algorithm which has merged multiple features intelligently is proposed to extract crack information. In this step, the non-negative feature and contrast feature are used to extract the basic crack information, and circular projection based on linearity feature is applied to enhance the crack area and eliminate noise. A series of experiments have been performed to test the proposed method, which shows that the proposed automatic extraction method is effective and advanced.

Hong, Hanyu; Wang, Shu; Zhang, Xiuhua; Jing, Genqiang

2013-08-01

130

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

131

Performance of segregated hot mix asphalt pavements  

Microsoft Academic Search

A laboratory study was conducted to evaluate the performance of segregated hot mix asphalt (HMA) pavements. The study involved simulating in-situ segregation of two current projects. Tests in the study were a laboratory wheel track test (PURWheel) and triaxial tests (including resilient modulus). For each project four segregation levels were determined based on field observation and subsequent analysis of gradation,

Zhenghao Wang

2000-01-01

132

Sensitivity of the LCA allocation procedure for BFS recycled into pavement structures  

Microsoft Academic Search

The purpose of this paper is twofold: to investigate the problems involved when performing an environmental assessment of various pavements structures and to establish the method applied to solutions proposed by official French guidelines. This assessment will be performed by employing the life cycle assessment (LCA) methodology specifically adapted to road pavements through a parametric environmental evaluation tool developed by

Shahinaz Sayagh; Anne Ventura; Tung Hoang; Denis François; Agnès Jullien

2010-01-01

133

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

134

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

135

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

136

Evaluation of cold planers for grinding PCC pavements  

Microsoft Academic Search

Attempts by two contractors to use cold planing equipment to restore riding quality to faulted PCC pavements are reported. It was found that while the equipment could remove substantially all faulting and greatly improved riding quality, there was severe damage to the concrete adjacent to random cracks and transverse joints in spite of condiderable effort to prevent it. Because of

B. F. Neal; J. H. Woodstrom

1978-01-01

137

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

138

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

...used. 2. The daytime color of non-fluorescent retroreflective materials may be measured...CIE observer shall be used. 3. For fluorescent retroreflective materials ASTM E991...luminous factor to be measured. The fluorescent luminous factor must be determined...

2010-04-01

139

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

...used. 2. The daytime color of non-fluorescent retroreflective materials may be measured...CIE observer shall be used. 3. For fluorescent retroreflective materials ASTM E991...luminous factor to be measured. The fluorescent luminous factor must be determined...

2011-04-01

140

Use of noncontact sensors for paving operations on airport pavements  

NASA Astrophysics Data System (ADS)

The Swedish National Road Administration has been using a laser range finder system for assessing longitudinal and transversa profiles of pavements for a number of years. The Civil Administration has expressed interest in trying automated methods for surveying airfield runways. Regardless of sampling method, the data re used as input for computer aided design of new pavement surfaces. Typically, the output will consist of tables and maps of where to pave and mill the old pavement surface. Adjusting an old surface to perfectly smooth standards may require continuously changing the new pavement layer thickness. Traditionally, this was often carried out with mechanical devices, usually in direct touch with a wire. Some manufacturers now offer non-contact devices for pavers such as ultra sound sensors as an alternative to the mechanical sensors thus eliminating the need for setting up sires. The method was tested in late 1997 after the output data were converted for a design to be read directly by a paver control unit. A larger test was done in the summer of 1998. The results were promising and the Royal Swedish Fortifications Administration decided to try the method on a taxiway in 1999. The present paper describes some of the experiences obtained with this method and computer controlled equipment in general.

Lenngren, Carl A.

1999-01-01

141

76 FR 67018 - Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather Information Systems  

Federal Register 2010, 2011, 2012, 2013

...Airport In-Pavement Stationary Runway Weather Information Systems AGENCY: Federal Aviation...Manufacturers of In-Pavement Stationary Runway Weather Information Systems...Passive In- Pavement Stationary Runway Weather Information Systems that meet the...

2011-10-28

142

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

143

Evaluation of pavement layers` interface bonding conditions using a falling weight deflectometer  

SciTech Connect

The paper describes advanced analysis procedures to evaluate pavement layers` interface bonding conditions using non-destructive techniques and Falling Weight Deflectometer surveys. The pavement mechanical properties in terms of the layers` moduli were evaluated under the impact of a dynamic loading by using the Falling Weight Deflectometer (FWD) surveys. The results revealed that the use of the advanced analysis procedures allows for more accurate calculation of the pavement mechanical properties and thus more accurate analysis of the pavement`s structure life. This is one of the advantages of the advanced analysis procedure since the restriction imposed on the conventional back calculation methods that full bonding between the individual layers exist, has been relaxed.

Al-Nageim, H.; Al-Hakim, B.; Lesley, L. [Liverpool John Moores Univ. (United Kingdom). School of the Built Environment

1997-07-01

144

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

145

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

146

Dielectric characterization of unstabilized aggregate base materials  

E-print Network

investigates the correlation of dielectric values obtained using the dielectric probe in the laboratory with those calculated from GPR measurements of granular base materials beneath different pavement surfaces in field conditions. The influence of the type...

Guthrie, William Spencer

2012-06-07

147

Evaluation of low temperature cracking in asphalt pavement mixes. Technical report  

SciTech Connect

This report examines the feasibility of using the thermal stress restrained specimen test to evaluate low temperature cracking in asphalt pavement mixes. Data were collected from laboratory and field evaluations. Various mixing, aging, and compaction methods were used to prepare test samples with materials obtained from two WYDOT highway projects. Field data were obtained from two recently built test sections to compare with laboratory test results. Pavement condition surveys quantified low temperature cracking of both test sections after one winter. Temperature data for these projects sites were also collected. Pavement condition and temperature data were compared to results from the thermal stress restrained specimen test.

Ksaibati, K.; Erickson, R.

1998-10-01

148

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

149

Pavement performance equations. Final report  

SciTech Connect

The WSDOT PMS data base was used to develop regression equations for three pavement surface types: bituminous surface treatments, asphalt concrete, and portland-cement concrete. The primary regression equations developed were to predict Pavement Condition Rating (PCR) which is a measure of the pavement surface distress (ranges from 100 (no distress) to below 0 (extensive distress)). Overall, the equations fit the data rather well given the expected variation of pavement performance information. The relative effects of age (time since construction or reconstruction) were illustrated for the three surface types.

Mahoney, J.P.; Kay, R.K.; Jackson, N.C.

1988-03-01

150

Pavement Systems Analyses.  

National Technical Information Service (NTIS)

Contents: Prestressed concrete highway pavement at Dulles International Airport; Relative effects of structural variables on the performance of continuous pavements; Finite-element analysis of concrete slabs and its implications for rigid pavement design;...

B. F. Friberg, T. J. Pasko

1973-01-01

151

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

152

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

153

COLORADO DEPARTMENT OF TRANSPORTATION Sustainability of Concrete Pavement  

E-print Network

COLORADO DEPARTMENT OF TRANSPORTATION Sustainability of Concrete Pavement I-225 - Mississippi to 6 · 2 Mile Reconstruction Existing: · 4 Lane Divided Highway · 8" Concrete Pavement (Recycled on-site) · 4" Asphalt Overlay (Recycled off-site) Project Design: · 6 Lane Divided Highway · 13" Concrete

154

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, 57�78, 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.

155

Recycled asphalt pavement as a base and sub-base material  

SciTech Connect

Laboratory and field investigations were conducted to evaluate the use of recycled asphalt pavement (RAP) in roadway base and sub-base applications. The laboratory resilient modulus test results showed RAP has comparable strength with dense graded aggregate base and sub-base material used in the state of New Jersey. Using the spectral-analysis-of-the-surface-waves method (SASW), the field testing program evaluated the elastic modulus of the RAP base in the field and verified the laboratory results. The field test results showed higher modulus and stiffness for RAP than the dense graded aggregate base normally used in state of New Jersey.

Maher, M.H.; Gucunski, N.; Papp, W.J. Jr. [Rutgers Univ., Piscataway, NJ (United States). Dept. of Civil and Environmental Engineering

1997-12-31

156

Determining the sidewalk pavement width by using pedestrian discomfort levels and movement characteristics  

Microsoft Academic Search

This paper presents a sidewalk pavement width design method for making more pedestrian friendly and walk-inspiring sidewalk\\u000a pavements in the urban area. Instead of using the current sidewalk pavement width design standard that usually leads to having\\u000a minimum values, this research investigated pedestrians’ preferences on the levels of service, surveyed actual foot path trajectories\\u000a in the sidewalk pavements, and observed

Sangyoup Kim; Jaisung Choi; Yongseok Kim

2011-01-01

157

Asphalt Pavement Aging and TemperatureAsphalt Pavement Aging and Temperature Dependent Properties using a FunctionallyDependent Properties using a Functionally  

E-print Network

Asphalt Pavement Aging and TemperatureAsphalt Pavement Aging and Temperature Dependent Properties Analysis Time Integration Analysis Application Examples: Asphalt Pavement Summary and Conclusions #12) � Large fraction produced as hot-mix asphalt (HMA) � Most common form of pavement surfacing material (96

Paulino, Glaucio H.

158

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 pavement temperature could change the texture surface of the pavement. The aim of this work is to analyze the influence of the surface temperature on the macrotexture of a semidense asphalt pavement located in an urban

Boyer, Edmond

159

Leaching of organic contaminants from storage of reclaimed asphalt pavement  

Microsoft Academic Search

Recycling of asphalt has been promoted by rapid increases in both the use and price of petroleum?based bitumen. Semi?volatile organic compounds in leachates from reclaimed asphalt pavement, measured in field samples and in laboratory column test, were analysed through a GC\\/MS screen?test methodology. Sixteen PAH (polyaromatic hydrocarbons) were also analysed in leachates from the column study. The highest concentrations of

Malin Norin

2004-01-01

160

Micro-topographic analysis of shell pavements formed by aeolian transport in a wind tunnel simulation  

NASA Astrophysics Data System (ADS)

Beach surfaces containing shell materials represent one end-member of a range of environments in which armoring is the primary control on wind erosion. Unlike spheres and cylinders which have formed the basis of theoretical model formulation and much of the early work in wind tunnels, mollusc shells have complex and non-uniform shapes which vary with their orientation. Identification of shell perimeter, height and frontal area relative to the bed area (roughness density) is therefore a formidable task, but nonetheless is essential for modeling sediment entrainment from beach surfaces. A methodology is suggested in this paper for capturing and analyzing these geospatial data, in the context of a wind tunnel simulation designed to improve understanding of the geophysical processes involved in armoring. For deposits where non-erodible shells represent half of the volume of the parent material, the surface appears to be highly stable to wind erosion from the outset, although minor reworking of the intervening, erodible sediment does occur. In comparison, the shell coverage must increase to approximately 30% during wind erosion events in order for any given beach surface to stabilize, especially beach deposits with a low concentration of shells by volume. With suitable calibration, the Raupach shear stress partitioning model can be forced to perform well in predicting the threshold conditions for particle entrainment. However, this approach overlooks the pivotal involvement of particle impact and ricochet in the creation and sculpting of the armored bed. As a case in point, when the shells are removed from digital elevation models of armored beach surfaces formed in aeolian systems, the adjusted topography is not suggestive of the presence of coherent flow structures (e.g., horseshoe vortices and wedge shaped shelter areas) as assumed to exist in the stress partitioning approach for isolated flows. This would suggest that future work on the armoring of natural surfaces affected by wind erosion must allow for more complexity in the flow perturbation.

McKenna Neuman, Cheryl; Li, Bailiang; Nash, David

2012-12-01

161

An analysis of some properties of paving asphalts in Texas as they relate to pavement performance  

E-print Network

AN ANALYSIS OF SOME PROPERTIES OF PAVING ASPHALTS IN TEXAS AS THEY RELATE TO PAVEMENT PERFORMANCE A Thesis by EMMETT HAYGOOO DUBOSE, JR. Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August, 1980 Major Subject: Civil Engineering AN ANALYSIS OF SOME PROPERTIES OF PAVING ASPHALTS IN TEXAS AS THEY RELATE TO PAVEMENT PERFORMANCE A Thesis by EMMETT HAYGOOD DUBOSE, JR. Approved as to style and content by...

DuBose, Emmett Haygood

2012-06-07

162

Field study of effects of construction procedures on concrete pavement surfaces  

E-print Network

PIELD STUDY OF EPPECTS OP CONSTRUCTION PROCEDURES ON CONCRETE PAVEMENT SURFACES A Thesis by JEFFREY LELAND DAVIS Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OP... SCIENCE May 1973 Major Subject: Civil Engineering FIELD STUDY OF EFFECTS OF CONSTRUCTION PROCEDURES ON CONCRETE PAVEMENT SURFACES A Thesis by JEFFREY LELAND DAVIS Approved as to style and content by: ai of ommittee (Head of Department (Member...

Davis, Jeffrey Leland

2012-06-07

163

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

164

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

E-print Network

of cooling dense urban areas and reducing the urban heat11 island effect has been studied since the 1990's; pavement heat flux; pavement-watering; urban heat island; climate change25 adaptation; heat wave26 1 [3], this technique is viewed as an efficient means of reducing urban31 heat island (UHI) intensity

Paris-Sud XI, Université de

165

Full-Depth Pavement Reclamation with Foamed Asphalt: FWD Backcalculation on Interstate Highway 80 Rehabilitation Sections  

Microsoft Academic Search

The conclusions from the backcalculation analysis are as follows: The overall stiffness values of the two pavement structures indicated by the surface moduli are similar. The variation along the section is typical of that of other projects in which the pavement structure is relatively homogenous. The average backcalculated stiffness of the cold foam material combined with the existing asphalt concrete

John T Harvey; Pengcheng Fu; Nicholas Coetzee; Per Ullidtz

2005-01-01

166

Geotextiles in Flexible Pavement Construction  

ERIC Educational Resources Information Center

People everywhere in the developed world regularly drive on paved roads. Learning about the construction techniques and materials used in paving benefits technology and construction students. This article discusses the use of geosynthetic textiles in pavement construction. It presents background on pavements and describes geotextiles and drainage…

Alungbe, Gabriel D.

2004-01-01

167

Stiffness characterisation of full-scale airfield test pavements using computational intelligence techniques  

Microsoft Academic Search

The falling weight deflectometer (FWD) is a non-destructive test equipment used to assess the structural condition of highway and airfield pavement systems and to determine the moduli of pavement layers. The backcalculated moduli are not only good pavement layer condition indicators but are also necessary inputs for conducting mechanistic based pavement structural analysis. In this study, artificial neural networks (ANNs)-based

Kasthurirangan Gopalakrishnan; Halil Ceylan

2008-01-01

168

Assessment of durability performance of "Early-Opening-to-Traffic" Portland Cement Concrete pavement and patches  

E-print Network

ASSESSMENT OF DURABILITY PERFORMANCE OF "EARLY-OPENING-TO-TRAFFIC" PORTLAND CEMENT CONCRETE PAVEMENT AND PATCHES A Thesis by PRADHUMNA BABU SHRESTHA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of thc requirements for the degree of M A STER OF SCIENCE August 1999 Major Subject: Civil Engineering ASSESSMENT OF DURABILITY PERFORMANCE OF "EARLY-OPENING-TO-TRAFFIC" PORTLAND CEMENT CONCRETE PAVEMENT AND PATCHES A Thesis by PRADHUMNA BABU...

Shrestha, Pradhumna Babu

2012-06-07

169

Effect of pervious and impervious pavement on the rhizosphere of American Sweetgum (Liquidambar styraciflua)  

E-print Network

Mature trees help to offset urban area problems caused by impervious pavement. Trees in paved areas remain unhealthy due to a poor root zone environment. The objective of this experiment was to test if soil under pervious concrete, with greater...

Viswanathan, Bhavana

2012-07-16

170

Truck fleet model for design and assessment of flexible pavements  

NASA Astrophysics Data System (ADS)

The mechanistic empirical method of flexible pavement design/assessment uses a large number of numerical truck model runs to predict a history of dynamic load. The pattern of dynamic load distribution along the pavement is a key factor in the design/assessment of flexible pavement. While this can be measured in particular cases, there are no reliable methods of predicting the mean pattern for typical traffic conditions. A simple linear quarter car model which aims to reproduce the mean and variance of dynamic loading of the truck fleet at a given site is developed here. This probabilistic model reflects the range and frequency of the different heavy trucks on the road and their dynamic properties. Multiple Sensor Weigh-in-Motion data can be used to calibrate the model. Truck properties such as suspension stiffness, suspension damping, sprung mass, unsprung mass and tyre stiffness are represented as randomly varying parameters in the fleet model. It is used to predict the statistical distribution of dynamic load at each measurement point. The concept is demonstrated by using a pre-defined truck fleet to calculate a pattern of statistical spatial repeatability and is tested by using that pattern to find the truck statistical properties that generated it.

Belay, Abraham; OBrien, Eugene; Kroese, Dirk

2008-04-01

171

Measurements of the Stiffness and Thickness of the Pavement Asphalt Layer Using the Enhanced Resonance Search Method  

PubMed Central

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; Mohd Nayan, Khairul Anuar

2014-01-01

172

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

173

Effects of pavement markings on vehicle paths in a dual left turn  

E-print Network

EFFECTS OF PAVEMENT MARKINGS ON VEHICLE PATHS IN A DUAL LEFT TURN A Thesis by KATHRYN FITZPATRICK SIMMONS Submitted t. o the Graduate College of Texas ASM University in partial fulfillment of the requi rements for the degree of MASTER... OF SCIENCE Augus. 1984 Major Subject: Civil Fngi neeri ng EFFECTS OF PAVEMENT MARKINGS ON VEHICLE PATHS IN A DUAL LEFT TURN A Thesis by KATHRYN FITZPATRICK SIMMONS Approved as to style and content by: Donald L. Woods (Chairman of Committee) John M...

Simmons, Kathryn Fitzpatrick

2012-06-07

174

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

2012-06-07

175

Asphaltic concrete overlays of rigid and flexible pavements  

NASA Astrophysics Data System (ADS)

The development of a mechanistic approach to overlay thickness selection is described. The procedure utilizes a deflection analysis to determine pavement rehabilitation needs. Design guides for selecting the overlay thickness are presented. Tolerable deflection-traffic load relationships and the deflection attenuation properties of asphaltic concrete were developed, representing the subgrade support conditions and properties of materials used in Louisiana. All deflection measurements on asphaltic concrete were corrected for the effect of temperature. Deflection measurements taken before and after overlay were also adjusted to minimize the effects of seasonal subgrade moisture variation.

Kinchen, R. W.; Temple, W. H.

1980-10-01

176

Characterization of Fatigue Performance of WesTrack Pavement Using Work Potential Theory  

Microsoft Academic Search

Superior Performing Asphalt Pavement (SuperPave) is the final product of SHRP asphalt research program and has been adopted by most of the state highway agencies in the united states. However, results from a well-controlled experimental construction project, WesTrack, are against SuperPave volumetric design method. For WesTrack pavements, the asphalt mixes with fine gradation performed than mixes with coarse gradation better

Haifang Wen

2003-01-01

177

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

E-print Network

changes during the different modes of aging processes. Unaged asphalts meeting the same specifications can show drastic differences in field performance under the same pavement conditions, as borne out by many field tests (10, 30, 54). Several... changes during the different modes of aging processes. Unaged asphalts meeting the same specifications can show drastic differences in field performance under the same pavement conditions, as borne out by many field tests (10, 30, 54). Several...

Lau, Chee Keung

2012-06-07

178

An investigation of factors that significantly affect pavement maintenance costs in Texas  

E-print Network

including average daily traffic, equivalent single axle loads, distress score, ride score, annual rainfall, annual freeze/thaw cycles, functional classification, as well as the district that maintains the pavement. For each pavement type and highway...

Fogle, Kendall Lee

2012-06-07

179

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

PubMed Central

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 and pavement cells of mature leaves. Single cell samples of these three cells types were collected by glass micro-capillaries. Real-time reverse transcription (RT)-PCR was used to analyse expression patterns of the following transcription factors: MYB23, MYB55, AtHB1, FILAMENTOUS FLOWER (FIL)/YABBY1 (YAB1), TRIPTYCHON (TRY) and CAPRICE (CPC). A difference in the expression patterns of TRY and CPC was revealed. Contrary to the CPC expression pattern, no transcripts of TRY could be detected in pavement cells. FIL/YAB1 was exclusively expressed in trichome cells. AtHB1 was highly expressed throughout all three cell types. MYB55 was higher expressed in basal cells than in trichome and pavement cells. MYB23 showed a pattern of low expression in pavement cells, medium in basal cells and high expression in trichomes. Expression patterns obtained by single cell sampling and real-time RT-PCR were compared to promoter GUS fusions of the selected transcription factors. Therefore, we regenerated two transgenic Arabidopsis lines that expressed the GUS reporter gene under control of the promoters of MYB55 and YAB1. In conclusion, despite their function in leaf morphogenesis, all six transcription factors were detected in mature leaves. Furthermore, single cell sampling and promoter GUS staining patterns demonstrated the predominant presence of MYB55 in basal cells as compared to pavement cells and trichomes. PMID:20101514

Schliep, Martin; Ebert, Berit; Simon-Rosin, Ulrike; Zoeller, Daniela

2010-01-01

180

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

181

The role of urban surfaces (permeable pavements) in regulating drainage and evaporation: development of a laboratory simulation experiment  

Microsoft Academic Search

Permeable pavements and similar stormwater control devices have not been exploited in the UK, in part because their adoption has been hindered by a lack of detailed knowledge of their hydrological performance. This paper describes a research programme that produced detailed information on the hydrological behaviour of a car park surface. The study involved the construction of full-scale permeable pavement

C. T. Andersen; I. D. L. Foster; C. J. Pratt

1999-01-01

182

Use of lug anchors to related pavement movement  

NASA Astrophysics Data System (ADS)

Minnesota Department of Transporatation's policy is that grades in the 3 to 5 percent and greater range are steep and may require lug anchors. Standard lug anchor spacing varies from 150 feet, center to center, for 3 percent grades to 75 feet, center to center, for 5 percent and greater grades. Conclusions are: (1) that lug anchors do prevent the downhill movement of the concrete pavement; (2) that when lug anchors are used a perforated pipe system also be built to collect the surface water that enters the pavement structure thus eliminating the anticipated base pumping and pavement settlement.

Oakey, S. A.

1980-04-01

183

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 Seinäjoki 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.

Poikajärvi, J.; Peisa, K.; Narbro, A.

2012-04-01

184

Automated pavement crack detection  

E-print Network

AUTOMATED PAVEMENT CRACK DETECTION A Thesis by ASHOK MADHAVA RAO Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1991 Major Subject...: Electrical Engineering AUTOMATED PAVEMENT CRACK DETECTION A Thesis by ASHOK MADHAVA RAO Approved as to style and content by . c Norman C. Grisw d (Chair of Committ ) Nasser Kehtarnavaz (Member) g, J~, Karan Watson Robert L. Lytt (Member) Jo W...

Rao, Ashok Madhava

2012-06-07

185

Continuous monitoring of mining induced strain in a road pavement using fiber Bragg grating sensors  

NASA Astrophysics Data System (ADS)

This paper describes the application of fiber Bragg grating (FBG) based sensors for monitoring road pavement strains caused by mining induced ground subsidence as a result of underground longwall coal mining beneath a major highway in New South Wales, Australia. After a lengthy planning period, the risks to the highway pavement were successfully managed by the highway authority and the mining company through a technical committee. The technical committee comprised representatives of the mining company, the highway authority and specialists in the fields of pavement engineering, geotechnical engineering and subsidence. An important component of the management strategy is the installation of a total of 840 strain and temperature sensors in the highway pavement using FBG arrays encapsulated in glass-fiber composite cables. The sensors and associated demodulation equipment provide continuous strain measurements along the pavement, enabling on-going monitoring of the effects of mining subsidence on the pavement and timely implementation of planned mitigation and response measures to ensure the safety and serviceability of the highway throughout the mining period.

Nosenzo, Giorgio; Whelan, B. E.; Brunton, M.; Kay, Daryl; Buys, Henk

2013-06-01

186

Continuous monitoring of mining induced strain in a road pavement using fibre Bragg grating sensors  

NASA Astrophysics Data System (ADS)

This paper describes the application of Fibre Bragg Grating (FBG) based sensors for monitoring road pavement strains caused by mining induced ground subsidence as a result of underground longwall coal mining beneath a major highway in New South Wales, Australia. After a lengthy planning period, the risks to the highway pavement were successfully managed by the highway authority and the mining company through a technical committee. The technical committee comprised representatives of the mining company, the highway authority and specialists in the fields of pavement engineering, geotechnical engineering and subsidence. An important component of the management strategy is the installation of a total of 840 strain and temperature sensors in the highway pavement using FBG arrays encapsulated in glass-fibre composite cables. The sensors and associated demodulation equipment provide continuous strain measurements along the pavement, enabling on-going monitoring of the effects of mining subsidence on the pavement and timely implementation of planned mitigation and response measures to ensure the safety and serviceability of the highway throughout the mining period.

Whelan, B. E.; Brunton, M.; Nosenzo, Giorgio; Kay, Daryl; Buys, Henk

2012-02-01

187

Systematic conversion of single walled carbon nanotubes into n-type thermoelectric materials by molecular dopants.  

PubMed

Thermoelectrics is a challenging issue for modern and future energy conversion and recovery technology. Carbon nanotubes are promising active thermoelectic materials owing to their narrow bandgap energy and high charge carrier mobility, and they can be integrated into flexible thermoelectrics that can recover any waste heat. We here report air-stable n-type single walled carbon nanotubes with a variety of weak electron donors in the range of HOMO level between ca. -4.4 eV and ca. -5.6 eV, in which partial uphill electron injection from the dopant to the conduction band of single walled carbon nanotubes is dominant. We display flexible films of the doped single walled carbon nanotubes possessing significantly large thermoelectric effect, which is applicable to flexible ambient thermoelectric modules. PMID:24276090

Nonoguchi, Yoshiyuki; Ohashi, Kenji; Kanazawa, Rui; Ashiba, Koji; Hata, Kenji; Nakagawa, Tetsuya; Adachi, Chihaya; Tanase, Tomoaki; Kawai, Tsuyoshi

2013-01-01

188

Leaching of organic contaminants from storage of reclaimed asphalt pavement.  

PubMed

Recycling of asphalt has been promoted by rapid increases in both the use and price of petroleum-based bitumen. Semi-volatile organic compounds in leachates from reclaimed asphalt pavement, measured in field samples and in laboratory column test, were analysed through a GC/MS screen-test methodology. Sixteen PAH (polyaromatic hydrocarbons) were also analysed in leachates from the column study. The highest concentrations of semi-volatile compounds, approximately 400 microg l(-1), were measured in field samples from the scarified stockpile. Naphthalene, butylated hydroxytoluene (BHT) and dibutyl phthalate (DBP) were the most dominant of the identified semi-volatiles. The occurrence of these compounds in urban groundwater, also indicate high emission rates and persistent structures of the compounds, making them potentially hazardous. Car exhausts, rubber tires and the asphalt material itself are all probable emission sources, determined from the organic contaminants released from the stockpiles. The major leaching mechanism indicated was dissolution of organic contaminants from the surface of the asphalt gravels. In the laboratory column test, the release of high-molecular weight and more toxic PAH was higher in the leachates after two years than at the commencement of storage. The concentrations of semi-volatiles in leachates, were also several times lower than those from the field stockpile. These results demonstrate the need to follow up laboratory column test with real field measurements. PMID:15176747

Norin, Malin; Strömvall, A M

2004-03-01

189

Implications of reliability in mechanistic/empirical pavement design applications  

E-print Network

At present there are many design procedures for both asphalt and concrete pavement structures. The object of any one of these design procedures being to produce a quality riding structure that will satisfy the design engineer and the riding public...

Killingsworth, Brian Mark

2012-06-07

190

User's Guide: Cold-Mix Recycling of Asphalt Concrete Pavements.  

National Technical Information Service (NTIS)

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 wit...

J. E. Shoenberger

1992-01-01

191

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

192

Material-specific effects of hydrated lime on the properties and performance behavior of asphalt mixtures and asphaltic pavements  

Microsoft Academic Search

This study evaluates hydrated lime-treated hot-mix asphalt (HMA) mixtures through various laboratory tests, including the dynamic modulus test and performance tests to characterize permanent deformation and fatigue damage resistance both in displacement-controlled and force-controlled modes. Two different asphalt mixtures — the asphalt concrete mixture and the fine aggregate asphalt matrix mixture — which differ only in the amount of additional

Francisco Thiago Sacramento Aragão; Junghun Lee; Yong-Rak Kim; Pravat Karki

2010-01-01

193

Development of a Pavement Maintenance and Rehabilitation Project Formation and Prioritization Methodology that Reflects Agency Priorities and Improves Network Condition  

E-print Network

deficiencies through on-site inspection and execution of M&R projects (Haas and Hudson 1978). These concepts are demonstrated in the case of the Texas 2 Department of Transportation (TxDOT) whose pavement management data and processes are the subject...) (Haas et al. 2001). The PCI incorporates data from 19 different types of pavement distresses as well as their severity and quantity (Moazami et al. 2011). In Texas, the Condition Score (CS) replaces PCI as the indicator of pavement condition. In two...

Narciso, Paul John Ross

2013-07-22

194

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

195

Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates for the TXDOT Pavement Management Information System - Final Report.  

National Technical Information Service (NTIS)

This project conducted a thorough review of the existing Pavement Management Information System (PMIS) database, performance models, needs estimates, utility curves, and scores calculations, as well as a review of District practices concerning the three b...

A. Wimsatt, A. T. Papagiannakis, C. Chang-Albitres, C. Gurganus, I. Abdallah, J. Weissmann, N. Gharaibeh, S. Nazarian, S. Saliminejad, T. Freeman

2012-01-01

196

Effects of impervious pavements on reducing runoff in an arid urban catchment  

NASA Astrophysics Data System (ADS)

The progressive urbanization of US arid and semi-arid southwestern territories has transformed undeveloped aridlands into dynamic, radially expanding metropolitan centers. As these mature, infill development further reduces undeveloped area, inversely coupling surface imperviousness to infiltration rates, with a subsequent increase in runoff generation. Intensified runoff carries undesirable environmental consequences, magnifying urban flooding events and concentrations, transport, and propagation of contaminants. Pervious pavements offer one potential solution for decreased urban infiltration. At present, the application potential of pervious pavements as an effective urban infiltration management tool exceeds its exploitation. While entirely eliminating urban Total Impervious Area is not a feasible solution, pervious pavements significantly reduce Effective Impervious Area at costs competitive with traditional Best Management Practices. Previous research into pervious pavements has largely consisted of laboratory prototypes or small-scale field experiments, with a heavy bias towards parking lots. In this study we explore the effectiveness of pervious pavements in increasing infiltration, thus decreasing runoff volume during summer monsoonal and winter convective rainfall events in an 8 ha residential catchment in Scottsdale, Arizona. Analysis focuses on the interaction dynamics between surface area of pervious pavement application and its net effect on runoff response at the catchment level. Hydrological response was modeled using MAHLERAN (Model for Assessing Hillslope-Landscape Erosion, Runoff and Nutrients), a spatially explicit, event-based model, parameterized at a spatial resolution of 0.25 sq m. Data for model parameterization was obtained from analysis of aerial imagery and field-based monitoring of surface properties. The model was tested against measurements of flow at the catchment outlet for multiple rainfall events with total event rainfall ranging from 5 mm to 25 mm. Model testing shows total event discharge simulated well, although low Nash-Sutcliffe coefficients for events indicate a poor fit between the shape and timing of the modeled and monitored hydrograph, which we attribute to poor characterization of friction factors in urban catchments. Scenario-based model analysis tested catchment response to substitution of pervious for conventional pavement by percent and pavement-function scenarios. Results are consistent with previous findings in that short duration-high intensity storms trigger threshold infiltration capacity, past which pervious pavement damping of runoff volume levels off, approaching conventional levels. However at the modeled catchment scale, this initial damping represents a significant reduction in volume, peak flow velocity, and contaminant loading potential. Urban surface drainage networks concentrate and channel flow along roads: the capacity of pervious pavements to simultaneously increase infiltration directly at location of greatest runoff and mitigate inflow effects from remote points has compelling potential as a hydrologic and urban systems engineering tool.

Epshtein, O.; Turnbull, L.; Earl, S.

2011-12-01

197

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.

198

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

199

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

200

Experimental pavement delineation treatments  

NASA Astrophysics Data System (ADS)

Visibility and durability of materials used to delineate shoulders and medians adjacent to asphalt pavements were evaluated. Materials evaluated were polysulfide and coal tar epoxies, one and two component polyesters, portland cement, acrylic paints, modified-alkyd traffic paint, preformed plastic tape, and thermoplastic markings. Neat applications, sand mortars, and surface treatments were installed in several geometric patterns including cross hatches, solid median treatments, and various widths of edge lines. Thermoplastic pavement markings generally performed very well, providing good visibility under adverse viewing conditions for at least 4 years. Thermoplastic 4 in. wide edge lines appear to provide adequate visibility for most conditions.

Bryden, J. E.; Lorini, R. A.

1981-06-01

201

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

202

PERFORMANCE-BASED CONTRACTING IN CONSTRUCTION PHASE AND MAINTENANCE PHASE OF PAVEMENT  

NASA Astrophysics Data System (ADS)

Performance-based contracting for pavement in Japan started as performance warranties in construction phase, in 1999. Recently, road agencies have recognized the applicability of this type of contracting in outsourcing of maintenance activities. The objectives of this study are to clarify the issues of performance specifying in construction phase and maintenance phase of pavement, and to propose measures to be taken. This paper, with the recognition that the life of each pavement depends on performance standards for various attributes, reviews domestic and foreign examples of performance-based contracting. A performance standard based on the average of current practices can enhance product quality and service life with a warranty contract. Repair thresholds and response time for each deficiency should be considered as performance standards in maintenance phase.

Yoshida, Takeshi

203

Determination of the Presence Conditions of Pavement Markings using Image Processing  

E-print Network

.............................................................................................................................. 101    xii LIST OF FIGURES Page Figure 1 A Dual Relationship between the ? ? ? and ? ? ? Coordinates... markings: longitudinal lines, transverse lines, arrows, words and symbol markings, and special markings. The Manual on Uniform Traffic Control Devices (MUTCD) (1) defines that pavement markings are commonly placed using paint or thermoplastic materials...

Ge, Hancheng

2012-10-19

204

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 stress–strain response of asphalt pavement then can be quantified based on a single-variable perturbation. This

Han Zhu; Julie E. Nodes

2000-01-01

205

PRESERVING THE LONG LIFE CONCRETE PAVEMENT NETWORK OF THE WASHINGTON STATE DEPARTMENT OF TRANSPORTATION  

E-print Network

PRESERVING THE LONG LIFE CONCRETE PAVEMENT NETWORK OF THE WASHINGTON STATE DEPARTMENT The Washington State Department of Transportation (WSDOT) has about 2,360 lane miles of concrete pavements of these pavements combined with what WSDOT has learned in the intervening 40-50 years gives a high level

206

The clogging behaviour and treatment efficiency of a range of porous pavements  

Microsoft Academic Search

This paper presents the findings of a laboratory investigation into the clogging behaviour of three different porous pavements that were most representative of the available range and their pollutant removal efficiency over time. These pavements were monolithic Porous Asphalt (PA), Permapave (PP), and modular Hydrapave (HP). The pavements were dosed with a semi-synthetic stormwater mixture over a continuous period of

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

207

Environmental Assessment of Pavement Alternatives: Decision-Making in Light of  

E-print Network

Environmental Assessment of Pavement Alternatives: Decision-Making in Light of Current Knowledge, Davis, USA and University of California Pavement Research Center Davis, Berkeley UCLA Lake Arrowhead Symposium October 17-19, 2010 #12;What is the pavement infrastructure? � Freeways, highways � Roads

Handy, Susan L.

208

Pavement Design TTP Orientation Seminar  

E-print Network

Pavement Design TTP Orientation Seminar 2013 #12;What are Pavements? · Engineered structures vehicles ­Freight and freight handling ­Trains and trams ­Aircraft and spacecraft #12;Pavement Types · Surface Treatment ­ Thin sprayed asphalt on granular bases · Permeable Pavement ­ Open graded asphalt

Handy, Susan L.

209

Pavement Design TTP Orientation Seminar  

E-print Network

Pavement Design TTP Orientation Seminar 2010 #12;What are Pavements? · Engineered structures vehicles ­Freight and freight handling ­Trains and trams ­Aircraft and spacecraft #12;Pavement Types · Surface Treatment ­ Thin sprayed asphalt on granular bases · Permeable Pavement ­ Open graded asphalt

Handy, Susan L.

210

Pavement Design TTP Orientation Seminar  

E-print Network

Pavement Design TTP Orientation Seminar 2011 #12;What are Pavements? · Engineered structures vehicles ­Freight and freight handling ­Trains and trams ­Aircraft and spacecraft #12;Pavement Types · Surface Treatment ­ Thin sprayed asphalt on granular bases · Permeable Pavement ­ Open graded asphalt

Handy, Susan L.

211

A Study of the Performance of Three Asphalt Pavement Rehabilitation Strategies  

Microsoft Academic Search

This study analyzes the performance of three common hot mix asphalt rehabilitation strategies on 149 pavements over a period of seven years. All three strategies place two-inch overlays on the pavement to be rehabilitated. The first strategy includes an overlay on the existing pavement after sweeping the surface and applying a tack coat. The second strategy places the overlay after

Christopher Schmidt

212

Comparing finite element and constitutive modelling techniques for predicting rutting of asphalt pavements  

Microsoft Academic Search

This paper focuses on a comprehensive evaluation of the effects of different finite element (FE) modelling techniques and material constitutive models on predicting rutting in asphalt pavements under repeated loading conditions. Different simplified 2D and more realistic 3D loading techniques are simulated and compared for predicting asphalt rutting. This study also evaluates and compares the rutting performance predictions using different

Rashid K. Abu Al-Rub; Masoud K. Darabi; Chien-Wei Huang; Eyad A. Masad; Dallas N. Little

2012-01-01

213

Comparing finite element and constitutive modelling techniques for predicting rutting of asphalt pavements  

Microsoft Academic Search

This paper focuses on a comprehensive evaluation of the effects of different finite element (FE) modelling techniques and material constitutive models on predicting rutting in asphalt pavements under repeated loading conditions. Different simplified 2D and more realistic 3D loading techniques are simulated and compared for predicting asphalt rutting. This study also evaluates and compares the rutting performance predictions using different

Rashid K. Abu Al-Rub; Masoud K. Darabi; Chien-Wei Huang; Eyad A. Masad; Dallas N. Little

2011-01-01

214

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.

215

Extended wavelength InGaAs infrared detector arrays based on three types of material structures grown by MBE  

NASA Astrophysics Data System (ADS)

Extended wavelength InGaAs infrared detector arrays in 1.0~2.5?m spectral rang based on three types of material structures grown by MBE were studied. The first type InGaAs detectors, marked by sample 1#, were fabricated using Pi- N epitaxial materials, mesa etching technique, side-wall and surface passivating film. The second type InGaAs detectors, marked by sample 2#, were fabricated using N-i-P epitaxial materials, mesa etching technique, side-wall and surface passivating film. The third type InGaAs detectors, marked by sample 3#, were fabricated using n-i-n epitaxial materials, planar diffusion process and surface passivating coating. I-V curves, low frequency noise and response spectra of these detectors were measured at the different temperature. The response spectra of these detectors cover 1.0~2.5?m wavelength range. The dark current density of three types InGaAs detectors are 28nA/cm2, 2?A/cm2, 9?A/cm2 at 200K and -10mV bias voltage, respectively. Compared to Sample 2# and Sample 3#, sample 1# presents the lower dark current at the same temperature and the same bias voltage, which mainly results in the improvement of surface passivation film and the depth of mesa etching. The frequency spectrum of the noise of sample 1# has an inflection point at about 10Hz frequency, 1/f noise play an obviously role in the detectors below the 10Hz frequency.

Gong, Haimei; Li, Xue; Li, Tao; Tang, Hengjing; Shi, Ming; Shao, Xiumei; Zhang, Yonggang

2014-06-01

216

Life Cycle Assessment of Pavements: A Critical Review of Existing Literature and Research  

SciTech Connect

This report provides a critical review of existing literature and modeling tools related to life-cycle assessment (LCA) applied to pavements. The review finds that pavement LCA is an expanding but still limited research topic in the literature, and that the existing body of work exhibits methodological deficiencies and incompatibilities that serve as barriers to the widespread utilization of LCA by pavement engineers and policy makers. This review identifies five key issues in the current body of work: inconsistent functional units, improper system boundaries, imbalanced data for asphalt and cement, use of limited inventory and impact assessment categories, and poor overall utility. This review also identifies common data and modeling gaps in pavement LCAs that should be addressed in future work. These gaps include: the use phase (rolling resistance, albedo, carbonation, lighting, leachate, and tire wear and emissions), asphalt fumes, feedstock energy of bitumen, traffic delay, the maintenance phase, and the end-of-life phase. This review concludes with a comprehensive list of recommendations for future research, which shed light on where improvements in knowledge can be made that will benefit the accuracy and comprehensiveness of pavement LCAs moving forward.

Santero, Nicholas; Masanet, Eric; Horvath, Arpad

2010-04-20

217

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

218

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

219

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

220

Generation of phase nuclei by solitons of the new "undulator" type in martensitic phase transitions of crystalline materials  

NASA Astrophysics Data System (ADS)

The microdynamics of large-amplitude nonlinear lattice vibrations of plutonium and uranium materials has been investigated at high reactor temperatures in the ranges of martensitic phase transitions. Topologically new large-amplitude solitons of the "undulator" type have been revealed. Transverse and longitudinal "undulator" solitons in crystals with hexagonal and cubic symmetry, depending on the direction of motion, have different kinematic and amplitude characteristics, which differ from the characteristics of the previously known solitons. The transverse "undulator" solitons, like electrons in undulators, are observed with periodic atomic displacements orthogonal to the direction of soliton propagation. The longitudinal "undulator" solitons with displacements of atoms in the direction of soliton propagation are characterized by periodic delays with two-step velocities on the trajectory in a certain analogy with two-period engineering undulator devices. It has been shown that, at high energies, such "undulator" solitons of two types generate nuclei of a new phase in early stages of structural phase transitions.

Dubovsky, O. A.; Orlov, A. V.

2013-08-01

221

Development of ground-penetrating radar equipment for detecting pavement condition for preventive maintenance  

NASA Astrophysics Data System (ADS)

The report documents the development of a ground penetrating radar (GPR) system for locating potential maintenance problems in highway pavements. The report illustrates how GPR has the potential to detect four defects in pavements: stripping in an asphalt layer; moisture in base layer; voids or loss of support under rigid pavements; and overlay delamination.

Smith, S. S.; Scuillion, T.

1993-10-01

222

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

223

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

224

AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT  

E-print Network

AN IMPROVED DYNAMIC MODEL FOR THE STUDY OF A FLEXIBLE PAVEMENT A. El Ayadi 1 , B. Picoux 1 , G to study a Falling Weight Deectometer test conducted on a exible pavement. These dynamic models take with in situ measurements recorded on an instrumented pavement; such a comparison has indicated the importance

Avignon et des Pays de Vaucluse, Université de

225

Reduction of traffic and tire/pavement noise: 1st year results of the Arizona Quiet Pavement Program-Site III  

NASA Astrophysics Data System (ADS)

The Arizona Quiet Pavement Pilot Program overlaid major freeway segments in the Phoenix area with an Asphalt Rubber Friction Course (ARFC). The overlay was placed on various Portland Cement Concrete Pavement (PCCP) textures. Traffic noise reductions were evaluated by performing wayside traffic noise measurements and tire/pavement source level measurements. First year results for three different study sites are presented in this paper. Depending on the texture of the initial PCCP and microphone locations, reductions of up to 12 dBA in wayside traffic noise levels were measured. Similar reductions of tire/pavement source levels were measured. Results of the two methods are compared. Traffic conditions monitored during the measurements were modeled using the Federal Highway Administration's Traffic Noise Model (TNM 2.5) to compare modeled levels to those measured for PCCP and AFRC overlay conditions. The model under predicted levels for PCCP conditions and over predicted levels for AFRC conditions. The magnitude of under or over prediction varied with distance. The effect of propagation was examined and was aided by simultaneous measurements of wind conditions made by Arizona State University. TNM 2.5 was used to identify sound wall heights that were equivalent to the traffic noise reductions provided by the AFRC overlay.

Reyff, James A.; Donavan, Paul

2005-09-01

226

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

227

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

228

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

229

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 pavement section has been built on the full scale accelerated pavement testing facility of IFSTTAR

Boyer, Edmond

230

Hypolithic Microbial Community of Quartz Pavement in the High-Altitude Tundra of Central Tibet  

PubMed Central

The hypolithic microbial community associated with quartz pavement at a high-altitude tundra location in central Tibet is described. A small-scale ecological survey indicated that 36% of quartz rocks were colonized. Community profiling using terminal restriction fragment length polymorphism revealed no significant difference in community structure among a number of colonized rocks. Real-time quantitative PCR and phylogenetic analysis of environmental phylotypes obtained from clone libraries were used to elucidate community structure across all domains. The hypolithon was dominated by cyanobacterial phylotypes (73%) with relatively low frequencies of other bacterial phylotypes, largely represented by the chloroflexi, actinobacteria, and bacteriodetes. Unidentified crenarchaeal phylotypes accounted for 4% of recoverable phylotypes, while algae, fungi, and mosses were indicated by a small fraction of recoverable phylotypes. Electronic supplementary material The online version of this article (doi:10.1007/s00248-010-9653-2) contains supplementary material, which is available to authorized users. PMID:20336290

Wong, Fiona K. Y.; Lacap, Donnabella C.; Lau, Maggie C. Y.; Aitchison, J. C.; Cowan, Donald A.

2010-01-01

231

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

232

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

233

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 pavement types. Costs were calculated for one mile in one direction for initial construction and for the maintenance activities anticipated over a 50-year life span for each of the pavement types under consideration

234

Predicting pavement distress in oil field areas  

SciTech Connect

A study on oil field traffic characteristics was performed and a procedure was developed for assessing current and future effects of oil field truck traffic on surface-treated (stage construction type) pavements. A computer program calculates several types of pavement distress and serviceability parameters to evaluate pavement performance under various axle load repetitions. Stepwise regression analysis of 132 surface-treated pavement sections led to the development of individual distress equations for rutting, raveling, flushing, alligator cracking, patching, longitudinal and transverse cracking, and failures (potholes). The versatility of the program provides a means of anticipating early pavement failures due to increased axle load repetitions. The program also provides the basic framework for computing the effects of other ''special-use'' truck traffic demands.

Mason, J.M.; Scullion, T.; Stampley, B.E.

1983-05-01

235

Predicting pavement distress in oil field areas  

SciTech Connect

A study on oil field traffic characteristics was performed and a procedure was developed for assessing current and future effects of oil field truck traffic on surface-treated (stage construction type) pavements. A computer program calculates several types of pavement distress and serviceability parameters to evaluate pavement performance under various axle load repetitions. Stepwise regression analysis of 132 surface-treated pavement sections led to the development of individual distress equations for rutting, raveling, flushing, alligator cracking, patching, longitudinal and transverse cracking, and failures (potholes). The versatility of the program provides a means of anticipating early pavement failures due to increased axle load repetitions. The program also provides the basic framework for computing the effects of other ''special-use'' truck traffic demands.

Mason, J.M.; Scullion, T.; Stampley, B.E.

1984-05-01

236

The role of urban surfaces (permeable pavements) in regulating drainage and evaporation: development of a laboratory simulation experiment  

Microsoft Academic Search

Abstract: Permeable pavements and similar stormwater control devices have not been exploited in the UK, in part because their adoption,has been hindered,by a lack of detailed knowledge,of their hydrological performance. This paper describes a research programme,that produced,detailed information,on the hydrological behaviour of a car park surface. The study involved the construction,of full-scale permeable,pavement,model,car park structures and a rainfall simulator for

C. T. Andersen; I. D. L. Foster; C. J. Pratt

1999-01-01

237

Analysis, testing and verification of the behavior of composite pavements under Florida conditions using a heavy vehicle simulator  

NASA Astrophysics Data System (ADS)

Whitetopping (WT) is a rehabilitation method to resurface deteriorated asphalt pavements. While some of these composite pavements have performed very well carrying heavy load, other have shown poor performance with early cracking. With the objective of analyzing the applicability of WT pavements under Florida conditions, a total of nine full-scale WT test sections were constructed and tested using a Heavy Vehicle Simulator (HVS) in the APT facility at the FDOT Material Research Park. The test sections were instrumented to monitor both strain and temperature. A 3-D finite element model was developed to analyze the WT test sections. The model was calibrated and verified using measured FWD deflections and HVS load-induced strains from the test sections. The model was then used to evaluate the potential performance of these test sections under critical temperature-load condition in Florida. Six of the WT pavement test sections had a bonded concrete-asphalt interface by milling, cleaning and spraying with water the asphalt surface. This method produced excellent bonding at the interface, with shear strength of 195 to 220 psi. Three of the test sections were intended to have an unbonded concrete-asphalt interface by applying a debonding agent in the asphalt surface. However, shear strengths between 119 and 135 psi and a careful analysis of the strain and the temperature data indicated a partial bond condition. The computer model was able to satisfactorily model the behavior of the composite pavement by mainly considering material properties from standard laboratory tests and calibrating the spring elements used to model the interface. Reasonable matches between the measured and the calculated strains were achieved when a temperature-dependent AC elastic modulus was included in the analytical model. The expected numbers of repetitions of the 24-kip single axle loads at critical thermal condition were computed for the nine test sections based on maximum tensile stresses and fatigue theory. The results showed that 4" slabs can be used for heavy loads only for low-volume traffic. To withstand the critical load without fear of fatigue failure, 6" slabs and 8" slabs would be needed for joint spacings of 4' and 6', respectively.

Tapia Gutierrez, Patricio Enrique

238

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

239

RESEARCH REPORT 1250-1 EFFECT OF RECLAIMED ASPHALT PAVEMENT  

E-print Network

with the Federal Highway Administration. 16. Abstract While the use of reclaimed asphalt pavement (RAP) in asphalt system has prompted a need for specific Superpave guidelines for the use of RAP. In this study asphalts. The result of this study is a methodology for determining the effect of RAP on rheological

Texas at Austin, University of

240

Measurement and effects of segregated hot mix asphalt pavement  

Microsoft Academic Search

Asphalt mixture segregation is the nonuniform distribution of coarse and fine aggregate components. Because of segregation, early distress of asphalt pavement results. A test that identifies asphalt mixture segregation would be a significant contribution to asphalt technology.^ There are several factors that lead to segregation. Segregation can occur during stockpiling and handling of aggregate, and during mixing, storage, transport, and

Ronald Christopher Williams

1996-01-01

241

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

242

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

243

IMPLEMENTATION OF A DATABASE AND INFORMATION SYSTEM FOR FORENSIC INVESTIGATION OF PAVEMENTS 6. Performing Organization Code  

Microsoft Academic Search

16. Abstract This report describes the implementation of a database and information system for forensic investigation of pavements by enhancing the 1998 version of the ForenSys database software. The enhanced ForenSys database software can serve as the center component of an integrated forensic information and analysis system for analyzing forensic related data and information and producing forensic reports. In the

Zhanmin Zhang; Chunrong Zhou

244

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

245

Article title misstates the role of pavement sealers.  

PubMed

The claim made in the title of Witter et al. (2014) "Coal-tar-based sealcoated pavement: A major PAH source to urban stream sediments" is not supported by the data presented. The author's use of Pearson correlation coefficients is insufficient to indicate causation. The application of spatial analysis and principle component analysis did not include sealer specific inputs, so provides no basis for the claim. To test the hypothesis that sealers are a source of PAHs in the stream studied, EPA's Chemical Mass Balance (CMB) source evaluation model was applied to Witter's sediment data. CMB found an excellent fit (R(2) > 0.999) between measured and modeled PAH concentrations when sealers were not included as a potential source. This finding does not support Witter et al. (2014) claim that sealers are a major source of PAHs. PMID:24373812

O'Reilly, Kirk

2014-08-01

246

An evaluation of pavement markings and raised pavement markers at left exit lane drops  

E-print Network

components; more drivers are affected, interactions in the traffic stream are more turbulent, and the potential for confusion and accidents is substantially greater. Exit-only signs and pavement markings are two methods used to communicate an exit lane drop...

Lance, Marty Tina

2012-06-07

247

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

248

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

249

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

1995-01-01

250

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

251

Assessment of the performance of rigid pavement back-calculation through finite element modeling  

NASA Astrophysics Data System (ADS)

This study focuses on examining the behavior of rigid pavement layers during the Falling Weight Deflectometer (FWD) test. Factors affecting the design of a concrete slab, such as whether the joints are doweled or undoweled and the spacing between the transverse joints, were considered in this study. Explicit finite element analysis was employed to investigate pavement layers' responses to the action of the impulse of the FWD test. Models of various dimensions were developed to satisfy the factors under consideration. The accuracy of the finite element models developed in this investigation was verified by comparing the finite element- generated deflection basin with that experimentally measured during an actual test. The results showed that the measured deflection basin can be reproduced through finite element modeling of the pavement structure. The resulting deflection basins from the use FE modeling was processed in order to backcalculate pavement layer moduli. This approach provides a method for the evaluation of the performance of existing backcalculation programs which are based on static elastic layer analysis. Based upon the previous studies conducted for the selection of software, three different backcalculation programs were chosen for the evaluation: MODULUS5.0, EVERCALC4.0, and MODCOMP3. The results indicate that ignoring the dynamic nature of the load may lead to crude results, especially during backcalculation procedures.

Shoukry, Samir N.; William, Gergis W.; Martinelli, David R.

1999-02-01

252

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

253

Sensitivity analysis of flexible pavement response and AASHTO 2002 design guide for properties of unbound layers  

E-print Network

Unbound granular materials are generally used in road pavements as base and subbase layers. The granular materials provide load distribution through aggregate contacts to a level that can help the subgrade to withstand the applied loads. Several...

Masad, Sanaa Ahmad

2004-09-30

254

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

255

Developing a pavement management system using data fusion of physical features.  

E-print Network

??Pavement assessment is still plagued by the expensive and time-consuming distress data collection method. The VOTERS (Versatile Onboard Traffic Embedded Roaming Sensors) project has successfully… (more)

Aleti, Tarun Reddy

2014-01-01

256

Analysis of rigid pavement distresses on interstate highway using decision tree algorithms  

Microsoft Academic Search

This paper describes the application of two decision tree algorithms, Logistic Regression Trees with Unbiased Selection (LOTUS)\\u000a and Classification Rule with Unbiased Interaction Selection and Estimation (CRUISE), to identify prevailing distress types\\u000a that affect pavement maintenance decision making. The maintenance history of the selected sections within Interstate highway\\u000a I-90 in the State of Wisconsin is modeled to build decision trees.

Myungook Kang; Minkwan Kim; Joo Hyoung Lee

2010-01-01

257

Pavement evaluation and rehabilitation  

SciTech Connect

The 20 papers in this report deal with the following areas: determination of layer moduli using a falling weight deflectometer; evaluation of effect of uncrushed base layers on pavement performance; the effect of contact area shape and pressure distribution on multilayer systems response; sensitivity analysis of selected backcalculation procedures; performance of a full-scale pavement design experiment in Jamaica; subsealing and load-transfer restoration; development of a demonstration prototype expert system for concrete pavement evaluation; numerical assessment of pavement test sections; development of a distress index and rehabilitation criteria for continuously reinforced concrete pavements using discriminant analysis; a mechanistic model for thermally induced reflection cracking of portland cement concrete pavement with reinforced asphalt concrete overlay; New Mexico study of interlayers used in reflective crack control; status of the South Dakota profilometer; incorporating the effects of tread pattern in a dynamic tire excitation mechanism; external methods for evaluating shock absorbers for road-roughness measurements; factor analysis of pavement distresses for surface condition predictions; development of a utility evaluation for nondestructive-testing equipment used on asphalt-concrete pavements; estimating the life of asphalt overlays using long-term pavement performance data; present serviceability-roughness correlations using rating panel data; video image distress analysis technique for Idaho transportation department pavement-management system; acceptability of shock absorbers for road roughness-measuring trailers.

Ali, N.A.; Khosla, N.P.; Johnson, E.G.; Hicks, R.G.; Uzan, J.

1987-01-01

258

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 3.7×10 11 and 3.2×10 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, Göran; Gustafsson, Mats

259

9 CFR 354.247 - Table showing types of materials.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Table showing types of materials. 354.247 Section 354.247 Animals and Animal Products FOOD SAFETY...and Precautions Against Contamination of Products § 354.247 Table showing types of materials....

2010-01-01

260

Effects of pavement surface characteristics and textures on skid resistance  

E-print Network

of . Tire Iree-Rolling Miode. Slipping Mode. Drive slin Brake soli Skidding Mode. Field Miithods of Measurinp Skid Resistance Stopping-Distance Method Deceleration M thod. Skid Trailer Method. Pavement Surface Texture Methods of Measuring Texture...EASJJRED ON AGGREGA. 'IES. 85 LIST OI' FIGURES F IGURE Page Friction character istics of tires operating in the brake slip mode. (From reference 3). I'riction characteristics of tires operating in the cornering slip mode. (I'rom reference 3) Percent decrease...

Tomita, Hisao

2012-06-07

261

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

262

Thickness estimation of subsurface layers in asphalt pavement using monstatic ground penetrating radar  

E-print Network

Penetrating Radar (GPR)[2] Short pulse radar have been used to detect, locate and characterize surface or airborne targets. Application of similar equipment for subsurface exploration has received a lot of attention over last decade. Short pulse radars have... Processor Receiver Circulat /isolat Receiver Signal Processor To Display Unit To Display Unit Antenna EfS7ATfC Pavement surface Pavement Layer 1 Pavement Layer 2 Pavement Layer 3 Fig 1. 2. 1 Monostatic GPR(leftl; Bistatic GPR(rightl The function...

Lau, Chun Lok

2012-06-07

263

User's guide: Hot-mix recycling of asphalt concrete pavements  

NASA Astrophysics Data System (ADS)

This guide provides the technical information required to implement the application of hot-mix recycling of asphalt concrete pavements. Included are details on application, benefits/advantages, limitations/disadvantages, and costs associated with this technology. Information is provided on three demonstration sites at Fort Gillem, Georgia; Fort Leavenworth, Kansas; and Fort Benjamin Harrison, Indiana. 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 appendices.

Shoenberger, James E.

1993-05-01

264

User's guide: Hot-mix recycling of asphalt concrete pavements  

Microsoft Academic Search

This guide provides the technical information required to implement the application of hot-mix recycling of asphalt concrete pavements. Included are details on application, benefits\\/advantages, limitations\\/disadvantages, and costs associated with this technology. Information is provided on three demonstration sites at Fort Gillem, Georgia; Fort Leavenworth, Kansas; and Fort Benjamin Harrison, Indiana. Also provided is information concerning funding, procurement, maintenance, and performance

James E. Shoenberger

1993-01-01

265

An investigation into the predictive performance of pavement marking retroreflectivity measured under various conditions of continuous wetting  

E-print Network

This thesis research investigated the predictive performance of pavement marking retroreflectivity measured under various conditions of continuous wetting. The researcher compared nighttime detection distance of pavement markings in simulated rain...

Pike, Adam Matthew

2007-04-25

266

A novel method of bitumen extraction from asphalt pavement  

SciTech Connect

A new method of extracting bitumen from asphalt pavement mixtures has been developed which does not require chlorinated or aromatic compounds for solvents. The preferred solvent is cyclohexane (although cyclopentane may be used) at high temperatures and pressures. The new method requires equipment that is less costly than the centrifuge method currently used and takes less time than extractions with Bioact but more time than when chlorocompounds are used.

Houser, T.J. (Western Michigan Univ., Kalamazoo (United States))

1990-07-01

267

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

E-print Network

Administration. 16. ABSTRACT This study investigated the influence of several factors on the adhesive bondEVALUATION 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

268

Using finite element analysis of retroreflective raised pavement markers to recommend testing procedures for simulating their field performance  

E-print Network

Retroreflective Raised Pavement Markers (RRPMs) supplement other pavement markings to provide guidance to road users. Previous research concerning durability of the RRPMs suggests that their performance has been degrading over the years. One...

Agrawal, Ravi Prakash

2006-08-16

269

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

270

Modelling the effect of various factors on the condition of pavement marking  

Microsoft Academic Search

Poorly maintained pavement marking might certainly contribute to road accidents. The cost of road accidents is estimated to be 10–25 billion Canadian dollars annually. Accordingly, it is necessary for municipalities to develop a strategic cost-effective plan in order to renew and restripe pavement markings. Therefore, the objective of the present research is to model the effect of various factors on

Emad Elwakil; Ahmed Eweda; Tarek Zayed

2012-01-01

271

Development of Field Data for Effective Implementation of Mechanistic Empirical Pavement Design Procedure.  

National Technical Information Service (NTIS)

This report provides summary of the work that was carried out to assess the merits of the Mechanistic Empirical Pavement Design approach and attempts to calibrate the procedure for application in Nebraska. Mechanistic Empirical (M-E) design of pavements i...

A. Azizinamini, M. A. Stanigzai, N. Ala

2009-01-01

272

Modelling of Mechanical Properties of Cement Concrete Incorporating Reclaimed Asphalt Pavement  

Microsoft Academic Search

In many countries there is a trend to recycle wastes obtained during pavement maintenance or reconstruction, and to forbid the landfill of these products. Thus, in some circumstances it can be tempting to use reclaimed asphalt pavement (RAP) in new hydraulic concrete mixtures. This paper presents experimental data and modelling about the effect of RAP incorporation on cement concrete mechanical

Vincent Mathias; Thierry Sedran; François de Larrard

2009-01-01

273

Depletion of E. coli in permeable pavement mineral aggregate storage and reuse systems.  

PubMed

Permeable pavement reservoirs provide an important opportunity for the harvesting and storage of stormwater for reuse. This research aims to determine whether storage in dolomite, calcite and quartzite mineral aggregates in the base course of a permeable pavement impacts on the survival of the pathogen indicator organism Escherichia coli (E. coli) in storage. The reasons for depletion were also investigated. Twelve model permeable pavement storage reservoirs were filled, in triplicate, with dolomite, calcite and quartzite. Three reservoirs contained no aggregate. After filling with pathogen spiked rainwater, the concentration of E. coli was examined for 22 days in the reservoirs. The reservoirs were then agitated to determine if there was E. coli present which was not in aqueous suspension. The results of the experiments show that there is no significant difference in the depletion of E. coli found in reservoirs without aggregate, and those filled with dolomite or calcite. The rate of depletion was found to be significantly lower in the quartzite filled reservoirs. Agitation of the reservoirs yielded increases in the aqueous concentration of E. coli in all reservoir types, suggesting that the bacteria are adhering to the surface of the mineral aggregate and to the reservoir walls. PMID:19955632

Myers, B R; Beecham, S; van Leeuwen, J A; Keegan, A

2009-01-01

274

Enantiomeric separation and quantification of ephedrine-type alkaloids in herbal materials by comprehensive two-dimensional gas chromatography  

Microsoft Academic Search

The separation of ephedrine-type alkaloids and their enantiomers in raw herbs and commercial herbal products was investigated by carrying out enantioselective separation in the first-dimension column (containing ?-cyclodextrin as the chiral selector) of a comprehensive two-dimensional gas chromatography (GC×GC) system, whereas a polar polyethylene glycol capillary column was used for separation in the second dimension. Naturally occurring ephedrine-type alkaloids and

Min Wang; Philip J. Marriott; Wing-Hong Chan; Albert W. M. Lee; Carmen W. Huie

2006-01-01

275

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

Microsoft Academic Search

The October 1999 Mw 7.1 Hector Mine earthquake in the Mojave Desert, California, generated 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, (3) moats around loosened, embedded boulders, (4) filling of abandoned cobble sockets, boulder moats, and other depressions with gravel,

P. K. Haff

2005-01-01

276

Load rating of light pavement structures  

E-print Network

recognized. The resilient modulus may be expressed as (38 39) KE E=KIP where K), K& = constants, and 0 = bulk str ess or the first stress invariant . Various values of KI, K& have been recommended for six different road base materials (39). 10... is the bulk stress or the first stress invariant, and KT the unknown coefficient defining the material. This value shall be referred to as the KI-value hereafter. The range of K2-values was reported to be between 0. 30 to 0. 60 (2) 20 NUMBER OF BLOWS 40...

Chua, Koon Meng

2012-06-07

277

Linear elastic analysis of pavement structure under non-circular loading  

Microsoft Academic Search

Conventional methods for road and airport pavement analyses, such as BISAR and GAMES, were developed based on a cylindrical coordinate system. Because of the loading symmetry due to the assumption that a circular uniformly distributed load is acting on the pavement surface, it was useful to use a cylindrical coordinate system. However, depending on the magnitude of the tire load,

James W. Maina; Yoshiaki Ozawa; Kunihito Matsui

2012-01-01

278

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

279

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

280

On the characterization of flexible pavement rutting using creep model-based finite element analysis  

Microsoft Academic Search

A new approach for characterizing flexible pavement rutting using creep model-based finite element analysis (FEA) is presented in this paper. A matrix of FEA was carefully designed so that pavements with low and high traffic volumes, low and high rutting levels, and different structural layer thickness combinations were all included. Transverse wheel wander distribution and non-uniform tire contact stresses were

Hongbing Fang; John E. Haddock; Thomas D. White; Adam J. Hand

2004-01-01

281

Effects of an uncrushed base layer on pavement performance. Final report  

SciTech Connect

In 1974, the Alaska Department of Highways decided to save money and fuel by removing the base course and placing the asphalt-concrete surface directly on the surface of the Glenn Highway Widening project. The original two lanes had been constructed with a crushed-base course in 1969, thus providing an excellent comparison of the performance of the two bases. Results showed that the uncrushed base course performed better than the crushed-base course: the resilient modulus was higher and the permanent deformation was lower. The uncrushed base is apparently superior because of a larger maximum particle size and greater maximum density. An analysis of the future performance of the roadway with equal thickness of asphalt indicates that the pavement over the uncrushed base would have a longer life than the pavement over the crushed base by 54%.

Johnson, E.G.; Hicks, R.G.

1987-06-01

282

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

283

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

284

Evaluation of reclaimed asphalt pavement binder stiffness without extraction and recovery  

Microsoft Academic Search

A new testing procedure to estimate the low-temperature stiffness of the reclaimed asphalt pavement (RAP) binder was developed.\\u000a In the testing procedure, the Superpave™ Bending Beam Rheometer (BBR) with special modifications and binder blending charts\\u000a by Asphalt Institute were utilized. Modifications involved the development of a new kind of sample mold and different testing\\u000a parameters were made to BBR testing

Tao Ma; Xiao-ming Huang; U. B. Hussain

2011-01-01

285

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

2011-11-03

286

The effects of coal tar based pavement sealer on amphibian development and metamorphosis.  

PubMed

Coal tar based pavement sealers are applied regularly to parking lots and contain significant levels of polycyclic aromatic hydrocarbons (PAHs). Recently a connection between elevated levels of PAHs in streams and storm water runoff from parking lots has been identified. We tested the hypothesis that coal tar based pavement sealers could alter the survival, growth, and development of amphibians using a model species, Xenopus laevis. Ten fertilized individuals were placed singly into containers containing one of four treatment groups: control, low, medium, and high (respective nominal concentrations 0, 3, 30, and 300 ppm TPAH). All of the individuals in the high exposure group died by the sixth day of exposure. By day 14 there were significant patterns of stunted growth (p<0.0001) and slower development (p=0.006) in the medium and high exposure groups relative to the control and low treatment groups. When the experiment ended on day 52 the control and low-dose individuals had achieved more advanced developmental stages than the medium group (p=0.0007). These data indicate that these commonly used coal tar based pavement sealers may potentially affect the amphibian taxa living in areas that receive storm water runoff. PMID:16557355

Bryer, Pamela J; Elliott, Jan N; Willingham, Emily J

2006-04-01

287

Testing Guide This testing guide is a product of an FHWA 17-state pooled fund: Material and Construction  

E-print Network

Construction of portland cement concrete pavements is a complex process. A small fraction of the concrete of America, March 2008 This material is one product of phase 3 of a multi-year effort supported by a Federal

288

Rubber-modified hot-mix asphalt pavement by dry process  

Microsoft Academic Search

This paper focuses on tyre rubber-modified hot-mix asphalt for traffic pavements fabricated by dry process. Fine granulated crumbed rubber from discarded tyres was mixed with heat aggregates and after a short delay time, an ordinary bitumen binder was added to the mixture in the plug mill. The research was partially carried out in the laboratory (designing the optimum mixture composition)

F. Hernández-Olivares; B. Witoszek-Schultz; M. Alonso-Fernández; C. Benito-Moro

2009-01-01

289

23 CFR 971.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

... Federal lands pavement management system (PMS). In addition...the AASHTO's “Pavement Management Guide.” 1 1 “Pavement Management Guide,” AASHTO...nature of the transportation network. These different...

2010-04-01

290

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

E-print Network

College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE January, 1959 Major Subject: Civil Engineering A STUDY OF CERTAIN ELASTIC AND PLASTIC STRAINS INDUCED IN FLEXIBLE PAVENENT SYSTENS BY REPETITIVE MEREL.... Acknowledgements are due Mr. R. E. Schiller, Associate Professor of Civil Engineering, and Dr. W. H. Nedderman, Professor of Civil Engineering, for their helpful assistance in reviewing the manuscript; and to Mr. L. E. Stark, Associate Research Engineer, and Mr...

Meyer, Kirby Thomas

2012-06-07

291

Pavement roughness on expansive clays  

E-print Network

PAVEMENT ROUGHI'JESS ON EXPANSIVE CLAYS A Thesis by Manuel Oli van Velasco Submitted to the Graduate College Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1980 Major Subject...: Civil Engineerina PAVEMENT ROUGHNESS ON EXPANSIVE CLAYS A Thesis by Manuel Olivan Velasco Approved as to style and content by: R t L. L ton ? Chairm Wayne A. nlap - Member Luis F. Costa - Member ames F. Slowey - Member Donald McDonald - Head...

Velasco, Manuel O

2012-06-07

292

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

293

Multimodal approach to seismic pavement testing  

USGS Publications Warehouse

A multimodal approach to nondestructive seismic pavement testing is described. The presented approach is based on multichannel analysis of all types of seismic waves propagating along the surface of the pavement. The multichannel data acquisition method is replaced by multichannel simulation with one receiver. This method uses only one accelerometer-receiver and a light hammer-source, to generate a synthetic receiver array. This data acquisition technique is made possible through careful triggering of the source and results in such simplification of the technique that it is made generally available. Multiple dispersion curves are automatically and objectively extracted using the multichannel analysis of surface waves processing scheme, which is described. Resulting dispersion curves in the high frequency range match with theoretical Lamb waves in a free plate. At lower frequencies there are several branches of dispersion curves corresponding to the lower layers of different stiffness in the pavement system. The observed behavior of multimodal dispersion curves is in agreement with theory, which has been validated through both numerical modeling and the transfer matrix method, by solving for complex wave numbers. ?? ASCE / JUNE 2004.

Ryden, N.; Park, C.B.; Ulriksen, P.; Miller, R.D.

2004-01-01

294

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

295

The calculation of shadow prices for industrial wastes using distance functions: An analysis for Spanish ceramic pavements firms  

Microsoft Academic Search

This paper deals with the calculation of shadow prices for two industrial wastes generated on their production processes by 18 firms belonging to the Spanish ceramic pavements industry. These prices are then used to calculate an extended productivity index which takes into consideration wastes going with the production of marketable goods. We follow the methodological approach first proposed by Färe

Ernest Reig-Mart??nez; Andrés Picazo-Tadeo; Francesc Hernández-Sancho

2001-01-01

296

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

297

Life Cycle Assessment of Pavements: A Critical Review of Existing Literature and Research  

E-print Network

albedos through the use fly ash in concrete pavements [81].design, asphalt concrete mix design, use of fly ash, use offly ash, RAP, shredded rubber tires, crushed glass, plastics, and crushed concrete.

Santero, Nicholas

2010-01-01

298

The impact of maintenance and rehabilitation strategies on the pavement network value  

E-print Network

The maintenance and rehabilitation of road infrastructure demands a great investment of time and money. The deterioration of pavement condition over time due to environmental factors and increasing traffic loads combined with the limitation of funds...

Chang Albitres, Carlos Martin

2012-06-07

299

Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates: Phase I Activities.  

National Technical Information Service (NTIS)

This report documents the results of two completed Phase I tasks for the project titled, Evaluation and Development of Pavement Scores, Performance Models and Needs Estimates. These tasks involved a literature review and a review of the current Texas Pave...

A. Wimsatt, N. G. Gharaibeh, T. Freeman, Y. Zou

2011-01-01

300

California DOT 1. Briefly summarize your current pavement smoothness requirements.  

E-print Network

California DOT 1. Briefly summarize your current pavement smoothness requirements. For HMA pavement to OGFC placed on existing pavement not constructed under the same project. If concrete pavement is placed ordered. 39-1.12B Straightedge The top layer of HMA pavement must not vary from the lower edge of a12-foot

301

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

302

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

303

Sulfur-extended asphalt pavement: a three-year progress report. Final report  

SciTech Connect

This report documents post-construction performance of a sulfur-extended asphalt (SEA) pavement and a conventional pavement used as a control, monitored over a 3-year period. The SEA pavement used 30% sulfur by total weight of the binder. Both pavements were placed under New York State specifications during the summer of 1980 on Rtes 118 and 202 in Westchester County, New York. After 3 years, overall condition of both the SEA and control pavements was satisfactory. The two did not differ significantly in deflection, rutting, friction, or aggregate degradation. Data obtained from analysis of pavement cores showed that the stability of the SEA mix was equal to or higher than that of the control at all ages. Similarly, its resilient modulus was greater at all ages and temperatures. Although tensile-strength ratios measured for both mixes indicated a potential for stripping, virtually none was observed in any of the field cores for either pavement at any age.

Van Bramer, T.F.

1986-10-01

304

A mechanistic model for the prediction of stresses, strains, and displacements in continuously reinforced concrete pavements  

E-print Network

of the requirement for the degree of MASTEP. OF SCIENCE May 1888 Major Subject: Civil Engineering A MECHANISTIC MODEL FOR THE PREDICTION OF STRESSES, STRAINS, AND DISPLACEMENTS IN CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS A Thesis RICHARD PAUL PALMER... of the requirement for the degree of MASTEP. OF SCIENCE May 1888 Major Subject: Civil Engineering A MECHANISTIC MODEL FOR THE PREDICTION OF STRESSES, STRAINS, AND DISPLACEMENTS IN CONTINUOUSLY REINFORCED CONCRETE PAVEMENTS A Thesis RICHARD PAUL PALMER...

Palmer, Richard Paul

2012-06-07

305

9 CFR 354.247 - Table showing types of materials.  

...Contamination of Products § 354.247 Table showing types of materials. Equipment, utensils, and facilities Iron Stainless steel and monel metal Aluminum Galvanized iron Holding pens A A A A Overhead conveyors A A A A...

2014-01-01

306

In-place engineering properties of recycled and stabilized pavement layers  

E-print Network

, some of the districts have been actively recycling thin surfaced pavements and stabilizing bases in an attempt to correct deterioration and increase the structural capacity. In a one pass operation the existing surface and base are mixed and stabilized...

Syed, Imran Majidali

2012-06-07

307

Evaluation of in-pavement Flashing Lights on a Six-lane Arterial Pedestrian Crossing  

E-print Network

included a solar array, batteries, three poles with light-activating push buttons (one at each curb and one of Figure 1. FIGURE 1. Cars stopping for pedestrian crossing while in-pavement lights are flashing. The in

Prevedouros, Panos D.

308

A decision process framework: selecting strategies for rehabilitation of rigid pavements subjected to high traffic volumes  

E-print Network

Concrete pavements, underdesigned for today's levels of traffic, are deteriorating rapidly. Maintenance, rehabilitation, and reconstruction activities (MRR) have become more widespread and costly. State highway agencies are often being asked to do...

Valls, Marc Edouard Josep

2012-06-07

309

Stress relaxation of cellular silicone material: 1985 (condensation type only)  

SciTech Connect

The long-term (10 years) stress relaxation properties of cellular silicone material at room temperature are under evaluation. A condensation-type polymer is in test. The condensation-type base material used ammonium chloride as the leachable filler to form the cellular material. The cellular material was compounded to yield densities of 0.34 and 0.52 g/cm/sup 3/ for thickness of 1.17, 1.52, and 2.54 mm. These density-thickness combinations were compressed to nominal compressions of 20 and 40 percent with nine replicates at each condition. A specially designed fixture is used to maintain a specific compression on the cellular sample, and a universal test machine acquires the load data. Currently, the predicted 10-year load retention is between 65.1 and 67.3 percent of the original load for the condensation-type material.

Schneider, J.W.

1986-07-01

310

Consolidation of continuously reinforced concrete pavements  

E-print Network

that the presence of chemical or mineral admixtures will affect the rheological properties of a concrete mixture. With the advent of superplasticizers there is a lack of information concerning their implications in the C R C P industry. There is a need... that the presence of chemical or mineral admixtures will affect the rheological properties of a concrete mixture. With the advent of superplasticizers there is a lack of information concerning their implications in the C R C P industry. There is a need...

Winn, Dan Parker

2012-06-07

311

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

312

Estimating the Fine Soil Fraction of Desert Pavements Using Ground Penetrating Radar  

Microsoft Academic Search

A reconnaissance tool that can estimate the clay content and satu- rated hydraulic conductivity (Ks) of well-developed desert pavements has immediate applications for researchers and practitioners who work in arid environments. We examined the use of surface-based ground penetrating radar (GPR) to rapidly approximate these properties on six, 100-m-long transects for two different aged (|100000 vs. 4000 yr) desert pavement

Darren G. Meadows; Michael H. Young; Eric V. McDonald

2006-01-01

313

Wearability of Portland Cement Concrete Pavement Finishes  

E-print Network

finish, brush finish, tines finish, trowel finish for control or a combination finish) was applied. The test specimens were then subjected to one of four curing methods (Polvethylene Sheet, Nhite Pigmented Curing Compound, Monomolecular Film... with the Bhite Pigmented Curing Compound, or a moist curing method consisting of 7 days at 73'F and 95 percent relative humidity and the remainder of the 28 day curing period at 73'F and 25 percent relative humidity) for 28 days. After a 28 dav strength...

McKeen, William Rew

2012-06-07

314

Structure elucidation of alkaline earth impregnated MCM-41 type mesoporous materials obtained by direct synthesis: An experimental and theoretical study  

NASA Astrophysics Data System (ADS)

In this work, MCM-41 were synthesized hydrothermally and functionalized with calcium and strontium salts by direct method, using the Si/M = 50 molar ratio, in order to elucidate the way as the alkaline earth is incorporated on MCM-41 molecular sieve. The materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, nitrogen adsorption-desorption and theoretical calculations by DFT method. Experimental results and computer simulations showed that the alkaline earths were incorporated on MCM-41 through a complex structure, which negatively influences on basic sites formation.

Paz, Gizeuda L.; Silva, Francisco das Chagas M.; Araújo, Maciel M.; Lima, Francisco das Chagas A.; Luz, Geraldo E.

2014-06-01

315

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

Microsoft Academic Search

Tire–pavement 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

316

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

317

Regular Inspection and Maintenance Guidance for Porous Pavements  

E-print Network

. Signage should display limitation of design load (i.e. passenger vehicles only, light truck traffic, etc the pavement in accordance with the minimum design standards. This page provides guidance on maintenance non-design loads. Damaged areas may be repaired by use of infrared heating and rerolling of pavement

318

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; López-Martínez, Jerónimo; McWhirter, Judi L

2012-12-15

319

23 CFR 972.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2010 CFR

... Federal lands pavement management system (PMS). In addition...the AASHTO's “Pavement Management Guide.”2 2 “Pavement Management Guide,” AASHTO...the nature of the pavement network. These different...

2010-04-01

320

Portland Cement Concrete Pavement Shannon Golden, Alabama DOT  

E-print Network

be measured by weight. The substitution of each mineral admixture (GGBFS, Fly Ash, Silica Fume) for Portland* (Maximum % Substitution) Fly Ash (Maximum % Substutution) Silica Fume (Maximum % Substitution) 50 % 0 % 0Portland Cement Concrete Pavement Shannon Golden, Alabama DOT PORTLAND CEMENT CONCRETE PAVEMENT

321

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

322

Use of Illinois by-product residues for paving materials  

SciTech Connect

Tests were conducted in a field demonstration project to determine if by-products of fluidized bed and pulverized coal combustions (FBC and PCC) cm be used in production of surface wearing course pavements for secondary/county roads. Various proportions of pre-hydrated FBC spent bed, as a fine aggregate; PCC fly ash, as a primary cementitious binder, with or without low dosage of portland cement; and crushed limestone coarse aggregate were blended at their optimum moisture content to produce zero-slump concrete mixtures. Pavement slabs of 6 ft by 12 ft were constructed by compacting 10 in. loose fresh matrix into 8 in. final thickness, in two lifts, using a self-propelled steel vibratory roller. No other surface finish treatments were used. Information gathered in this paper makes the user of roller compacted concrete (RCC) containing FBC/PCC by-product residues aware of the fact that excellent engineering characteristics can be attained even when little or no portland cement is used. After 18 months from the date of initial casting, the pavement sections are crack-free and remain in excellent surface condition.

Ghafoori, N.; Wang, L.; Kassel, S. [Southern Illinois Univ., Carbondale, IL (United States)

1996-12-31

323

Rutting and drainage design methodology for a concrete block pavement  

E-print Network

Concrete block pavements (CBP) have historically been hics. used in low trafficked applications as an alternative to asphalt and concrete pavement because of their aesthetic quality. However, concrete block pavements have not been used for high...

Poduska, Daryl Jason

2012-06-07

324

Development of statistical wet weather model to evaluate frictional properties at the pavement-tire interface on hot mix asphalt concrete  

E-print Network

Skid resistance on wet pavements is influenced by friction at the tire-pavement interface as well as overall hot mix asphalt (HMA) performance. It is important to control aggregate, asphalt, and mix properties to achieve desirable frictional...

Bedi, Harpreet

2012-06-07

325

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

326

Performance of an enhanced pervious pavement system loaded with large volumes of hydrocarbons.  

PubMed

Five litres of lubricating oil and two 8.5 litre batches of diesel were deposited on each of two hydraulically isolated experimental enhanced pervious pavement parking bays. The 50 mm aggregate subbases of the two bays were of either recycled concrete or crushed limestone. The bays were constructed in such a way that a near-surface gravity separator was created by the arranging of the outlet pipes such that a permanent pool of water was maintained in the system and water could only enter from below the level of any floating oil. Dissolved/dispersed hydrocarbons were measured at acceptable concentrations when monitoring was carried out over a period of approximately 5 months. The maximum concentration was 7.2 mg/l and of all the samples collected only 3% exceeded the 5 mg/l limit applied in the UK for a class 1 interceptor, and the majority of samples had hydrocarbon concentrations of less than 2 mg/l. Much more significant is the fact that no free product was discharged from either system up to the time the experiment was dismantled 2 years from the first oil application despite the fact that sufficient hydrocarbon had been added to each pavement to produce a film on a water surface of over 500 hectares. PMID:25225930

Newman, Alan P; Puehmeier, Tim; Shuttleworth, Andy; Pratt, Christopher J

2014-01-01

327

On the thermomechanical deformation behavior of duplex-type materials  

NASA Astrophysics Data System (ADS)

Two-phase duplex-type materials possess microstructures containing roughly the same amounts of the constituent phases whose grains form interwoven networks. Duplex stainless steels are typical representatives of this material group. In these steels the constituent phases austenite and ferrite have different coefficients of thermal expansion. On pure thermal loading or thermomechanical loading the yield strength of the phases can be exceeded. Specimens of a forged duplex steel with a uniaxially anisotropic micro-structure deform irreversibly even under pure thermal cycling conditions with a monotonic accumulation of strain. The results of a systematic finite element based micromechanical analysis of the thermomechanical deformation behavior of duplex steels are presented and discussed. The analysis is based on a quantitative characterization of both the real and model microstructures. Additionally, an extended constitutive material law for the thermomechanical loading of the duplex steel is proposed. For dual-phase materials this description incorporates an additional thermomechanical strain increment as a very important contribution to the total strain increment. Both the micromechanical model and the analytical model are used to analyse the experimental findings from dilatometer tests. The micromechanical approach allows the evolution of the irreversible strains in the two phases generated in a thermal cycle to be modeled. It is shown that the matrix-phase is always more deformed than the inclusion-phase, irrespective of which of the two phases (austenite or ferrite) forms the matrix. This prediction is confirmed by electron microscopic observations of a thermally cycled duplex steel. Based on these results a mechanism driving the ratchet effect is proposed.

Siegmund, T.; Werner, E.; Fischer, F. D.

1995-04-01

328

Modeling runoff response of pervious pavement systems at a catchment scale O. Epshtein1, L. Turnbull2, and S. Earl2  

E-print Network

Modeling runoff response of pervious pavement systems at a catchment scale O. Epshtein1, L of Sustainability, Arizona State University 1. INTRODUCTION The application potential of pervious pavements urban Total Impervious Area (TIA) is not a feasible solution, pervious pavements operate as self

Hall, Sharon J.

329

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

330

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.

331

Recycling crumb rubber modified asphalt pavements (revised). Final research report, September 1992August 1994  

Microsoft Academic Search

There has been concern that the legislative mandate to use waste rubber in paving applications will result in a severe environmental problem when it becomes necessary to recycle these pavements. If successful recycling is possible, the long term performance of these pavements becomes a concern. The results of this study indicate that it is possible to recycle this material. However,

W. W. Crockford; D. Makunike; R. R. Davison; T. Scullion; T. C. Billiter

1995-01-01

332

UNBURNED MATERIAL IN THE EJECTA OF TYPE Ia SUPERNOVAE  

SciTech Connect

The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at Almost-Equal-To 6300 A which is attributed to C II {lambda}6580. An alternative identification of this absorption as H{alpha} is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 A absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely Almost-Equal-To 1000 km s{sup -1} above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10{sup -3} to 10{sup -2} M{sub Sun }. The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for objects which show carbon.

Folatelli, Gaston; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken'ichi [Institute for the Physics and Mathematics of the Universe (IPMU), University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Phillips, M. M.; Morrell, Nidia; Campillay, Abdo; Gonzalez, Sergio; Roth, Miguel [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Stritzinger, Maximilian [The Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, 10691 Stockholm (Sweden); Burns, Christopher R.; Freedman, W. L.; Madore, Barry F; Persson, S. E. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara St., Pasadena, CA 91101 (United States); Hamuy, Mario [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Mazzali, Paolo [Max-Planck Institut fuer Astrophysik, Karl-Schwarzschild-Str. 1, 85748 Garching (Germany); Boldt, Luis [Argelander Institut fuer Astronomie, Universitaet Bonn, Auf dem Huegel 71, D-53111 Bonn (Germany); Contreras, Carlos [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, P.O. Box 218, Victoria 3122 (Australia); Salgado, Francisco [Leiden Observatory, Leiden University, P.O. Box 9513, NL-2300 RA Leiden (Netherlands); Suntzeff, Nicholas B., E-mail: gaston.folatelli@ipmu.jp [George P. and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Department of Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States)

2012-01-20

333

Unburned Material in the Ejecta of Type Ia Supernovae  

NASA Astrophysics Data System (ADS)

The presence of unburned material in the ejecta of normal Type Ia supernovae (SNe Ia) is investigated using early-time spectroscopy obtained by the Carnegie Supernova Project. The tell-tale signature of pristine material from a C+O white dwarf progenitor star is the presence of carbon, as oxygen is also a product of carbon burning. The most prominent carbon lines in optical spectra of SNe Ia are expected to arise from C II. We find that at least 30% of the objects in the sample show an absorption at ?6300 Å which is attributed to C II ?6580. An alternative identification of this absorption as H? is considered to be unlikely. These findings imply a larger incidence of carbon in SNe Ia ejecta than previously noted. We show how observational biases and physical conditions may hide the presence of weak C II lines, and account for the scarcity of previous carbon detections in the literature. This relatively large frequency of carbon detections has crucial implications on our understanding of the explosive process. Furthermore, the identification of the 6300 Å absorptions as carbon would imply that unburned material is present at very low expansion velocities, merely ?1000 km s-1 above the bulk of Si II. Based on spectral modeling, it is found that the detections are consistent with a mass of carbon of 10-3 to 10-2 M ?. The presence of this material so deep in the ejecta would imply substantial mixing, which may be related to asymmetries of the flame propagation. Another possible explanation for the carbon absorptions may be the existence of clumps of unburned material along the line of sight. However, the uniformity of the relation between C II and Si II velocities is not consistent with such small-scale asymmetries. The spectroscopic and photometric properties of SNe Ia with and without carbon signatures are compared. A trend toward bluer color and lower luminosity at maximum light is found for objects which show carbon. This paper includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile, and the Gemini Observatory, Cerro Pachon, Chile (Gemini Program GS-2008B-Q-56). This work is based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (ESO Programmes 076.A-0156, 078.D-0048, 080.A-0516, and 082.A-0526).

Folatelli, Gastón; Phillips, M. M.; Morrell, Nidia; Tanaka, Masaomi; Maeda, Keiichi; Nomoto, Ken'ichi; Stritzinger, Maximilian; Burns, Christopher R.; Hamuy, Mario; Mazzali, Paolo; Boldt, Luis; Campillay, Abdo; Contreras, Carlos; González, Sergio; Roth, Miguel; Salgado, Francisco; Freedman, W. L.; Madore, Barry F.; Persson, S. E.; Suntzeff, Nicholas B.

2012-01-01

334

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

335

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

336

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

E-print Network

in the walls, and the local radio station are coursing through your body. Is it something to worry about much over time, either in the tissues of your body, or in sensitive electronic equipment, they can. In high dosages, X-rays and gamma-rays require shielding to reduce their health effects, otherwise

337

GEOLOGICAL NOTE Desert Pavement: An Environmental Canary?  

E-print Network

GEOLOGICAL NOTE Desert Pavement: An Environmental Canary? P K. Haft Division of Earth and Ocean 27708 Ie-mail: /wff@geo.duke_eciul ABSTRACT Ongoing ctisruption of ancient, varnished desert pavement that the pavement disturbances reported here ~ue rarc on the millcnnhll time scale of desert varnish format ion

Ahmad, Sajjad

338

Pavement roughness and skid properties  

NASA Astrophysics Data System (ADS)

Road roughness and roadway safety as it relates to both surface and air transportation are discussed. The role of road roughness in vehicle ride, the measurement of roughness, the evaluation of riding confort, and the effect of grooving pavements are discussed. The effects of differential pavement friction on the response of cars in skidding maneuvers is discussed.

339

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

340

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... 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

2012-06-07

341

Application of Graded Finite Elements for Asphalt Pavements  

E-print Network

vertically graded material properties. This grading is caused primarily by temperature gradients and aging interface conditions, complex tire load patterns, and temperature and asphalt aging effects. Most thickness and selection of surface materials to avoid premature failure. One shortcoming of commercially

Paulino, Glaucio H.

342

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

E-print Network

Pavement (RAP), Recycled Asphalt Shingles (RAS), and Different Virgin Binder Sources on Performance of the Blended Binder for Mixes with Higher Percentages of RAP and RAS University UC Davis Principal Investigator that is routinely recycled increases, it becomes more desirable to use significantly higher amounts of RAP and RAS

California at Davis, University of

343

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

344

1 INTRODUCTION A typical flexible pavement system includes four  

E-print Network

1 INTRODUCTION A typical flexible pavement system includes four distinct layers: asphalt concrete course in order to reduce costs or to minimize capil- lary action under the pavement. Figure 1: Cross-section of flexible pavement system (Muench 2006) Pavement distress may occur due to either traffic or environmental

Zornberg, Jorge G.

345

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.

346

Graded Viscoelastic Approach for Modeling Asphalt Concrete Pavements  

NASA Astrophysics Data System (ADS)

Asphalt concrete pavements exhibit severely graded properties through their thickness due to oxidative aging effects, which are most pronounced at the surface of the pavement and decrease rapidly with depth from the surface. Most of the literature to date has focused on use of layered-elastic models for the consideration of age stiffening. In the current work, a graded viscoelastic model has been implemented within a numerical framework for the simulation of asphalt pavement responses under thermal and mechanical loading. The graded viscoelastic work is extension of the previous work by Paulino and Jin [1], Mukherjee and Paulino [2], and Buttlar et al. [3]. A functionally graded generalized Maxwell model has been used in the development of a constitutive model for asphalt concrete considering aging and temperature gradients. The aging gradient data from laboratory test results reported by Apeagyei [4] is used for obtaining material properties for the graded viscoelastic model. Finite element implementation of the constitutive model incorporates the generalized iso-parametric formulation (GIF) proposed by Kim and Paulino [5], which leads to the graded viscoelastic elements used in this work.

Dave, Eshan V.; Buttlar, William G.; Paulino, Glaucio H.; Hilton, Harry H.

2008-02-01

347

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

348

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

349

Effects of Rejuvenating Agents on Superpave Mixtures Containing Reclaimed Asphalt Pavement  

Microsoft Academic Search

Rejuvenator is not a commonly used softening agent to be used in recycling of reclaimed asphalt pavement RAP. In this study, Superpave mixtures containing RAP were designed using rejuvenating agents, including a rejuvenator and a softer binder, and subsequently evaluated in terms of the volumetric results, obtained the indirect tensile strength ITS of samples as well as evaluating the mixtures

Junan Shen; Serji Amirkhanian; Jennifer Aune Miller

2007-01-01

350

Automated crack control analysis for concrete pavement construction  

E-print Network

The focus of this research is on the control of random cracking in concrete paving by using sawcut notch locations in the early stages of construction. This is a major concern in concrete pavement construction. This research also addresses a...

Jang, Se Hoon

2005-11-01

351

Construction and testing of crumb rubber modified hot mix asphalt pavement. Interim report  

SciTech Connect

This study was structured towards addressing that portion of ISTEA which directs the individual states to conduct studies on the recyclability of crumb rubber modified hot mix asphalt (CRMHMA), and the technical performance of CRMHMA pavement by monitoring the construction and evaluating the performance of highway test sections in which CRMHA is removed by cold milling and recycled into new HMA through a hot mix asphalt plant. This project is to be constructed in two phases, the CRMHMA will be built in the first phase and approximately one year later it will be recycled. This report deals with the first phase in which the objective was to further document the construction, engineering characteristics, and performace of CRMHMA.

Albritton, G.E.; Gatlin, G.R.

1996-08-01

352

Re-Evaluation of the AASHTO-Flexible Pavement Design Equation with Neural Network Modeling  

PubMed Central

Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance. PMID:25397962

Ti?demir, Mesut

2014-01-01

353

LONG-TERM PERFORMANCE OF HIGH-VOLUME FLY ASH CONCRETE-PAVEMENTS  

Microsoft Academic Search

This investigation was undertaken to evaluate the long -term performance of concrete pavements made with high volumes of Class F and Class C fly ash (FA). Six different mixtures, three mixtures with Class C fly ash up to 70% cement replacement and three mixtures with Class F fly ash up to 60% cement replacement, were used. Long-term performance tests were

Tarun R. Naik; Shiw S. Singh; Rudolph N. Kraus; Bruce W. Ramme

354

Re-Evaluation of the AASHTO-Flexible Pavement Design Equation with Neural Network Modeling.  

PubMed

Here we establish that equivalent single-axle loads values can be estimated using artificial neural networks without the complex design equality of American Association of State Highway and Transportation Officials (AASHTO). More importantly, we find that the neural network model gives the coefficients to be able to obtain the actual load values using the AASHTO design values. Thus, those design traffic values that might result in deterioration can be better calculated using the neural networks model than with the AASHTO design equation. The artificial neural network method is used for this purpose. The existing AASHTO flexible pavement design equation does not currently predict the pavement performance of the strategic highway research program (Long Term Pavement Performance studies) test sections very accurately, and typically over-estimates the number of equivalent single axle loads needed to cause a measured loss of the present serviceability index. Here we aimed to demonstrate that the proposed neural network model can more accurately represent the loads values data, compared against the performance of the AASHTO formula. It is concluded that the neural network may be an appropriate tool for the development of databased-nonparametric models of pavement performance. PMID:25397962

Ti?demir, Mesut

2014-01-01

355

Pavement rehabilitation and funds allocation for a transportation network  

E-print Network

PAVEMENT REHABILITATION AND FUNDS ALLOCATION FOR A TRANSPORTATION NETWORK A Thesis by ALVARO STEIN Submitted to the Graduate College of Texas ASM University in Partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1985 Major Subject: Industrial Engineering PAVEMENT REHABILITATION AND FUNDS ALLOCATION FOR A TRANSPORTATION NETWORK A Thesis by ALVARO STEIN Approved as to style and content by: Donald R. Smith (Co-Chai rman of Committee) Robe L. tton...

Stein, Alvaro

2012-06-07

356

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

357

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

358

Evaluation of geogrids for stabilising weak pavement subgrade Xiaochao Tang1  

E-print Network

according to both laboratory tests and full- scale field experiments (Barksdale et al. 1989, Al-Qadi et al* and Angelica Palomino2 Department of Civil and Environmental Engineering, The Pennsylvania State University-scale interface test results, including direct shear and pull-out, and accelerated pavement testing (APT) results

Palomino, Angelica M.

359

Environmental Effects of Pervious Pavement as a Low Impact Development Installation in Urban Regions - Chapter 13  

EPA Science Inventory

Pervious pavement systems can be used to reduce stormwater runoff volume and are efficient at removing solids from runoff; however, the pollutant removal efficiency for nutrients, metals, and organic contaminants is yet to be determined due to either a lack of data or inconsisten...

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 (15.210 mg per 100 g initial solid) was recorded in invert sugar treated pineapple cube packed in HDPE pouch after 6 months of storage. PMID:25114348

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

2014-08-01

361

Effects of environment and construction procedures on concrete pavement surfaces  

E-print Network

'': ). A total of 56 sidewalk size slabs w . . re cast in era' ro))ed environmental rooms. Parameters invest. igated included type of subbase, method of cense) idetion (ribration), type of. finish, type of curing method, and curing environment. Also..., the slabs werc. utilized to determine the eff. acts of wind on the evapor-'tion rate of water iree the suh face of the el ajar . This was accomplished by genera" ing wind over the surface of the slab :After a 28 day curing period the slabs werc. removed...

Wrbas, Ronald Otto

2012-06-07

362

Speckle techniques for pavement surface analysis  

NASA Astrophysics Data System (ADS)

Speckle techniques are investigated for the characterization of pavement surface microtexture, particularly, height variations from one up to about ten micrometers in amplitude. Using the scalar diffraction theory of Kirchhoff, some simulations of the speckle contrast were carried out to bring out some patterns in case of a subjective speckle whose grains are not resolved by CCD photodetectors and in the case of a two-scale surface texture. We deduce the possibility of characterizing the fineness of the microtexture or its evolution versus wear modifying. The method is also experimentally applied to some reference surfaces (abrasive papers with various finenesses) and some models of pavement surfaces at various steps of wear.

Hun, Catherine; Caussignac, Jean-Marie; Bruynooghe, Michel M.

2003-05-01

363

Infiltration Through Desert Pavements, Mojave Desert, CA, USA  

NASA Astrophysics Data System (ADS)

Desert pavements consist of a surface layer of closely packed gravel that overlies thin, gravel-poor vesicular A (Av) soil horizon. Pavements are prominent features in arid and semi-arid environments and can be found on a variety of landforms of significantly diverse ages ranging from Holocene to Tertiary. Well-developed Av profiles form distinct and highly structured prismatic peds. These fine-grained, structured soils can exhibit drastically reduced infiltration rates, rendering some localized areas nearly impermeable and greatly impacting soil development, plant and biota diversity, and groundwater recharge. We sought to study how desert pavement development can impact the hydraulic conductivity characteristics in localized areas (order of 10s of cm). Field sites were chosen at the Mojave Natural Preserve, near Kelso Dunes, CA, USA, which has been the location of considerable prior research by the second author. The sites vary by parent material, clay and silt content, surface age, and variable degree of surface clast cover. Transects were chosen that traversed pavement surfaces of variable development (well developed to poorly developed). Hydraulic conductivity was determined with a tension infiltrometer conducted at different tensions and initial water contents (to better estimate the potential for preferential flow). Sites with dry initial conditions were first analyzed at zero tensions to promote inter-ped flow. After allowing soil peds to hydrate and expand, the tests were run again at a range of soil tensions to promote matrix flow. Differences in saturated conductivities (measured and fitted) were attributed to preferential flow around desiccated peds. Soil texture and structure were measured and described, respectively, allowing for the correlation of conductivity functions to soil surface age and physical characteristics.

Young, M. H.; McDonald, E. V.; Caldwell, T. C.; Benner, S. G.

2003-04-01

364

Improvement of thermal cycle characteristics of a planar-type solid oxide fuel cell by using ceramic fiber as sealing material  

Microsoft Academic Search

The objective of this paper is to improve the endurance of solid oxide fuel cell (SOFC) against thermal cycles by reducing the stress caused by the difference in thermal expansion coefficients of alloy separator and electrolyte. The thermal cycle characteristics were improved by using a ceramic fiber for the sealing material. The ceramic fiber seemed to play the role of

S Taniguchi; M Kadowaki; T Yasuo; Y Akiyama; Y Miyake; K Nishio

2000-01-01

365

Stratified soils under stone pavements as tools for palaeoenvironment reconstruction  

NASA Astrophysics Data System (ADS)

Stone pavements in climate-sensitive arid environments are often genetically associated with their underlying soil. Such soils are in general accretionary but also show features of stratification, resulting from changing environmental conditions, as well as alteration by pedogenesis. We thus regard soil-sediment profiles under stone pavements as distinctive archives of past geomorphic and pedologic processes. Deciphering the evolution allows reconstruction of landscape dynamics. Cima Volcanic Field, eastern Mojave Desert, California, has been in the focus of several studies. However, a detailed stratigraphic investigation of soils developed on basaltic lava flows of known age has not been conducted. We present descriptions of pedologic, stratigraphic and mineralogic properties of a sequence of soil profiles situated on a basaltic lava flow of middle Pleistocene age. We infer several phases of aeolian, fluvial, mass movement and pedologic activity of different nature. The archive reveals a complex evolution that can be attributed to specific environmental conditions in this climate-sensitive region, though numerical dating is preliminary. However, stratified, cumulic soils associated with desert pavements can be regarded as a unique type of archive, recording processes not traced in any other proxy record.

Dietze, M.; Kleber, A.

2009-04-01

366

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

Microsoft Academic Search

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

N. Gupta; G. Abramczyk

2012-01-01

367

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

368

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

369

Pervious Pavement System Evaluation  

EPA Science Inventory

Pervious pavement is a low impact development stormwater control. The Urban Watershed Management Branch of the U.S. Environmental Protection Agency in Edison, NJ, is evaluating concrete pavers as a popular implementation. The pollutant removal of a bench-scale permeable interlo...

370

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

371

The Upper Eocene crustose coralline algal pavement in the Colli Berici, north-eastern Italy  

Microsoft Academic Search

A crustose coralline algal pavement, identified in Upper Eocene (Priabonian) shallow water, middle- ramp carbonates in north-eastern Italy (Colli Berici, Southern Alps), represents a rare example of this facies. The crustose pavement consists of a coralline crust bindstone with a wackestone-packstone matrix, and is characterised by the dominance of crustose coralline thalli composed primarily of melobesioids (Lithothamnion and Mesophyllum) and

Davide Bassi

372

Use of Illinois by-product residues for highway materials  

SciTech Connect

This paper reports on a field study intended to investigate the feasibility of utilizing fluidized bed combustion (FBC) and pulverized coal combustion (PCC) residues in pavement construction. Various mixtures of FBC spent bed blended with and without natural river sand, as a fine aggregate; PCC fly ash with or without a low dosage of portland cement, as a cementitious binder; and natural crushed limestone, as a coarse aggregate; were compacted at their optimum moisture content, and subjected to a series of tests in order to ascertain their suitability for road applications. It was found that FBC/PCC mixtures display excellent strength, deformation, and abrasion properties. While the addition of portland cement (5% by weight of total dry solid) did not improve the compressive strength, it marginally enhanced the tensile strength, abrasion wear, and freezing and thawing resistance of the roller compacted concrete slabs. The influence of moisture (wet or dry) at various curing ages reduced as the fly ash content of the matrix increased. The linear expansion characteristics of the field slabs were minimal and virtually non-existent. Over a year after the date of casting of the slabs, the pavement sections are crack-free and remain in excellent surface condition.

Ghafoori, N. [Southern Illinois Univ., Carbondale, IL (United States)

1996-10-01

373

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

374

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 of steel dowels due to the application of de-icing salts causes severe deterioration of concrete highway

375

Softening agents for recycling asphalt pavement  

SciTech Connect

An asphaltic composition is described consisting essentially of: comminuted aged asphaltic pavement material; an effective amount, from about 2% to about 15 % by weight of a blend of an agent selected from the group consisting of a soft asphalt cement, a conventional asphalt cement, and a cutback asphalt, with a nitrogen-containing, adhesion-improving, anti-stripping agent comprising a sewage sludge-derived oil, or a fraction thereof, said sewage sludge-derived oil comprising a mixture of saturated aliphatic hydrocarbons, monoaromatic hydrocarbons, diaromatic hydrocarbons, polyaromatic hydrocarbons, polar compounds and basic, pyridene-soluble compounds, having the following elemental chemical composition: nitrogen, about 3.4% to about 5% by weight; oxygen, about 5.8% to about 6.9% by weight; sulfur, about 0.3% to about 0.8% by weight; hydrogen, about 9.7% to about 10.4%, and carbon, about 76.9% to about 79.8%.

Sawatzky, H.; Clelland, F.I.; Farnand, B.A.; Houde, J. Jr.

1993-08-10

376

Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages.  

PubMed

Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries were studded tires are used. In this work, we investigated the inflammatory effect of PM10 generated from the wear of studded tires on two different types of pavement. As comparison, we also investigated PM10 from a traffic-intensive street, a subway station, and diesel exhaust particles (DEP). Human monocyte-derived macrophages, nasal epithelial cells (RPMI 2650), and bronchial epithelial cells (BEAS-2B) were exposed to the different types of particles, and the secretion of IL-6, IL-8, IL-10, and TNF-alpha into the culture medium was measured. The results show a significant release of cytokines from macrophages after exposure for all types of particles. When particles generated from asphalt/granite pavement were compared to asphalt/quartzite pavement, the granite pavement had a significantly higher capacity to induce the release of cytokines. The granite pavement particles induced cytokine release at the same magnitude as the street particles did, which was higher than what particles from both a subway station and DEP did. Exposure of epithelial cells to PM10 resulted in a significant increase of TNF-alpha secreted from BEAS-2B cells for all types of particles used (DEP was not tested), and the highest levels were induced by subway particles. None of the particle types were able to evoke detectable cytokine release from RPMI 2650 cells. The results indicate that PM10 generated by the wear of studded tires on the street surface is a large contributor to the cytokine-releasing ability of particles in traffic-intensive areas and that the type of pavement used is important for the level of this contribution. Furthermore, the airway inflammatory potential of wear particles from tires and pavement might be of a greater magnitude than that of DEP. PMID:16608163

Lindbom, John; Gustafsson, Mats; Blomqvist, Göran; Dahl, Andreas; Gudmundsson, Anders; Swietlicki, Erik; Ljungman, Anders G

2006-04-01

377

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2012 CFR

...2012-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2012-04-01

378

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2013 CFR

...2013-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2013-04-01

379

23 CFR 970.208 - Federal lands pavement management system (PMS).  

...2014-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2014-04-01

380

23 CFR 970.208 - Federal lands pavement management system (PMS).  

Code of Federal Regulations, 2011 CFR

...2011-04-01 false Federal lands pavement management system (PMS). 970.208...Systems § 970.208 Federal lands pavement management system (PMS). In addition... (i) An inventory of the physical pavement features including the number of...

2011-04-01

381

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

382

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

Microsoft Academic Search

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

Shoenberger

1992-01-01

383

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

384

A Review of Roadway Water Movement for Beneficial Use of Recycled Materials  

Microsoft Academic Search

The purpose of this chapter is to provide a comprehensive review of water movement in roadways so that this knowledge may be used in environmental impact studies of traditional and recycled pavement materials. Long term leaching of contaminants is dictated in part by the hydrology of the roadway environment. To determine the hydraulic regimes in the field, ingress and egress

Defne S. Apul; Kevin H. Gardner; Taylor T. Eighmy

385

Wear of hard materials by hard particles  

SciTech Connect

Hard materials, such as WC-Co, boron carbide, titanium diboride and composite carbide made up of Mo2C and WC, have been tested in abrasion and erosion conditions. These hard materials showed negligible wear in abrasion against SiC particles and erosion using Al2O3 particles. The WC-Co materials have the highest wear rate of these hard materials and a very different material removal mechanism. Wear mechanisms for these materials were different for each material with the overall wear rate controlled by binder composition and content and material grain size.

Hawk, Jeffrey A.

2003-10-01

386

Fatigue behavior of SMA and HMA mixtures  

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 the micro and macro cracks gradually takes place. The indirect tensile tests was carried out on hot mix asphalt HMA and stone matrix asphalt SMA mixtures

F. Moghadas Nejad; E. Aflaki; M. A. Mohammadi

2010-01-01

387

Concept Learning as a Function of the Type of Material and Type of Classification.  

ERIC Educational Resources Information Center

This reports the effects of the number of relevant stimulus dimensions and figural versus verbal stimuli on the concept learning ability of college students. Results force a consideration of mediational variables in explaining this form of cognitive learning. A set of verbal materials analogous to a set of dimensionalized figural materials was…

Ramsay, James G.

388

Interior Air Pollution in Automotive Cabins by Volatile Organic Compounds Diffusing from Interior Materials: I. Survey of 101 Types of Japanese Domestically Produced Cars for Private Use  

Microsoft Academic Search

The types and concentrations of organic compounds in the interior air of 101 different types of Japanese domestically produced private-use cars were examined. All the vehicles had been registered in the summer season as new cars and were less than 3 years old. The airborne compounds in the cabins were collected for 24h under static condition with the engine stopped

Toshiaki Yoshida; Ichiro Matsunaga; Kimiko Tomioka; Shinji Kumagai

2006-01-01

389

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, Hernan M.; Vincent, Benoit; Navarro, Fernando R.

2014-01-01

390

Methane and carbon monoxide emissions from asphalt pavement: Measurements and estimates of their important to global budgets  

SciTech Connect

The authors measured emissions of methane from asphalt surfaces used in pavement for roadways. Maximum emissions were 22 mg/m{sup 2}/hr for 1- to 4-week-old pavement during maximum sunlight intensity. Emissions were much smaller at low sunlight intensity and dropped off to negligible amounts at night. Smaller emissions were observed for asphalt pavement of 2.5 to 3 years approximate age under similar conditions. Comparison measurements of carbon monoxide emissions resulted in maximum emissions of about 2.6 mg/m{sup 2}hr for 1-week-old pavement. These findings indicate that emissions of CH{sub 4} and CO are a function of both sunlight and temperature. Based on these results, methane emissions from asphalt pavement cannot be a significant source of atmospheric methane as compared to other identified methane sources. Therefore, although asphalt methane emissions are a form of fossil fuel methane, they cannot explain the relatively high fraction of {sup 14}C-depleted methane in the atmosphere.

Tyler, S.C.; Dlugokencky, E.; Zimmerman, P.R.; Cicerone, R.J. (National Center for Atmospheric Research, Boulder, CO (USA)); Lowe, D.C. (Institute of Nuclear Sciences, Lower Hutt (New Zealand))

1990-08-20

391

Resilient modulus and permanent deformation testing of unbound granular materials  

E-print Network

Numerous research efforts have been devoted to characterizing the behavior of granular materials, which is one of the main concerns of pavement engineers. For better understanding of this behavior, laboratory tests where in-situ stress conditions...

Kancherla, Anuroopa

2005-11-01

392

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

393

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

394

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

395

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 ...

396

Material characterization for studing flexible pavement behavior in fatigue and permanent deformation  

Microsoft Academic Search

Mixtures' performances in fatigue and rutting were investigated. Different aggregates and gradations were studied in these mixtures. The aggregates and gradations chosen were investigated using Marshall design criteria. These aggregates were first evaluated for basic material characteristics such as specific gravity and water absorption for both fine and course fractions. Also, the Marshall stability, density and air voids contents were

M. R. N. Elmitiny

1980-01-01

397

An overview of waste materials recycling in the Sultanate of Oman  

Microsoft Academic Search

Various wastes and by-product materials are generated in the Sultanate of Oman including reclaimed asphalt pavement (RAP) aggregate, demolition concrete, cement by-pass dust (CBPD), copper slag, petroleum-contaminated soils (PCS), discarded tires, incinerator ash, and others. Recycling of such materials in construction is not practiced. Research data are also minimal into the potential use of selected materials in construction applications. This

R Taha; A Al-Rawas; K Al-Jabri; A Al-Harthy; H Hassan; S Al-Oraimi

2004-01-01

398

The impact of die attach material on type II popcorn cracking  

Microsoft Academic Search

Recent advances in packaging design, processes and materials have been effective in eliminating or reducing the occurrence of type I and II popcorn failures. However, type II popcorn failures remain prevalent. This paper features a vigorous investigation on the properties of various die attach materials and attempts to correlate the measured properties to the type II popcorn failure rate using

K. C. Chan; T. C. Chai; E. H. Wong; T. B. Lim

1998-01-01

399

Complex Modulus Prediction of Asphalt Concrete Pavement Cores  

E-print Network

and Texas field cores and three types of asphalt mixtures including hot mix asphalt (HMA), foaming warm mix asphalt (FWMA), and Evotherm warm mix asphalt (EWMA) were used. There were nearly forty field cores with different aging times from these three...

Ling, Meng

2013-12-02

400

Fast Error Estimates For Indirect Measurements: Applications To Pavement Engineering  

E-print Network

Fast Error Estimates For Indirect Measurements: Applications To Pavement Engineering Carlos that is difficult to measure directly (e.g., lifetime of a pavement, efficiency of an engine, etc). To estimate y computation time. As an example of this methodology, we give pavement lifetime estimates. This work

Kreinovich, Vladik

401

Availability of applied heavy metals as a function of type of soil material and metal source  

SciTech Connect

The authors applied the heavy metals Cd, Cu, Ni, and Zn, as sulfate salts and as lime-stabilized, digested Washington, D.C., sewage sludge, to surface and subsurface horizon materials of six Maryland soils in the greenhouse. Rates of metal addition were equivalent to field rates of 224 metric tons (t)/ha of the sludge. Corn (Zea mays L.) was grown for 30 d, 13 mo after treatment application, and the tissue was analyzed for metals. Yields of plant material were generally enhanced by sludge and suppressed by metal salts. Tissue levels of both Cd and Zn were considerably elevated. In general the sludge did not elevate tissue Cu and Ni, whereas metal salts slightly elevated tissue Cu and Ni with some soil materials. An interaction between type of soil material and source of metal on plant tissue metal levels was observed. Essentially inert soil materials tended to produce tissue with the highest metal levels when metal-salt-treated, but with the lowest metal levels when sludged. Conversely, reactive soil materials, tended to produce tissue with relatively lower levels of metals than other materials when metal-salt-treated, but with relatively high levels when sludged.

Korcak, R.F.; Fanning, D.S.

1985-07-01

402

Porous Pavement in Cold Climates Part: Performance and Cost  

E-print Network

Porous Pavement in Cold Climates Part: Performance and Cost Onondaga Environmental Institute 17 #12;Overview 1. Hydrology of Permeable Pavements 2. Water Quality Performance 3. Hydraulic Performance However, a large number of installations STILL continue to be sub-standard 4 #12;Porous Pavement Design

403

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally  

E-print Network

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded � Verification � Concluding Remarks Part � II (Companion presentation) � Asphalt Pavements � Effect of Aging: Asphalt concrete pavements (Part II) E1 E2 E3 Eh 1 2 3 h #12;Graded Finite Elements Graded Elements

Paulino, Glaucio H.

404

MANUAL FOR WEB-BASED TXDOT RIGID PAVEMENT Sureel Saraf  

E-print Network

0-5445-P2 MANUAL FOR WEB-BASED TXDOT RIGID PAVEMENT DATABASE Authors: Sureel Saraf Moon Won TxDOT Project 0-5445: Project Level Performance Database for Rigid Pavements in Texas SEPTEMBER 2007, REV. JULY-Based Information System for Rigid Pavements User's Manual Texas Department of Transportation July 9, 2009 #12

Texas at Austin, University of

405

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally  

E-print Network

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded � II � Asphalt Pavements � Effect of Aging � Simulations � Concluding Remarks #12;3 Objectives Develop) Correspondence Principle based formulation Application: Asphalt concrete pavements (Part II) #12;4 Asphalt

Paulino, Glaucio H.

406

Urban evaporation rates for water-permeable pavements.  

PubMed

In urban areas the natural water balance is disturbed. Infiltration and evaporation are reduced, resulting in a high surface runoff and a typical city climate, which can lead to floods and damages. Water-permeable pavements have a high infiltration rate that reduces surface runoff by increasing the groundwater recharge. The high water retention capacity of the street body of up to 51 l/m(2) and its connection via pores to the surface lead to higher evaporation rates than impermeable surfaces. A comparison of these two kinds of pavements shows a 16% increase in evaporation levels of water-permeable pavements. Furthermore, the evaporation from impermeable pavements is linked directly to rain events due to fast-drying surfaces. Water-permeable pavements show a more evenly distributed evaporation after a rain event. Cooling effects by evaporative heat loss can improve the city climate even several days after rain events. On a large scale use, uncomfortable weather like sultriness or dry heat can be prevented and the urban water balance can be attenuated towards the natural. PMID:20818060

Starke, P; Göbel, P; Coldewey, W G

2010-01-01

407

Highway pavement distress evaluation: Modeling measurement error  

Microsoft Academic Search

There has been a proliferation of inspection technologies to quantify distresses on highway pavement systems. These technologies employ varying measurement principles and are subject to measurement errors. Estimates of measurement errors are therefore required in order to select among these techniques, and to get accurate assessments of pavement condition. There is abundant literature concerning techniques available for the numerical study

Frannie Humplick

1992-01-01

408

Preparation and performance of a new type of blue light-emitting material ?-Alq 3  

Microsoft Academic Search

In this article, ?-Alq3 was synthesized by a novel method, which can act as a new type of blue light-emitting material. Performance of ?-Alq3 was investigated by SEM, UV–vis absorption spectra, photoluminescence (PL) spectra and electroluminescence (EL) spectra. Finally, it was concluded that grain shape of ?-Alq3 is close to column, absorption band of electron transition from HOMO orbit in

Bingshe Xu; Hua Wang; Yuying Hao; Zhixiang Gao; Hefeng Zhou

2007-01-01

409

STONE PAVEMENTS IN DESERTS! RONALD U. COOKE  

E-print Network

STONE PAVEMENTS IN DESERTS! RONALD U. COOKE ABSTRACT. Stone pavenlents are armored surfaces compnsing intricate mosaics of coarse particles, usually only one or two stones thick, set on or in fine processes, nlay vary greatly from place to place. STONE pavements are defined as armored surfaces comprising

Ahmad, Sajjad

410

Concrete Pavement Sustainability Sustainability Track Leadership  

E-print Network

#12;What Else is Happening? · FHWA advocating "Green Paving" technologies ­ Recycled concrete, twoTrack 13: Concrete Pavement Sustainability #12;Sustainability Track Leadership Committee Members package for concrete pavement sustainability (initiated1/10) · A conference on sustainability of concrete

411

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded Viscoelastic Model, Part-I: Development,  

E-print Network

Asphalt Pavement Aging and Temperature Dependent Properties through a Functionally Graded simulations, correspondence principle, finite-element method Abstract. Asphalt concrete pavements to climatic conditions are the major cause of such graded non-homogeneity. Current pavement analysis

Paulino, Glaucio H.

412

Variability of hot mix asphalt produced with reclaimed asphalt pavement  

E-print Network

t distribution and an F-test. The following conclusions are obtained: i) RAP is better used in producing a mix with a relatively small top size 3/8" (Type S-III mix) or 1/2'' (Type S-I mix), and not with a sieve size larger than 1" (Type S-II mix); ii) RAP...

Yang, Guiqin

2012-06-07

413

Temperature Dependent Tensile Fracture Stress of n- and p-Type Filled-Skutterudite Materials  

SciTech Connect

While materials with excellent thermoelectric performance are most desirable for higher heat to electrical energy conversion efficiency, thermoelectric materials must also be sufficiently mechanically robust to withstand the large number of thermal cycles and vibrational stresses likely to be encountered while in service, particularly in automotive applications. Further these TE materials should be composed of non-toxic and naturally abundant constituent elements and be available as both n- and p-type varieties. Skutterudite based thermoelectric materials seemingly fit this list of criteria. In this contribution we report on the synthesis, tensile fracture strengths, low temperature electrical and thermal transport properties, and coefficients of thermal expansion (CTE), of the n-type skutterudite La{sub 0.05({+-}0.01)}Ba{sub 0.07({+-}0.04)}Yb{sub 0.08({+-}0.02)}Co{sub 4.00({+-}0.01)}Sb{sub 12.02({+-}0.03)} and the p-type Ce{sub 0.30({+-}0.02)}Co{sub 2.57({+-}0.02)}Fe{sub 1.43({+-}0.02)}Sb{sub 11.98({+-}0.03)}. Both materials have tensile fracture strengths that are temperature independent up to 500 C, and are in the range of {approx}140 MPa as measured by a three point bend flexure test fixture described herein. The CTE's were measured by dual rod dilatometry and were determined to be 10.3 ppm/C for the n-type material and 11.5 ppm/C for p-type up to 450 C.

Salvador, James R. [GM R& D and Planning, Warren, Michigan; Yang, Jihui [General Motors Corporation; Wereszczak, Andrew A [ORNL; Wang, Hsin [ORNL; Cho, Jung Y [GM R& D and Planning, Warren, Michigan

2011-01-01

414

MEASUREMENT OF CONTACT STRESSES FOR DIFFERENT TRUCK TIRE TYPES TO EVALUATE THEIR INFLUENCE ON NEAR-SURFACE CRACKING AND RUTTING  

Microsoft Academic Search

Two pavement distress mechanisms have become more prevalent in recent years: near-surface rutting and surface-initiated wheelpath cracking. Some possible factors causing these failure mechanisms include higher traffic volumes, use of lower-quality materials, and changes in tire type and structure. Although all of these factors may play a role, this study concentrated on the effects of changes in tire type and

Leslie Myers; Reynaldo Roque; Byron Ruth; Christos Drakos

1999-01-01

415

Dopant type and/or concentration selective dry photochemical etching of semiconductor materials  

DOEpatents

Disclosed is a method of selectively photochemically dry etching a first semiconductor material of a given composition in the presence of a second semiconductor material which is of a composition different from said first material, said second material substantially not being etched during said method. The method comprises subjecting both materials to the same photon flux of an energy greater than their respective direct bandgaps and to the same gaseous chemical etchant under conditions where said etchant would be ineffective for chemical etching of either material were the photons not present, said conditions also being such that the resultant electronic structure of the first semiconductor material under said photon flux is sufficient for the first material to undergo substantial photochemical etching under said conditions and being such that the resultant electronic structure of the second semiconductor material under said photon flux is not sufficient for the second material to undergo substantial photochemical etching under said conditions. In a preferred mode, the materials are subjected to a bias voltage which suppresses etching in n- or p-type material but not in p- or n-type material, respectively; or suppresses etching in the more heavily doped of two n-type or two p-type materials.

Ashby, C.R.H.; Dishman, J.L.

1985-10-11

416

The genus Argulus (Crustacea: Branchiura) in Africa: redescriptions of type-material collected by W.A. Cunnington during the Lake Tanganyika Expedition in 1913, with notes on A. giganteus Lucas and A. arcassonensis Cuénot  

Microsoft Academic Search

Of the 11 specimens of Argulus Müller, 1785 examined during the present study, nine are recognised as valid. The two-specimens collected by W.A. Cunnington (1913) during the Expedition to Lake Tanganyika are redescribed. In these redescriptions, many species-specific features have been identified which facilitate identification when comparing with all other species of Argulus recorded from Africa. The type-material of A.

Sophie K. Rushton-Mellor

1994-01-01

417

A Yield Strength Model for Partially Saturated Unbound Granular Material  

Microsoft Academic Search

The predominant mode of distress for unbound pavement layers is the permanent deformation of the layer either through gradual deformation or rapid shear failure. Both these forms of permanent deformation have been linked to the shear strength of the material by researchers. Conventionally, the shear strength of the material is characterised with the Mohr-Coulomb shear strength parameters of the material.

Hechter L. Theyse; Francis T. H. Legge; Pieter C. Pretorius; Herman Wolff

2007-01-01

418

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... 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...

Alam, Shah Manzoor

2012-06-07

419

Materials research on EPS20 and EPS15 under representative conditions in pavement structures  

Microsoft Academic Search

The investigation of the mechanical characteristics of expanded polystyrene (EPS) with bulk densities of 15 kg\\/m3 (EPS15) and 20 kg\\/m3 (EPS20) under different hydro-thermal conditions is described. In the experiments, the EPS was tested under the expected loading, moisture and temperature conditions defined as representative for sub-base conditions. Firstly, hydro-thermal research on EPS was presented. Water absorption of EPS is

M. Duškov

1997-01-01

420

4/28/2010 1Porous Pavements Porous Pavements  

E-print Network

benefits Why Look at New Pavement Approaches? #12;4/28/2010 4Porous Pavements 4Porous Pavements Alternative) ·! Farmington Schools - Parking lot ·! Mound Commercial Center - Parking lot ·! Park Rapids Mixed Use

Minnesota, University of

421

Using the Multi-Depth Deflectometer to study pavement response  

E-print Network

the permanent deformation behavior and the state of stress in the modeled pavement layer. This three-dimensional 0 ( F E. J AJ J L )~r SUBGRADE SIMULATED BY 660 MECHANO - LA'TTICE UNITS MODIFIED BY INFLUENCE FACTORS ~ 9000LD (60 kN ) WHEEL PATH... the permanent deformation behavior and the state of stress in the modeled pavement layer. This three-dimensional 0 ( F E. J AJ J L )~r SUBGRADE SIMULATED BY 660 MECHANO - LA'TTICE UNITS MODIFIED BY INFLUENCE FACTORS ~ 9000LD (60 kN ) WHEEL PATH...

Yazdani, Jamshed Iqbal

2012-06-07

422

Crumb rubber modifier (CRM) in asphalt pavement: Summary of practices in Arizona, California, and Florida. Interim report, 1 February-30 June 1995  

SciTech Connect

Highway agencies have been evaluating crumb rubber modifier (CRM) in hot mix asphalt (HMA) since the 1970`s. Three agencies, Arizona, California, and Florida, currently use CRM in HMA at levels that would approach or exceed the mandate in Section 1038 of the Intermodal Surface Transportation Efficiency Act of 1991. This report documents the use of CRM in HMA in these three States. In particular, it addresses issues including thickness design, materials and mix design, construction procedure, including control, and pavement performance. The report also addresses the following questions: (1) What processes are used, (2) Why are they used, (3) How are they performing.

Hicks, R.G.; Lundy, J.R.; Leahy, R.B.; Hanson, D.; Epps, J.

1995-09-01

423

1 INTRODUCTION Flexural fatigue is one of the main failure modes in asphalt mixtures and flexible pavement  

E-print Network

1 INTRODUCTION Flexural fatigue is one of the main failure modes in asphalt mixtures and flexible or strain), depending on the mode of laoding. 1.1 Fatigue Flexural fatigue due to repeated traffic loading resistance and the stiffness modulus is necessary to use any design method of the flexible road pavements

Paris-Sud XI, Université de

424

On material characterization of paper coating materials by microindentation testing  

Microsoft Academic Search

Microindentation as a method for determining important material properties of paper coating materials is studied experimentally\\u000a and numerically. The bulk of the investigation is concentrated upon the short-lived elastic part of a spherical indentation\\u000a test, but determination of the failure stress of the coating is also discussed. The results indicate that microindentation\\u000a can be a powerful tool for material characterization

Christophe Barbier; Per-Lennart Larsson; Sören Östlund; Nils Hallbäck; Michael Karathanasis

2005-01-01

425

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

426

Reducing Conflicts between Motor Vehicles and Pedestrians: The Separate and Combined Effects of Pavement Markings and a Sign Prompt  

ERIC Educational Resources Information Center

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…

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

2004-01-01

427

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

EPA Science Inventory

To meet the need for long-term, 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...

428

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

E-print Network

's permeability. To investigate the unsteady (dynamic) fluid flow in asphalt pavements, a 3D fluid flow model, University of Maryland, 1163 Glenn Martin Hall, College Park, Maryland, 20742. E-mail: aydilek@eng.umd.edu 3 was developed using the lattice Boltzmann (LB) method. The model was validated using the well- known closed form

Aydilek, Ahmet

429

Effect of different types of litter material for rearing broilers.  

PubMed

1. Coir dust was evaluated as broiler litter in comparison with sawdust and rice husk using 135 commercial broilers. Forty-five broiler chicks were reared to 42 d on a 50 mm layer of each of these litters. 2. Birds reared on coir dust showed no difference in food consumption, body weight gain, food conversion efficiency production number and survivability in comparison to those reared on saw dust and rice husk. 3. It was concluded that coir dust is suitable as broiler litter when cheaply available. PMID:11081418

Swain, B K; Sundaram, R N

2000-07-01

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

A sensitivity analysis of the Texas flexible pavement system  

E-print Network

. stab. )Granular Base Thick. 12/10 6/6 ESAL 20E6 4E6 Pl Subgrade 10 Subgrade Modulus 7000 psi 18000 psi Surface Thickness 3. 5" 2. 0' Shoulder Type Paved Unpaved AC Type (Base} AC 20 AC 10 % Voids/% AC (Base) 5/7 7/4 Granular Base Mod Wus 60, 000... BASE 10 YR. ASPH STAB BASE 1 YR, ASPH STAB BASE 10 YR ASPH/GRN BASE 1 YR, ASPH/GRN BASE 10 YR, 7 6 5 4 3 2 1 0 1 2 3 'I 5 6 CqAC/EP AqEA ( 1OP Sy. 1 OALHART Figure 4: Cracked Area Comparison Between Location and Time. GRANULAR BASE 1 YR...

Henry, Claude Patrick

2012-06-07

432

PHYSIOLOGICAL INFORMATION FOR PAVEMENT HEALTH MONITORING BASED ON SURFACE RIDE QUALITY  

NASA Astrophysics Data System (ADS)

Pavement ride quality testing has traditionally been based on subjective questionnaire ratings. The questionnaire survey has ability to directly measure the sense of road users' ride quality. However, it is difficult to quantify the evaluation results based on the questionnaire due to its lack of objectivity. This study examines pavement health monitoring method using physiological information such as heart rate variability (HRV) for detecting mental stress of road users toward pavement ride quality. First, a results of a driving simulator experiment shows that potential mental stress caused by road roughness can be observed in high-frequency oscillations in 0.15-0.4Hz of HRV processed by continuous wavelet transform. Then, the high-frequency oscillations of HRV is summarized as an index related to the mental stress that makes objective ride quality evaluation possible. Finally, this study indicates that the index contributes to improve the accuracy of pavement health monitoring based on surface ride quality.

Tomiyama, Kazuya; Kawamura, Akira; Takahashi, Kiyoshi; Ishida, Tateki

433

Determination of total retronecine esters-type hepatotoxic pyrrolizidine alkaloids in plant materials by pre-column derivatization high-performance liquid chromatography.  

PubMed

A pre-column derivatization high-performance liquid chromatography method with diode array detection was developed and validated to determine the total retronecine esters-type hepatotoxic pyrrolizidine alkaloids (RET-HPAs) in herbs. The RET-HPAs reacted with o-chloranil in methanolic solution heated for 3 h, and an oxidative derivative was produced that could be detected at a maximal absorption of 223 nm. The analysis was performed using a C18 column with an isocratic elution of methanol and aqueous 0.01% triethylamine (adjusted to pH 4 with formic acid), and the detection was carried out with DAD at 223 nm. The validation of the method included linearity, sensitivity, recovery and stability. It showed a good linear regression (r(2) > 0.9900) in the range of 2.5-250 microM with a limit of detection (S/N = 3) of 0.5 microM. The method provided desirable repeatability with overall intra- and inter-day variations of less than 4.6%. The obtained recoveries for both of the extraction and derivatization process were between 94.6 and 100.7% (n = 3). PMID:19277972

Xiong, Ai-Zhen; Yang, Li; Zhang, Fang; Yang, Xue-Jing; Wang, Chang-Hong; Wang, Zheng-Tao

2009-06-01

434

Application of pyrolized carbon black from scrap tires in asphalt pavement design and construction  

SciTech Connect

According to EPA reports (1991) of the over 242 million waste generated each year in the United State, 5% are exported, 6% recycled, 11% incinerated, and 78% are landfilled, stockpiled, or illegally dumped. A variety of uses for these tires are being studied. Among these is pyrolysis which produces 5 5% of oil, 25% of carbon black, 9% of steel, 5% of fiber and 6% of gas. Pyrolized carbon black contains 9 % of ash, 4% of sulfur, 12% of butadine copolymer and 75% of carbon black. The objective of this research is to investigate the viability of using PCB as an additive in hot mix asphalt. The use of PCB in asphalt pavement is expected not only to improve the performance of conventional asphalt, but also to provide a means for the mass disposal of waste fires.

Park, T.; Coree, B.J. [Indiana Department of Transportation, West Lafayette, IN (United States). Division of Research; Lovell, C.W. [Purdue Univ., West Lafayette, IN (United States). School of Civil Engineering

1995-12-31

435

Elastic and plastic properties of soils influencing the design of rigid pavements  

E-print Network

construction of the pavement. The in ter ior lo a d ? ing pos it ion was f r e e f r om these ir regu la r it ie s to a la rge degree and to ja H H H W C J s> H CD H-# p U a o ?* j n > IS) c u H CO W H O n... ^ ' - ? , > 3 05 1 - ? o u m ; tn jrJ ? ? u> 1 0 t + W U ?S. S' ? P> ^ ^ ^ j ' -t tn f - : C ? ** H ? W 13 g S W S w A j , ? o m s u q f j j e o i j u c p e a T U D E tr E C ilO M 14 e o CM < 0 JO Q...

Khuri, Fuad I.

2013-10-04

436

Differentiation of Lactobacillus Species by Molecular Typing  

Microsoft Academic Search

A total of 64 type, reference, clinical, health food, and stock isolates of microaerophilic Lactobacillus species were examined by restriction fragment length polymorphisms. Of particular interest were members of six of the eight species most commonly recovered from the vaginas of healthy premenopausal women, namely, Lactobacil- lus jensenii, L. casei, L. rhamnosus, L. acidophilus, L. plantarum, and L. fermentum. Six

WEI ZHONG; KEVIN MILLSAP; HANNA BIALKOWSKA-HOBRZANSKA; GREGOR REID

1998-01-01

437

Model studies of stresses in upper layers of pavements  

E-print Network

REVIEW ON STRESS STUDIES 2 . 1 Studies P r b r to 1920 5 2 . 2 The B a te s R oad T e s t 6 2 .3 W e s t e r g a a rd A n a ly s is f o r C on c r e t e P a vem en ts 8 2 . 4 A r l in g ton T e s t s 12 2 .5 M od e l S tud ies at Iowa... ode l P or t land C em en t C on c r e t e Slab 56 6 . 4 A spha lt ic C on c r e t e O ve r la y and A spha lt ic C on c r e t e M ode l Slab 60 VII. A P PL IC AT ION OF SR -4 STRAIN GAGES 7. 1 G en e ra l 72 7 .2 A p p l ic a...

Subbaraju, Bhupatiraju

2013-10-04

438

9 CFR 354.247 - Table showing types of materials.  

Code of Federal Regulations, 2013 CFR

...INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Maintenance of Sanitary Conditions and Precautions... Cooling tanks and racks A A A Utensils for handling edible products A A A Framework (of equipment) A...

2013-01-01

439

9 CFR 354.247 - Table showing types of materials.  

Code of Federal Regulations, 2011 CFR

...INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Maintenance of Sanitary Conditions and Precautions... Cooling tanks and racks A A A Utensils for handling edible products A A A Framework (of equipment) A...

2011-01-01

440

9 CFR 354.247 - Table showing types of materials.  

Code of Federal Regulations, 2012 CFR

...INSPECTION AND CERTIFICATION VOLUNTARY INSPECTION OF RABBITS AND EDIBLE PRODUCTS THEREOF Maintenance of Sanitary Conditions and Precautions... Cooling tanks and racks A A A Utensils for handling edible products A A A Framework (of equipment) A...

2012-01-01

441

Life-Cycle Assessment of Highway Pavement Alternatives in Aspects of Economic, Environmental, and Social Performance  

E-print Network

, hazardous waste, toxic releases, water withdrawals, and transportation movements. The analysis results indicate that CRCP be the most cost-efficient and sustainable choice among the selected rigid pavement alternatives as it requires the lowest life...

Mao, Zhuting

2012-10-19

442

Development of design criteria pertaining to signing, pavement markings, and geometric cross-section for improved two-lane section (Texas Super 2)  

E-print Network

The purpose of this research was to establish the optimum driver information strategy regarding Super 2 passing lane sections in Texas. A Driver Survey and a Before and After Study examining proposed skip stripe pavement marking, signing...

Heard, Barry Don

2012-06-07

443

Accretion of ferromanganese nodules that form pavement in Second Connecticut Lake, New Hampshire  

PubMed Central

We discovered ferromanganese nodules that measure up to 46 cm in diameter with stromatolitic growth patterns in the western central near-shore portion of Second Connecticut Lake, Pittsburg, New Hampshire. They occur as four distinct morphotypes: irregular laminated convex plates that form concentric rings around a nucleating center (“domed-plate”), continuous pustular pavements that extend >10 m2 (“pustular”), nonlaminated and nonnucleated masses with pebbles scattered throughout the matrix (“lattice”), and small nonnucleated laminated structures >2 cm (“cup”) in water depths between 5 and 12 m. An estimated growth rate of 26 mm/100 years was determined from oxide deposits on datable debris. X-ray fluorescence showed an elemental composition comparable with that of nodule structures in other lakes. These sedimentary structures, the first seen in any of the six New England states, are the most morphologically distinct and varied lacustrine ferromanganese nodules known so far. PMID:17978181

Asikainen, Celeste A.; Werle, Sean F.

2007-01-01

444

Material processing by the internal path type CO{sub 2} laser robot  

SciTech Connect

The AMPI has introduced CO{sub 2} laser processing equipment featuring 50kW class output which is the greatest in the world. The equipment integrates a 50kW class CO{sub 2} laser oscillator, with a portal three-dimensional processing device and an internal path type CO{sub 2} laser robot, that is, robot with an integrated laser path. It offers a high degree of freedom in access to workpieces, enabling thereby flexible processing. The essential parameters which exert significant influence upon the laser welding performance are the defocused distance at the laser-irradiated point, the stand-off height (distance between welding nozzle and workpiece), as well as the kind and flow rate of shielding gas. The authors investigated the relationship between the penetration depth and these parameters for workpieces of mild steel and stainless steel respectively, in order to determine optimal values of the parameters. Besides, on the basis of the optimal values thus obtained, the relationship between penetration depth and welding speed was studied. This paper reports the summary of the equipment and main characteristics of the high power CO{sub 2} laser robot demonstrated by the investigation.

Matsumoto, Toshifumi; Fukuda, Naoaki; Kondo, Yasuo [Advanced Materials Processing Institute, Kinki (Japan)] [and others

1996-12-31

445

Pavement Thickness Design Parameter  

E-print Network

Pavement Thickness Design Parameter Impacts 2012 Municipal Streets Seminar November 14, 2012 Paul D Thickness Design · Design Traffic ­ Average daily traffic volume ­ Percent trucks on the street · Usually 2RoadXpress (Asphalt Institute) ­ American Concrete Paving Association · StreetPave ­ AASHTO 1993 Pavement Design Guide

446

Dynamic response of guardrail systems encased in pavement mow strips  

E-print Network

and numerical simulation and to develop predictive, full-scale simulations that enable assessment of the performance of guardrail systems encased in mow strips. To develop a test matrix of mow strip designs in preparation for possible testing, a state...

Seckinger, Nathaniel Ryan

2012-06-07

447

Cosmogenic 3 He surface-exposure dating of stone pavements  

E-print Network

control sur- face stability and hydrology, record activities of chemical and physical processes on desert and water or alternating shrinking and swelling of soil horizons, implying that gravel is concentrated-swell processes of soils, causing upward migration of clasts to the land surface (Cooke et al., 1993; Thomas, 1989

Ahmad, Sajjad

448

Multi-period optimization of pavement management systems  

E-print Network

on the Application of Optimization Approaches to PMS ........5 II.3. Solution Procedure for Multi Dimensional Binary Knapsack Problems..9 III MODEL AND SOLUTION APPROACH.....................................................12 III.1. Introduction... first. Since the proposed methodology in this research is for solving multi dimensional binary knapsack problems, the second part of the review will be devoted to that area. II.2. Literature on the Application of Optimization Approaches to PMS...

Yoo, Jaewook

2004-09-30

449

Assessment of Top-Down Cracking Causes in Asphalt Pavements  

Microsoft Academic Search

Cracks observed at the surface may have several origins and causes. A crack may either begin at the bottom or at the top of an asphalt layer. Cracking originated at the top of asphalt layers (top-down cracking) observed in temperate-climate countries is a degradation mechanism which has not been fully researched. In order to access this \\

E. Freitas; P. Pereira

450

Layer equivalency factors and deformation characteristics of flexible pavements  

E-print Network

stress of first stress invar1ant (8 = a& + a + a3), 2 ps i Kl K2 KI K2 exper1 mental test constants Russ1an E uation The Russ1an equation is the nickname of a deflect1on equation which 1s based on an approx1mate elastic theory. Th1s theory uses a 24... stress of first stress invar1ant (8 = a& + a + a3), 2 ps i Kl K2 KI K2 exper1 mental test constants Russ1an E uation The Russ1an equation is the nickname of a deflect1on equation which 1s based on an approx1mate elastic theory. Th1s theory uses a 24...

Hung, Jung-Tsann

2012-06-07

451

Toward an Improved Model of Asphalt Binder Oxidation in Pavements  

E-print Network

and oxygen transport model, coupled with binder reaction kinetics, provides the basis for such calculations. A one-dimensional thermal transport model, coupled with site-specific model parameters and recent improvements in the availability of required input...

Prapaitrakul, Nikornpon

2011-02-22

452

Evaluation of Surface Infiltration Testing Procedures in Permeable Pavement Systems  

EPA Science Inventory

The ASTM method (ASTM C1701) for measuring infiltration rate of in-place pervious concrete provides limited guidance on how to select testing locations, so research is needed to evaluate how testing sites should be selected and how results should be interpreted to assess surface ...

453

Induced activity of several candidate superconductor materials in a tokamak-type fusion reactor  

Microsoft Academic Search

The induced activity and compositional change of several superconducting materials such as Nb-based alloys, V-based alloys and MgB2 have been evaluated with a numerical calculation. We assume that the materials are irradiated for 10 MW a\\/m2 at the magnet of the inboard position of a tokamak-type fusion reactor with a neutron wall loading of 1 MW\\/m2. The materials are Nb3Sn,

T. Noda; T Takeuchi; M Fujita

2004-01-01

454

Pavement management and weigh-in-motion. Transportation research record  

SciTech Connect

The 15 papers in the report deal with the following areas: development of a preventive maintenance algorithm for use in pavement-management systems; pavement-performance prediction model using the Markov Process; roadway modeling and data conversion for a transportation-facilities information system; development of a methodology to estimate pavement maintenance and repair costs for different ranges of pavement-condition index; new techniques for modeling pavement deterioration; pavement management at the local government level; a comprehensive ranking system for local-agency pavement management; expert system as a part of pavement management; MAPCON: a pavement-evaluation data-analysis computer system; a microcomputer procedure to analyze axle load limits and pavement damage responsibility; selected results from the first three years of the Oregon automatic monitoring demonstration project; automated acquisition of truck-tire pressure data; calibration and accuracy testing of weigh-in-motion systems; accuracy and tolerances of weigh-in-motion systems; on-site calibration of weigh-in-motion systems.

Cation, K.A.; Shahin, M.Y.; Scullion, T.; Lytton, R.L.; Butt, A.A.

1987-01-01

455

Monitoring of the Permeable Pavement Demonstration Site at the Edison Environmental Center (Poster)  

EPA Science Inventory

This is a poster on the permeable pavement parking lot at the Edison Environmental Center. The monitoring scheme for the project is discussed in-depth with graphics explaining the instrumentation installed at the site. ...

456