Note: This page contains sample records for the topic types of pavements by material from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: November 12, 2013.
1

Variability of pavement noise benefit by vehicle type  

NASA Astrophysics Data System (ADS)

The Volpe Center Acoustics Facility, in support of the California Department of Transportation (Caltrans), is participating in a long-term study to assess several types of pavement for the purpose of noise abatement. On a four-mile stretch of a two-lane highway in Southern California, several asphalt pavement overlays are being examined. Acoustical, meteorological, and traffic data are collected in each pavement overlay section, where microphones are deployed at multiple distances and heights. Single vehicle pass-by events are recorded primarily for three vehicle types: automobiles, medium trucks, and heavy trucks. Data are analyzed to determine the noise benefit of each pavement as compared to the reference dense-graded asphaltic concrete (DGAC); this includes a modified Statistical Pass-By Index as well as average Lmax values for each vehicle type. In addition, 1/3-octave band data are examined. Automobiles and heavy trucks are the focus of this paper, where benefits due to pavement will be presented for three pavement types: open-graded asphaltic concrete (OGAC) of 75 mm thickness, open-graded asphaltic concrete (OGAC) of 30 mm thickness, and rubberized asphaltic concrete, Type O (open) (RAC) of 30 mm thickness. Average Lmax values and spectral data show that noise benefits due to pavement can vary by vehicle type.

Rochat, Judith L.; Read, David R.

2005-09-01

2

Variability of pavement noise benefit by vehicle type  

Microsoft Academic Search

The Volpe Center Acoustics Facility, in support of the California Department of Transportation (Caltrans), is participating in a long-term study to assess several types of pavement for the purpose of noise abatement. On a four-mile stretch of a two-lane highway in Southern California, several asphalt pavement overlays are being examined. Acoustical, meteorological, and traffic data are collected in each pavement

Judith L. Rochat; David R. Read

2005-01-01

3

Characterization of Unbound Pavement Materials From Virginia Sources for Use in the New Mechanistic-Empirical Pavement Design Procedure.  

National Technical Information Service (NTIS)

The implementation of mechanistic-empirical pavement design requires mechanistic characterization of pavement layer materials. The subgrade and base materials are used as unbound, and their characterization for Virginia sources was considered in this stud...

M. S. Hossain

2010-01-01

4

Skid Resistance of Pavement Marking Materials: Volume I.  

National Technical Information Service (NTIS)

The skid resistance of typical pavement marking materials is determined. A data base of full-scale locked-wheel skid resistance is presented for typical traffic paints of various formulations, hot spray and extruded thermoplastics, cold preformed plastics...

D. A. Anderson G. F. Hayhoe J. J. Henry

1981-01-01

5

Water Quality Performance of Three Side-by-Side Permeable Pavement Surface Materials: Three Year Update  

EPA Science Inventory

Communities are increasingly installing structural low impact development (LID) practices to mange stormwater and reduce pollutant loads associated with stormwater runoff. Permeable pavement is a LID practice that has limited research on working-scale, side-by-side performance o...

6

Pavement management and rehabilitation of portland cement concrete pavements  

NASA Astrophysics Data System (ADS)

Pavement management and rehabilitation projects and techniques are discussed. The following topics are discussed: economic analyses and dynamic programming in resurfacing project selection; implementation of an urban pavement management system; pavement performance modeling for pavement management; illustration of pavement management: from data inventory to priority analysis; rehabilitation of concrete pavements by using portland cement concrete overlays; pavement management study: Illinois tollway pavement overlays; resurfacing of plain jointed-concrete pavements; design procedure for premium composite pavement; model study of anchored pavement; prestressed concrete overlay at O'Hare International Airport: in-service evaluation; and, bonded portland cement concrete resurfacing.

Zegeer, C. V.; Agent, K. R.; Rizenbergs, R. L.; Curtayne, P. C.; Scullion, T.; Pedigo, R. D.; Hudson, W. R.; Roberts, F. L.; Karan, M. A.; Haas, R.

7

Prediction of pavement roughness  

NASA Astrophysics Data System (ADS)

A simplified procedure has been developed for considering roughness in pavement design. The procedure utilizes statistical parameters to generate stochastic pavement material properties and profiles. A methodology was developed for predicting the rutting of a pavement section due to applied traffic. Thus the predicted rut depth can be applied to the profiles yielding a predicted surface profile. This profile can then be used to determine a measure of pavement roughness.

Barker, W. R.

1982-09-01

8

Sustainable Construction Case History: Fly Ash Stabilization of Recycled Asphalt Pavement Material  

Microsoft Academic Search

A case history is described where Class C fly ash was used to stabilize recycled pavement material (RPM) during construction\\u000a of a flexible pavement in Waseca, MN, USA. The project consisted of pulverizing the existing hot-mix asphalt (HMA), base,\\u000a and subgrade to a depth of 300 mm to form RPM, blending the RPM with fly ash (10% by dry weight) and

Lin Li; Craig H. Benson; Tuncer B. Edil; Bulent Hatipoglu

2008-01-01

9

Finite Element Simulation of Structural Performance on Flexible Pavements with Stabilized Base/Treated Subbase Materials under Accelerated Loading.  

National Technical Information Service (NTIS)

Accelerated pavement testing (APT) has been increasingly used by state highway agencies in recent years for evaluating pavement structures and/or materials. However, running an APT experiment is expensive. It requires costly accelerated loading devices an...

X. Chen X. Yang Z. Wu

2011-01-01

10

Contemporary biogenic formation of clay pavements by eucalypts: further support for the phytotarium concept  

PubMed Central

Background and Aims Clayey (sodosolic) pavements were studied in lateral root catchments of eucalypts where mixed myrtaceous:proteaceous vegetation was colonizing a dune of quartzitic sand blown out from a playa lake during late Pleistocene times. The site at Chillinup in south-west Western Australia provided an opportunity to examine these signature pavements in an unequivocally recent setting, and to assess their effects on competing non-eucalypt vegetation. Methods Pavements were located, and their extents and depths assessed by probing with steel rods, followed by corings and pit excavations using an air spade. Listings of plant species, growth forms and root morphologies were assembled for different vegetation zones in a representative transect across the dune. A deep cutting through the dune provided details on pavement morphology and modifications to the sand deposit bioengineered by eucalypt and heath vegetation. Key Results Clay pavements comprised closely spaced, round-topped columns whose mean diameters and depths varied between eucalypt species. Incipient pavement formation was characterized by clumps of clay deposited around fine root material. Pavements appeared to have been synthesized in situ from locally accessed and imported constituents. Understoreys on superficial pavements of a tree eucalypt were considerably less dense and biodiverse than on the deeper pavements of two mallee species, whilst most profuse vegetation cover was encountered in heath on unmodified (non-pavemented) sand. Certain species were restricted to superficially located pavements, whilst other ‘generalist’ species occurred widely across the dune. Relict pavements formed by earlier generations of eucalypts were present in certain areas of the transect and in soil profiles of the cutting. Some relict pavements colonized by proteaceous shrubs were overprinted with ferricrete. Conclusions Clay pavements formed by eucalypts have pronounced effects on understorey vegetation and may have been instrumental in establishment of the complex mosaics of mallee-woodland and proteaceous heathland observed across semi-arid landscapes of south-west Western Australia. Findings are related to earlier observations on the range of plant-mediated changes in soil profiles discussed in the recently advanced ‘Phytotarium’ concept.

Pate, John S.; Verboom, William H.

2009-01-01

11

APPLICATION OF EMPIRICAL AND MECHANISTIC-EMPIRICAL PAVEMENT DESIGN PROCEDURES TO Mn\\/ROAD CONCRETE PAVEMENT TEST SECTIONS  

Microsoft Academic Search

Current pavement design procedures are based principally on empirical approaches. The introduction of new materials and the significant increase in traffic volumes have brought uncertainty to their prediction of pavement behavior. The current trend toward developing more mechanistic-empirical type pavement design methods led Minnesota to develop the Minnesota Road Research Project (Mn\\/ROAD). The project consists of 40 heavily instrumented test

T. R. Burnham

12

Quantification of Smoothness Index Differences Related to Long-Term Pavement Performance Equipment Type.  

National Technical Information Service (NTIS)

The Long-Term Pavement Performance (LTPP) program was designed as a 20-year study of pavement performance. A major data collection effort at LTPP test sections is the collection of longitudinal profile data using inertial profilers. Three types of inertia...

R. W. Perera S. D. Kohn

2005-01-01

13

Nitrogen Transformations in Three Types of Permeable Pavement  

EPA Science Inventory

In 2009, USEPA constructed a 0.4-ha (1-ac) parking lot at the Edison Environmental Center in Edison, NJ, that incorporated three different permeable pavement types - permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). The driving lanes...

14

Development of Field Performance Evaluation Tools and Program for Pavement Marking Materials: Technical Report.  

National Technical Information Service (NTIS)

Historically the prequalification or selection of pavement marking materials (PMMs) is mainly based on product specifications and lab testing, which do not correlate well with the field performance of the products. On the other hand, there is no consensus...

A. Pike H. Ge P. Carlson Y. Zhang

2011-01-01

15

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

16

Non-linear dynamic analysis of flexible and rigid pavements  

Microsoft Academic Search

Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linear elastic material properties and static loading conditions. In reality, pavement materials are not linear elastic materials. For example, asphalt mixtures are viscoelastic materials and cohesive soils are elastic-plastic materials. Also truck loads are moving loads. The difference between the closed form analysis assumptions and

Sameh Mohamed Zaghloul

1993-01-01

17

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

18

Real-time measurement and high-speed identification of highway pavement surface deformation  

Microsoft Academic Search

Pavement distress status is very important to investigate and evaluate pavement condition, which is characterized by distress types, degree and area. The measurement of three dimensions structure of pavement surface is of great value for the judgment of pavement distress status. Optical three dimensional profilometry is a well established technique for the measurement of three dimensions surface profiles, which has

Lin Fu; Anzhi He; Zhenhua Li

2006-01-01

19

Development of Methodology to Include the Strength Contribution of Select Subgrade Materials in Pavement Structure.  

National Technical Information Service (NTIS)

This study was conducted to develop a methodology to incorporate the structural contribution of working platforms, including those constructed with industrial by-products, into the design of flexible pavements. Structural contribution of the working platf...

T. B. Edil C. H. Benson W. H. Kim B. F. Tanyu

2005-01-01

20

Chapter 26 The use of alternative and improved construction materials and geosynthetics in pavements  

Microsoft Academic Search

Traditional construction materials can be scarce or very expensive for several civil engineering works. Nowadays, significant increases in the cost of construction materials can also be a consequence of environmental restriction to their exploitation. Thus, there is an increasing interest on the use of low grade construction materials in pavements and other earth works. This work deals with the use

Lilian R. de Rezende; José Camapum de Carvalho; Ennio M. Palmeira

2005-01-01

21

Development of Paving Material for Footpath and CAR Park Pavement Using Granite Soil  

NASA Astrophysics Data System (ADS)

It is required to develop new paving materials for pavements, such as footpaths, car parks, etc., in parks, having good landscape. Such paving materials have been already developed, but these do not have sufficient strength, abrasion resistance and frost resistance. In this study, a new paving was examined material using cement, sand and granite soil. The mix proportion of this material tested was 2:4:4 of cement, sand and granite soil by mass. The maximum flexural and compressive strength were both obtained at a water content of 14% of the total mass, and the strength were several times larger than that of paving material on the market consisting of 10% of cement and 90% granite soil. The abrasion resistance was tested according to ASTM C 779, and this resistance was about four times greater than that of the paving material on the market. The frost resistance was obtained high value compared with the concrete of 72% in water cement ratio by a new simple resisting test method for freezing and thawing using liquid nitrogen and warm water. It is considered that this new paving material is applicable to pavement for footpath, car park, etc.

Nagamachi, Masaharu; Mizuguchi, Hiroyuki; Inoue, Kentaro; Kamada, Koichi

22

Low cost pavement marking materials based on plasticized sulfur  

NASA Astrophysics Data System (ADS)

Pavement marking was made more cost effective by reducing the cost of the marking materials. A low cost marking material based on sulfur was developed. Elemental sulfur is a hard, brittle, crystalline material which, on heating, melts to a thin liquid that can be spray applied. If molten elemental sulfur is spray applied to the road as markings, it will on application solidify, crack and adhere poorly to the road. The first ten high speed trucks that ride over the markings will remove them. To make a useful sulfur based pavement marking material it was necessary to chemically modify (plasticize) the sulfur and mix it with fillers and pigments such that it had all of the characteristics desired of a pavement marking material. Yellow and white formulations were developed. For identification they were given the names YS-EIGHT and WS-EIGHT for the yellow and white formulations.

Dale, J. M.

1982-04-01

23

Predicting in-service fatigue life of flexible pavements based on accelerated pavement testing  

NASA Astrophysics Data System (ADS)

Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. Traditionally, the estimation of the expected fatigue field performance has been based on the laboratory bending beam test. Full-scale Accelerated Pavement Testing (APT) is an alternative to laboratory testing leading to advances in practice and economic savings for the evaluation of new pavement configurations, stress level related factors, new materials and design improvements. This type of testing closely simulates field conditions; however, it does not capture actual performance because of the limited ability to address long-term phenomena. The same pavement structure may exhibit different response and performance under APT than when in-service. Actual field performance is better captured by experiments such as Federal Highway Administration's Long-Term Pavement Performance (LTPP) studies. Therefore, to fully utilize the benefits of APT, there is a need for a methodology to predict the long-term performance of in-service pavement structures from the results of APT tests that will account for such differences. Three models are generally suggested to account for the difference: shift factors, statistical and mechanistic approaches. A reliability based methodology for fatigue cracking prediction is proposed in this research, through which the three models suggested previously are combined into one general approach that builds on their individual strengths to overcome some of the shortcomings when the models are applied individually. The Bias Correction Factor (BCF) should account for all quantifiable differences between the fatigue life of the pavement site under APT and in-service conditions. In addition to the Bias Correction Factor, a marginal shifty factor, M, should be included to account for the unquantifiable differences when predicting the in-service pavement fatigue life from APT. The Bias Correction Factor represents an improvement of the currently used "shift factors" since they are more general and based on laboratory testing or computer simulation. By applying the proposed methodology, APT performance results from a structure similar to an in-service structure can be used to perform four-point bending beam tests and structural analysis to obtain an accurate estimate of the necessary Bias Correction Factor to estimate in-service performance.

Guo, Runhua

24

Material Selection and Design Consideration for Moisture Damage of Asphalt Pavement.  

National Technical Information Service (NTIS)

Moisture damage is a primary mode of distress occurring in Nebraska hot mix asphalt (HMA) pavements. The use of hydrated lime has been recommended for Nebraska HMA pavements to mitigate moisture-related damage. There are several techniques of introducing ...

J. E. S. Lutif Y. Kim

2006-01-01

25

Evaluation of Bituminous Materials Used in Pavement Recycling Projects at Tyndall, Macdill, and Hurlburt Air Force Bases.  

National Technical Information Service (NTIS)

This report presents results of a study involving bituminous materials from Tyndall and MacDill Air Force Bases and Hurlburt Field. These materials included Reclaimed Asphalt Pavement (RAP), modifiers, virgin asphalts, and new aggregates. A tentative modi...

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

1987-01-01

26

STATUS OF POROUS PAVEMENT RESEARCH  

EPA Science Inventory

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

27

Design of perpetual asphalt pavements  

Microsoft Academic Search

The design conception of overseas perpetual pavement is introduced. Based on the successful experience on the improvement of asphalt pavement structure abroad,which can change the prensent situation of using single semi-rigid base asphalt pavements in our country,the design method of perpetual asphalt pavement is studied.The different pavement structures can be applied reasonablely.The earlier impairments of asphalt pavements can be prevented

Chang Hongxing; Zhao Jun; Tang Jiyu

2011-01-01

28

MATERIALS CHARACTERIZATION AND ECONOMIC CONSIDERATIONS OF COLD-MIX RECYCLED ASPHALT PAVEMENTS (MIX-DESIGN, GUIDELINES, ANALYSES, BITUMINOUS, INDIANA)  

Microsoft Academic Search

Recycling of asphalt pavements has become a common rehabilitation and maintenance process since the mid 1970s. The state of the art of designing and constructing pavements composed of recycled materials has now advanced to a point where recycling is considered as an alternative to conventional procedures for most paving projects.^ An in-depth evaluation of cold-mix recycling techniques was undertaken and

LUIS HUMBERTO CASTEDO-FRANCO

1985-01-01

29

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

30

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

1996-12-31

31

DETERMINATION OF STRESS-DEPENDENT MATERIAL PROPERTIES WITH THE FWD, FOR USE IN THE STRUCTURAL ANALYSIS OF PAVEMENTS USING FINITE ELEMENT ANALYSIS TECHNIQUES  

Microsoft Academic Search

The stress-dependent and nonlinear behaviour of granular pavement materials is well known. It is however expensive and time consuming to determine the properties of such materials in a laboratory. It has been shown that, as part of pavement investigation, the drop sequence of the Falling Weight Deflectometer (FWD) measurements can be successfully adjusted and used in the determination of material

S. J. Bredenhann; K. J. Jenkins

32

Effects of temperature and water on pavement performance  

SciTech Connect

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

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

1987-01-01

33

An Investigation of the Smoothness Characteristics of Highway Pavement Surfaces.  

National Technical Information Service (NTIS)

The report briefly describes Illinois' study of riding quality of newly constructed pavement, modifications made to the sensing devices of the BPR-Type Roughometer to improve its capabilities in measuring short pavement sections and to increase the operat...

J. E. LaCroix

1976-01-01

34

Use of Precast Slabs for Pavement Rehabilitation on I-66.  

National Technical Information Service (NTIS)

Highway agencies continuously strive to expedite pavement construction and repairs and to evaluate materials and methods to provide long-lasting pavements. As part of this effort, agencies have used precast concrete slabs for more than 10 years with succe...

C. Ozyildirim M. S. Hossain

2012-01-01

35

Evaluation of Poisson's Ratio for Use in the Mechanistic Empirical Pavement Design Guide (MEPDG).  

National Technical Information Service (NTIS)

The pavement design industry is moving towards the use of mechanistic principles in designing flexible pavements. To determine the resultant strains in the pavement system using these principles, two material properties are required; 1) modulus and 2) Poi...

A. Maher T. Bennert

2008-01-01

36

Degradation Modeling of Polyurea Pavement Markings.  

National Technical Information Service (NTIS)

Polyurea is a long life pavement marking material used for assets requiring long periods of uninterrupted accessibility. Knowing the performance characteristics of such markings is critical to asset management planning focused on maximizing marking materi...

J. D. Needham

2011-01-01

37

Non-linear finite element analysis of flexible pavements  

Microsoft Academic Search

A research study is being undertaken to incorporate the realistic material properties of the pavement layers and the moving traffic load, in the analysis of flexible pavements, using the finite element theory. As a preliminary step taken herein in this direction, a pavement structure where field measurements have been carried out when subjected to a cyclic loading, is selected and

Muhammad N. S. Hadi; B. C. Bodhinayake

2003-01-01

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

Avoiding Early Failure of Intersection Pavements.  

National Technical Information Service (NTIS)

The primary mode of failure of the intersections studied was rutting with shoving in some cases. The leading materials related cause of pavement failure was asphalt content in excess of the designed value. Most of the mixtures studied contained relatively...

M. Ameri-Gaznon J. W. Button D. Perdomo D. N. Little D. G. Zollinger

1989-01-01

40

Latex improvement of recycled asphalt pavement  

NASA Astrophysics Data System (ADS)

The performance of a single unmodified milled recycled asphalt concrete was compared to milled asphalt concrete modified by addition of three types of rubber latex. Latex was added at 2, 3, 5, and 8 percent latex by weight of asphalt in the asphalt concrete. Lattices used were a styrene butadiene (SBR), a natural rubber (NR), an acrylonitrile butadiene (NBR), and four varieties of out of specification SBR lattices. Marshall tests, while indecisive, showed a modest improvement in properties of SBR and NR added material at 3 and 5 percent latex. Addition of NBR latex caused deterioration in Marshall stability and flow over that of control. Repeated load tests were run using the indirect tensile test, analyzed by the VESYS program, which computes life of pavements. Repeated load tests showed improvement in asphalt concrete life when 3 and 5 percent SBR was added. Improvement was also shown by the out of specification SBR.

Drennon, C.

1982-08-01

41

Application of Energy Concepts to the Performance of Airfield Pavements.  

National Technical Information Service (NTIS)

Pavement engineers have not been able to predict the performance of pavement systems prior to actual construction and operational utilization. A solution to this problem was obtained by verifying the following hypothesis developed from energy concepts: A ...

M. E. Harr W. H. Highter

1973-01-01

42

Effects of Temperature and Water on Pavement Performance,  

National Technical Information Service (NTIS)

The 12 papers in the report deal with the following areas: procedures for estimation of asphalt concrete pavement moduli at in situ temperatures; stress caused by temperature gradient in portland cement concrete pavements; characterizing temperature effec...

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

1987-01-01

43

A Field Evaluation of the Use of FBC Flyash for Barnyard Pavement  

Microsoft Academic Search

Pavement of muddy barnyards benefits livestock health by keeping animal feet and udders dryer and cleaner. In spring 1995, fluidized bed combustion (FBC) flyash was installed as a pavement material for barnyards on a farm approximately 40 miles north of Harrisburg, PA. The flyash was transported dry to the site in pneumatic tank trucks and hydrated to approximately 35% using

W. L. Stout; T. L. Nickeson; Paul Cunningham

44

Interaction of Vehicles and Pavements.  

National Technical Information Service (NTIS)

The 9 papers in this report deal with the following areas: problems encountered in using vehicle ride as a criterion of pavement roughness; evaluation of panel rating methods for assessing pavement ride quality; high-speed road monitoring system; use of r...

B. E. Quinn J. B. Nick M. S. Janoff P. G. Jordan J. Porter

1983-01-01

45

Development of an In situ Method for Continuous Evaluation of the Resilient Modulus of Pavement Subgrade.  

National Technical Information Service (NTIS)

Pavement designs, materials and uses vary around the world, but engineers typically employ the resilient moduli of pavement materials as the primary means of evaluating those materials. Unfortunately, the majority of tests used to determine the resilient ...

M. P. Rits

1992-01-01

46

In-Situ Recycling of Deteriorated Concrete Airport Pavements by Rubblization  

Microsoft Academic Search

Rubblization is a method of in-situ recycling of deteriorated concrete pavements. The rubblized layer behaves as a tightly keyed, interlocked, high-density unbound base. At the Federal Aviation Administration's (FAA) National Airport Pavement Test Facility (NAPTF), three rigid airport pavements with 30.5-cm (12-in.) thick concrete slabs on different support systems were rubblized after being trafficked to failure (shattered slab condition) using

N. Garg; D. R. Brill; William J. Hughes

47

How Dutch drinking water production is affected by the use of herbicides on pavements  

Microsoft Academic Search

About forty per cent of drinking water in The Netherlands is produced from surface water. Dutch water companies, that have to rely on this source, are dealing with major water quality problems due to the use of herbicides on pavements. Voluntary measures and bans have had only limited effect on the reduction of emissions of herbicides that runoff from pavements

A. D. Bannink

48

Evaluating stepping displacements of pedestrian concrete pavements connected by EPDM rubber and PVC joiners  

Microsoft Academic Search

Pedestrian concrete pavements (sidewalks) are usually made of continuous slabs with simple control joints at a specified interval. Simple control joints such as breaking score lines or saw cuts are created on the pedestrian concrete pavements mainly to relieve stresses resulting from friction and also to avoid displacement\\/unplanned cracking. However, these joints have no load transfer mechanism and therefore the

Y. C. Koay; Y. M. Xie; S. Setunge

2008-01-01

49

Fracture of highway and airport pavements  

NASA Astrophysics Data System (ADS)

Existing solutions for the stresses in a cracked slab containing a crack and supported by an elastic foundation are extended to obtain the stress intensity factor (SIF) for a crack in a pavement subjected to moving vehicular loads. In the existing solutions the stresses can be obtained only for a uniform bending stress (before the crack occurs) along the crack surface. For pavements subjected to moving vehicular loads, the stress distribution along the crack surface is not uniform and the approximation of a uniform stress is often unsatisfactory. The present work extends the above solutions to cover more realistic loading of highway and airport pavements. This facilitates the application of the principles of fracture mechanics to the fatigue crack propagation and fracture of pavements. Beginning with a part-through semi-elliptical starter crack, the crack is assumed to grow under load and the SIF is presented at various stages of crack growth, from the starter crack into a short through-crack that eventually becomes a very long through-crack. Some examples of the fracture of typical rigid and flexible highway and airport pavements are presented to show the need to consider fracture in the design of pavements.

Ramsamooj, D. V.

1993-03-01

50

State-of-the-Art Review of Cold in-Place Recycling of Asphalt Pavements in tne Northern Plains Region.  

National Technical Information Service (NTIS)

Cold In-Place Recycling (CIR) is defined as a rehabilitation technique in which the existing pavement materials are reused in-place without the application of heat. The reclaimed asphalt pavement (RAP) material is obtained by milling, planning, or crushin...

N. Suleiman

2002-01-01

51

Thin-lift recycling of asphalt pavement. SAE Paper 760662  

Microsoft Academic Search

Five basic steps of efficient and economical continuous thin-lift asphalt pavement recycling are listed and the design features of the Cutler Repaver are described. The huge, mobile, self-propelled asphalt paving plant utilizes the five steps with integrated components as follows: softening the old road surface with radiant heat produced by ceramic emitters; loosening a thin layer of old material with

Winderlin

1976-01-01

52

Application of Full-Scale Accelerated Pavement Testing. A Synthesis of Highway Practice.  

National Technical Information Service (NTIS)

This synthesis, which describes the state of the practice for full-scale accelerated pavement testing (APT), will be of interest to state department of transportation (DOT) pavement design and materials engineers; DOT research staff, including field and l...

J. B. Metcalf

1996-01-01

53

Design, Management, and Operation of Pavements.  

National Technical Information Service (NTIS)

The 5 papers in the report deal with the following areas: Pavement response and load restrictions on spring thaw-weakened flexible pavements; Use of thermistors and spring road management; Method for determining optimal blading frequency of unpaved roads;...

M. S. Rutherford Barcomb Alfelor

1989-01-01

54

Stabilization of Existing Subgrades to Improve Constructibility during Interstate Pavement Reconstruction. A Synthesis of Highway Practice.  

National Technical Information Service (NTIS)

This synthesis will be of interest to state DOT construction, geotechnical, materials, and pavement system design engineers, engineering geologists, and research engineers, and others concerned with the constructibility of new pavements over existing subg...

J. G. Laguros G. A. Miller

1997-01-01

55

Enhancement of Resilient Modulus Data for the Design of Pavement Structures in Florida.  

National Technical Information Service (NTIS)

The resilient modulus (MR) of pavement materials is an essential parameter for mechanistically based pavement design procedures. However, measuring the resilient modulus of a particular site has been a complex and difficult task. The process, as outlined ...

C. C. Ling W. V. Ping

2007-01-01

56

Evaluation of pervious concrete pavement performance in cold weather climates  

Microsoft Academic Search

Pervious concrete pavement is a sustainable and environmentally conscious paving material. Use of pervious concrete pavement in freeze–thaw climates in Canada has been minimal to date. This paper describes the performance to date of five field sites in Canada. The test areas are monitored continually, starting at the construction stage, to understand the behaviour of pervious concrete in climates in

Vimy Henderson; Susan Tighe

2011-01-01

57

Evaluation of pervious concrete pavement performance in cold weather climates  

Microsoft Academic Search

Pervious concrete pavement is a sustainable and environmentally conscious paving material. Use of pervious concrete pavement in freeze–thaw climates in Canada has been minimal to date. This paper describes the performance to date of five field sites in Canada. The test areas are monitored continually, starting at the construction stage, to understand the behaviour of pervious concrete in climates in

Vimy Henderson; Susan Tighe

2012-01-01

58

Development of an Automated Procedure for Implementing Resilient Modulus Test for Design of Pavement.  

National Technical Information Service (NTIS)

The resilient modulus (MR) of pavement materials is an essential parameter for mechanistically based pavement design procedure. A resilient modulus database, Soil Lab Assistant (SLA) was developed to store the available MR test results and to facilitate s...

W. V. Ping Z. Yang

2005-01-01

59

RESILIENT POISSON'S RATIO OF HYDRAULIC, GRADED IRON AND STEEL SLAG BASE-COURSE MATERIAL FOR PAVEMENT RESPONSE ANALYSIS  

NASA Astrophysics Data System (ADS)

This paper discusses resilient Poisson's ratio of hydraulic, graded iron and steel slag base-course material based on a series of repeated loading triaxial compression tests on the specimens compacted with a maximum dry density and an optimum water content a nd cured for 0, 28, 91 and 365 days. It is shown that resilient Poisson's ratio for no cured specimens is stress dependent in such a way that it increases with deviatoric stress and decreases with mean effective principal stress. As curing time increases, however, the magnitude of resilient Poisson's ratio becomes smaller and its stress dependency vanishes: at curing time of one year, resilient Poisson's ratio appears independent on both mean effective principal and deviatoric stresses and can be taken as constant. Resilient Poisson's ratio can be well expressed by a power function of these two stresses. It is indicative that stress-dependency in resilient Poisson's ratio fades away after hydraulicity has sufficiently developed, which may justify the use of a constant value for resilient Poisson's ratio in pavement response analyses.

Yoshida, Nobuyuki

60

Analysis of Flexible Pavements Reinforced with Geogrids  

Microsoft Academic Search

Effectiveness of glass fiber grids as a reinforcement of the asphalt layer in a flexible pavement system was investigated.\\u000a The study involved both laboratory experimental work and computer analysis of pavement sections. Twenty flexible pavement\\u000a sections (with and without glass fiber grids) were constructed and tested in the laboratory as a part of the experimental\\u000a study. The laboratory-scale pavement sections

Hema Siriwardane; Raj Gondle; Bora Kutuk

2010-01-01

61

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

62

Extending the Life of Asphalt Pavements (OR09-086A), Part I (1).  

National Technical Information Service (NTIS)

The goal of this project was to identify common features of good and poorly performing asphalt pavements. The types of asphalt pavements included in the study were grouped into four categories: new construction, crush & shape with HMA surface, mill & resu...

H. L. Von Quintus R. Perera

2011-01-01

63

Evaluation of Flexible Pavement Performance Life in Florida.  

National Technical Information Service (NTIS)

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. Tw...

W. V. Ping Y. He

1998-01-01

64

Pavement Roughness and Serviceability.  

National Technical Information Service (NTIS)

The Pennsylvania Department of Transportation, through the Pavement Evaluation Section in the Bureau of Materials, Testing and Research, has been doing research since 1968 in the field of pavement roughness trends. The interim report concerns the program ...

J. G. Hopkins

1972-01-01

65

The Effect of a Fabric Membrane on the Structural Behaviour of a Granular Road Pavement.  

National Technical Information Service (NTIS)

The performance under vehicle loading of an unbound granular pavement laid on a soft clay subgrade was compared with that of a similar pavement which included a fabric membrane between the granular material and the soil. The pavements were trafficked simu...

J. F. Potter E. W. H. Currer

1981-01-01

66

Investigation of Recycling Bituminous Pavements.  

National Technical Information Service (NTIS)

Interest in cold-mixed in-place recycling of asphalt pavements is becoming more widespread. This final report summarized the findings of four major studies conducted over a period of 5 years. Guidelines were developed that would enable the paving engineer...

M. Tia A. Iida J. McKinney L. Wood

1983-01-01

67

COMPARISON OF A MECHANISTIC-EMPIRICAL DESIGN MODEL TO MEASURED PERFORMANCE FOR BASE-REINFORCED PAVEMENTS  

Microsoft Academic Search

A mechanistic-em pirical design method for geosynthetic base-reinforced flexible pavements has recently been proposed, where this method shares common features with a nationally recognized mechanistic-empirical method developed for conventional unreinforced flexible pavements. The method recently developed for reinforced pavements contains components for material and damage models for the different layers of the pavement cross section, testing methods for identification of

Steve W. Perkins; Eli L. Cuelho

68

Prevention of Early Pavement Deterioration.  

National Technical Information Service (NTIS)

This study was done to identify the major forms and causes of early pavement distress, and to recommend changes in specifications or policies to prevent the distress. Three major forms of distress in Utah were identified as follows: (1) Unstable mixes, (2...

D. I. Anderson D. E. Peterson M. L. Wiley

1978-01-01

69

Performance of Reclaimed Asphalt Pavement on Unpaved Roads.  

National Technical Information Service (NTIS)

The University of Wyoming's LTAP Center conducted a study examining the performance of reclaimed, recycled asphalt pavement (RAP) on unpaved roads in three Wyoming counties. Fifteen material and dust suppression treatment combinations were examined. Mater...

G. Huntington K. Ksaibati S. Koch

2011-01-01

70

Evaluation of flexible pavement crack sealing methods used in Utah  

NASA Astrophysics Data System (ADS)

Criteria to improve the effectiveness of Utah's flexible pavements crack sealing practice were studied. Field measurements, in-depth interviews questionaires were used. Findings indicate that flexible pavement cracking is a significant problem in the Far West, Rocky Mountains, Great Lakes and New England. Choice of materials is effected by storage requirements and equipment available. Prepackaging of materials designed for crack sealing has resulted in improvements in control of mix and material properties. Low temperature and freeze thaw cycles significantly effect the amount of thermal cracking and the performance of crack sealant. Ductile sealants, such as Crumb rubber/asphalt cement mixes, in combination with routing appear to offer substantial gains in sealant life and performance.

Belangie, M. C.; Anderson, D. I.

1981-01-01

71

Implementation of Mechanistic Pavement Design: Field and Laboratory Implementation.  

National Technical Information Service (NTIS)

One of the most important parameters needed for 2002 Mechanistic Pavement Design Guide is the dynamic modulus (E*). The dynamic modulus (E*) describes the relationship between stress and strain for a linear viscoelastic material. The E* is the prime mater...

A. Maher N. Gucunski T. Bennert

2005-01-01

72

Fourth Cycle of Pavement Research at the Pennsylvania Transportation Research Facility. Volume 7. Fourth Cycle of Pavement Research Summary Report.  

National Technical Information Service (NTIS)

The fourth cycle of research at the Pennsylvania Transportation Institute's Pennsylvania Transportation Research Facilities involved the evaluation of the structural behavior of a variety of bituminous and portland cement pavement materials, including ope...

D. A. Anderson W. P. Kilareski D. R. Luhr

1984-01-01

73

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

PubMed

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

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

2010-10-01

74

Geogrid mechanism in low-volume flexible pavements: accelerated testing of full-scale heavily instrumented pavement sections  

Microsoft Academic Search

This study uses full-scale accelerated testing to provide new insight into the effectiveness of geogrids on the performance of low-volume flexible pavements. Although several previous studies reported that geogrids improve pavement performance by enhancing its structural capacity and reducing distress potential, this study goes further to quantify the effectiveness of geogrids, specify the mechanism of the reinforcement they provide and

Imad L. Al-Qadi; Samer Dessouky; Erol Tutumluer; Jayhyun Kwon

2011-01-01

75

Plastic deformation behaviour of pavement granular materials under low traffic loading  

Microsoft Academic Search

This paper analyses the permanent deformation performance of an unbound granular material for base layers of low traffic roads.\\u000a The material has been subjected to repeated triaxial loads. Three models were fitted to express the cumulative permanent strain\\u000a as a function of the number of load cycles. In general, the predictions of two models previously studied by other researchers\\u000a proved

I. Pérez; L. Medina; J. Gallego

2010-01-01

76

Airfield Rigid Pavement Structural Design-A Review of Main Aspects and Methods of Analysis  

NASA Astrophysics Data System (ADS)

Airfield pavements present a number of characteristics that make their design considerably different from that of road pavements. Apart from load magnitude and it's frequency, maintenance issues and pavement strength classification reporting are aspects that must be considered in the design phase. In the present paper, these aspects are analysed in the light of traditional and new methods of airfield pavement analysis. Parametric studies are performed in order to study the effects of different factors, such as pavement structure, layer thickness, material strength, effects of temperature, load transfer across joints and traffic characteristics.

Tiago Bonucci, Pereira

2010-05-01

77

Use of scrap rubber in asphalt pavement surfaces  

NASA Astrophysics Data System (ADS)

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 percent 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, Robert A.; Roberts, Richard J.; Blackburn, Robert R.

1991-12-01

78

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

79

Evaluating the Effect of Slab Curling on IRI for South Carolina Concrete Pavements.  

National Technical Information Service (NTIS)

Concrete pavements are known to curl due to a temperature gradient within the concrete caused by both daily and seasonal temperature variations. This research project measured the magnitude of concrete pavement slab curling of two newly constructed jointe...

A. M. Johnson B. C. Smith L. W. Gibson W. H. Johnson

2010-01-01

80

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

81

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

NASA Astrophysics Data System (ADS)

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

Beg, Muhammad Arif

82

Recycling of water-susceptible pavements  

NASA Astrophysics Data System (ADS)

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

Maupin, G. W.

1980-05-01

83

Assessment of the Uretek Process on Continuously Reinforced Concrete Pavement, Jointed Concrete Pavement, and Bridge Approach Slabs.  

National Technical Information Service (NTIS)

This study evaluates the rehabilitation method utilizing the injection of Uretek (polyurethane) into the pavement structures on continuously reinforced concrete pavement (CRCP), jointed concrete pavement (JCP), and bridge approach slabs. The polyurethane ...

K. Gaspard M. Morvant

2004-01-01

84

SEASONAL AND LOAD RESPONSE INSTRUMENTATION OF THE WAY30 PERPETUAL PAVEMENTS  

Microsoft Academic Search

A perpetual asphalt concrete pavement test section was completed along US-30 in Wayne County, OH, as part of the Wooster by-pass, in the fall of 2005. This project represents a collaborative effort between the Ohio Department of Transportation (ODOT) and the asphalt concrete paving industry with the purpose of evaluating the performance of these novel pavements. Perpetual asphalt concrete pavements

Michael T. Romanello

85

Parametric Study of Factors Affecting Flexible-Pavement Performance  

Microsoft Academic Search

A new 'Whole-Life' Pavement Performance Model (WLPPM) that is capable of making deterministic pavement damage predictions due to realistic traffic and environmental loading has been developed. A vehicle simulation is used to generate dynamic tire forces that are a function of distance along the pavement. These dynamic tire forces are then combined with the appropriate pavement primary response influence functions

A. C. Collop; D. Cebon

1995-01-01

86

How Dutch drinking water production is affected by the use of herbicides on pavements.  

PubMed

About forty per cent of drinking water in The Netherlands is produced from surface water. Dutch water companies, that have to rely on this source, are dealing with major water quality problems due to the use of herbicides on pavements. Voluntary measures and bans have had only limited effect on the reduction of emissions of herbicides that runoff from pavements into surface water in The Netherlands. The effects on the production of drinking water from surface water should play a role in the authorisation of pesticides. Stricter regulations, including mandatory emission reduction measures and certification, are necessary. The enforcement of existing Dutch surface water pollution laws should solve part of the problem. Due to the international nature of most of the surface water used for drinking water supply, it is necessary that other countries take measures as well. European legislation brings a solution closer if implemented well and seriously enforced. The threat of strict legislation keeps pressure on the transition towards decreasing the dependence on chemicals for weed control on pavements. PMID:15053113

Bannink, A D

2004-01-01

87

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

1999-05-01

88

DEVELOPING A TRACK MODEL FOR TESTING THE ROAD PAVEMENT UNDER REPEATED MOVING SURFACE LOADS  

Microsoft Academic Search

It is not uncommon to see road pavement damage in areas near road intersections. One type of pavement failure found on major roads appears to be caused by frequent decelerations and accelerations of heavy vehicles near signalized intersections. The effects of such repeated surface tractions on road pavement have not been widely studied yet. Proposed in this paper is the

Jim Shiau; Tagarajan Perumal; Michael Benjamin; Selvan Pather; Ron Ayers

89

Calibration of Mechanistic-Empirical Models for Cracking and Rutting of New Pavements Using Heavy Vehicle Simulator Tests  

Microsoft Academic Search

The Heavy Vehicle Simulator (HVS) is ideally suited for initial calibration of Mechanistic-Empirical models for pavement design. The HVS may be seen as a large scale laboratory equipment, with detailed control of materials, loads and environment, and with the possibility of carrying the tests through to failure. In-situ pavements, used for long term observation of pavement performance, are normally designed

Per Ullidtz; John Harvey; Khalid Ghuzlan; Bor-Wen Tsai; Bruce Steven

90

Long-Term Performance of Stone Interlayer Pavement  

Microsoft Academic Search

This paper presents an evaluation of long-term performance of an alternative flexible pavement design referred to here as stone interlayer pavement. This pavement design was introduced to reduce\\/defer reflective cracking experienced with soil-cement bases. The stone interlayer pavement consisted of a crushed limestone base on top of a cement-stabilized base. The performance of the stone interlayer pavement was compared to

Hani Titi; Masood Rasoulian; Mark Martinez; Byron Becnel; Gary Keel

2003-01-01

91

Accelerated Pavement Testing of Load Transfer through Aggregate Interlock and the influence of Crack Width and Aggregate Type - a case study  

Microsoft Academic Search

It is well known that performance of plain jointed concrete pavements depends on aggregate interlock to transfer load from the one slab to the next. In order to quantify the relative contribution of crack width and the strength of the aggregate to the long- term performance of a plain jointed pavement, experimental sections of road were built using different aggregates

P J Strauss; B D Perrie

92

Layer coefficients for NHDOT pavement materials  

NASA Astrophysics Data System (ADS)

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

Janoo, Vincent C.

1994-09-01

93

ANALYSIS OF GROUP MAINTENANCE STRATEGY -ROAD PAVEMENT AND SEWERAGE PIPES-  

NASA Astrophysics Data System (ADS)

Recently, it is critical to manage deteriorating sewerage and road facilities efficiently and strategically. Since the sewerage pipes are mostly installed under road pavement, the works for the replacement of the sewerage pipes are partially common to the works for the road. This means that the replacement cost can be saved by coordinating the timing of the replacements by sewerage pipe and road pavement. The purpose of the study is to develop the model based on Markov decision process to derive the optimal group maintenance policy so as to minimize lifecycle cost. Then the model is applied to case study area and demonstrated to estimate the lifecycle cost using statistical data such as pipe replacement cost, road pavement rehabilitation cost, and state of deterioration of pipes and road pavement.

Tanimoto, Keishi; Sugimoto, Yasuaki; Miyamoto, Shinya; Nada, Hideki; Hosoi, Yoshihiko

94

Characterization of highway traffic noise generated by rigid pavement contraction joints  

NASA Astrophysics Data System (ADS)

Contraction joints in rigid (concrete) pavements are required to permit expansion of each monolithic section of roadway. At higher speeds, the major source of highway noise is attributed to vehicle tire/roadway interaction. Current concerns about limiting the impact of highway traffic noise has forced transportation agencies to consider strategies to control noise generated by tire/roadway interaction. Within this work the difference in noise generated by 1/4- vs 3/8-in. joint widths is conducted. The study focuses on passenger vehicles including a sedan and a light duty van/truck. Both vehicle in-cabin and roadside noise levels are measured for vehicle speeds of 50, 60, and 70 miles per hour. For the sedan, the minimum and maximum observed in-cabin differences were determined to be 1.08 and 1.82 dB(A), respectively. Minimum and maximum observed roadside differences are 1.19 and 2.58 dB(A), respectively. Van tests resulted in minimum and maximum observed in-cabin differences of 0.60 and 1.09 dB(A) and minimum and maximum observed roadside differences of 1.05 and 3.18 dB(A), respectively. This paper contains details of reference standards, test methods, and the results obtained.

Ellis, Lawrin T.; Niezrecki, Christopher; Bloomquist, David

2003-04-01

95

Evaluation of Joint Sealants of Concrete Pavements.  

National Technical Information Service (NTIS)

This report document investigation of concrete pavement joint sealants which began with project 1371 'Evaluation of Joint Sealants.' The purpose of the continued investigation is to propose specification and test protocol for joint sealants in concrete pa...

A. H. Gurjar T. Tang D. G. Zollinger

1997-01-01

96

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

Microsoft Academic Search

Compared to mid-latitude deserts, the properties, formation and evolution of desert pavements and the underlying vesicular layer in Antarctica are poorly understood. This study examines the desert pavements and the vesicular layer from seven soil chronosequences in the Transantarctic Mountains that have developed on two contrasting parent materials: sandstone–dolerite and granite–gneiss. The pavement density commonly ranges from 63 to 92%

James G. Bockheim

2010-01-01

97

Laboratory Evaluation of Selected Syncrude Products and Upgraded By-Products as Pavement Recycling Agents. Final Report, Part II.  

National Technical Information Service (NTIS)

Based on the information presented in this report, the following conclusions appear warranted: (1) Selected syncrude products and upgraded by-products have the potential for use as recycling agents for asphalt pavements. The syncrude recycling agents exhi...

J. W. Button

1984-01-01

98

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

SciTech Connect

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

Dowdy, M.L.

1987-08-04

99

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

100

Automatic inspection of pavement cracking distress  

Microsoft Academic Search

This paper presents the 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 8x8 pixels and each cell is classified as a non-crack or crack cell using the grayscale information of the border pixels. Whether a crack cell can be regarded as a basic element (or seed)

B. Xu; Y. Huang

2005-01-01

101

Pavement Recycling Guidelines for State and Local Governments. Participant's Reference Book.  

National Technical Information Service (NTIS)

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...

P. S. Kandhal R. B. Mallick

1997-01-01

102

Development of a life cycle assessment tool for construction and maintenance of asphalt pavements  

Microsoft Academic Search

The increasing use of recycled materials in asphalt pavements calls for environmental assessment of such impacts as the energy input and CO2 footprint. Life cycle assessment (LCA) is being accepted by the road industry for such purpose. It aims to quantify and collate all the environmental impacts from the life time of the product or process. This paper reviews relevant LCA

Yue Huang; Roger Bird; Oliver Heidrich

2009-01-01

103

Pavements Recycling Guidelines for State and Local Governments (on CD-ROM).  

National Technical Information Service (NTIS)

This participant's reference book was developed to support a 2-day workshop on pavement recycling guidelines for state and local governments. Recycling or reuse of existing asphalt pavement materials to produce new pavement materials has the following adv...

1998-01-01

104

Impact of Variation in Materials Properties on Asphalt Pavement Life: Evaluation of a Questionnaire.  

National Technical Information Service (NTIS)

In an effort to collect information on the status of quality control procedures and the use of pay adjustment factors, a questionnaire was distributed to all state agencies, the District of Columbia, and the Federal Highway Administration. Each agency was...

R. M. Moore J. E. Wilson J. P. Mahoney R. G. Hicks

1981-01-01

105

Evaluation of Engineering Properties of Hot Mix Asphalt Concrete for the Mechanistic-Empirical Pavement Design  

Microsoft Academic Search

Hot Mix Asphalt (HMA) is a viscoelastic material and has been broadly used in pavement structures. It is important to understand the mechanism of complex behaviors of HMA mixtures in field for improving pavement mechanical performance. Aggregate gradation and asphalt binder are two key factors that influence the engineering properties of HMA. The asphalt binder plays a significant role in

Yuan Xiao

2009-01-01

106

Proceedings of the National Seminar on Asphalt Pavement Recycling.  

National Technical Information Service (NTIS)

The 19 papers in this report deal with the following areas: economics of recycling; seminar on asphalt pavement recycling overview of project selection; cost and energy considerations in project selection for recycling asphalt pavements; specifications re...

S. P. LaHue F. N. Finn W. J. Halstead R. C. Ingberg D. R. Gallagher

1980-01-01

107

Development of Predictive Equations Based on Pavement Condition Index Data.  

National Technical Information Service (NTIS)

This research project evaluated runway pavement condition survey information in order to develop models or equations capable of predicting future pavement performance and projected life expectancy. The data was obtained from the Federal Aviation Administr...

C. V. Floro

1992-01-01

108

Evaluation of Pavement Damage due to New Tire Designs.  

National Technical Information Service (NTIS)

The objective of this study is to evaluate pavement damage due to new tire designs using accelerated pavement testing (APT) and finite element (FE) modeling. Three tire configurations were investigated in this study, including the newly developed wide-bas...

H. Wang I. L. Al-Qadi

2009-01-01

109

Surface Distresses Detection of Pavement Based on Digital Image Processing  

Microsoft Academic Search

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

Aiguo Ouyang; Chagen Luo; Chao Zhou

2010-01-01

110

Role of conductive spreader layer in reducing surface temperature of HMA pavements  

Microsoft Academic Search

Rutting is a common type of shear failure-related deformation in asphalt (hot mix asphalt, HMA) pavements. It occurs over time as a result of slow, repeated heavy loads from vehicles moving along the wheel path. This problem is most noticeable when the pavement is at a high temperature and its stiffness is the lowest. Previous investigations have concluded that flowing

Sankha Bhowmick; Matthew Medas; Rajib B. Mallick

2012-01-01

111

Guayule Plant: A Renewable, Domestic Source of Binder Materials for Flexible Pavement Mixtures.  

National Technical Information Service (NTIS)

The guayule (pronounced 'why-YOU-lee') plant grows in arid and semi-arid regions (e.g. the southwestern U.S.) and is a source of natural rubber. It was cultivated and processed during the World War II rubber shortage and is currently being processed prima...

D. N. Richardson S. M. Lusher

2013-01-01

112

Evaluation of Temporary Pavement Marking Systems for Resurfacing Zones. Appendix B. Driver Comprehension of Temporary Pavement Marking Systems.  

National Technical Information Service (NTIS)

This document contains the results of the driver comprehension experiment of the selected temporary pavement marking systems, including the comprehension of selected traffic signs. The following temporary pavement marking systems were included in this stu...

H. T. Zwahlen T. Schnell

1996-01-01

113

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

114

Development of laser system to measure pavement rutting  

Microsoft Academic Search

Asphalt pavement rutting is one of the most common and destructive pavement distresses observed on U.S. roads, particularly in the urban environment at intersections. They are an important indicator of the structural integrity of the pavement as well as having an impact on road user safety. For these reasons, most road agencies regularly monitor the levels of rut depths on

Hongzhi Wang

2005-01-01

115

LIFE CYCLE COST ANALYSIS OF PORTLAND CEMENT CONCRETE PAVEMENTS  

Microsoft Academic Search

Project conducted in cooperation with the Federal Highway Administration. 16. Abstract This report describes the development of a new life cycle cost analysis methodology for portland cement concrete pavements — one that considers all aspects of pavement design, construction, maintenance, and user impacts throughout the analysis period. It predicts pavement performance using state-of-the-art performance models and reliability concepts, from which

William James Wilde; Steve Waalkes; Rob Harrison

1999-01-01

116

A model of whole?life flexible pavement performance  

Microsoft Academic Search

A new 'whole-life' pavement performance model (WLPPM), that is capable of making deterministic pavement damage predictions due to realistic traffic and environmental loading, has been developed. A vehicle simulation is used to generate dynamic tyre forces that are a function of distance along the road. These dynamic tyre forces are then combined with the appropriate pavement primary response influence functions

A. C. Collop; D. Cebon

1995-01-01

117

Physically Meaningful Harmonization of Tire\\/Pavement Friction Measurement Devices  

Microsoft Academic Search

Accurate characterization and evaluation of tire\\/pavement friction is critical in assuring runway and highway safety. Historically, Pavement Friction Measurement Devices (PFMDs) employing different measuring mechanisms have been used to evaluate tire\\/pavement friction. They yield significantly disparate friction coefficients under the same contact conditions. Currently, an empirically developed data harmonization method based on a reference device (Dynamic Friction Tester (DFT)) is

Madhura Priyanga Nishshanke Rajapakshe

2011-01-01

118

COMPUTATIONAL MODELING OF PERPETUAL PAVEMENTS USING THE MEPDG VERSION 0.910 SOFTWARE  

Microsoft Academic Search

Because of their long structural life, many US States are exploring the use of perpetual pavements on some of their major highways. By definition, a perpetual pavement (PP) is a thick rut-resistant and fatigue (bottom-up)-resistant pavement structure designed to have a structural life in excess of 50 years, often designed for heavily-trafficked highways. During their service lives, PP structures generally

Lubinda F. Walubita

119

Pavement Design,  

National Technical Information Service (NTIS)

The 12 papers in the report deal with the following areas: nine-year performance evaluation of Arizona's prestressed concrete pavement; FEACONS III computer program for analysis of jointed concrete pavements; thickness design of roller-compacted concrete ...

R. L. Powers J. P. Zaniewski M. Tia J. M. Armaghani C. L. Wu

1987-01-01

120

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

121

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

NASA Astrophysics Data System (ADS)

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

Plati, Christina; Georgiou, Panos; Loizos, Andreas

2013-04-01

122

Air Purification Pavement Surface Coating by Atmospheric Pressure Cold Plasma  

NASA Astrophysics Data System (ADS)

This study develops an atmospheric pressure cold plasma (APCP) reactor to produce activated radicals from precursor molecules, and to immobilize nano titanium dioxide (TiO2) powder to substrate pavement materials. TiO2 has photocatalytic properties and under UV light can be used to oxidize and remove volatile organic compounds (VOCs) and nitrogen oxides (NOx) from the atmosphere. Although TiO2 treated paving materials have great potential to improve air quality, current techniques to adhere TiO2 to substrate materials are either not durable or reduce direct contact of TiO2 with UV light, reducing the photocatalytic effect. To solve this technical difficulty, this study introduces APCP techniques to transportation engineering to coat TiO2 to pavement. Preliminary results are promising and show that TiO2 can be incorporated successfully into an APCP environment and can be immobilized at the surface of the asphalt substrate. The TiO2 coated material with APCP shows the ability to reduce nitrogen oxides when exposed to UV light in an environmental chamber. The plasma reactor utilizes high voltage streamers as the plasma source.

Westergreen, Joe; Pedrow, Patrick; Shen, Shihui; Jobson, Bertram

2011-11-01

123

Impact of Truck Loading on Design and Analysis of Asphaltic Pavement Structures - Phase III.  

National Technical Information Service (NTIS)

This study investigated the impact of the realistic constitutive material behavior of asphalt layer (both nonlinear inelastic and fracture) for the prediction of pavement performance. To this end, this study utilized a cohesive zone model to consider the ...

H. Ban Y. R. Kim

2012-01-01

124

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

125

Reconstruction of a pavement geothermal deicing system  

SciTech Connect

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

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

1999-03-01

126

Intelligent Estimation of Compressive Strength of the Pavement Layers Stabilized by the Combination of Bitumen Emulsion and Cement  

Microsoft Academic Search

The Application of the different types of additive materials such as lime, cement bitumen and the combination of them are considered as a main issue by the relating experts. In order to promote the bearing capacity of road, these materials, individually, or with the attendance of other materials add to sub base layers. During the recent years, road builders have

Mehrdad Aryafar; Abdoul R. Ghotbi; Mehdi Aryafar; Amin Avaei

2008-01-01

127

Effect of Fillers on the Pavement Performance of Asphalt Binder  

Microsoft Academic Search

The effects of fillers , such as mineral fillers , cement and fibers , on the pavement performance of asphalt binder are quantitatively investigated by rheology methodology. The results show that fillers can obviously improve the high2temperature performance of asphalt binder with different degrees , and that , in the same proportion of mixture , cement has a stronger improving

Zou Gui; Yuan Yan; Zhang Xiao

2005-01-01

128

Experimental estimation of the relative deterioration of flexible pavements under increased axle loads  

Microsoft Academic Search

The deterioration of Australia's unbound granular pavements with a wearing surface of stone aggregate embedded in a thin bituminous binder seal is likely to increase with increases in axle loads due to the predicted doubling of the freight task carried by heavy vehicles travelling interstate over the next 15 years. Experimental pavement deterioration data gained from accelerated load testing (ALT)

Tim Charles Martin

2011-01-01

129

Fast detection and symptom analysis of cracks in highway asphalt pavement  

Microsoft Academic Search

A method for real-time fast detection and symptom analysis of cracks in highway asphalt pavement is proposed. At the first step, the fissure characteristic of the acquired and de-noised pavement images is analyzed and then extracted by the method based on gray value comparison between the current pixel and its neighboring pixels, the false cracks are deleted by using the

Hanyu Hong; Xiuhua Zhang; Jiuyang Yu

2009-01-01

130

Flexible Pavement Overlay Design by Dynamic Deflections. Phase 2.  

National Technical Information Service (NTIS)

The report summarizes a comprehensive study to develop a flexible pavement overlay design procedure based on Falling Weight Deflectometer (FWD) deflections for the South Carolina Department of Highways and Public Transportation (SCDHPT). The study include...

R. L. Baus A. M. Johnson

1992-01-01

131

Evaluation of western and eastern shale oil residua as asphalt pavement recycling agents.  

National Technical Information Service (NTIS)

The objective of this investigation was to perform a preliminary evaluation of the utility of residual materials prepared from Green River Formation (western) and New Albany Shale (eastern) shale oils as recycling agents for aged asphalt pavement. Four pe...

P. M. Harnsberger R. E. Robertson

1990-01-01

132

Determination of Critical Loading Position on Tied-Arch Bridge Deck Pavement  

Microsoft Academic Search

The universal finite element software of ANSYS was utilized in the mechanical analysis of pavement system on bridge deck. Firstly, the enveloping surface of the interface stress on bridge deck pavement was determined by means of moving loads. Then loads were arranged across the maximum stress influence surface of all the layers according to the criterion. Finally the variation laws

Han Cunjie

2010-01-01

133

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

Microsoft Academic Search

To the southwest of Lake Eyre (South), South Australia, silcrete boulders exposed by the erosion of the surrounding fine sediments undergo mechanical weathering to form desert pavement. Successive palaeoshorelines of Lake Eyre have exposed an age-related sequence of different stages in the weathering of the boulders. This study investigates desert pavement development in this saline environment. In addition, it attempts

Asma Al-Farraj

2008-01-01

134

Effect of temperature variation on pavement responses using 3D multilayered elastic analysis  

Microsoft Academic Search

The response of flexible pavement is largely influenced by the resilient modulus of the pavement profile. Different methods\\/approaches have been adopted in order to estimate or measure the resilient modulus of each layer assuming an average modulus within the layer. To account for the variation in the modulus of elasticity with depth within a layer, the layer should be divided

Wael Alkasawneh; Ernian Pan; Feng Han; Ronghua Zhu; Roger Green

2007-01-01

135

Determination of Coefficient of Thermal Expansion Effects on Louisiana's PCC Pavement Design.  

National Technical Information Service (NTIS)

With the development of the Mechanistic Empirical Pavement Design Guide (MEPDG) as a new pavement design tool, the coefficient of thermal expansion (CTE) is now considered a more important design parameter in estimating pavement performance including crac...

H. C. Shin Y. Chung

2011-01-01

136

Multiscale Assessment of Low-Temperature Performance of Flexible Pavements  

Microsoft Academic Search

The increase of heavy-load traffic within Europe requires the development of appropriate tools for the assessment of existing\\u000a and new road infrastructure. In this paper, such a tool is presented, combining multiscale material modeling of asphalt with\\u000a structural analysis of flexible pavements representing plate-like structures at low temperatures. At this temperature regime,\\u000a rapid cooling of the road surface in consequence

E. Aigner; R. Lackner; M. Spiegl; M. Wistuba; R. Blab; H. Mang

137

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

Microsoft Academic Search

Electrical resistance tomography (ERT) was used to follow the infiltration of water into pavement section at the UC Berkeley Richmond Field Station. A volume of pavement 1m square and 1.29 m deep was sampled by an ERT array consisting of electrodes in 9 drilled holes plus 8 surface electrodes. The data were collected using a computer controlled data acquisition system

M. Buettner; B. Daily; A. Ramirez

1997-01-01

138

Pavement distress detection and severity analysis  

NASA Astrophysics Data System (ADS)

Automatic recognition of road distresses has been an important research area since it reduces economic loses before cracks and potholes become too severe. Existing systems for automated pavement defect detection commonly require special devices such as lights, lasers, etc, which dramatically increase the cost and limit the system to certain applications. Therefore, in this paper, a low cost automatic pavement distress evaluation approach is proposed. This method can provide real-time pavement distress detection as well as evaluation results based on the color images captured from a camera installed on a survey vehicle. The entire process consists of two main parts: pavement surface extraction followed by pavement distress detection and classification. In the first part, a novel color segmentation method based on a feed forward neural network is applied to separate the road surface from the background. In the second part, a thresholding technique based on probabilistic relaxation is utilized to separate distresses from the road surface. Then, by inputting the geometrical parameters obtained from the detected distresses into a neural network based pavement distress classifier, the defects can be classified into different types. Simulation results are given to show that the proposed method is both effective and reliable on a variety of pavement images.

Salari, E.; Bao, G.

2011-02-01

139

Simplified ME Approach for the Design of Flexible Pavement Structures  

Microsoft Academic Search

This paper presents a simplified design procedure, which depends mainly on finite elements analysis considering the same input variables used in the traditional AASHTO empirical design methodology. The multiple regression equation developed considered the subgrade resilient modulus (Mr), Equivalent Single Axle Load (ESAL) repetitions, and the dynamic behavior of flexible pavements by incorporating vehicle speed. The outputs of this model

Osama Abaza

140

Laser-Based 3D Data Acquisition System for the Analysis of Pavement Distress and Roughness.  

National Technical Information Service (NTIS)

In this report we deal with the detection and classification of pavement cracks. Currently, ConnDOT is using Wisecrax which is a commercial product supplied by Roadware. We develop a 3D laser based technique to detect the cracks in a certain pavement sect...

B. Javidi D. Kim S. Kishk

2004-01-01

141

Influence of pavement macrotexture on PM10 emissions from paved roads: A controlled study  

NASA Astrophysics Data System (ADS)

This paper investigates influence of pavement macrotexture on paved road PM10 emissions. This study was conducted on different paved roadway types (local, collector and minor arterial) in the Las Vegas Valley, Nevada. Pavement macrotexture was measured using the ASTM E 965 sand patch method and the Digital Surface Roughness Meter™ (DSRM™). A controlled constant soil loading with known PM10 fraction was applied to cleaned road surfaces. The Desert Research Institute's (DRI) Mini-PI-SWERL™ (Portable In-Situ Wind ERosion Lab) was used to estimate PM10 mass emissions and cumulative mass emitted from pavement surfaces. PM10 mass emissions using controlled applied soil loadings generally declined with increasing pavement macrotexture at all applied shear levels. The relationships were statistically significant, and indicate that pavement macrotexture may need to be included in future development of revised paved road PM10 emissions factors.A change in the slope of emitted PM10 mass and pavement macrotexture occurred between 0.8 and 0.9 mm mean texture depth (MTD). Anomalies in PM10 mass emissions were observed at MTDs exceeding 1.2 mm. Two-way frequency distributions of pavement surface features obtained from DSRM measurements were analyzed to explain the observed anomalies. Results showed that pavement surface feature size distributions may influence on PM10 emissions from paved roads at similar MTDs.PM10 mass emissions were found to linearly depend on adjusted mode size of the pavement surface aggregate. A sharp decrease in friction velocities, computed from wind erosion theory, at MTDs above 0.9 mm matched an observed sharp decrease in PM10 emissions rates at MTDs above 0.9 mm, indicating that classical wind erosion theory could be adapted for non-erodible pavement surfaces and linearly relate PM10 emissions rates to applied shear stress at an aerodynamic roughness height of 0.075 mm.

China, Swarup; James, David E.

2012-12-01

142

Overview of the 'PAVER' Pavement Management System and Economic Analysis of Field Implementing the 'PAVER' Pavement Management System.  

National Technical Information Service (NTIS)

This paper presents the results of an economic analysis performed on implementing the PAVER system at a military installation. PAVER is a pavement management system developed by the U.S. Army Corps of Engineers over the past 10 years for use by military i...

M. Y. Shahin S. D. Kohn

1982-01-01

143

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

144

Fast detection and symptom analysis of cracks in highway asphalt pavement  

NASA Astrophysics Data System (ADS)

A method for real-time fast detection and symptom analysis of cracks in highway asphalt pavement is proposed. At the first step, the fissure characteristic of the acquired and de-noised pavement images is analyzed and then extracted by the method based on gray value comparison between the current pixel and its neighboring pixels, the false cracks are deleted by using the computed measurement of crack features, thus the true fissures are detected. The most important step is the symptom analysis of the cracks in the pavement image, all the data could be analyzed and be the basis for the agencies to remedy and manage the pavement. Quantities of images are processed and the results show that the proposed method can detect the pavement distress information actually, and has robustness and availability.

Hong, Hanyu; Zhang, Xiuhua; Yu, Jiuyang

2009-10-01

145

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

146

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

147

Finite element modelling of flexible pavements on soft soil subgrades  

Microsoft Academic Search

The effect of tyre pressure, wheel configuration and axle load variations of a transportation truck, on structural performance of a flexible road pavement with thin asphalt surfacing layer and soft peat soil subgrade was evaluated using the finite element method. The pavement structure was modelled as two-dimensional four-layer stratum using ANSYS\\/ED finite element suite. The pavement model was subjected to

R. M. Mulungye; P. M. O. Owende; K. Mellon

2007-01-01

148

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

149

Pavement Roughness and Rideability.  

National Technical Information Service (NTIS)

The report contains a description of a new method for assessing pavement roughness. The method is based on a statistical transform between the physical measure of a pavement profile and the subjective rating of pavement rideability. This transform is expr...

M. S. Janoff J. B. Nick P. S. Davit G. F. Hayhoe

1985-01-01

150

Practical applications of nondestructive evaluation for airport pavement analysis  

NASA Astrophysics Data System (ADS)

This paper discusses the equipment and methodologies currently used for nondestructive testing (NDT) and nondestructive evaluation (NDE) of the structural capacity of military and civil airport pavements, including: (1) commonly used equipment and test methods for measuring pavement response to dynamic loads; (2) qualitative and quantitative evaluation of NDT data; (3) methods for back-calculating layer properties from NDT data; (4) layered elastic methods for evaluating pavement performance using processed NDT data; and (5) application of analytical results for developing pavement rehabilitation and management strategies.

McQueen, Roy D.; Guo, Edward

1995-07-01

151

Millimeter-wave nondestructive evaluation of pavement conditions  

NASA Astrophysics Data System (ADS)

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

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

2012-03-01

152

Pavement Distresses at Intersections.  

National Technical Information Service (NTIS)

Asphaltic concrete pavements at intersections and their approaches, where traffic is required to stop and start, exhibit several types of distress. Among the more prominent forms of these distresses are deep rutting, pushing and shoving, and severe washbo...

D. Q. Hunsucker B. W. Meade

1995-01-01

153

Fatigue life prediction of asphalt concrete pavement using a harmony search algorithm  

Microsoft Academic Search

This paper proposes an efficient Harmony Search (HS) algorithm for determining the material parameters of a fatigue cracking\\u000a model based on Accelerated Pavement Testing (APT). APT is preferred over typical laboratory experiments and testing because\\u000a APT can simulate field pavement performance. The main advantage of the HS heuristic algorithm is its ability to find the best\\u000a global solution of a

Youngchan Suh; Sungho Mun; Insoo Yeo

2010-01-01

154

Finite Element Evaluation of Pervious Concrete Pavement for Roadway Shoulders.  

National Technical Information Service (NTIS)

Pervious concrete has provided an effective solution for storm runoff for parking lots, sidewalks, bike trails, and other applications. It should be readily adaptable for use on roadway shoulders. Being a relatively new material for use in pavement for ro...

A. Alam L. Haselbach W. Cofer

2011-01-01

155

Use of artificial living system for pavement distress survey  

Microsoft Academic Search

Automation of pavement surface distress survey is of considerable interest since it facilitates road maintenance. Pavement distress detection algorithm is proposed, which includes preprocessing and artificial life algorithm. In nature, bee population consists of different species of bees. Different species of bees cooperate with others and build combs. The process of building combs is based on a bottom-up structure instead

H. G. Zhang; Q. Wang

2004-01-01

156

Field observations and numerical models of GPR response from vertical pavement cracks  

NASA Astrophysics Data System (ADS)

High resolution ground-coupled GPR is useful for determining thickness, deterioration, jointing and cracks in pavements. Although only millimetres in width, vertical cracks can present a significant target in reflection profiles. On composite pavements, consisting of asphalt over concrete, we have observed responses at locations above joints in the underlying concrete that we attribute to cracks within the asphalt layer. On some asphalt pavement, we observed significantly stronger diffraction and waveguide effects responses at a 250 MHz centre frequency rather than at 1000 MHz, despite the small crack apertures. Using numerical modelling we show the importance of crack filling material, crack aperture, crack height, asphalt conductivity and the GPR centre frequency on the observed response. Our observations and models clearly show the potential of GPR to detect and characterise vertical cracks. We recommend a multi-frequency approach to GPR surveys of pavement: high frequency for crack characterisation and lower frequency for crack detection.

Diamanti, Nectaria; Redman, David

2012-06-01

157

Shear Fatigue Behaviour of Tack Coats in Pavements  

Microsoft Academic Search

For many years, pavement engineers use mechanistic design methods that are based on algorithms to compute stresses, strains and displacements in a flexible pavement structure, or in a multi-layered structure in general. Most of these methods assume, to ease the modelling of the structure and the computation process, that the layers are fully bonded or completely unbounded to each other.

Malick Diakhate; Annabelle Phelipot; Anne Millien; Christophe Petit

2006-01-01

158

Evaluation of superheavy load movement on flexible pavements  

Microsoft Academic Search

Due to industrial plant expansion, superheavy load moves have increased drastically in Louisiana within the past decade. This paper presents a case study of a superheavy load movement with over 1.8-million kg loads on a flexible pavement. The study included pavement structural analysis under superheavy load and the estimation of cost attributable to the movement. The structural evaluation was performed

Xingwei Chen; Jeffrey R. Lambert; Ching Tsai; Zhongjie Zhang

2012-01-01

159

Comparison of test specimen preparation techniques for pervious concrete pavements  

Microsoft Academic Search

The objective of this study was to evaluate different pervious concrete test specimen preparation techniques in an effort to produce specimens having properties similar to in-place pervious concrete pavement. Cylinders and slabs were cast using pervious concrete from three different paving projects using different procedures. The comparisons of cast specimens to pavement cores were based on infiltration rate, density, and

Bradley J. Putman; Andrew I. Neptune

2011-01-01

160

Reducing traffic noise with quieter pavements  

NASA Astrophysics Data System (ADS)

In recent years, interest has increased in the use of pavement type to reduce traffic noise. This has been driven by public concern over noise from freeways and state transportation agencies' interest in using pavement instead of sound walls to mitigate traffic noise. Beginnings of the recent interest go back to 1998 with the formation of the Institute for Safe, Quiet & Durable Highways at Purdue University and the initiation long-term research by the California Department of Transportation (Caltrans) on the effectiveness of quieter pavements. In 2002, the State of Arizona announced plans to overlay 115 miles of concrete freeway in the greater Phoenix area with a quieter asphalt rubber surface. This turned into the first Quiet Pavement Pilot Program in partnership between Federal Highway Administration (FHWA) and the Arizona Department of Transportation. Since that time, the FHWA in cooperation with the American Association of State Highway Transportation Agencies conducted a fact finding ``Scan'' tour in Europe to evaluate their quiet pavement technology and policy. This was followed by the first comparative tire/pavement noise testing in the US and Europe using the same procedures and test tires. The results, issues, and future directions surrounding these activities will be discussed.

Donavan, Paul

2005-09-01

161

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

162

THE OPTIMAL IMPLEMENTATION POLICY OF PAVEMENT INSPECTION WITH DETERIORATION UNCERTAINTY  

NASA Astrophysics Data System (ADS)

This study proposes a methodology to nd the optimal inspection policy for road pavement with uncertain deterioration processes. Since the deterioration progresses are characterized by a lot of uncertainty, the pavement conditions cannot be deterministically evaluated unless the inspection or repair activities are carried out. The road administrators have to make the decisions of whether repair should be implemented based upon the results of inspection. In this paper, the value of the inspection is evaluated by use of real option theory, and the optimal inspection and repair model is formulated to investigate the optimal inspection frequencies and repair policy which may minimize the expected life cycle costs. Finally, the validity of the methodology presented in the paper is investigated by a case study dealing with the expressway in the real world.

Kobayashi, Kiyoshi; Eguchi, Masayuki; Oi, Akira; Aoki, Kazuya; Kaito, Kiyoyuki

163

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

164

Influential factors on deicing performance of electrically conductive concrete pavement  

Microsoft Academic Search

The deicing experiment of carbon fiber reinforced electrically conductive concrete (CFRC) slab was conducted in laboratory\\u000a at first, then the deicing process of CFRC pavement was analyzed by means of finite element method (FEM). At last, based on\\u000a the energy conservation law and the computing results of finite element method, the influential factors including the setting\\u000a of electric heating layer,

Tang Zuquan; Qian Jueshi; Li Zhuoqiu; Wu Chuanming

2006-01-01

165

Rehabilitation Strategies for Highway Pavements.  

National Technical Information Service (NTIS)

NCHRP Project 1-38 was conducted to develop a process for selection of appropriate rehabilitation strategies for the ranges of pavement types and conditions found in the United States. A review of the pavement rehabilitation practices of State DOTs, and t...

C. E. Correa K. T. Hall R. P. Elliot S. H. Carpenter

2001-01-01

166

Relationships between laboratory measured HMA material and mixture properties and pavement performance at WesTrack  

NASA Astrophysics Data System (ADS)

For years researchers and practitioners alike in the pavements and materials industry have attempted to establish relationships between laboratory measured material and mixture properties and actual pavement performance. The ultimate goal of any highway agency is to have performance related specifications, which require such relationships. This sounds simple enough, but in reality such a task is not so simple due to the extremely complex behavior of hot mix asphalt. Due to the fact that it takes many years to evaluate new materials and methodologies, the use of accelerated loading facilities such as WesTrack for evaluation purposes becomes very advantageous. The research presented here produces multiple permanent deformation performance relationships for the WesTrack project, some of which may be extended to other environments. An attempt to develop similar fatigue performance relationships was unsuccessful due partially to the lack of fatigue distress at WesTrack to date. Additionally, mix design and some quality control data summaries are presented for the project along with an investigation into a potential cause of the premature rutting of coarse Superpave mixes. The investigation resulted in the development of precision statements for the ASTM D5821-95 coarse aggregate angularity test method and a better understanding of the sensitivity of coarse Superpave mixtures.

Hand, Adam J. T.

167

Subsurface defect detection in first layer of pavement structure and reinforced civil engineering structure by FRP bonding using active infrared thermography  

NASA Astrophysics Data System (ADS)

In many countries road network ages while road traffic and maintenance costs increase. Nowadays, thousand and thousand kilometers of roads are each year submitted to surface distress survey. They generally lean on pavement surface imaging measurement techniques, mainly in the visible spectrum, coupled with visual inspection or image processing detection of emergent distresses. Nevertheless, optimisation of maintenance works and costs requires an early detection of defects within the pavement structure when they still are hidden from surface. Accordingly, alternative measurement techniques for pavement monitoring are currently under investigation (seismic methods, step frequency radar). On the other hand, strengthening or retrofitting of reinforced concrete structures by externally bonded Fiber Reinforced Polymer (FRP) systems is now a commonly accepted and widespread technique. However, the use of bonding techniques always implies following rigorous installing procedures. To ensure the durability and long-term performance of the FRP reinforcements, conformance checking through an in situ auscultation of the bonded FRP systems is then highly suitable. The quality-control program should involve a set of adequate inspections and tests. Visual inspection and acoustic sounding (hammer tap) are commonly used to detect delaminations (disbonds) but are unable to provide sufficient information about the depth (in case of multilayered composite) and width of debonded areas. Consequently, rapid and efficient inspection methods are also required. Among the non destructive methods under study, active infrared thermography was investigated both for pavement and civil engineering structures through experiments in laboratory and numerical simulations, because of its ability to be also used on field. Pulse Thermography (PT), Pulse Phase Thermography (PPT) and Principal Component Thermography (PCT) approaches have been tested onto pavement samples and CFRP bonding on concrete samples in laboratory. In parallel numerical simulations have been used to generate a set of time sequence of thermal maps for simulated samples with and without subsurface defect. Using this set of experimental and simulated data different approaches (thermal contrast, FFT analysis, polynomial interpolation, singular value decomposition…) for defect location have been studied and compared. Defect depth retrieval was also studied on such data using different thermal model coupled to a direct or an inverse approach. Trials were conducted both with an uncooled and cooled infrared camera with different measurement performances. Results obtained will be discussed and analysed in the paper we plan to present. Finally, combining numerical simulations and experiments allows us discussing on the sensitivity influence of the infrared camera used to detect subsurface defects.

Dumoulin, Jean; Ibos, Laurent

2010-05-01

168

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

169

Modeling and Model Verification; Testing Pavement Layers and Materials; and Low-Cost Drainage Structures.  

National Technical Information Service (NTIS)

The 12 papers included in this volume represent three general groups. They contain information for those who are interested in numerical and centrifuge modeling, testing and evaluation of pavements, and low-cost drainage structures. In the first group of ...

1995-01-01

170

Pavement Marking Warranty Specifications. A Synthesis of Highway Practice. NCHRP Synthesis 408.  

National Technical Information Service (NTIS)

This synthesis study updates information on the use of pavement marking warranties by U.S. state departments of transportation (DOTs) and Canadian provincial/territorial transportation agencies. It also reviews road construction warranty experience in Eur...

M. J. Markow

2010-01-01

171

Evaluation of Latex Polymers to Resist Stripping in Asphalt Pavements in Oregon.  

National Technical Information Service (NTIS)

This study assessed the effectiveness of latex polymer anti-stripping treatment by inspecting and evaluating the condition of pavements constructed in Oregon from 1997-2001. Ten hot mix asphalt concrete paving projects were identified throughout the state...

M. Lynde E. Brooks

2005-01-01

172

Effect of Drainage in Unbound Aggregate Bases on Flexible Pavement Performance.  

National Technical Information Service (NTIS)

It has been well demonstrated that a positive subsurface drainage is beneficial in enhancing pavement performance and thus extending pavement service life. Typical permeable base materials include asphalt/cement-treated, open-graded aggregates and unbound...

M. Tao M. Y. Abu-Farsakh

2008-01-01

173

Economic Analysis of Roadway Occupancy for Freeway Pavement Maintenance and Rehabilitation. Volume 2. Users Manual.  

National Technical Information Service (NTIS)

A computer program was developed to perform an Economic Analysis of Roadway Occupancy for Maintenance and Rehabilitation EAROMAR. The user specifies the pavement design and traffic. The program generates hourly traffic volume by trip purpose, direction an...

B. C. Butler

1974-01-01

174

Influence of Vehicle Parameters on the Dynamics of Pavement Structure Due to Vehicle-Road Interaction  

Microsoft Academic Search

A three-dimensional vehicle-road interference system was established in this work. A moving vehicle was simplified to a quarter-vehicle model. An infinite plate on Kelvin foundation was employed to model the pavement system. Through integral transform, the time-dependent displacement and stress of the pavement are obtained by linking together the characteristics of a road profile and a moving vehicle. The spatial

Haoyu Li; Shaopu Yang; Shaohua Li

2009-01-01

175

Development of a Regional Pavement Performance Database for the AASHTO (American Association of State Highway and Transportation Officials) Mechnistic-Empirical Pavement Design Guide. Part 1. Sensitivity Analysis.  

National Technical Information Service (NTIS)

Optimization of transportation facilities for capacity and pavement condition could be achieved with mechanistic analysis of pavement structures. This report is focused on using the AASHTO M-E Design Guide (MEPDG) to show the results of quantitative sensi...

S. Kesiraju H. Bahia T. M. Adams

2007-01-01

176

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

PubMed

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

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

2013-08-03

177

Laboratory Study of Concrete Properties to Support Implementation of the New AASHTO Mechanistic-Empirical Pavement Design Guide.  

National Technical Information Service (NTIS)

Properties of concrete embodying materials typically used in Wisconsin paving projects were evaluated in support of future implementation of the AASHTO Mechanistic-Empirical Pavement Design Guide (MEPDG). The primary concrete properties studied were compr...

J. Silva J. B. Effinger R. Li S. M. Cramer

2012-01-01

178

AUTOMATED PAVEMENT IMAGING PROGRAM (APIP) FOR PAVEMENT CRACKS CLASSIFICATION AND QUANTIFICATION - A PHOTOGRAMMETRIC APPROACH  

Microsoft Academic Search

The evaluation of pavement conditions is an important part of pavement management. Traditionally, pavement condition data are gathered by human inspectors who walk or drive along the road to assess the distresses and subsequently produce report sheets. This visual survey method is not only time consuming and costly but more importantly it compromises the safety of the field personnel. With

M. Mustaffar; T. C. Ling

1998-01-01

179

Viscoelastic modelling for asphalt pavements - Software ViscoRoute  

Microsoft Academic Search

Huet-Sayegh model (1963) gives a set of constitutive equations of a visco-elastic material which accounts well for the behaviour of asphalt pavement layers, especially regarding thermal effects. This model allows rather good predictions of experimental data. The French pavement design method consists in a pavement mechanistic analysis based on the Burmister multilayer elastic model (1943) -LCPC software ALIZE (1982)-. In

A. Chabot; P. Tamagny; D. Poché; D. Duhamel

180

Investigation of the Frictional Resistance of Seal Coat Pavement Surfaces.  

National Technical Information Service (NTIS)

Numerous factors, including aggregate characteristics, construction variables, traffic volume, and environment, are believed to be affecting the frictional performance of highway pavements. The objective of this phase of the study was to investigate the e...

M. A. U. Abdul-Malak C. G. Papaleontiou D. W. Fowler A. H. Meyer

1988-01-01

181

Prediction of Hydroplaning Potential from Runoff Characteristics of Highway Pavements.  

National Technical Information Service (NTIS)

A computer program, HYDROP, was developed to predict hydroplaning potential resulting from uniform rainfall of any intensity on sections of highway pavement with varying degrees of topographic irregularity. The program uses a kinematic-wave approximation ...

J. R. Reed D. F. Kibler R. S. Heubner G. W. Marks

1985-01-01

182

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

183

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

2012-01-01

184

Condition of Longitudinal Steel in Illinois Continuously Reinforced Concrete Pavements.  

National Technical Information Service (NTIS)

An investigation was made of several CRC pavements constructed within Illinois to determine the extent of corrosion occurring on the longitudinal reinforcement at transverse cracks. The effect of crack width, crack spacing, depth of reinforcement, slab th...

J. S. Dhamrait F. K. Jacobsen D. R. Schwartz

1973-01-01

185

Cost-Effectiveness Analysis of Enhancing the Pavement-Related Information Systems at the Texas Department of Transportation.  

National Technical Information Service (NTIS)

Research Project 0-4186 entitled, 'Cradle-to-Grave Monitoring of Pavements and Pavement Management Information System (PMIS) Functionality Enhancement Planning,' is intended to develop strategic plans for integrating the pavement-related databases at the ...

A. Karoonsoontawong Z. Zhang R. B. Machemehl

2003-01-01

186

Evaluation of Reclaimed Asphalt Pavement for Surface Mixtures.  

National Technical Information Service (NTIS)

Indiana Department of Transportation (INDOT) has successfully used Reclaimed Asphalt Pavement (RAP) for decades because of its economic and environmental benefits. However, until recently, INDOT has disallowed the use of RAP in asphalt surface mixtures be...

A. Shah K. J. Kowalski R. S. McDaniel

2012-01-01

187

Calibration of Pavement Response Models for the Mechanistic-Empirical Pavement Design Method.  

National Technical Information Service (NTIS)

Most pavement design methodologies assume that the tire-pavement contact stress is equal to the tire inflation pressure and uniformly distributed over a circular contact area. However, tire-pavement contact area is not in a circular shape and the contact ...

J. A. Prozzi R. Luo

2007-01-01

188

Investigation of Premature Distresses in Flexible Pavements.  

National Technical Information Service (NTIS)

The study was undertaken to investigate the growing concern regarding premature distresses in flexible pavements in North Carolina and to identify the causes and mechanisms associated with these untimely failures. This objective was approached through ext...

N. P. Khosla

1985-01-01

189

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

...and Color-Difference Measurement by Tristimulus (Filter) Colorimetry.â The latter test method specified bidirectional geometry...luminous factor must be determined using bispectral fluorescent colorimetry. Commercial instruments are available which allow...

2010-04-01

190

Equivalency of Crushed Rock with Industrial By-Products and Geosynthetic-Reinforced Aggregates Used for Working Platforms During Pavement Construction.  

National Technical Information Service (NTIS)

A study was conducted to define an equivalency criterion for five materials used for working platforms during pavement construction on a poor subgrade: conventional crushed rock (referred to as 'breaker run') and four alternatives (i.e. Grade 2 granular b...

C. H. Benson T. B. Edil B. F. Tanyu W. H. Kim

2005-01-01

191

Concrete Pavement Technology Program: Evaluating the Use of Fiber-Reinforced Polymer Bars in Continuously Reinforced Concrete Pavement.  

National Technical Information Service (NTIS)

This TechBrief discusses the potential use of fiber-reinforced polymer (FRP) bars in continuously reinforced concrete pavements (CRCP). Relative advantages and disadvantages of FRP bars are presented, and some specific considerations for the use of FRP ba...

2009-01-01

192

Study on pavement technologies to mitigate the heat island effect and their effectiveness  

Microsoft Academic Search

Recently, the heat island effect in large cities has become a social issue in Japan. Pavements are thought to be one of the main causes of the heat island effect as they cover wide area of cities. Therefore, new pavements, such as water retention pavements or heat shield pavements, have been developed and used as countermeasures by the central and

K. Kubo; H. KIDO

193

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

NASA Astrophysics Data System (ADS)

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

Plati, Christina; Loizos, Andreas

2013-10-01

194

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

195

DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA ABSTRACT  

SciTech Connect

Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavements/soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

G.A. Valentine; C.D. Harrington

2005-08-26

196

DESERT PAVEMENTS AND SOILS ON BASALTIC PYROCLASTIC DEPOSITS AT LATHROP WELLS AND RED CONE VOLCANOES, SOUTHERN NEVADA  

SciTech Connect

Formation of desert pavement and accretionary soils are intimately linked in arid environments such as the Mojave Desert. Well-sorted fallout scoria lapilli at Lathrop Wells (75-80 ky) and Red Cone ({approx}1 Ma) volcanoes (southern Nevada) formed an excellent starting material for pavement, allowing infiltration of eolian silt and fine sand that first clogs the pore space of underlying tephra and then aggrades and develops vesicular A (Av) horizons. Variations in original pyroclast sizes provide insight into minimum and maximum clast sizes that promote pavement and soil formation: pavement becomes ineffective when clasts can saltate under the strongest winds, while clasts larger than coarse lapilli are unable to form an interlocking pavement that promotes silt accumulation (necessary for Av development). Contrary to predictions that all pavements above altitudes of {approx}400 m would have been ''reset'' in their development after late Pleistocene vegetation advances (about 15 ka), the soils and pavements show clear differences in maturity between the two volcanoes. This indicates that either the pavement soils develop slowly over many 10,000's of years and then are very stable, or that, if they are disrupted by vegetation advances, subsequent pavements are reestablished with successively more mature characteristics.

G.A. Valentine; C.D. Harrington

2005-08-10

197

GPR abilities in investigation of the pavement transversal cracks  

NASA Astrophysics Data System (ADS)

This paper describes the results of an investigation into the capabilities of the GPR technique within the field of pavement crack diagnostics. Initially, laboratory tests were performed on prototypes simulating idealized cracks. Next, long-term visual observation and repeated GPR scanning were performed, on three roads of semi-rigid construction, several hundreds of meters long and subjected to heavy traffic. Furthermore, a road of rigid construction was tested, having a more than 70-year history of use. In several cases the cracks were probed by drillings, in order to recognize structures responsible for signal generation, or to explain reasons of signal lacking.

Krysi?ski, Lech; Sudyka, Jacek

2013-10-01

198

Impact of Airport Pavement Deicing Products on Aircraft and Airfield Infrastructure. A Synthesis of Airport Practice.  

National Technical Information Service (NTIS)

Airfield pavement deicing and anti-icing are essential activities to maintain safe winter operations of the aviation industry. Airfield pavement deicing products (PDPs) traditionally consisting of urea or glycols have become less popular owing to their ad...

X. Shi

2008-01-01

199

Winter Tenting of Highway Pavements. Test Program and Discussion of Causes and Mechanisms.  

National Technical Information Service (NTIS)

Tenting consists of localized frost heaving in the immediate vicinity of transverse pavement cracks. It produces a highly irregular riding surface, leads to premature pavement-surface deterioration, occurs on highways designed for high traffic volumes and...

M. A. Kestler A. S. Krat G. E. Roberts

2000-01-01

200

Structural Evaluation Methodology for Pavements Based on Dynamic Deflections.  

National Technical Information Service (NTIS)

A framework for structural evaluation of pavements based on dynamic deflections is presented. A self-iterative procedure has been developed to estimate insitu Young's moduli of pavement layers by using the approach of inverse application of layered elasti...

W. Uddin A. H. Meyer W. R. Hudson K. H. Stokoe

1985-01-01

201

Long-Term Pavement Monitoring: Colorado's Evaluation of the Pilot Case Study.  

National Technical Information Service (NTIS)

The report documents Colorado's involvement in the Long-term Pavement Monitoring pilot case study. Besides the data collection procedure that was recommended by FHWA, Colorado investigated the current network level pavement monitoring program, which consi...

W. Hutter

1984-01-01

202

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

203

Contributions of PG Graded Asphalt to low Temperature Cracking Resistance of Pavement  

Microsoft Academic Search

The purpose of this research was to study and evaluate the role that asphalt binders play in the resistance of asphalt pavements to low temperature 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

Ssu-Wei Loh; J. Olek

1999-01-01

204

Influence of binder and mixture properties on the performance of AC pavements  

Microsoft Academic Search

This study was conducted as a part of an on-going program to validate the SUPERPAVE binder selection program introduced in the U.S. in 1995. The SUPERPAVE system recognizes that the behavior of hot mix asphalt (HMA) depends on the temperature, loading and aging conditions and allow for material selection process that aids in the prevention of premature pavement distress. To

Ayesha Shah

2004-01-01

205

GEOSYNTHETIC-REINFORCED PAVEMENT SYSTEM : TESTING & DESIGN  

Microsoft Academic Search

A large scale experimental program was presented in this paper, aimed at the improvement of the understanding, and evaluation of the structural contribution of geosynthetic reinforcement to pavement systems. The structural contribution of a geogrid was quantified by the increase in the layer coefficient of the base course material. Design parameters derived from the laboratory testing were analyzed and presented.

FILIPPO MONTANELLI

206

Continuously Reinforced Concrete Overlays of Flexible Pavements on Trunk Road A2.  

National Technical Information Service (NTIS)

The design and construction of continuously reinforced concrete (CRC) overlays on flexible pavements of Trunk Road A2 are described. The existing pavements were dual carriageways of flexible construction built in 1975-76; isolated sections had failed comp...

J. M. Gregory

1983-01-01

207

Pavement Quality Indicators. Five Year Report (2009-2013) for the Nebraska Department of Roads.  

National Technical Information Service (NTIS)

The Nebraska Department of Roads (NDOR) conducts an annual examination of pavement conditions on Nebraska's interstate and federal highway system. During these examinations, indicators of pavement quality are measured directly or compiled from parameters ...

C. Villaneueva W. Jensen

2013-01-01

208

Analysis and Contrast of Different Pervious Pavements for Management of StormWater in a Parking Area in Northern Spain  

Microsoft Academic Search

Pervious pavements are rainwater control systems that filter and store rainwater, reducing runoff formation and the risk of\\u000a urban flooding. In addition, these sustainable urban drainage systems provide an additional source of water for non-potable\\u000a use, which implies a cost and energy saving. An experimental 45 place parking lot consisting of five different types of pervious\\u000a pavements was constructed in

Elena Gomez-Ullate; Elena Castillo-Lopez; Daniel Castro-Fresno; Joseba Rodriguez Bayon

2011-01-01

209

Effects of Heavy-Vehicle Characteristics on Pavement Response and Performance.  

National Technical Information Service (NTIS)

This report will be of special interest to pavement-design and pavement-management engineers, as well as the transportation planners and transportation-agency chief administrative officers responsible for funding the transportation network, allocating cos...

T. D. Gillespie S. M. Karamihas M. W. Sayers M. A. Nasim W. Hansen N. Ehsan D. Cebon

1993-01-01

210

Development of a Rigid Pavement Forensics Knowledge Management System to Retain TxDOT Corporate Knowledge.  

National Technical Information Service (NTIS)

This report summarizes cooperative efforts to gather and make available in a knowledge management system both tacit and currently documented knowledge of rigid pavement forensic methods, tools, and the valuable insights into rigid pavement performance pri...

P. E. Krugler C. M. Chang-Albitres R. L. Robideau

2006-01-01

211

Evaluation of Polyester Fiber Reinforced Concrete for use in Cement Concrete Pavement Works  

Microsoft Academic Search

Polyester Fiber Reinforced Concrete (PFRC) has been evaluated for use as a cement concrete pavement material. The study focused on laboratory evaluation of various mechanical and durability properties of PFRC, with and without fly ash. Few tests were also conducted at the age of 24 months to study the long-term behaviour of PFRC. The PFRC exhibited improved flexural and compressive

Saroj Gupta; V. V. L. Kanta Rao; Jayabrata Sengupta

2008-01-01

212

Impact of traffic intensity and pavement aggregate size on road dust particles loading  

NASA Astrophysics Data System (ADS)

Road dust emissions severely hamper PM10 urban air quality and their burden is expected to increase relatively to primary motor exhaust emissions. Beside the large influence of climate and meteorology, the emission potential varies widely also from one road to another due to numerous factors such as traffic conditions, pavement type and external sources. Nevertheless none of these factors is sufficiently known for a reliable description in emission modelling and for decision making in air quality management. In this study we carried out intensive road dust measurement campaigns in South Spain, with the aim of investigating the relationship between emission potential (i.e. road dust load) and traffic intensity, pavement aggregate size and distance from braking zones. Results indicate that, while no impact from braking activity can be drawn on the bulk road dust mass, an increase in traffic intensity or mean pavement aggregate size clearly reduce the single vehicle emission potential.

Amato, F.; Pandolfi, M.; Alastuey, A.; Lozano, A.; Contreras González, J.; Querol, X.

2013-10-01

213

Simulated aircraft load testing and non-destructive evaluation of bituminous pavements  

Microsoft Academic Search

The US Federal Aviation Administration's National Airport Pavement Test Facility was constructed to generate full-scale accelerated pavement test data for the development of advanced airport pavement design criteria. During the first round of traffic testing, a six-wheel (Boeing 777) landing gear and a four-wheel (Boeing 747) landing gear were trafficked on flexible test pavements until they were deemed failed. Non-destructive

Kasthurirangan Gopalakrishnan; Marshall R. Thompson

2008-01-01

214

Characterization and use of tropical gravels for pavement construction in West Africa  

Microsoft Academic Search

Road transportation is increasingly becoming one of the key factors for promoting economic growth in most developing countries. However, transport and road research in the tropics has received relatively little attention. Experiences in road construction in the tropics within the past 50 years or so have established that local materials specifications and pavement construction technologies have to be developed in

M. D. Gidigasu

1991-01-01

215

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

Microsoft Academic Search

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

K. Ksaibati; R. Erickson

1998-01-01

216

A numerical approach to evaluate the risk of differential surface icing on pavements with insulated sections  

Microsoft Academic Search

This paper presents the results of a numerical study on the differential icing risk at the surface of pavements with insulated sections in the Province of Quebec, Canada. Differential icing situations occur when slippery conditions form on the surface of insulated pavement sections while adjacent conventional pavement sections maintain dry surface conditions. A heat transfer model that considers the climate

Jean Côté; Jean-Marie Konrad

2005-01-01

217

Evaluation and Decision Strategies for the Routine Maintenance of Concrete Pavement  

Microsoft Academic Search

This paper is to provide assistance for the pavement evaluation and selection of method of repair for routine maintenance relative to the extension of service life. The visual identification of various distress types is discussed, and evaluation techniques using nondestructive testing are introduced that are key to determining proper routine maintenance activities. According to the areas selected from the simplified

Youn su Jung; Dan G. Zollinger; Thomas J. Freeman

218

Evaluation of Grade and Straightedge Tolerances in Federal Aviation Administration Pavement Construction Specifications  

Microsoft Academic Search

Federal Aviation Administration (FAA) specifications for runway, taxiway, and apron pavements contain acceptance criteria based on grade and straightedge tolerances (1). Recent specifications have focused on measured profile indices as a primary acceptance measure for pavement smoothness during construction. The FAA recognizes this and funds research into runway pavement ride quality with the goal of quantifying smoothness acceptance criteria. The

Jeffrey Rapol

219

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

220

Pavement Management and Evaluation.  

National Technical Information Service (NTIS)

The 9 papers in this report deal with the following areas: optimization of long-range major rehabilitation of airfield pavements; development and implementation of Alberta's pavement information and needs system; predicting reductions in service life of s...

D. H. Artman J. S. Liebman M. I. Darter M. A. Karan T. J. Christison

1983-01-01

221

Full-Depth Pavement Reclamation with Foamed Asphalt: Final Report  

Microsoft Academic Search

A comprehensive study on full-depth reclamation (FDR) of pavements with foamed asphalt has been completed for the California Department of Transportation by the University of California Pavement Research Center. A literature review revealed that very little research had been carried out on the reclamation of thick asphalt pavements (multiple overlays over a relatively weak base or subgrade). A mechanistic sensitivity

David Jones; P. Fu; John T Harvey; F. Halles

2008-01-01

222

Production of Fullerenes from Plant Materials and used Carbon Materials by Means of a Chip-Injection-Type J×B Arc Reactor  

Microsoft Academic Search

By using a chip-injection-type J×B arc reactor, carbon material chips of, for example, charcoal, activated carbon, sumi (Chinese ink stick), synthetic rubber and carbon black are well arc-sublimated in He gas and fullerenes are successfully produced from these materials. From the viewpoints of effective use of plant resources, recycling of used carbon materials and environmental low-emission technology, the utilization of

Tetsu Mieno

2000-01-01

223

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

SciTech Connect

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

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

1995-07-01

224

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

225

Superplasticized concretes for rehabilitation of bridge decks and highway pavements  

NASA Astrophysics Data System (ADS)

Two mixes, one with medium workability and high cement content suitable for bridge deck replacement and another with high workability suitable for structural and pavement concrete were selected for intensive study. For these mixes, properties of the fresh concrete (slump, vebe time, flow table spread, air content, initial and final setting times) are reported. The effects of retempering are described. The influence of three types of cements on the properties of plastic and hardened concrete is explained. Complete results of the following tests are presented: compressive strength, tensile strength, flexural strength, static modulus of elasticity, dynamic modulus of elasticity, pulse velocity and dry unit weight at 1, 3, 28 and 90 days curing. The selected concretes had high durability and satisfactory resistance against deicer scaling.

Ramakrishnan, V.; Coyle, W. V.

1981-01-01

226

Subsurface defect detection in first layer of pavement structure and reinforced civil engineering structure by FRP bonding using active infrared thermography  

Microsoft Academic Search

In many countries road network ages while road traffic and maintenance costs increase. Nowadays, thousand and thousand kilometers of roads are each year submitted to surface distress survey. They generally lean on pavement surface imaging measurement techniques, mainly in the visible spectrum, coupled with visual inspection or image processing detection of emergent distresses. Nevertheless, optimisation of maintenance works and costs

Jean Dumoulin; Laurent Ibos

2010-01-01

227

Pervious Pavement System Evaluation-Paper  

EPA Science Inventory

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

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

Cost-effective selection and multi-period scheduling of pavement maintenance and rehabilitation strategies  

NASA Astrophysics Data System (ADS)

An optimization methodology is developed for determining the most cost-effective maintenance and rehabilitation (M&R) activities for each pavement section in a highway pavement network, along an extended planning horizon. A multi-dimensional 0-1 knapsack problem with M&R strategy-selection and precedence-feasibility constraints is formulated to maximize the total dollar value of benefits associated with the selected pavement improvement activities. The solution approach is a hybrid dynamic programming and branch-and-bound procedure. The imbedded-state approach is used to reduce multi-dimensional dynamic programming to a one-dimensional problem. Bounds at each stage are determined by using Lagrangian optimization to solve a relaxed problem by means of a sub-gradient optimization method. Tests for the proposed solution methodology are conducted using typical data obtained from the Texas Department of Transportation.

Yoo, J.; Garcia-Diaz, A.

2008-03-01

230

Investigation of frictional properties on wire combed PCC (Portland Cement Concrete) pavement surfaces  

NASA Astrophysics Data System (ADS)

This report involves PCC Pavements constructed with surface textures produced by a wide variety of wire combs. A small amount of testing was also performed on PCCP with other textures as a follow up of previous research on frictional properties. A limited amount of noise evaluation by rating panels and sound level (dbA) meters was conducted to assist in selection of an optimum the spacing for wire combs on future PCC Pavement projects. Included in this report is a brief description of each major project with summaries of friction number tests, standpatch texture depth tests, and sound level measurements.

1982-09-01

231

A design system for rigid pavement rehabilitation  

NASA Astrophysics Data System (ADS)

The development, use, and applicability of a rigid pavement rehabilitation design system, RPRDS, developed for use by the Texas State Department of Highways and Public Transportation is described. Like other pavement design systems, RPRDS makes use of the systems approach to incorporate a number of pavement design and analytical models into a computer program, RPRDS-1, for the generation, analysis, and comparison of numerous pavement design strategies. Basically, RPRDS generates a number of feasible overlay design strategies based on user inputs, performs a present value cost analysis on each, and then presents those which are optimal.

Seeds, S. B.; McCullough, B. F.; Hudson, W. R.

1982-01-01

232

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

233

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

234

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

SciTech Connect

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

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

1997-07-03

235

Accelerated performance testing of concrete pavement with short slabs  

Microsoft Academic Search

A new concept for designing concrete pavements by optimising the slab geometry in order to reduce the slab thickness as well as to minimise the mechanical load transfer devices has recently been proposed. Theoretically, the reduced slab size lowers the load and curling-induced tensile stresses and concomitantly a thinner concrete slab can be constructed. Full-scale test sections were constructed and

Jeffery R. Roesler; Victor G. Cervantes; Armen N. Amirkhanian

2011-01-01

236

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

237

Effect of Performance Model Accuracy on Optimal Pavement Design  

Microsoft Academic Search

In the first part of this paper, an analysis of the data collected during the American Association of State Highway Officials (AASHO) Road Test, based on probabilistic duration modeling techniques, is presented. Duration techniques enable the stochastic nature of pavement failure time to be evaluated as well as censored data to be incorporated in the statistical estimation of the model

Samer Madanat; Jorge A. Prozzi; Michael Han

2002-01-01

238

Impact of compressed natural gas fueled buses on street pavements  

Microsoft Academic Search

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

D. Yang; R. Harrison

1995-01-01

239

STRUCTURAL EVALUATION OF FLEXIBLE PAVEMENTS USING NON DESTRUCTIVE TESTS  

Microsoft Academic Search

The aim of this paper is to contribute to the improvement of the methodologies used in structural pavement evaluation, concerning in particular the backcalculation of layer moduli based on Falling Weight Deflectometer (FWD) together with Ground Penetrating Radar (GPR) test results and using Artificial Neural Network (ANN) technique for the analysis. A brief description of the test procedures and analysis

Simona Fontul

240

Impact of Compressed Natural Gas Fueled Buses on Street Pavements.  

National Technical Information Service (NTIS)

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 con...

D. Yang R. Harrison

1995-01-01

241

DEVELOPMENT OF A HYDROPHOBIC SUBSTANCE TO MITIGATE PAVEMENT ICE ADHESION  

EPA Science Inventory

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

242

Implementation of Warm-Mix Asphalt Mixtures in Nebraska Pavements.  

National Technical Information Service (NTIS)

The primary objective of this research is to evaluate the feasibility of several WMA mixtures as potential asphalt paving mixtures for Nebraska pavements. To that end, three well-known WMA additives (i.e., Sasobit, Evotherm, and Advera synthetic zeolite) ...

H. Ban J. Zhang Y. R. Kim

2012-01-01

243

Reclaimed Asphalt Pavement in Asphalt Mixtures: State of the Practice.  

National Technical Information Service (NTIS)

With increased demand and limited aggregate and binder supply, hot mix asphalt (HMA) producers discovered that reclaimed asphalt pavement (RAP) is a valuable component in HMA. As a result, there has been renewed interest in increasing the amount of RAP us...

A. Copeland

2011-01-01

244

Characterisation of interface bonding between hot-mix asphalt overlay and concrete pavements: modelling and in-situ response to accelerated loading  

Microsoft Academic Search

This study investigates the effects of pavement interface conditions on hot-mix asphalt (HMA) overlay response using the laboratory and field measurements accompanied by a numerical analysis. A laboratory and accelerated testing programme were conducted as part of a comprehensive study to determine the optimum tack coat application rate for HMA–Portland cement concrete (PCC) composite pavements by Leng et al. (2008,

Hasan Ozer; Imad L. Al-Qadi; Hao Wang; Zhen Leng

2011-01-01

245

Characterisation of interface bonding between hot-mix asphalt overlay and concrete pavements: modelling and in-situ response to accelerated loading  

Microsoft Academic Search

This study investigates the effects of pavement interface conditions on hot-mix asphalt (HMA) overlay response using the laboratory and field measurements accompanied by a numerical analysis. A laboratory and accelerated testing programme were conducted as part of a comprehensive study to determine the optimum tack coat application rate for HMA–Portland cement concrete (PCC) composite pavements by Leng et al. (2008,

Hasan Ozer; Imad L. Al-Qadi; Hao Wang; Zhen Leng

2012-01-01

246

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

NASA Astrophysics Data System (ADS)

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

Krysi?ski, L.; Sudyka, J.

2012-04-01

247

FIELD TESTING THE EFFECTIVENESS OF PERVIOUS PAVEMENTS AS A WATER SENSITIVE URBAN DESIGN INITIATIVE  

Microsoft Academic Search

Pervious pavements in car parks and driveways reduce peak discharge and the volume of runoff flowing in to urban drains and improve the water quality by trapping the sediments in the infiltrated water. This reduces the risk of pollutants such as suspended solids and particle bound chemicals such as phosphorous, nitrogen, heavy metals and oils and hydrocarbons entering receiving waters.

N. Kadurupokune; N. Jayasuriya

248

influence of post-consumer recycled asphalt shingles on hot mix asphalt containing fractionated recycled asphalt pavement  

Microsoft Academic Search

As the cost of construction materials continue to rise and place financial constraints on transportation agencies, engineers are looking for sustainable methods that minimize construction costs and optimize the selection of materials used in asphalt pavements. Two methods that are beginning to receive considerable attention for highway construction are adding post-consumer recycled asphalt shingles (RAS) to hot mix asphalt (HMA)

Andrew Aaron Cascione

2010-01-01

249

A Research on the Association of Pavement Surface Damages Using Data Mining  

NASA Astrophysics Data System (ADS)

The association of pavement surface damages used to rely on the judgments of the experts. However, with the accumulation of data in the pavement surface maintenance database and the improvement of Data Mining, there are more and more methods available to explore the association of pavement surface damages. This research adopts Apriori algorithm to conduct association analysis on pavement surface damages. From the experience of experts, it has been believed that the association of road damages is complicated. However, through case studies, it has been found that pavement surface damages are caused among longitudinal cracking, alligator cracking and pen-holes, and they are unidirectional influence. In addition, with the help of association rules, it has been learned that, in pavement surface preventative maintenance, the top priority should be the repair of longitudinal cracking and alligator cracking, which can greatly reduce the occurrence of pen-holes and the risk of state compensations.

Hung, Ching-Tsung; Chang, Jia-Ray; Chen, Jian-Da; Chou, Chien-Cheng; Chen, Shih-Huang

250

Damage Analysis of Jointed Plain Concrete Pavements in Indiana, Part I: Finite Element Modeling and Damage Analysis, Part II: INDISLAB, A Software for Jointed Plain Concrete Pavement Design  

Microsoft Academic Search

Current design procedures for concrete pavements do not account for several factors that can influence their service life. In this work, these factors are investigated and the findings are integrated into a procedure for better predicting longterm performance of concrete pavements. To achieve this, sophisticated finite element techniques are employed and parametric studies are performed. The findings are then integrated

Elisa D. Sotelino; Alireza Asgari; Andrew C. Saksa; Guillermo Cedeno

2005-01-01

251

Investigations by fluorescence techniques of the mechanism of formation of silica- and alumina-based MCM-41-type materials  

Microsoft Academic Search

Silica- and alumina-based mesostructured MCM-41-type materials were obtained at low temperature in the presence of cationic (cetyltrimethylammonium bromide (CTAB) or chloride) and anionic (sodium dodecylsulfate) surfactants, respectively, by modifying the pH of the corresponding clear precursor solutions.In situ fluorescence techniques were used to study the first steps of formation of these mesostructured solids prior to precipitation. For the silica-based system

Lorette Sicard; Jörn Frasch; Michel Soulard; Bénédicte Lebeau; Joël Patarin; Tim Davey; Raoul Zana; Frédéric Kolenda

2001-01-01

252

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

253

Excogitated Composite Multifunctional Layer for Pavement Systems.  

National Technical Information Service (NTIS)

The study evaluated a three-dimensional excogitated composite multifunctional (ECM) layer design for pavement construction. Research was conducted in the design and selection of materials that would satisfy the geometry and multi-functional requirements o...

B. J. Dempsey

1995-01-01

254

Assessment and upgrading of in-service heavy duty pavements to long life  

Microsoft Academic Search

The context of long-life pavements (LLP) is winning specific international interest the last years; especially in regards to the upgrading of existing pavements to LLP, which constitutes the main focus of the present research study. For this reason, a detailed assessment of the in situ condition of a heavy-duty highway pavement was performed, based on a comprehensive long-term monitoring approach

Andreas Loizos

2006-01-01

255

Evaluation of non-uniform tyre contact stresses on thin asphalt pavements  

Microsoft Academic Search

Improved quantification of the shape and distribution of actual tyre-pavement contact stresses resulted in enhanced definitions of 3D-tyre-pavement contact stresses for the design and analysis of flexible pavements. It is now possible to describe the 3D-load\\/stress regimes with a series of discrete load values that were measured using Stress-In-Motion (SIM) technology, as well as being predicted from trained Artificial Neural

M De Beer; C Fisher; F J Jooste

256

Influence of vertical load models on flexible pavement response—an investigation  

Microsoft Academic Search

This paper aims to illustrate the influence of moving loads on pavement analysis, namely their characteristics and time distribution. Firstly, a state-of-the-art load model for pavement analysis is presented. Components of traffic load (contact stresses), their magnitude and time distribution, the tyre-pavement contact area and the characterization of a moving load according to dynamic and static formulations are introduced. Secondly,

C. Vale

2008-01-01

257

Rehabilitation Techniques for Stripped Asphalt Pavements.  

National Technical Information Service (NTIS)

Asphalt stripping is a fairly common form of distress for pavements in Montana, particularly for pavements that were surfaced with an open-graded friction course. Currently, the technique for rehabilitating these pavements involves the costly removal of m...

D. R. Johnson R. B. Freeman

2002-01-01

258

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

Microsoft Academic Search

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

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

259

Mobile acoustic system for the detection of surface-breaking cracks in pavement  

NASA Astrophysics Data System (ADS)

Monitoring the structural condition of road and airport pavement is an extremely critical task to ensure the safety and efficiency of teh transportation. The topic is relevant to both civil and military transportation infrastructure. The presence of damage in pavement, including surface cracking, depressions, swells, and wear, is inevitable due to the sever environmental and service loads that these structures must be subject to. Existing NDE techniques aimed at assessing the structural condition of pavement include Falling Weight Deflectometer, Ground Penetrating Radar, and acoustic methods based on surface waves. This paper presents improvements to the traditional surface-wave method for the detection of surface-breaking cracks in pavement. The advances include 1) the modeling of the problem as dipsersive waves propagating in a multilayer system, 2) the inclusion of post-processing algorithms based on the Wavelet Transform to improve the sensitivity and accuracy of the inspection, and 3) the use of non-contact, air-coupled acoustic detectors to enhance the mobility of the inspection unit. The crack detection procedure consists of first generating a dispersive wave with an impulse hammer, and then measuring the changes in velocity, amplitude and/or frequency content as the wave travels across the flaw with the aid of the Continuous Wavelet Transform. Multilayer wave propagation modeling provides a better understanding of the experimental results by predicting how the various frequencies interact with cracks of different depths. The results of field tests will be presented for both rigid (concrete-based) and flexible (bitumen-based) pavement with surface cracks.

Marzani, Alessandro; Rizzo, Piervincenzo; Lanza di Scalea, Francesco; Benzoni, Gianmario

2004-07-01

260

Characterization of Microporous Carbon Materials by Means of a New Gamma-Type Adsorption Isotherm Equation  

Microsoft Academic Search

A new numerical procedure, based on the simulated annealing algorithm (SA), for optimizing the parameters of a new recently developed gamma-type adsorption isotherm equation is proposed. This procedure is verified for three modeled adsorption isotherms assuming some arbitrarily chosen shapes of the pore size distribution function (asymmetrical bell-shaped functions possessing one or two points of inflection and decreasing to a

Piotr Kowalczyk; Artur P. Terzyk; Piotr A. Gauden

2001-01-01

261

POROUS PAVEMENT: RESEARCH; DEVELOPMENT; AND DEMONSTRATION  

EPA Science Inventory

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

262

Internal Materials and structural Investigations of C-type Asteroid using carry-on Impactor by Hayabusa-2  

NASA Astrophysics Data System (ADS)

Recent explorations carried out by spacecraft provided important information regarding the physical properties of asteroids, particularly their bulk density and surface morphology. For example, Hayabusa spacecraft launched in 2003 investigated 25143 Itokawa, an S-type asteroid, after it arrived at 25143 Itokawa in September, 2005. Hayabusa has made a large amount of scientific discoveries and technological achievements during its stay, and left Itokawa in December, 2005 in order to deliver us the surface material. Observations by the Hayabusa spacecraft revealed that 25143 Itokawa has a rubble-pile structure owing to the re-accumulation of disrupted impact fragments. Itokawa has a high porosity (˜40%), probably because of the macro-porosity among the disrupted fragments. Based on such previous observations, it is proposed that the internal structures of asteroids have diversity in bulk densities and porosities. However, we have no direct observational data for the internal structure and materials. It is possible that the surface materials of small bodies seriously damaged by cosmic ray exposure. Thus, we should investigate the chemical and physical properties of the internal material. Also, we need to investigate the internal structure in order to understand the formation history. Now we are planning the study of the next asteroid exploration mission in 2014. From the point of the scientific objective, 1999 JU3, a C-type asteroid, was chosen as the target; C-type asteroids are considered to have more primitive material such as organic matters in comparison to Itokawa, an S-type asteroid. The spacecraft called as Hayabusa-2 basically follows the design of Hayabusa spacecraft. But, we will develop some new equipment to investigate the C-type asteroid, especially a carry-on impactor for the internal materials and structural investigations. The impactor will be shoot on the asteroid at ˜2km/s in order to expose the internal materials via crater formation and induce seismicity by the impact. The size and weight of impactor is restricted because the possible payload mass of Hayabusa-2 is not so large; its system should be very simple. If we use the rocket motor, the acceleration distance becomes large and the guidance system is necessary for the accurate impact. Additionally, the impact will cause a serious contamination by mechanical mixture of the impactor into the asteroid sample during crater formation process. Hence we adopt powerful explosive to accelerate the metal impact head and we shorten the accelerate time (less than 1 ms). In the presentation we will give an overview of a C-type asteroid investigation using the small carry-on impactor of Hayabusa-2.

Okamoto, Chisato; Takagi, Yasuhiko; Yano, Hajime; Saiki, Takanao; Tsuda, Yuichi; Yoshikawa, Makoto

263

Effects of Various Deicing Chemicals on Pavement Concrete Deterioration  

Microsoft Academic Search

The deleterious effects of deicers on concrete pavements and bridges have concerned concrete researchers for several decades. The present study experimentally investigates the effects of different deicers on concrete deterioration. Laboratory simulations of environmental conditions (wet\\/dry and freeze\\/thaw cycling) were conducted on highway concrete samples with various deicer chemicals (NaCl, CaCl 2, MgCl2, calcium magnesium acetate (CMA) of 5 different

HYOMIN LEE; ROBERT D. CODY; ANITA M. CODY; PAUL G. SPRY

264

Evaluation of western and eastern shale oil residua as asphalt pavement recycling agents  

SciTech Connect

The objective of this investigation was to perform a preliminary evaluation of the utility of residual materials prepared from Green River Formation (western) and New Albany Shale (eastern) shale oils as recycling agents for aged asphalt pavement. Four petroleum asphalts were first aged by a thin-film accelerated-aging test, which simulates long service life of asphalt in pavement. The aged asphalts were mixed (recycled) with Green River Formation shale oil distillation residua to restore the original viscosities. Separately, for comparison, a commercial recycling agent was used to recycle the aged asphalts under the same circumstances. The recycled asphalts were reaged and the properties of both binder and asphalt-aggregate mixtures studied. Originally, the same study was intended for an eastern shale residua. However, the eastern shale oil distillation residua with the required flash point specification also had the properties of a viscosity builder; therefore, it was studied as such with asphalts that do not achieve sufficient viscosity during processing to serve as usable binders. Results show that Green River Formation shale oil residuum can be used to restore the original asphalt properties with favorable rheological properties, the shale oil residuum has a beneficial effect on resistance to moisture damage, the low-temperature properties of the shale oil residuum recycled asphalts are not adversely affected, and the low-temperature properties of the shale oil residuum recycled asphalts are dependent upon the chemistry of the mixture. The eastern shale oil residua was blended with soft petroleum asphalts. Results show the products have higher viscosities than the starting materials, the rheological properties of the soft asphalt-eastern shale oil residue blends are acceptable, and the eastern shale oil residue has dispersant properties despite its high viscosity. 11 refs., 3 figs., 9 tabs.

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

1990-03-01

265

Experimental AC (Asphalt Concrete) overlays of PCC pavement  

NASA Astrophysics Data System (ADS)

A series of experimental asphalt concrete (AC) overlays was constructed over an existing distressed portland cement concrete pavement on Interstate 80 near Boca, California. The experimental overlays included rubberized dense-graded AC, rubberized open-graded AC, a rubber flush coat interlayer, dense-graded AC with short polyester fibers and Bituthene interlayer strips. The report presents a description and discussion of AC mix batching, construction observations, laboratory testing, overlay covering, and initial performance evaluation.

Smith, R. D.

1983-11-01

266

Field application and performance of concrete overlay for pavement rehabilitation  

Microsoft Academic Search

A test section of concrete overlay was constructed and monitored for one year to evaluate the feasibility as a rehabilitation\\u000a alternative for deteriorated concrete pavement in Korea. The test section of 2-lane 290m long on 88 Highway near Jirisan I\\/C\\u000a included 25cm unbonded and 6cm and 10cm bonded concrete overlays. High early-strength slag cement was used in the overlay\\u000a concrete

Kyong-ku Yun; Young-chan Suh

1999-01-01

267

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

268

Photoluminescence study of p -type ZnO:Sb prepared by thermal oxidation of the Zn-Sb starting material  

Microsoft Academic Search

We have investigated photoluminescence (PL) from Sb-doped p -type ZnO films obtained by thermal oxidation of the Zn-Sb starting material. Very well resolved PL spectra were obtained from samples, with the hole concentration above 1×1017cm-3 . Acceptor binding energy is determined to be 137meV from free electron to acceptor transitions. The binding energy between the acceptor and the exciton obtained

E. Przezdziecka; E. Kaminska; I. Pasternak; A. Piotrowska; J. Kossut

2007-01-01

269

Determination of nitroaromatic and nitramine type energetic materials in synthetic and real mixtures by cyclic voltammetry.  

PubMed

Nitro-explosives contain reducible aromatic -NO2 groups or cyclic >N-NO2 bonds that may undergo reductive cleavage. This work reports the development of a cyclic voltammetric (CV) assay for nitro-aromatics (trinitrotoluene (TNT), dinitrotoluene (DNT)) and nitramines (1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)) using a glassy carbon electrode. This determination was first used for these energetic materials by resolving current responses of reduction potentials primarily due to one constituent but partly contributed by other constituents. Calibration curves of current intensity versus concentration were linear in the range of 30-120mgL(-1) for RDX with a limit of detection (LOD) of 10.2mgL(-1), 40-120mgL(-1) for HMX (LOD=11.7mgL(-1)), 40-120mgL(-1) for TNT (LOD=11.2mgL(-1)), and 40-140mgL(-1) for DNT (LOD=10.8mgL(-1)). Results showed that the CV method could provide a sensitive approach for the simultaneous determination of RDX and TNT in synthetic and real mixtures. Deconvolution of current contributions of mixtures at peak potentials of constituents was performed by multiple linear regression. The proposed method was successfully applied to the analysis of military explosives comp A5 and octol, and method validation was performed both against HPLC on a comp B (TNT+RDX) sample and against GC-MS on real post-blast residual samples containing both explosives. PMID:24054661

Uzer, Ay?em; Sa?lam, Sener; Tekdemir, Yasemin; Ustamehmeto?lu, Belk?s; Sezer, Esma; Erça?, Erol; Apak, Re?at

2013-06-29

270

Simultaneous effects of salted water and water flow on asphalt concrete pavement deterioration under freeze–thaw cycles  

Microsoft Academic Search

The presence of water flow on road surfaces may lead to early deterioration of bituminous pavements. The adverse impacts of various anti-freezing materials on road surface performance have drawn the attention of many researchers. However, the simultaneous effects of salted water and water flow on the deterioration of road surfaces, particularly under freeze–thaw conditions, have not been adequately addressed. This

Behnam Amini; Saleh Sharif Tehrani

2012-01-01

271

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

SciTech Connect

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

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

2004-11-08

272

Analytical investigation of the effects of dowel misalignment on concrete pavement joint opening behaviour  

Microsoft Academic Search

Experimental and analytical investigations were conducted to evaluate the effects of dowel misalignment on the joint opening behaviour and associated distresses in concrete pavement joints. The experimental investigations focused on pavement specimens with one or two misaligned dowel bars at the joints, and the results included the pull-out force-joint opening responses and the observations of damage (spalling, cracking, etc.). Numerical

Milind Prabhu; Amit Varma; Neeraj Buch

2009-01-01

273

Use of Innovative Computer Technology and Optical Texture Properties in the Analysis of Pavement Digital Images  

Microsoft Academic Search

Digital image based automated pavement crack detection and classification technology has seen vast improvements in the recent years. In spite of these developments, although pavement crack lengths and widths can be evaluated using state-of-the-art software with a reasonable accuracy, no reported evidence is found in extending this technology to evaluate crack depths. Hence a preliminary study was carried out to

Saumya Priyadari Amarasiri

2011-01-01

274

A study on the determination method of the rut deduct value in the calculation of asphalt pavement condition index  

Microsoft Academic Search

According to the domestic and foreign studies on the determination methods of rut deduct value and in combination with the comparative analysis on the measured data and the actual pavement condition in entitative engineering, the thesis analyzed the advantages and disadvantages of the current methods to determine rut deduct value and proposed a continuous type calculating formula to determine rut

Shixiu Mo; Lingyun Kong

2011-01-01

275

Hydraulic Property Determination of Vesiculated Soil Peds in Desert Pavement Environments  

Microsoft Academic Search

Desert 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. Desert pavements consist of a surface layer of closely packed gravel, typically one stone thick, that overlies a silt-rich vesicular A (Av) soil horizon. The vesicular horizon is composed of highly structured,

D. G. Meadows; M. H. Young; T. G. Caldwell; E. V. McDonald

2003-01-01

276

Unified Methodology for Airport Pavement Analysis and Design. Volume 1: State of the ART.  

National Technical Information Service (NTIS)

An assessment of the state of the art of airport pavement analysis and design is presented. The objective is to identify those areas in current airport pavement analysis methodology that need to be substantially improved from the perspective of airport pa...

J. P. Zaniewski

1991-01-01

277

Unified Methodology for Airport Pavement Analysis and Design. Volume 1. State of the Art.  

National Technical Information Service (NTIS)

This report presents an assessment of the state of the art of airport pavement analysis and design. The objective is to identify those areas in current airport pavement analysis methodology that need to be substantially improved from the perspective of ai...

J. P. Zaniewski

1991-01-01

278

Theoretical approach to electromagnetic monitoring of road pavement applied geophysics and stochastical model  

Microsoft Academic Search

Road pavement performances are of great importance for driving comfort and safety. Monitoring and rehabilitation activities are always extremely strategic and crucial. The points of strength of advanced non-destructive techniques for road pavement monitoring essentially are: (1) reliability, (2) significance in the space domain, (3) efficiency and (4) quickness. One of the most relevant and widely used technologies is the

Andrea Benedetto

2004-01-01

279

Training Development for Pavement Preservation.  

National Technical Information Service (NTIS)

This research project strives to help the Iowa Department of Transportation (DOT) fully achieve the full benefits of pavement preservation through training on proper selection, design, and application of pavement preservation treatments. In some cases, th...

A. Morandeira C. T. Jahren J. Mallen

2013-01-01

280

Research and Development of GIS Airport Pavement Management System Based on MapX  

Microsoft Academic Search

The load of airport have increased accordingly with the continuous development of air transportation. In order to enhance the maintenance and rehabilitation efficiency of airport pavement, the geographic information system (GIS) airport pavement management system(APMS) based on MapX are being developed in Hunan, one province in middle China. This paper introduce the software and hardware platform, design opinion, main structure

Zhi-Ren Liu; XiangHua Yue

2009-01-01

281

A NEW APPROACH TO PAVEMENT DESIGN USING LIME STABILISED SUBGRADES  

Microsoft Academic Search

This paper outlines various design procedures that have been known to be used and some of the shortcomings in their approach to specify suitable material properties and layer thickness. Each procedure provides a slightly different solution. The aim of this paper to propose a new design approach using either a mechanistic or empirical pavement analysis methods to find the pavement

George Vorobieff; Greg Murphy

2003-01-01

282

Guidelines for Permitting Overloads; Part 1: Effect of Overloaded Vehicles on the Indiana Highway Network  

Microsoft Academic Search

Closed form analysis is commonly used to analyze pavement structures. This type of analysis assumes linear elastic material properties and static loading conditions. In reality, pavement materials are not linear elastic materials. For example, asphalt mixtures are viscoelastic materials and cohesive soils are elastic-plastic materials. Also truck loads are moving loads. The difference between the closed form analysis assumptions and

Sameh Mohamed Zaghloul; Thomas D. White

1994-01-01

283

An Overview of Pervious Concrete Applications in Stormwater Management and Pavement Systems  

Microsoft Academic Search

Recent interest in the use of Portland Cement Pervious Concrete (PCPC) for pavements has been very high, due primarily to the Federal Clean Water Act mandate that government agencies and private entities manage stormwater runoff—both quantity and quality. Such pavements are full depth and are currently being placed primarily in parking lot applications and areas of limited truck traffic. Pervious

V. R. Schaefer; M. T. Suleiman; K. Wang; J. T. Kevern; P. Wiegand

284

Research on tensile strength characteristics of bridge deck pavement bonding layers  

Microsoft Academic Search

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

Shaopeng Wu; Jun Han

2009-01-01

285

Validation of a Pavement Response Model Using Full-scale Field Tests  

Microsoft Academic Search

This paper provides details on a field verification program undertaken to validate the applicability of a finite-layer mechanistic model that has been selected to perform pavement response calculations. The proposed pavement response model is more realistic since it can handle moving traffic loading conditions, and it takes into consideration important factors such as vehicle speed and the non-uniform stress distributions

Raj V. Siddharthan; N. Krishnamenon; Mohey El-Mously; Peter E. Sebaaly

2002-01-01

286

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

Microsoft Academic Search

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,

Armelle Chabot; Chupin Olivier; Lydie Deloffre; Denis Duhamel

2010-01-01

287

ASPHALT CONCRETE PAVEMENT STRENGTHENING AND MODELLING OF ITS EFFECT ON ROAD EVENNESS  

Microsoft Academic Search

Lithuania has a sufficiently well-developed road network, the quality of which still falls very much behind the standards used in the EU. The process of pavement distress is gradually accelerated by the following factors: a considerable increase in the amount of heavy vehicles, acceptance of 11.5 t permissible axle load within the EU member-states (10.0 t in the former Soviet

V. Puodžiukas; Z. Kamaitis

1999-01-01

288

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

SciTech Connect

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

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

2011-02-05

289

Development of fiber Bragg-grating-based soil pressure transducer for measuring pavement response  

Microsoft Academic Search

A soil pressure transducer by using fiber Bragg grating (FBG) sensors associated with a circular diaphragm is developed. The FBG based transducers can be used for pavement performance study and weigh-in-motion measurement. We consider three methods of bonding the FBG to the diaphragm: (1) radially, (2) radially, inside a glass capillary, and (3) circumferentially. The investigation of strain-gradient induced spectral

Chia-Chen Chang; Gregg Johnson; Sandeep T. Vohra; Bryan Althouse

2000-01-01

290

New types of cellulose materials obtained by an alternative spinning method  

Microsoft Academic Search

Conclusions ALCERU, Lyocell, Newcell, and Tencel (the order is alphabetical and not by importance) are thus alternative hydrated cellulose fibres fabricated by a method with a low degree of harmfulness. Is this only a name or is it also a hope, as for viscose wool fibre 60 years ago? In our opinion, this is much more than only the beginning

C. Burger; R. Maron; C. Michels; K. P. Mick

1996-01-01

291

Evaluation and verification of two systems for mechanistic structural design of asphalt concrete pavements in Nebraska  

NASA Astrophysics Data System (ADS)

The VESY-3-A mechanistic design system for asphalt pavements was field verified for three pavement sections at two test sites in Nebraska. PSI predictions from VESYS were in good agreement with field measurements for a 20 year old 3 layer pavement located near Elmwood, Nebraska. Field measured PSI values for an 8 in. full depth pavement also agreed with VESYS predictions for the study period. Rut depth estimates from the model were small and were in general agreement with field measurements. Cracking estimates were poor and tended to underestimate the time required to develop observable fatigue cracking in the field. Asphalt, base course and subgrade materials were tested in a 4.0 in. diameter modified triaxial cell. Test procedures used dynamic conditioning and rest periods to simulate service conditions.

Sneddon, R. V.

1982-07-01

292

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

293

Consolidation and thermoelectric properties of n-type bismuth telluride based materials by mechanical alloying and hot pressing  

Microsoft Academic Search

Bismuth telluride based n-type thermoelectric materials were prepared via the route of mechanical alloying (MA) and subsequent hot pressing (HP) process. Influence of hot press process parameters on the thermoelectric properties was investigated. Increasing hot pressing temperature from 340 to 400°C, the figure of merit of the hot pressed sample increases rapidly, and then it grows slowly and no improvement

J. Y. Yang; X. A. Fan; R. G. Chen; W. Zhu; S. Q. Bao; X. K. Duan

2006-01-01

294

Investigating Longevity of Corrosion Inhibitors and Performance of Deicer Products under Storage or after Pavement Application.  

National Technical Information Service (NTIS)

This study evaluated the longevity of corrosion inhibitors and the performance of inhibited deicer products under storage or after pavement application. No significant degradation of corrosion inhibitor or loss of chlorides was seen during the months of f...

A. Creighton D. Cross K. Fortune L. Fay M. Johnson M. M. Peterson R. Smithlin X. Shi Z. Yang

2011-01-01

295

Evaluation of Superpave and Modified Superpave Mixtures by Means of Accelerated Pavement Testing (Planning and Design Phase).  

National Technical Information Service (NTIS)

A cooperative research study was carried out by the Florida Department of Transportation (FDOT) and the University of Florida to evaluate the long-term rutting performance of Superpave mixtures and SBS-modified Superpave mixtures using the Heavy Vehicle S...

M. Tia R. Roque O. Sirin

2001-01-01

296

Implication of Aggregates in the Construction and Performance of Sea Coat Pavement Overlays (Revised).  

National Technical Information Service (NTIS)

The overall objective of this study, of which this research is the first phase, is to investigate and develop design criteria which will provide and maintain adequate pavement friction. Specifically, these objectives are to: develop a comprehensive, long-...

A. H. Meyer D. W. Fowler M. A. U. Abdul-Malak

1992-01-01

297

Calibration and Validation of the Enhanced Integrated Climatic Model for Pavement Design.  

National Technical Information Service (NTIS)

This report summarizes the results of research to evaluate, calibrate, and validate the Enhanced Integrated Climatic Model (EICM) incorporated in the original Version 0.7 (July 2004 release) of the Mechanistic-Empirical Pavement Design Guide (MEPDG) softw...

C. E. Zapata W. N. Houston

2008-01-01

298

Field and Laboratory Evaluation of Resilient Modulus Measurements on Florida Pavement Soils. Executive Summary.  

National Technical Information Service (NTIS)

This study summarizes a field and laboratory study to evaluate the resilient modulus of Florida pavement soils. The objectives were to conduct field and laboratory experiment programs and to develop the correlation relationships from the test results. Bas...

W. V. Ping Y. Wang Z. Yang

2000-01-01

299

Economic Analysis of Roadway Occupancy for Freeway Pavement Maintenance and Rehabilitation. Volume 3. Program Documentation.  

National Technical Information Service (NTIS)

A computer program developed to perform an Economic Analysis of Roadway Occupancy for Maintenance and Rehabilitation EAROMAR is documented. Input includes pavement design, thickness, lanes, project length, initial and final year traffic. The program gener...

B. C. Butler S. W. Hopkins

1974-01-01

300

Pavement Management 2011: Volume 2. Transportation Research Record: Journal of the Transportation Research Board, No. 2226.  

National Technical Information Service (NTIS)

TRBs Transportation Research Record: Journal of the Transportation Research Board, No. 2226 includes 16 papers that address calibration, prediction mechanisms, modeling, validation, and implementation issues related to the MechanisticEmpirical Pavement De...

2011-01-01

301

Improving the Properties of Reclaimed Asphalt Pavement for Roadway Base Applications.  

National Technical Information Service (NTIS)

The objective of this study was to improve Reclaimed Asphalt Pavements (RAP) strength in base course applications while reducing creep to an acceptable level using compaction techniques, fractionating, blending with high quality base course aggregate, and...

A. J. Petersen A. M. Bleakley A. M. Sajjadi B. S. Diouf E. H. Kalajian P. J. Cosentino R. E. Krajcik T. J. Misilo

2012-01-01

302

Construction and Preliminary HVS Tests of PreCast Concrete Pavement Slabs  

Microsoft Academic Search

This report presents the details on the construction and preliminary load tests on an experimental pavement comprised of ten pre-cast slabs of the pavement known as the Super-Slab® System, installed at the intersection of I-15 and SR210, in San Bernardino County in southern California. The construction of the test section consisted of: (a) Construction of a cement-treated base (CTB), (b)

Erwin R. Kohler; Louw du Plessis; Hechter Theyse

2008-01-01

303

International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking  

Microsoft Academic Search

The International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking was held in Hanover, N.H., on 6-8 May 1987. The objective was to review and summarize the existing knowledge of the causes of low-temperature transverse cracking of asphalt concrete pavement. Discussion also suggested directions for future research needed to more fully understand the mechanisms of the causes of low-temperature cracking. Overlays

James A. Scherocman

1991-01-01

304

International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking  

NASA Astrophysics Data System (ADS)

The International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking was held in Hanover, N.H., on 6-8 May 1987. The objective was to review and summarize the existing knowledge of the causes of low-temperature transverse cracking of asphalt concrete pavement. Discussion also suggested directions for future research needed to more fully understand the mechanisms of the causes of low-temperature cracking. Overlays were not discussed.

Scherocman, James A.

1991-02-01

305

Wavelet-aided pavement distress image processing  

Microsoft Academic Search

A wavelet-based pavement distress detection and evaluation method is proposed. This method consists of two main parts, real-time processing for distress detection and offline processing for distress evaluation. The real-time processing part includes wavelet transform, distress detection and isolation, and image compression and noise reduction. When a pavement image is decomposed into different frequency subbands by wavelet transform, the distresses,

Jian Zhou; Peisen S. Huang; Fu-Pen Chiang

2003-01-01

306

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

307

Fracture behavior of geosynthetic interlayers in road pavements  

SciTech Connect

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

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

1998-09-01

308

Evaluation of Geosynthetic Reinforced Flexible Pavement Systems Using Two Pavement Test Facilities.  

National Technical Information Service (NTIS)

The project was initiated to provide additional test section data to better define the influence of traffic loading type and geosynthetic reinforcement type. The loading provided to the test sections forming the basis of the models described above consist...

S. W. Perkins

2002-01-01

309

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

NASA Astrophysics Data System (ADS)

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

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

1998-12-01

310

The Effects of Coal Tar Based Pavement Sealer on Amphibian Development and Metamorphosis  

Microsoft Academic Search

Coal tar based pavement sealers are applied regularly to parking lots and contain significant levels of polycyclic aromatic\\u000a hydrocarbons (PAHs). Recently a connection between elevated levels of PAHs in streams and storm water runoff from parking\\u000a lots has been identified. We tested the hypothesis that coal tar based pavement sealers could alter the survival, growth,\\u000a and development of amphibians using

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

2006-01-01

311

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

SciTech Connect

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

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

2008-08-15

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

Improvement of Pavement Maintenance Activities using Geographic Information Systems in Abu Dhabi  

Microsoft Academic Search

The paper explores improving the efficiency of pavement maintenance decision-making process using GIS\\/GPS integration. A research project has been conducted on a selected study area (Sector: East 4\\/1 and West 4) in the roads network of Abu Dhabi Island. Distress data collection (i.e. defected areas) has been carried out using media that facilitates real-time data transfer and\\/or downloading. The Pavement

Ahmed El-Mowafy; Mostafa Abo-Hashema; Ahmed Ba-Obaid

314

Network-Level Deflection Data Collection for Rigid Pavements.  

National Technical Information Service (NTIS)

The existing rigid pavement deflection data contained in the PES database are evaluated and found to be inadequate for any network-level study of the structural behavior of rigid pavements. The PES data were evaluated by comparing them with existing data ...

E. Perrone T. Dossey W. R. Hudson

1994-01-01

315

Paperless Pavement Condition Rating System Development. (Includes Executive Summary).  

National Technical Information Service (NTIS)

The Pavement Condition Rating (PCR) system has been used by Ohio DOT as a means of establishing non-routine maintenance needs on highway sections for over 10 years. The PCR system develops a numerical rating for a segment of pavement which reflects the se...

J. C. Gilfert K. F. Conner

1996-01-01

316

Precast Repair of Continuously Reinforced Concrete Pavement.  

National Technical Information Service (NTIS)

An investigation into the applicability of precast slabs for rapid repair of CRCP is presented. Analytical techniques are used to study loading of repair slabs due to volume change, wheel loads, and lifting, with detailed results presented in several of t...

G. E. Elkins B. F. McCullough W. R. Hudson

1979-01-01

317

Mitigation of Horseshoe Damage to Pavements.  

National Technical Information Service (NTIS)

The Pennsylvania Department of Transportation (PennDOT) has a successful history of negotiating with the Amish in the Commonwealth on transportation issues. Observations of damage to the surface of the roads they travel with horses and buggies have led to...

G. L. Gleason H. Bahia S. M. Stoffels T. A. Bitonti

1995-01-01

318

Wavelet-based pavement distress detection and evaluation  

Microsoft Academic Search

An automated pavement inspection system consists of image acquisition and distress image processing. The former is accomplished with imaging sensors, such as video cameras and photomultiplier tubes. The latter includes distress detection, isolation, classification, evaluation, segmentation, and compression. We focus on wavelet-based distress detection, isolation, and evaluation. After a pavement image is decomposed into different-frequency subbands by the wavelet transform,

Jian Zhou; Peisen S. Huang; Fu-Pen Chiang

2006-01-01

319

Evaluation of Pavement Surface Properties and Vehicle Interaction.  

National Technical Information Service (NTIS)

The papers in the report relate to skid resistance, road roughness, braking, vehicle control, pavement performance and serviceability, design, and measurement systems for evaluating surface properties and vehicle interaction.

J. C. Burns R. J. Peters

1973-01-01

320

Reconstruction of a pavement geothermal deicing system  

Microsoft Academic Search

In 1948, US 97 in Klamath Falls, Oregon was routed over Esplanade Street to Main Street and through the downtown area. In order to widen the bridge across the US Bureau of Reclamation A Canal and to have the road cross under the Southern Pacific Railroad main north-south line, a new bridge and roadway were constructed at the beginning of

1999-01-01

321

Rigid Pavement Database: Overview and Data Collection Plan.  

National Technical Information Service (NTIS)

The rigid pavement (RP) database contains historical distress data obtained from more than 400 continuously reinforced concrete pavements (CRCP) and jointed concrete pavements (JCP) across the state of Texas. Data collection efforts began in 1974 and have...

T. Dossey T. Turen B. F. McCullough

1998-01-01

322

Pavement Management Activities.  

National Technical Information Service (NTIS)

The 12 papers in the report deal with the following areas: development and implementation of a new rehabilitation information and priority programming system (RIPPS); dynamic decision model for a pavement management system; life-cycle costing of paved Ala...

M. A. Karan R. C. G. Haas A. Cheetham T. J. Christison S. M. Khalil

1984-01-01

323

Federal Aviation Administration Airport Pavement Management and Airport Pavement Roughness Evaluation  

Microsoft Academic Search

This paper provides the status of two ongoing nondestructive testing (NDT) programs by the FAA: (1) PAVEAIR a web-based Airport Pavement Management System and (2) research subjective responses of pilots to vibrations induced by airport pavement roughness using a Boeing simulator. By 2011, the FAA is scheduled to complete a three-year effort to create an internet-based computer program for airport

Albert LARKIN; Gordon F. HAYHOE

324

Laboratory calibration of time-domain reflectometry and analysis of soil water content in Korea LTPP sections  

Microsoft Academic Search

The water content of pavement substructure can exert a great influence on the pavement performance. Recently, TDR (Time-Domain\\u000a Reflectometry) probe has been used to measure the water content of pavement substructure in the field. The accuracy of TDR\\u000a probe in the measurement of water content generally depends on the type, particle size, density, and temperature of the material,\\u000a necessitating the

Booil Kim

2010-01-01

325

OVERVIEW OF AN ACCELERATED PAVEMENT TESTING STUDY TO ASSESS THE PERFORMANCE OF MODIFIED BINDERS IN ASPHALT CONCRETE OVERLAYS  

Microsoft Academic Search

A comprehensive laboratory and accelerated pavement testing study on the use of terminal blend modified binders to limit reflective cracking in thin asphalt concrete overlays has recently been completed at the University of California Pavement Research Center. The experiment entailed the construction of a 90 m test road consisting of compacted clay subgrade, a 410 mm aggregate base and 90

D Jones; J Harvey; T Bressette

326

State-of-the-Practice: Rubblization of Airfield Pavements  

Microsoft Academic Search

With the airlines reporting passenger numbers returning to pre - September 11, 2001 levels, demand for more aircraft operations at the nation's airports is continuing to grow. This growth will continue to stress the nation's older concrete airport pavement infrastructure that has already served beyond its design and service limits for which it was constructed. As a result, a major

Mark Buncher; H. Wayne Jones

327

Subgrade soil index properties to estimate resilient modulus for pavement design  

Microsoft Academic Search

Mechanistic pavement design procedures based on elastic layer theory require characterization of each material in the pavement structure in terms of elastic moduli. Repeated triaxial load tests on cylindrical disturbed\\/undisturbed samples, yielding a resilient modulus, are frequently used for characterizing subgrade soil. Because of the complexities encountered with the test, in-situ and other laboratory tests would be desirable if a

A. M. Rahim

2005-01-01

328

The Response to Questionnaire Portion of Report No. 1; Preliminary Report, Control of Pavement Movements Adjacent to Structures.  

National Technical Information Service (NTIS)

The following two major questions wwere posed: 1. How prevalent is damage to structures from movement of rigid pavements in your State. 2. What action has been taken or considered to control, prevent or repair damage to structures from pavement movement. ...

1965-01-01

329

Use of recycled materials in highway construction. Final report  

SciTech Connect

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

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

1992-02-01

330

AN OPTIMAL MAINTENANCE MANAGEMENT MODEL FOR AIRPORT CONCRETE PAVEMENT  

NASA Astrophysics Data System (ADS)

In this paper, an optimal management model is formulated for the performance-based rehabilitation/maintenance contract for airport concrete pavement, whereby two types of life cycle cost risks, i.e., ground consolidation risk and concrete depreciation risk, are explicitly considered. The non-homogenous Markov chain model is formulated to represent the deterioration processes of concrete pavement which are conditional upon the ground consolidation processes. The optimal non-homogenous Markov decision model with multiple types of risk is presented to design the optimal rehabilitation/maintenance plans. And the methodology to revise the optimal rehabilitation/maintenance plans based upon the monitoring data by the Bayesian up-to-dating rules. The validity of the methodology presented in this paper is examined based upon the case studies carried out for the H airport.

Shimomura, Taizo; Fujimori, Yuji; Kaito, Kiyoyuki; Obama, Kengo; Kobayashi, Kiyoshi

331

Internal Materials and structural Investigations of C-type Asteroid using carry-on Impactor by Hayabusa-2  

Microsoft Academic Search

Recent explorations carried out by spacecraft provided important information regarding the physical properties of asteroids, particularly their bulk density and surface morphology. For example, Hayabusa spacecraft launched in 2003 investigated 25143 Itokawa, an S-type asteroid, after it arrived at 25143 Itokawa in September, 2005. Hayabusa has made a large amount of scientific discoveries and technological achievements during its stay, and

Chisato Okamoto; Yasuhiko Takagi; Hajime Yano; Takanao Saiki; Yuichi Tsuda; Makoto Yoshikawa

2010-01-01

332

Operating the Portable Seismic Pavement Analyzer.  

National Technical Information Service (NTIS)

The portable seismic pavement analyzer (PSPA) is a non-destructive testing device that measures the seismic modulus of concrete pavements. This report provides guidance on how to operate the PSPA including (a) general use and recommendations of the PSPA, ...

H. P. Bell

2006-01-01

333

Prefabricated Vertical Drains and Pavement Drainage Systems,  

National Technical Information Service (NTIS)

The 7 papers in the report deal with the following areas: Design, construction, and evaluation of West Virginia's first free-draining pavement system; Subbase permeability and pavement performance; Core flow-capacity requirements of geocomposite fin-drain...

J. S. Baldwin D. C. Long K. L. Highlands G. L. Hoffman B. J. Dempsey

1988-01-01

334

Detection of Circumstellar Material in a Normal Type Ia Supernova  

Microsoft Academic Search

Type Ia supernovae are important cosmological distance indicators. Each of these bright supernovae supposedly results from the thermonuclear explosion of a white dwarf star that, after accreting material from a companion star, exceeds some mass limit, but the true nature of the progenitor star system remains controversial. Here we report the spectroscopic detection of circumstellar material in a normal type

F. Patat; P. Chandra; R. Chevalier; S. Justham; Ph. Podsiadlowski; C. Wolf; A. Gal-Yam; L. Pasquini; I. A. Crawford; P. A. Mazzali; A. W. A. Pauldrach; K. Nomoto; S. Benetti; E. Cappellaro; N. Elias-Rosa; W. Hillebrandt; D. C. Leonard; A. Pastorello; A. Renzini; F. Sabbadin; J. D. Simon; M. Turatto

2007-01-01

335

Evaluation of concrete pavement service life using 3D nonlinear finite element analysis and nonlinear fatigue damage model  

Microsoft Academic Search

Current design procedures for concrete pavements do not account for several factors that can influence their service life. In this work, these factors are investigated and the findings are integrated into a procedure for better predicting long-term performance of concrete pavements. To achieve this, sophisticated finite element techniques are employed and parametric studies are performed. The findings are then integrated

Alireza Asgari

2004-01-01

336

Seismic monitoring of roadbeds for traffic flow, vehicle characterization, and pavement deterioration  

SciTech Connect

A road-side seismic monitoring system has been developed that includes not only instrumentation and fielding methods, but also data analysis methods and codes. The system can be used as either a passive or active monitoring system. In the passive mode, seismic signals generated by passing vehicles are recorded. Analysis of these signals provides information on the location, speed, length, and weight of the vehicle. In the active mode, designed for monitoring pavement degradation, a vibrating magnetostrictive source is coupled to the shoulder of the road and signals generated are recorded on the opposite side of the road. Analysis of the variation in surface wave velocity at various frequencies (dispersion) is used in an attempt to develop models of the near-surface pavement velocity structure. The monitoring system was tested at two sites in New Mexico, an older two-lane road and a newly-paved section of interstate highway. At the older site, the system was able to determine information about vehicle velocity, wheel-base length and weight. The sites showed significant differences in response and the results indicate the need for further development of the method to extract the most information possible for each site investigated.

Elbring, G.J.; Ormesher, R.C.; Holcomb, D.J.

1998-01-01

337

Desert pavements as indicators of soil erosion on aridic soils in north-east Patagonia (Argentina)  

NASA Astrophysics Data System (ADS)

Desert pavements are prominent features of many geomorphic surfaces in arid and semiarid lands. In the semiarid soils of north-eastern Patagonia, gravel cover in the shrub interspace areas of shrub-dominated communities is generally high, and contrast with that of grass-dominated patches where gravel cover is either absent or negligible. In the present study we analyze the relationship between soil erosion and desert pavement formation, in three sites, the upper, middle and lower slope positions of a flank pediment where well-conserved soils served as reference areas. We used the gravel cover and mass, as well as the thickness of the remnant A horizon, as determined by the depth of the Bt horizon of a Xeric Calciargid, as measures of soil erosion. Surface gravel at four cardinal points in respect to mounds associated with shrub-clumps was collected and the depth to the Bt horizon was determined. The mean thickness of the A horizon in the well-conserved soils were 11.3, 10.0 and 13.5 cm for the upper, middle and lower slope positions, respectively. For the same positions, the mean coarse fragment contents (> 2.0 mm) in the 0-10 cm depth of the A horizon in the well-conserved soils were 144, 92 and 119 g kg-1, and the mean surface gravel mass in the eroded patches were 5.3, 3.1 and 4.7 kg m-2. Surface gravel mass and depth of the remnant A horizon gave different estimates of the magnitude of soil erosion in the flank pediment. Thus, the mean/maximum soil loss, as determined by the mean gravel mass on the soil surface for the upper, middle and lower slope positions were, 28.3/68.2, 27.0/63.8 and 31.5/56.4 mm, respectively. These figures increased to a mean of 50.0, 52.5 and 82.0 mm for the same positions when soil loss was determined as the difference between the thickness of the A horizon of the well-conserved soil and that of the remaining A horizon in eroded patches. The loss of the A horizon by wind and water erosion seems to initiate the change from grass steppe to a stable shrub steppe characterized, in the shrub interspaces, by well-developed desert pavements. The strong correlation between surface gravel mass and the thickness of the remaining A horizon indicates that accelerated soil erosion has played an important role in the formation of desert pavements, and that desert pavements are good indicators of the extent and intensity of the erosion process in the Punta Ninfas area.

Rostagno, César M.; Degorgue, Gabriela

2011-11-01

338

Hydraulic Property Determination of Vesiculated Soil Peds in Desert Pavement Environments  

NASA Astrophysics Data System (ADS)

Desert 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. Desert pavements consist of a surface layer of closely packed gravel, typically one stone thick, that overlies a silt-rich vesicular A (Av) soil horizon. The vesicular horizon is composed of highly structured, prismatic soil peds, typically about 10 cm in diameter and less than 10 cm thick. Highly structured soils can greatly affect desert ecosystem development due to the impacts on local water balances. The concentration of silt and clay significantly reduces the infiltration rate and increases the water holding capacity, thereby reducing the penetration of wetting fronts. Field and laboratory studies were conducted to quantify the hydraulic properties of individual peds and pavement surfaces, and to ultimately use the information in a process-based evaluation of the soil moisture balance in arid environments. Field sites

Meadows, D. G.; Young, M. H.; Caldwell, T. G.; McDonald, E. V.

2003-12-01

339

Stress Relaxation of Cellular Silicone Material: 1985 (Condensation Type Only).  

National Technical Information Service (NTIS)

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 for...

J. W. Schneider

1986-01-01

340

Discrimination of source reactor type by multivariate statistical analysis of uranium and plutonium isotopic concentrations in unknown irradiated nuclear fuel material.  

PubMed

The problem of identifying the provenance of unknown nuclear material in the environment by multivariate statistical analysis of its uranium and/or plutonium isotopic composition is considered. Such material can be introduced into the environment as a result of nuclear accidents, inadvertent processing losses, illegal dumping of waste, or deliberate trafficking in nuclear materials. Various combinations of reactor type and fuel composition were analyzed using Principal Components Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLSDA) of the concentrations of nine U and Pu isotopes in fuel as a function of burnup. Real-world variation in the concentrations of (234)U and (236)U in the fresh (unirradiated) fuel was incorporated. The U and Pu were also analyzed separately, with results that suggest that, even after reprocessing or environmental fractionation, Pu isotopes can be used to determine both the source reactor type and the initial fuel composition with good discrimination. PMID:18774205

Robel, Martin; Kristo, Michael J

2008-09-05

341

Improving the Quality of Hot Bituminous Type Winter Patching Materials.  

National Technical Information Service (NTIS)

This report details the results of a study to improve the quality of hot bituminous type winter patching material. The principal material investigated was hot plant mix surface course material (meeting NJDOT Mix no. 5 grading) produced in McConnoughay por...

G. W. Indahl

1978-01-01

342

Pavement Drainage and Pavement-Shoulder Joint Evaluation and Rehabilitation  

Microsoft Academic Search

The objectives of this research were i) to evaluate the performance of pavement subdrainage systems ii) study the behavior of moisture conditions below pavements and iii) provide recommendations for unproved drainage criteria based on analysis of field data. Existing and retrofitted subdrainage collector systems were inspected through external visual inspection in combination with a probe for internal inspection. Distresses and

Zubair Ahmed; Thomas D. White; Philippe L. Bourdeau

1993-01-01

343

Capturing Solar Energy from Asphalt Pavements  

Microsoft Academic Search

The concept of extracting heat energy from asphalt pavements has been investigated in this study. The scope of work consisted of finite element modeling and testing with small and large scale asphalt pavement samples. Water flowing through copper tubes inserted within asphalt pavements samples were used as heat exchangers in the experiments. The rise in temperature of water as a

Rajib B. Mallick; Bao-Liang Chen; Sankha Bhowmick; Michael S. Hulen

344

Flexible pavement performance evaluation using deflection criteria  

Microsoft Academic Search

Flexible pavement projects in Nebraska were monitored for dynamic deflections, roughness, and distress for six consecutive years. Present surface conditions were characterized and data for evaluating rehabilitation needs, including amount of overlay, were provided. Data were evaluated and factors were isolated for determining the structural adequacy of flexible pavements, evaluating existing pavement strength and soil subgrade conditions, and determining overlay

R. J. Wedner

1980-01-01

345

State-of-the art guideline manual for design, quality control and construction of Sulfur-Extended-Asphalt (SEA) pavements  

Microsoft Academic Search

Sulfur-Extended-Asphalt (SEA) binders save asphalt, a potential energy source, by replacing some asphalt in conventional flexible pavement mixes with sulfur. These new binders appear to possess properties comparable to asphalt. The guideline manual discussed provides the highway community in both public and private organizations with the most definitive state-of-the-art guidelines extant for using these binders. Information on design, construction, quality

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

1980-01-01

346

Scattering and Absorption of Waves by Flat Material Strips Analyzed Using Generalized Boundary Conditions and Nystrom-Type Algorithm  

Microsoft Academic Search

The scattering of the - and -polarized plane waves by a thin flat homogeneous magneto-dielectric strip is considered. Assuming the strip to be thinner than the wavelength, we shrink its cross-section to themedian line wherethe generalized boundary conditions are imposed. The numerical solution is built on two sin- gular integral equations discretized using Nystrom-type numerical algorithm. The obtained results demonstrate

Olga V. Shapoval; Ronan Sauleau; Alexander I. Nosich

2011-01-01

347

Optical fiber based sensing system design for the health monitoring of multi-layered pavement structure  

NASA Astrophysics Data System (ADS)

This paper introduces an optical fiber based sensing system design for multi-layered pavement structural health monitoring. The co-line and integration design of FBG (Fiber Bragg Gating) sensors and BOTDR (Brillouin Optical Time Domain Reflectometry) sensors will ensure the large scale damage monitoring and local high accurate strain measurement. The function of pavement structure multi-scale shape measurement will provide real time subgrade settlement and rutting information. The sensor packaging methodology and strain transfer problem of the system will also be discussed in this paper. Primary lab tests prove the potential and feasibility of the practical application of the sensing system.

Liu, Wanqiu; Wang, Huaping; Zhou, Zhi; Li, Shiyu; Ni, Yuanbao; Wang, Geng

2011-11-01

348

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

NASA Astrophysics Data System (ADS)

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 known at different asphalt contents. To investigate rutting susceptibility for different mixes under study, a dynamic uniaxial loading in which the dynamic stress intensities were varied within a certain range to simulate field conditions was conducted. All mixtures studied in fatigue showed that the crack propagation rate versus stress intensity factors can be represented with a polynomial of a second degree. Statistical relations were developed to correlate the rutting and fatigue parameters under investigation in this study with other mix variables. The rutting parameters were found mostly to be influenced by asphalt contents and aggregate type. The fatigue parameters were found to be affected by asphalt contents, gradations and modulus of elasticity.

Elmitiny, M. R. N.

1980-03-01

349

Concrete Overlay as a Rehabilitation Option for Distressed Asphalt Pavements  

Microsoft Academic Search

Ultra-thin Whitetopping (UTW) involves placing a very thin concrete overlay 50 mm to 100 mm thick (2”-4”) on the milled surface of a distressed asphalt pavement. To investigate the performance of UTW placed over a flexible pavement subjected to slow and heavy moving wheel loads, whitetopping mixes were placed over a milled pavement surface in the Accelerated Pavement Testing (APT)

Sudarshan Rajan; J. Olek

2002-01-01

350

Polymer Concrete for Precast Repair of Continuously Reinforced Concrete Pavement on IH 30, Near Mt. Pleasant.  

National Technical Information Service (NTIS)

This report describes two punchout repairs made in a continuously reinforced concrete pavement (CRCP) using precast portland cement panels. The two repairs, one 12 foot by 12 foot, the other 6 foot by 6 foot, were completed and opened to traffic in one af...

A. H. Meyer B. F. McCullough D. W. Fowler

1981-01-01

351

Impact of Water on the Response and Performance of a Pavement Structure in an Accelerated Test  

Microsoft Academic Search

An accelerated load test using a Heavy Vehicle Simulator (HVS) was performed with the objective of investigating the response behaviour and performance of a commonly used pavement structure in Sweden. The structure consists of 10 cm asphalt bound layers, divided into surface course and bitumen base, over granular base and subbase resting on sandy subgrade. The structure was instrumented to

Sigurdur Erlingsson

2010-01-01

352

High altitude premium pavements  

NASA Astrophysics Data System (ADS)

The effect on performance that various additives and, or compaction had on the performance of pavements was evaluated. The following additives were evaluated: Anti-stripping additives, ground scrap rubber and carbon black. Samples were also evaluated at approximately 0, 3, 10 and 15% voids to determine the effect compaction had on the performance of the pavement. The resilient modulus, effect of water on cohesion of compacted bituminous mixtures and an accelerated moisture damage test was performed on each design mix. Most of the additives did not show significant, if any, improvement in the laboratory test results. The best improvement in laboratory test results came from the anti-stripping asphalt additives, which is one of the least costly and simplest to include in the pavement mixture.

Abel, F.; Proctor, J.

1980-02-01

353

Effective Pavement Marking Practices for Sealcoat and Hot-Mix Asphalt Pavements.  

National Technical Information Service (NTIS)

This report describes the tasks of research conducted to identify effective pavement marking practices for seal coat and hot-mix asphalt (HMAC) pavements in Texas. The researchers reviewed literature, determined current Texas Department of Transportation ...

T. J. Gates H. G. Hawkins E. R. Rose

2003-01-01

354

FULL SCALE HIGHWAY LOAD TEST OF FLEXIBLE PAVEMENT SYSTEMS WITH GEOGRID REINFORCED BASE COURSES  

Microsoft Academic Search

The use of geosynthetics to improve the performance of flexible pave- mentshasincreasedsignificantlyoverthe last decade. Thispaper describesa full scale testing research program that used a 20 kNmoving wheel load to determine the benefit of using a stiff biaxial geogrid between the base and subgrade of a flexible pavement system. The traffic benefit ratio (TBR) was defined as the ratio of the

J. G. Collin; T. C. Kinney; X. Fu

355

Project Report on the Continued Development and Analysis of the Flexible Pavement Database.  

National Technical Information Service (NTIS)

The original scope of TxDOT Research Project 0-6275 included continuing the development of the Texas Flexible Pavement database (TFPD) developed as part of Research Project 0-5513. The objective of 0-5513 was to deliver a database capable of hosting the d...

A. Banerjee A. de F. Smit J. A. Prozzi J. P. Aguiar-Moya P. Sivarm

2012-01-01

356

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

357

LONG-TERM IN-SITU INFILTRATION PERFORMANCE OF PERMEABLE CONCRETE BLOCK PAVEMENT  

Microsoft Academic Search

SUMMARY Since it is a design criteria for road drainage and sewer systems, the infiltration performance of permeable concrete block pavement (CBP) is of important significance during the service life of a road construction. Due to the entrainment of mineral and organic fines into the pores of porous concrete blocks or into the aggregates used in joints or openings, the

Soenke Borgwardt

358

Evaluation of Sealcoat in Pavements. University-Based Research, Education, and Technology Transfer Program.  

National Technical Information Service (NTIS)

Application of seal coat is one of the efficient and economical periodic maintenance activities used for the extension of the service life of pavements. This work is based on the study results on polymer modified emulsion application on test track and on ...

G. M. Sabnis B. K. Sharma

2001-01-01

359

International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking  

National Technical Information Service (NTIS)

The International State-of-the-Art Colloquium on Low-Temperature Asphalt Pavement Cracking was held in Hanover, N.H., on 6-8 May 1987. The objective was to review and summarize the existing knowledge of the causes of low-temperature transverse cracking of...

J. A. Scherocman

1991-01-01

360

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

361

DEVELOPMENT OF A SIMPLE PAVEMENT DIAGNOSTIC SYSTEM USING DYNAMIC RESPONSES OF AN ORDINARY VEHICLE  

NASA Astrophysics Data System (ADS)

Vehicle Intelligent Monitoring System (VIMS), which enables frequent quantitative assessment of road pavement condition, has been developed. The system, which utilizes an ordinary vehicle equipped with an accelerometer, GPS, and portable PC, is simple and inexpensive. VIMS evaluates road roughness by estimating the International Roughness Index (IRI) from the response of the vehicle traveling at a constant speed. At first, the repeatability of the dynamic response measurement is confirmed. Then, an IRI estimation method utilizing vertical responses of the vehicle has been proposed and its accuracy studied. Furthermore, IRI estimation calibration to account for differences in measurement vehicles and driving speeds has been discussed. Finally, VIMS is applied to expressways in Japan and national roads in the Philippines, which confirms the diagnostic capability of the system.

Asakawa, Hiroyuki; Nagayama, Tomonori; Fujino, Yozo; Nishikawa, Takafumi; Akimoto, Takashi; Izumi, Kimihiko

362

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

Microsoft Academic Search

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

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

2005-01-01

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

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

365

RECOGNITION DISTANCES OF DIFFERENT PAVEMENT ARROW DESIGNS DURING DAYTIME AND NIGHTTIME  

Microsoft Academic Search

This study was conducted to test the visibility of five designs for pavement marking arrows at both full scale and half scale. Two designs were standard arrows (the Ohio and Federal arrows), and three were elongated arrows (Australian, Swiss, and an experimental arrow). A field study was conducted at an abandoned airport test site for both daytime and nighttime (low-beam

Helmut T. Zwahlen; Thomas Schnell; Sarah Miescher

1999-01-01

366

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...

367

Numerical analysis of integral pavement\\/soil-wall structures in soft soil  

Microsoft Academic Search

In a country like the Netherlands, construction on weak and quite often wet soils is inevitable. The interaction between the pavement and the underlying foundation is then crucial to the overall construction performances. Focusing on this requirement, this contribution took an integrated approach in the analysis, including the development and implementation of constitutive models to capture the porosity and nonlinearity

Y. Zhao; X. Liu; A. Scarpas; C. Kasbergen; Arian de Bondt

2011-01-01

368

Permeability measurement and scan imaging to assess clogging of pervious concrete pavements in parking lots  

Microsoft Academic Search

This paper describes a study that used permeability measurement along with physical and hydrological characteristics of 20 pervious concrete pavements in parking lots throughout California. The permeability was measured at five locations: the main entrance, an area with no traffic, and three separate measurements within a parking space at each parking lot. Hydrological and physical site characteristics such as traffic

Masoud Kayhanian; Dane Anderson; John T. Harvey; David Jones; Balasingam Muhunthan

369

Automated Real-Time Pavement Crack Detection and Classification System.  

National Technical Information Service (NTIS)

Statistics published by the Federal Highway Administration indicate that the maintenance and rehabilitation of highway pavement in the United States requires over 17 billion dollars per year. Currently, maintenance and repairs account for nearly one-third...

C. Glazier H. D. Cheng

2007-01-01

370

Pervious Pavements: Installation, Operations and Strength. Part 1: Pervious Concrete.  

National Technical Information Service (NTIS)

Pervious pavement systems are now being recognized as a best management practice by the Environmental Protection Agency and the state of Florida. The pervious concrete system is designed to have enhanced pore sizes in the surface layer compared to convent...

E. Stuart I. Uju M. Chopra M. Hardin M. Wanielista

2011-01-01

371

Research on Fatigue of Asphalt Mixtures and Pavements in Nebraska.  

National Technical Information Service (NTIS)

Hydrated lime has been recognized by the asphalt research community as a material capable to enhance various asphalt mixture properties and performance. In an attempt to mitigate moisture related damage, the Nebraska Department of Roads (NDOR) requires th...

F. T. S. Aragao J. Lee Y. Kim

2008-01-01

372

PIXE Analysis of Several Types of Local Materials  

Microsoft Academic Search

PIXE including microbeam-PIXE technique has been applied extensively for characterization of various types of local materials in many different fields at King Fahd University of Petroleum & Minerals (KFUPM), Dhahran, Saudi Arabia. In this paper, microanalysis of rock samples from the northwest and northeast of the country was performed to determine economic feasibility of trace mineral exploration as well for

Motaheruddin Ahmed

373

Analysis of Calcite, Dolomite and Texture, and Their Roles in Premature Deterioration of Portland Cement Concrete Pavement in Kansas.  

National Technical Information Service (NTIS)

Premature deterioration of concrete pavement produced with Class I limestone indicated a need to better predict limestone that would be deleterious in the future while passing Class I test criteria. Using the information contained in the database prepared...

B. J. Smith R. G. Pollock

2000-01-01

374

The Catskill-Cairo Experimental Rigid Pavement: A Five-Year Progress Report.  

National Technical Information Service (NTIS)

This test road combines a variety of subgrade conditions with various subbase and base materials, as well as several pavement designs. In all, 30 different test sections were included for study of combinations of naturally occurring and experimental featu...

J. E. Bryden R. G. Phillips

1973-01-01

375

Detection of circumstellar material in a normal type Ia supernova.  

PubMed

Type Ia supernovae are important cosmological distance indicators. Each of these bright supernovae supposedly results from the thermonuclear explosion of a white dwarf star that, after accreting material from a companion star, exceeds some mass limit, but the true nature of the progenitor star system remains controversial. Here we report the spectroscopic detection of circumstellar material in a normal type Ia supernova explosion. The expansion velocities, densities, and dimensions of the circumstellar envelope indicate that this material was ejected from the progenitor system. In particular, the relatively low expansion velocities suggest that the white dwarf was accreting material from a companion star that was in the red-giant phase at the time of the explosion. PMID:17626848

Patat, F; Chandra, P; Chevalier, R; Justham, S; Podsiadlowski, Ph; Wolf, C; Gal-Yam, A; Pasquini, L; Crawford, I A; Mazzali, P A; Pauldrach, A W A; Nomoto, K; Benetti, S; Cappellaro, E; Elias-Rosa, N; Hillebrandt, W; Leonard, D C; Pastorello, A; Renzini, A; Sabbadin, F; Simon, J D; Turatto, M

2007-07-12

376

A high speed profiler based slab curvature index for jointed concrete pavement curling and warping analysis  

NASA Astrophysics Data System (ADS)

One of the biggest gaps of missing knowledge between accurate structural modeling of concrete pavement slab behavior and real pavement behavior is accounting for slab warping (locked-in curvature and moisture gradient effects) and curling (temperature gradient effects). Curling and warping are curvatures that can be present in a PCC slab that can cause corners and edges, or mid panel, of the slab to lift off of the ground resulting in relatively high deflection and stress in the system. The least understood type of curvature in slabs is apparent locked-in curvature, which can become excessive and control the overall behavior of the pavement system. This project is focused on quantifying slab curvatures and the effects of apparent locked-in curvature on the behavior and long-term performance of pavement systems. A high-speed profile analysis technique for detecting the amount of slab curvatures along pavement wheel paths is described. This signal processing technique can detect relatively small curvature variations in high-speed pavement elevation profiles obtained at normal highway operating speeds using special vehicles. A resulting curvature detection algorithm is applied to the Federal Highway Administration (FHWA) Long Term Pavement Performance (LTPP) database high-speed pavement profiles for jointed concrete pavements. The range and nature of slab curvatures detected in the profiles is described. The calculated locked-in curvature at the various pavement sites is compared to LTPP database information to evaluate curvature effects on pavement deterioration rates and the relation between site parameters and locked-in curvature. The significance of slab curvature is shown through statistics and predictive models developed for various pavement distress modes. It is shown that the amount of curvature locked into concrete slabs is one of the strongest factors in the FHWA LTPP data correlated to deterioration of pavements. This study shows that preventing locked-in slab curvature should be a top priority for PCC slabs in highway applications. The profile analysis routine and distress prediction models developed will be valuable tools for pavement designers, managers, and researchers.

Byrum, Christopher Ronald

377

A numerical model for the computation of concrete pavement moduli: a non-destructive testing and assessment method  

Microsoft Academic Search

The falling weight deflectometer (FWD) non-destructive testing technique has been used to monitor and assess the behaviour and performance of rigid pavement systems. In addition to the full-scale site investigation, tests were also carried out with the aid of a specifically developed laboratory scaled model of the FWD.A rigorous finite element model was developed to analyse a multi-layered pavement system

J. N. Karadelis

2000-01-01

378

Improvements in the application of infinite elements to the NIKE3D program for airport pavement response analysis  

Microsoft Academic Search

A 3D, nonlinear finite element program NIKE3D is used in the Federal Aviation Administration's pavement design and response analysis of the rigid pavement structures. In 2000, an infinite element method was added to the NIKE3D program to simulate the infinitely deep subgrade. Using infinite elements efficiently can reduce the total number of elements, thereby saving the computational time. However, some

Qiang Wang; David R. Brill

2012-01-01

379

Concrete pavement analysis: the first eighty years  

Microsoft Academic Search

This paper traces the evolution of analytical methods for concrete pavements over the period from the publication of Westergaard's early work in the 1920s until today. It is demonstrated that this development was accomplished in parallel with the birth and coming of age of geotechnical engineering, and was likewise pioneered by a number of colorful and distinguished personalities. Westergaard's analysis

Anastasios M. Ioannides

2006-01-01

380

Kansas Tire/Pavement Noise Study.  

National Technical Information Service (NTIS)

The purpose of this paper is to present the results of noise testing accomplished by the National Center for Asphalt Technology using a close-proximity noise trailer. The paper discusses the nature of tire/pavement noise and the results of testing selecte...

B. Waller D. I. Hanson R. S. James

2005-01-01

381

Reactor Material Program Fracture Toughness of Type 304 Stainless Steel  

SciTech Connect

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

Awadalla, N.G.

2001-03-28

382

Improved Drainage and Frost Action Criteria for New Jersey Pavement Design. Phase II. Data Analysis.  

National Technical Information Service (NTIS)

The feasibility of including open-graded drainage layers in their highway pavements was studied. Before constructing actual pavements with open-graded drainage layers, frost penetration depths and moisture content profiles beneath several pavements in New...

R. L. Berg

1979-01-01

383

Influence of asphalt pavement on damping ratio and resonance frequencies of timber bridges  

Microsoft Academic Search

Since timber bridges are light-weight structures with a high life-load to death-load ratio, they are susceptible to vibration and thus satisfying vibration serviceability is a governing design criterion. A good knowledge of the damping properties of timber bridges is therefore a key aspect for guaranteeing a sufficient serviceability. Since observations suggest that timber bridges with an asphalt pavement increase the

Sandy Schubert; Daniel Gsell; René Steiger; Glauco Feltrin

2010-01-01

384

Thermoelectric Performance of p-Type (Bi85Sb15)1- x Sn x Materials Prepared by a Pressureless Sintering Technique  

NASA Astrophysics Data System (ADS)

In this study, a series of Sn-doped (Bi85Sb15)1- x Sn x ( x = 0, 0.025, 0.05, 0.1, 0.2, 0.3) thermoelectric materials was fabricated through mechanical alloying followed by pressureless sintering. The crystal structure was characterized by x-ray diffraction. The electrical transport properties and thermal properties were measured in the temperature range from 77 K to 300 K. The electrical transport as a function of temperature appeared to be characteristic of a semimetal. The Seebeck coefficient gradually changed from negative to positive with increasing Sn doping, showing p-type electrical transport properties. It is found that the Seebeck coefficients of the p-type Bi-Sb alloys decrease with increasing dopant concentration of Sn, which may be due to increasing carrier concentration. Among the p-type alloys, the power factor of (Bi85Sb15)0.975Sn0.025 reached a maximum value of 1.3 × 10-3 W/mK2 at 265 K, and the optimum figure of merit value of 0.13 was obtained at 240 K. The results indicate that good p-type Bi-Sb alloys can be prepared by this synthesis procedure.

Chen, Zhen; Zhou, Min; Huang, Rongjin; Huang, Chuanjun; Song, Chunmei; Zhou, Yuan; Li, Laifeng

2012-06-01

385

Possibilities of ground penetrating radar usage within acceptance tests of rigid pavements  

NASA Astrophysics Data System (ADS)

Within the road pavement acceptance tests, destructive as well as non-destructive tests of individual road layers are performed to verify the standard requirements. The article describes a method for providing quick, effective and sufficiently accurate measurements of both dowel and tie bar positions in concrete pavements, using a two-channel ground penetrating radar (GPR). Measurements were carried out in laboratory and in-situ conditions. A special hand cart for field measurements, set for the testing requirements, was designed. It was verified that following the correct measuring and assessment method, it is possible to reach accuracy of determining the in-built rebar up to 1 cm in vertical direction and up to 1.5 cm per 11.5 m of measured length in horizontal direction. In the in-situ tests, GPR identification of possible anomalies due to the phase of concrete pavement laying was presented. In the conclusion, a measurement report is mentioned. The standard requirements for the position of dowels and tie bars cover maximum possible deviation of the rebar position from the project documentation in vertical and horizontal direction, maximum deflection of rebar ends to each other, and maximum translation of rebar in the direction of its longitudinal axis.

Stryk, Josef; Matula, Radek; Pospisil, Karel

2013-10-01

386

Application of Genetic Algorithm and Finite Element Method for backcalculating layer moduli of flexible pavements  

Microsoft Academic Search

The backcalculation program, GAPAVE, which uses the Genetic Algorithm (GA) and Finite Element Method (FEM), is developed to\\u000a predict the layer moduli from Falling Weight Deflectometer (FWD) deflections. The use of the FEM in the forward calculation\\u000a that incorporates the GA improves the accuracy in backcalculating the pavement layer moduli. The optimum GA parameters are\\u000a selected from sensitivity analysis for

Seong-Wan Park; Hee Mun Park; Jung-Joon Hwang

2010-01-01

387

Evaluation of the Performance of Cold-Mix Recycled Asphalt Concrete Pavement in Washington.  

National Technical Information Service (NTIS)

Often upgrading an aged asphalt concrete pavement involves overlaying a cracked pavement with new asphalt concrete. However, usually the substrate cracks reflect through the new overlay under repeated service loading. Full depth cold-mix recycled asphalt ...

K. Babaei J. P. Walter

1989-01-01

388

Pavement snow melting in Klamath Falls - rehabilitation of the ODOT Well  

SciTech Connect

This paper discusses the use of geothermal energy in pavement de-icing in Klamath Falls, Oregon. Due to a change in traffic routing in 1948, U.S. Highway 97 was routed with a new bridge and roadway through downtown Klamath Falls with an adverse 8 percent grade. Problems with traffic in winter led to the incorporation of a geothermal experiment in de-icing into the Oregon Department of Transportation (ODOT) construction project. The geothermal well was originally artesian, but the static water level has dropped over the years of usage, and the water temperatures at various depths have also dropped. Changes in city environmental regulations in 1985 have called for the elimination of all surface and sewer discharge from geothermal wells. Modifications to the existing pavement de-icing system which would bring it into compliance with the city ordinances are discussed in this paper.

Thurston, R.E. [Oregon Dept. of Transportation, Milwaukee, OR (United States); Culver, G.; Lund, J.W.

1995-02-01

389

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

390

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

391

Relating full-scale pavement rutting to laboratory permanent deformation testing  

Microsoft Academic Search

The study concerns the full-scale testing of a low-volume road pavement using the heavy vehicle simulator (HVS-Nordic) and the complementary testing of the same materials in the laboratory, especially using a repeated load triaxial test. The objective of the study was to develop an analytical method of calculating the permanent deformations on the basis of the stresses calculated by a

L. Korkiala-Tanttu; A. Dawson

2007-01-01

392

Discrimination Between Different Types of Material in Track Reconstruction With a Gaussian-Sum Filter  

Microsoft Academic Search

In the context of track reconstruction, the description of the material in a detector is frequently a simplified version of the detailed description used in the simulation. In particular, complex structures of different types of materials are often approximated by simple layers consisting of a material with average properties. Multiple scattering is then usually modeled by a Gaussian distribution, and

Rudolf Frhwirth

2006-01-01

393

Iron(III) phosphates obtained by thermal treatment of the Tavorite-type FePO4·H2O material: structures and electrochemical properties in lithium batteries.  

PubMed

Thermal treatment of the Tavorite-type material FePO(4)·H(2)O leads to the formation of two crystallized iron phosphates, very similar in structure. Their structural description is proposed taking into account results obtained from complementary characterization tools (thermal analyses, diffraction, and spectroscopy). These structures are similar to that of the pristine material FePO(4)·H(2)O: iron atoms are distributed between the chains of corner-sharing FeO(6) octahedra observed in FePO(4)·H(2)O and the octahedra from the tunnels previously empty, in good agreement with the formation of a Fe(4/3)PO(4)(OH)-type phase. The formation of an extra disordered phase was also proposed. These samples obtained by thermal-treatment of FePO(4)·H(2)O also intercalate lithium ions through the reduction of Fe(3+) to Fe(2+) at an average voltage of ~2.6 V (vs Li(+)/Li), with a good cyclability and a reversible capacity around 120 mA h g(-1) (>160 mA h g(-1) during the first discharge). PMID:22329737

Marx, Nicolas; Bourgeois, Lydie; Carlier, Dany; Wattiaux, Alain; Suard, Emmanuelle; Le Cras, Frédéric; Croguennec, Laurence

2012-02-13

394

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

395

Alternative Materials for Sustainable Transportation.  

National Technical Information Service (NTIS)

A shortage of asphalt and polymers is creating opportunities for engineers to utilize alternative pavement materials. Three types of bio oil, untreated bio oil (UTB), treated bio oil (TB) and polymer-modified bio oil (PMB) were studied in this research. T...

J. Mills-Beale Q. Dai X. Yang Z. You

2012-01-01

396

Flexible pavement performance evaluation using deflection criteria  

NASA Astrophysics Data System (ADS)

Flexible pavement projects in Nebraska were monitored for dynamic deflections, roughness, and distress for six consecutive years. Present surface conditions were characterized and data for evaluating rehabilitation needs, including amount of overlay, were provided. Data were evaluated and factors were isolated for determining the structural adequacy of flexible pavements, evaluating existing pavement strength and soil subgrade conditions, and determining overlay thickness requirements. Terms for evaluating structural condition for pavement sufficiently ratings were developed and existing soil support value and subgrade strength province maps were evaluated.

Wedner, R. J.

1980-04-01

397

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

398

STUDY OF THE RUTTING RESISTANCE OF ASPHALT SURFACING MIXTURES  

Microsoft Academic Search

With the increase of traffic and heavy vehicles, bleeding and rutting of asphalt pavements are the most commonly observed forms of pavement distress on roads in China. There are many factors that can affect rutting. In this study, the influences of binder type, binder content, aggregate grading, temperature and loading are evaluated by means of a wheel tracking test. Three

YANG JUN; ZHAO HAIBIN; CHEN JUN; QIAN GUOCHAO; PAN WEIYU; YANG YIWEN

399

Deterioration of the volcanic kerb and pavement stones in a humid environment in the city centre of Izmir, Turkey  

NASA Astrophysics Data System (ADS)

?zmir is the third largest city in Turkey and has being the centre of art, culture, tourism and trade activities throughout the 5,000 years of its history. Natural stones brought from different parts of the world have been widely used for construction of the prestigious buildings, monuments and roads etc., in the past in the city. Renovation of the street pavements and public gathering areas in the city centre has been undertaken by the Metropolitan Municipality in 2000 and continued through the year of 2001. These renovation activities have mainly been carried out in the streets running parallel to the sea shore. Volcanic rocks brought from the Central Anatolia Ankara-Gölba?? (andesites) and Kayseri-?ncesu (tuffs) have been used in the renovation works. These rocks have shown extensive deteriorations within 4 years of their usage between 2001 and 2005 under the influence of different environmental factors. In this study, the deteriorations developed in the recently placed volcanic rocks used as kerb and pavement stones in the city centre of ?zmir in the light of their mineralogical, chemical, physical and mechanical properties, used locations and the environmental factors are presented.

Yavuz, A. B.

2006-11-01

400

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

401

Alternate/Modified Binders for Asphalt Airfield Pavements.  

National Technical Information Service (NTIS)

This report documents a laboratory-based research effort to determine the effects of asphalt modifiers and alternate binders on asphalt airfield pavements. The modified binders were tested to determine their potential for reducing pavement deformation dis...

G. L. Anderton

1990-01-01

402

Sustainable Pavement Maintenance Practices. Research Results Digest 365.  

National Technical Information Service (NTIS)

This synthesis reports on the state of the practice in sustainable pavement maintenance and preservation. It is concerned and directed at quantifying and understanding how pavement maintenance and preservation practices minimize environmental impacts. The...

2011-01-01

403

Guidance for M-E Pavement Design Implementation.  

National Technical Information Service (NTIS)

The Mechanistic-Empirical Pavement Design guide developed under the National Cooperative Highway Research Program represents a dramatic change in how both rigid and flexible pavements are analyzed and designed. Recognizing the limitations of the current d...

D. H. Timm K. P. Davis R. E. Turochy

2010-01-01

404

Pavement damage model incorporating vehicle dynamics and a 3D pavement surface  

Microsoft Academic Search

This paper proposes a mechanistic-empirical pavement damage model to predict changes in 3D road profiles due to dynamic axle loads. The traffic is represented by a fleet of quarter cars which allows for statistical variability in model parameters such as velocity, suspension stiffness, suspension damping, sprung mass, unsprung mass and tyre stiffness. The fleet model generates statistical distributions of dynamic

A. Taheri; E. J. OBrien; A. C. Collop

2012-01-01

405

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

406

Magnetic ejection of diamagnetic sub-millimeter grains observed by a chamber-type ?G generator orientated to identify material of a single particle  

NASA Astrophysics Data System (ADS)

A principle to identify the material of a single particle without destroying the sample is examined by an experiment in microgravity (?G). Such an identification is important as a first stage of analyzing various grains of primitive materials. The identification was based on diamagnetic susceptibility ?DIA obtained from translation of the grain induced by a magnetic field. When a grain is released in an area of a monotonously decreasing field under ?G conditions, it will be ejected in the direction of the field reduction; here, the area is occupied with diffused gas medium. The material identification of a primitive grain is possible by comparing the measured ?DIA with published values; an intrinsic ?DIA value is assigned to a material according to a molecular orbital model. We report here that the ejection is realized for sub-mm-sized crystals of various organic and inorganic materials. By developing a short drop shaft (?G duration ˜0.5 s), the proposed material identification can be easily performed in an ordinary chamber. Using conventional methods, ?DIA cannot be detected for a small sample of diameter below the level of a millimetre. The achieved result is a step to realize the identification of micron-sized grains that compose primitive materials.

Hisayoshi, K.; Uyeda, C.; Kuwada, K.; Mamiya, M.; Nagai, H.

2013-03-01

407

Molecular mechanisms controlling pavement cell shape in Arabidopsis leaves  

Microsoft Academic Search

Pavement cells have an interlocking jigsaw puzzle-shaped leaf surface pattern. Twenty-three genes involved in the pavement\\u000a cell morphogenesis were discovered until now. The mutations of these genes through various means lead to pavement cell shape\\u000a defects, such as loss or lack of interdigitation, the reduction of lobing, gaps between lobe and neck regions in pavement\\u000a cells, and distorted trichomes. These

Pingping Qian; Suiwen Hou; Guangqin Guo

2009-01-01

408

Relation Between PAHs and Coal-Tar-Based Pavement Sealant in Urban Environments (Invited)  

Microsoft Academic Search

Since 2003, coal-tar-based sealant products have come under increased scrutiny as a source of PAHs in urban environments. Sealant (or sealcoat) is the black, shiny substance often applied to asphalt pavement, in particular parking lots and driveways, for esthetic and maintenance purposes. Coal-tar-based sealant, one of the two primary pavement sealant types on the market, typically is 20-35 percent coal-tar

B. J. Mahler; P. C. van Metre

2010-01-01

409

A numerical model for flexible pavements rut depth evolution with time  

NASA Astrophysics Data System (ADS)

A simplified method has been developed for the finite elements modelling of flexible pavements rut depth evolution with time. This method is based on the shakedown theory established by Zarka for metallic structures. The yield surface of Drucker-Prager and the plastic potential of Von Mises have been used. The simplified method determines straightforwardly the purely elastic state or the elastic shakedown state or the plastic shakedown state. The calibration of the simplified method with two unbound granular materials for roads under repeated loads triaxial tests, is explained. Then, a finite elements modelling of a flexible pavement has been carried out. Calculations of 2D and 3D have been performed and rut depth evolutions with time are shown, which underline the capabilities of the model to take into account the accumulation of plastic strains along the loading cycles. Copyright

Allou, Fatima; Chazallon, Cyrille; Hornych, Pierre

2007-01-01

410

AutoPAVER: A software package for automated pavement evaluation  

NASA Astrophysics Data System (ADS)

This research developed a method that improves data collection and reduces data entry times for Pavement Condition Index (PCI) surveys for use with PAVER, a pavement maintenance management system. The method, AutoPAVER, is a microcomputer software package used to analyze pictures of pavement surfaces and to forward the resulting analysis to PAVER. The user works interactively with the system to identify and classify pavement distresses. Distress measurement and data entry are done on the computer.

Ginsberg, Mark D.; Shahin, M. Y.; Walther, Jeanette A.

1990-07-01

411

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

PubMed Central

Although there is now convincing evidence that the infectivity of human immunodeficiency virus type 1 (HIV-1) is increased by incorporation of host intercellular adhesion molecule 1 (ICAM-1) in budding virions, the exact mechanism(s) through which ICAM-1 can so significantly affect HIV-1 biology remains obscure. To address this question, we focused our attention on the most proximal events in the virus life cycle. We made comparative analyses to estimate attachment and internalization of isogenic HIV-1 particles either lacking or bearing host-derived ICAM-1. Using attachment-and-entry assays and confocal fluorescence microscopy, we found that virus binding and uptake were both markedly enhanced by insertion of ICAM-1 within the virus envelope when PM1 lymphoid cells and primary human cells (i.e., peripheral blood lymphocytes and purified CD4+ T cells) were used as targets. Moreover, ICAM-1-bearing virions entered cells with faster uptake kinetics than viruses devoid of ICAM-1. Experiments conducted with fully competent viruses further confirmed the positive effect of virion-anchored host ICAM-1 on HIV-1 replication. Interestingly, subcellular-fractionation assays revealed that ICAM-1 incorporation modifies the HIV-1 entry route by increasing the level of viral material released in the cytosol, a process of internalization known to be mediated mainly by pH-independent membrane fusion and to result in productive infection. A virion-based fusion assay confirmed that the acquisition of ICAM-1 increases the efficiency of productive HIV-1 entry in primary CD4+ T lymphocytes. These observations provide new insights into how interactions other than those with gp120 and CD4-coreceptor complex can modulate the process of productive HIV-1 infection in CD4+ T lymphocytes, a cell target highly relevant to HIV-1 pathogenesis.

Tardif, Melanie R.; Tremblay, Michel J.

2003-01-01

412

Effect of Myrothecium sp. cellulase on different types of cellulose and cellulosic materials  

Microsoft Academic Search

Three types of cellulase preparations were applied to different types of cellulose and cellulosic materials. The action of\\u000a these types of cellulase on cellulose powder was increased with the increase of enzyme concentration. Both carboxymethyl cellulose\\u000a (CMC) and sodium carboxymethyl cellulose (Na-CMC) released high amounts of reducing sugar as affected by cellulase application.\\u000a Different types of paper pulp were moderately

E. A. Kassim

1983-01-01

413

Full-Cost Approach to Airport Pavement Management  

Microsoft Academic Search

Airport pavements are a key element of the commercial airport infrastructure that often are taken for granted. The current Federal Aviation Administration (FAA) endorsed pavement management system developed in the 1970's does not meet the needs of U. S. commercial service airports because it ignores all modes of pavement failure other than surface distress. Not only is it a time

Robert Harrison

414

A statistical analysis of circumstellar material in Type Ia supernovae  

NASA Astrophysics Data System (ADS)

A key tracer of the elusive progenitor systems of Type Ia supernovae (SNe Ia) is the detection of narrow blueshifted time-varying Na I D absorption lines, interpreted as evidence of circumstellar material surrounding the progenitor system. The origin of this material is controversial, but the simplest explanation is that it results from previous mass-loss in a system containing a white dwarf and a non-degenerate companion star. We present new single-epoch intermediate-resolution spectra of 17 low-redshift SNe Ia taken with XShooter on the European Southern Observatory Very Large Telescope. Combining this sample with events from the literature, we confirm an excess (˜20 per cent) of SNe Ia displaying blueshifted narrow Na I D absorption features compared to redshifted Na I D features. The host galaxies of SNe Ia displaying blueshifted absorption profiles are skewed towards later-type galaxies, compared to SNe Ia that show no Na I D absorption and SNe Ia displaying blueshifted narrow Na I D absorption features have broader light curves. The strength of the Na I D absorption is stronger in SNe Ia displaying blueshifted Na I D absorption features than those without blueshifted features, and the strength of the blueshifted Na I D is correlated with the B - V colour of the SN at maximum light. This strongly suggests the absorbing material is local to the SN. In the context of the progenitor systems of SNe Ia, we discuss the significance of these findings and other recent observational evidence on the nature of SN Ia progenitors. We present a summary that suggests that there are at least two distinct populations of normal, cosmologically useful SNe Ia.

Maguire, K.; Sullivan, M.; Patat, F.; Gal-Yam, A.; Hook, I. M.; Dhawan, S.; Howell, D. A.; Mazzali, P.; Nugent, P. E.; Pan, Y.-C.; Podsiadlowski, P.; Simon, J. D.; Sternberg, A.; Valenti, S.; Baltay, C.; Bersier, D.; Blagorodnova, N.; Chen, T.-W.; Ellman, N.; Feindt, U.; Förster, F.; Fraser, M.; González-Gaitán, S.; Graham, M. L.; Gutiérrez, C.; Hachinger, S.; Hadjiyska, E.; Inserra, C.; Knapic, C.; Laher, R. R.; Leloudas, G.; Margheim, S.; McKinnon, R.; Molinaro, M.; Morrell, N.; Ofek, E. O.; Rabinowitz, D.; Rest, A.; Sand, D.; Smareglia, R.; Smartt, S. J.; Taddia, F.; Walker, E. S.; Walton, N. A.; Young, D. R.

2013-09-01

415

A statistical analysis of circumstellar material in Type Ia supernovae  

NASA Astrophysics Data System (ADS)

A key tracer of the elusive progenitor systems of Type Ia supernovae (SNe Ia) is the detection of narrow blueshifted time-varying Na I D absorption lines, interpreted as evidence of circumstellar material surrounding the progenitor system. The origin of this material is controversial, but the simplest explanation is that it results from previous mass-loss in a system containing a white dwarf and a non-degenerate companion star. We present new single-epoch intermediate-resolution spectra of 17 low-redshift SNe Ia taken with XShooter on the European Southern Observatory Very Large Telescope. Combining this sample with events from the literature, we confirm an excess (˜20 per cent) of SNe Ia displaying blueshifted narrow Na I D absorption features compared to redshifted Na I D features. The host galaxies of SNe Ia displaying blueshifted absorption profiles are skewed towards later-type galaxies, compared to SNe Ia that show no Na I D absorption and SNe Ia displaying blueshifted narrow Na I D absorption features have broader light curves. The strength of the Na I D absorption is stronger in SNe Ia displaying blueshifted Na I D absorption features than those without blueshifted features, and the strength of the blueshifted Na I D is correlated with the B - V colour of the SN at maximum light. This strongly suggests the absorbing material is local to the SN. In the context of the progenitor systems of SNe Ia, we discuss the significance of these findings and other recent observational evidence on the nature of SN Ia progenitors. We present a summary that suggests that there are at least two distinct populations of normal, cosmologically useful SNe Ia.

Maguire, K.; Sullivan, M.; Patat, F.; Gal-Yam, A.; Hook, I. M.; Dhawan, S.; Howell, D. A.; Mazzali, P.; Nugent, P. E.; Pan, Y.-C.; Podsiadlowski, P.; Simon, J. D.; Sternberg, A.; Valenti, S.; Baltay, C.; Bersier, D.; Blagorodnova, N.; Chen, T.-W.; Ellman, N.; Feindt, U.; Förster, F.; Fraser, M.; González-Gaitán, S.; Graham, M. L.; Gutiérrez, C.; Hachinger, S.; Hadjiyska, E.; Inserra, C.; Knapic, C.; Laher, R. R.; Leloudas, G.; Margheim, S.; McKinnon, R.; Molinaro, M.; Morrell, N.; Ofek, E. O.; Rabinowitz, D.; Rest, A.; Sand, D.; Smareglia, R.; Smartt, S. J.; Taddia, F.; Walker, E. S.; Walton, N. A.; Young, D. R.

2013-11-01

416

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

417

Solar-reflective coating as a cooling overlay for asphalt pavement  

NASA Astrophysics Data System (ADS)

Rutting is one of the most serious problems on asphalt pavements. Decrease the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, nano sized particles filled polymer composite was developed as an overlay to reflect the solar energy and decrease the surface temperature of asphalt pavements. The overlay was composed of acrylic or epoxy resin filled with nano TiO2 or nano TiNO2. The solar reflection of the nano particle filled polymers was tested and the results showed that solar reflection effectiveness of the epoxy/TiO2 composite reached the highest value. The results of outdoor temperature test indicate that the solar-reflective overlay could decrease the surface temperature of asphalt pavements about 10 °C when the pavement temperature is about 60 °C. Pavement skid resistance was also tested, which expressed by micro/macrotexture depth and the results of which showed that both matrix was qualified after coated with aggregates on the surface.

Wang, He; Xu, Geng; Feng, Decheng; Zhong, Jing; Xie, Ning

2011-11-01

418

A Laboratory Investigation of Cold-Mix Recycled Bituminous Pavements.  

National Technical Information Service (NTIS)

In this laboratory study, the effects of different factors on the properties of a cold-recycled asphalt mixture were investigated. The factors investigated were the amount and type of added binder, the amount of added moisture, the added virgin aggregate,...

M. Tia

1978-01-01

419

Pavement distress detection and severity analysis  

Microsoft Academic Search

Automatic recognition of road distresses has been an important research area since it reduces economic loses before cracks and potholes become too severe. Existing systems for automated pavement defect detection commonly require special devices such as lights, lasers, etc, which dramatically increase the cost and limit the system to certain applications. Therefore, in this paper, a low cost automatic pavement

E. Salari; G. Bao

2011-01-01

420

Decision model in the laser scanning system for pavement crack detection  

NASA Astrophysics Data System (ADS)

Pavement crack detection plays an important role in the pavement maintaining and management. Recently, the laser scanning technique for pavement crack detection becomes more and more popular due to its ability of discriminating dark areas, which are not caused by pavement distress such as tire marks, oil spills, and shadows. However, this technique still bears some errors for pavement crack recognition errors, thus in the present work, the factors contributed to these errors in laser scanning system are first analyzed, and then a decision model for the laser scanning pavement crack detection system based on the hypothesis test is proposed. Experimental analyses and results show that this model not only allows us to build the relationship between the contribution factors and crack detection accuracy and to provide the criteria to compare the detection accuracy for the different roads, but also can be used to judge whether the crack exists with a reasonable number of deformed light stripes. Therefore, the proposed decision model can provide guidance on the pavement crack detection and has a practical value.

Sun, Xiaoming; Huang, Jianping; Liu, Wanyu

2011-12-01

421

Floatability of polymer materials modulated by frothers.  

PubMed

Flotation tests of 35 polymer materials were carried out to investigate their floatability modulated by frothers. Results of flotation tests demonstrated that polymer resins and soft PVC showed high floatability, floatability of hard PVC plastics was relatively low and was related to the frothers, and there exists significant difference in the floatability of different post-consumer plastics. Flotation rate of post-consumer plastics varies from 0% to 100%. Furthermore, three-category low-energy surface (LES) was defined based on the hydrophile index of the materials involved in this paper, and an adsorption model was proposed to explain the results of flotation and to discuss the floatability of polymer materials modulated by frothers. Frother molecules are prone to adsorb on the surface of bubble rather than LES at relatively low concentration, bubble adsorbed by frother molecules is prone to approach first-category LES rather than third-category LES, and the structure of liquid film is formed on the first-category LES at large concentration. Floatability of polymer materials modulated by frothers is further discussed: frothers increase the floatability of the first-category LES but decrease the floatability of the third-category LES, while the floatability of the second-category LES is related to the type of frothers. PMID:24084102

Wang, Hui; Wang, Chong-Qing; Fu, Jian-Gang

2013-09-29

422

Effect of skewed joints on the performance of jointed concrete pavement through 3D dynamic finite element analysis  

Microsoft Academic Search

The effect of skewing the transverse joints in concrete rigid pavements is studied through 3D finite element modelling. Models of multi-layered systems consisting of Portland cement concrete slabs, base and subgrade were developed. These consisted of slabs having straight as well as skewed joints. In order to study the state of stresses and strains in both straight and skewed slabs,

Mourad Y. Riad; Samir N. Shoukry; Gergis W. William; Michel R. Fahmy

2009-01-01

423

DNA-typing of cellular material on current conductors  

Microsoft Academic Search

The examination of deaths due to electricity may require a comparison between current marks on the body and the electrodes\\u000a suspected to have caused them. Normally the identification of the responsible electrode is carried out by analysing metal\\u000a traces on the current marks. We however examined the conductor for traces of biological material after experimentally produced\\u000a current marks. The surfaces

C. Ortmann; B. Rolf; G. Fechner

1998-01-01

424

Reduction of Minimum Required Weight of Cementitious Materials in WisDOT Concrete Mixes.  

National Technical Information Service (NTIS)

This project was designed to explore the feasibility of lowering the cementitious materials content (CMC) used in Wisconsin concrete pavement construction. The cementitious materials studied included portland cement, fly ash, and ground granulated blast f...

J. Anzalone K. Peterson L. Sutter

2011-01-01

425

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

426

Biofuel Co-Product Uses for Pavement Geo-Materials Stabilization.  

National Technical Information Service (NTIS)

The production and use of biofuels has increased in the present context of sustainable development. Biofuel production from plant biomass produces not only biofuel or ethanol but also co-products containing lignin, modified lignin, and lignin derivatives....

H. Ceylan K. Gopalakrishnan S. Kim

2010-01-01

427

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

428

Criteria for coal tar seal coats on airport pavements. Volume 1. State of the art. Final report  

SciTech Connect

Because coal tars are resistant to gasoline and jet fuel, they have been used for many years as a protective coating on asphalt pavement used for airport parking areas, ramps, taxiways and runways. Applications include both coal tar emulsions and rubberized coal tar emulsions, generally applied with sand added to provide skid resistance and stability to the seal coats. This report describes typical coal tar emulsion seal coat formulations and construction practices, and list major distress manifestations reported by agencies contacted in the first year of the study. Also described are the results of site visits to several airports where problems have been encountered,the results of limited laboratory test conducted by outside agencies, and the basic laboratory study being conducted as part of this research effort.

Shook, J.F.; Shannon, M.C.

1987-03-01

429

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

430

[Technology transfer of building materials by ECOMAT  

SciTech Connect

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

NONE

1996-01-01

431

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

Microsoft Academic Search

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

Melanie R. Tardif; Michel J. Tremblay

2003-01-01

432

Reflective Characteristics of Roadway Pavements during Wet Weather.  

National Technical Information Service (NTIS)

Roadway luminance is the preferred photometric basis for the design and evaluation of fixed lighting systems because it best represents the visual quality of brightness provided by lighting. The luminance of the roadway depends on the incident illuminatio...

M. Freedman L. E. Decina J. B. Nick E. I. Farber

1986-01-01

433

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

Microsoft Academic Search

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

Xinhua Wang; Simin Wang; Siwei Zhang; Deguo Wang

2008-01-01

434

Catalogue des Degradations des Revetements Hydrocarbones d'Ouvrages d'Art: Classification, Causes and Remedes (Catalogue of the Deterioration of Bituminous Pavements: Classification, Causes and Remedies).  

National Technical Information Service (NTIS)

The present report was initiated on the bases of both the information concerning the composition of the bridge pavements obtained through the bridge authorities in charge, and the visual inspection of about 500 bridges scattered throughout the whole Belgi...

C. de Backer

1984-01-01

435

Effect of Coarse-Aggregate Type on CRCP Thickness.  

National Technical Information Service (NTIS)

This study presents the development of thickness equivalencies between limestone and siliceous river gravel continuously reinforced concrete (CRC) pavements. A procedure to determine equivalent thicknesses when these two coarse-aggregate types are used is...

V. Torres-Verdin B. F. McCullough G. B. Peck

1983-01-01

436

Evaluating and Quantifying User Perception of Pavement Serviceability.  

National Technical Information Service (NTIS)

The overall objective of this investigation was to determine the validity of using physical measures of road roughness obtained by a Mays Road Meter as a surrogate of human responses in order to predict the user perception of ride quality or serviceabilit...

M. S. Janoff J. B. Nick

1983-01-01

437

Hei-way general purpose recycled asphalt material (RHM). Final report  

SciTech Connect

Utilization of Reclaimed Asphalt Pavement (RAP) in paving projects is a popular concept. It conserves material and can often provide an economical alternative to using virgin materials. The research summarizes the utilization of about 8000 tons of RAP in a project in Armstrong County (SR 3011 and SR 3013) using a proprietary process by Heilman Pavement Specialities. The mix is called Recycled Heilman Mix (RHM), which is prepared using a proprietary blend of asphalt cement (AC-5) and a rejuvenator mixed with equal weights of RAP and virgin aggregates in a batch-type pugmill. A control mix was produced by using 9.6 gallons per ton of E-5 emulsion and a blend of equal weights of RAP and coarse aggregates. The construction of the two sites were completed in September 1988 without any significant problems. A three-wheeled roller, ballasted rubber-tired roller and a second 1-ton tandem roller was used for compaction. There were no significant construction problems. RHM performed well on this project. The method of recycling asphalt pavements appears to be viable. RHM is stockpileable. Although RHM was 40 to 50 percent more expensive on the project, the life cycle costs on larger projects can be more competitive, especially when the cost of a seal coat is either avoided or delayed on RHM jobs when compared to E-5 mixes as control.

Dash, U.

1993-02-01

438

EVALUATION OF LOW TEMPERATURE CRACKING IN ASPHALT PAVEMENT MIXES  

Microsoft Academic Search

October 1998 , This report has been prepared with funds provided by the United States Department of Transportation to the Mountain-Plains Consortium (MPC). The MPC member,universities include North Dakota State University, Colorado State University, University of Wyoming, and Utah State University. The authors would like to express their appreciation to Dr. Anderson-Sprecher for helping with the statistical analysis and Dr.

Khaled Ksaibati; Ryan Erickson

439

Progress in the optimization of n-type and p-type SiGe thermoelectric materials  

NASA Astrophysics Data System (ADS)

A comprehensive experimental and theoretical work has been conducted in order to optimize the thermoelectric properties of Si80Ge20 materials and reach the goal of a combined figure of merit value of 0.85×10-3 K-1 averaged over 600-1000 C temperature range. Improvement for the n-type material have been obtained by determining the optimum amounts of gallium and phosphorus dopants necessary to achieve optimum carrier mobility and concentration. The emphasis is now on the good reproducibility of these results through understanding and control of the processing parameters relating microstructure and composition to the transport properties. The optimum doping level has now been firmly established for p-type materials, and work is concentrating on the reduction in thermal conductivity. BN ultra fine particles have been successfully incorporated into fully dense samples and have resulted in desired improvement of the figure of merit. Efforts are being made to reproduce these encouraging results.

Fleurial, Jean-Pierre; Vandersande, Jan; Scoville, Nancy; Bajgar, Clara; Beaty, John

1993-01-01

440

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

Microsoft Academic Search

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

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

2003-01-01

441

Mechanistic design concepts for conventional flexible pavements  

NASA Astrophysics Data System (ADS)

Mechanical design concepts for convetional flexible pavement (asphalt concrete (AC) surface plus granular base/subbase) for highways are proposed and validated. The procedure is based on ILLI-PAVE, a stress dependent finite element computer program, coupled with appropriate transfer functions. Two design criteria are considered: AC flexural fatigue cracking and subgrade rutting. Algorithms were developed relating pavement response parameters (stresses, strains, deflections) to AC thickness, AC moduli, granular layer thickness, and subgrade moduli. Extensive analyses of the AASHO Road Test flexible pavement data are presented supporting the validity of the proposed concepts.

Elliott, R. P.; Thompson, M. R.

1985-02-01

442

Microcomputer Analysis for Project Level PMS Life Cycle Cost Studies for Rigid Pavements. Volume 2. Overview of Program LCCLP-R.  

National Technical Information Service (NTIS)

The report presents a design analysis microcomputer program dealing with the project level Life Cycle Cost analysis for rigid pavements (LCCPR). The solution is based upon the costs associated with design, maintenance and rehabilitation of rigid and compo...

M. W. Witczak M. W. Mirza

1992-01-01

443

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

444

Development of Computer Modeling for Prediction of Temperature Distribution Inside Concrete Pavements.  

National Technical Information Service (NTIS)

Computer models are developed for predicting temperature in concrete pavements and rainwater infiltration into soil and subgrades due to weather changes. The models use an implicit finite-difference scheme which employs spatial factorization to implement ...

C. K. Hsieh C. Qin E. E. Ryder

1989-01-01

445

Evaluation of IDOT's Current Underdrain Systems.  

National Technical Information Service (NTIS)

The use of pavement underdrains became common practice in Illinois following the insurance of a Department underdrain policy in December 1970. Since that time, a variety of materials have been incorporated as underdrains. Concerns were raised in part by t...

J. B. DuBose

1995-01-01

446

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.

Asikainen, Celeste A.; Werle, Sean F.

2007-01-01

447

The Effects of Desert Pavements (Gravel Mulch) on Soil Micro-Hydrology  

NASA Astrophysics Data System (ADS)

The effect of desert pavements (gravel mulch) on near surface soil micro-hydrology has been inadequately studied. Micro-hydrology in arid ecosystems occurs due to a daily non rainfall atmospheric water cycle, consisting of an input phase (dew, fog, vapour adsorption) and an evaporation phase. A winter comparative study between a bare soil (control) and gravel mulch using the automated microlysimeter approach was conducted in Stellenbosch, South Africa in 2008. Results showed that dew deposition and direct water vapour adsorption were significantly higher into bare soil compared to gravel mulch. In contrast, however, soil moisture from rain persists for a longer time under gravel mulch compared to bare soil. This result suggests that the greatest impact of gravel mulch on soil micro-hydrology is towards conserving moisture and could explain why the treatment is used in dry-land agriculture in Mediterranean regions.

Kaseke, K. F.; Mills, A. J.; Henschel, J.; Seely, M. K.; Esler, K.; Brown, R.

2012-05-01

448

A real-time 3D scanning system for pavement rutting and pothole detections  

NASA Astrophysics Data System (ADS)

Rutting and pothole are the common pavement distress problems that need to be timely inspected and repaired to ensure ride quality and safe traffic. This paper introduces a real-time, automated inspection system devoted for detecting these distress features using high-speed transverse scanning. The detection principle is based on the dynamic generation and characterization of 3D pavement profiles obtained from structured light measurements. The system implementation mainly involves three tasks: multi-view coplanar calibration, sub-pixel laser stripe location, and pavement distress recognition. The multi-view coplanar scheme was employed in the calibration procedure to increase the feature points and to make the points distributed across the field of view of the camera, which greatly improves the calibration precision. The laser stripe locating method was implemented in four steps: median filtering, coarse edge detection, fine edge adjusting, stripe curve mending and interpolation by cubic splines. The pavement distress recognition algorithms include line segment approximation of the profile, searching for the feature points, and parameters calculations. The parameter data of a curve segment between two feature points, such as width, depth and length, were used to differentiate rutting, pothole, and pothole under different constraints. The preliminary experiment results show that the system is capable of locating these pavement distresses, and meets the needs for real-time and accurate pavement inspection.

Li, Qingguang; Yao, Ming; Yao, Xun; Yu, Wurong; Xu, Bugao

2009-08-01

449

Numerical Modelling of Thin Pavements Behaviour in Accelerated HVS Tests  

Microsoft Academic Search

Two thin road structures have been tested in accelerated testing by using a Heavy Vehicle Simulator (HVS). Both were surface dressed structures, one with a target 20 cm thick unbound base course layer and the other with the base divided into a 10 cm bitumen stabilized base over 10 cm unbound base. The tested road structures were instrumented to estimate

Sigurdur Erlingsson

2007-01-01

450

Development of Guidelines for Posting Load Limits on Pavements.  

National Technical Information Service (NTIS)

The purpose of the research was to develop rational guidelines for the posting of load limits. To evaluate the effect of axle loads under a variety of conditions, a theoretical analysis was conducted that considered various load magnitudes and configurati...

E. G. Fernando D. R. Luhr H. N. Saxena

1985-01-01

451

Sources, Measurement and Effects of Segregated Hot Mix Asphalt Pavement.  

National Technical Information Service (NTIS)

There are several factors that lead to segregation. Segregation can occur during stockpiling and handling of aggregate and during mixing storage, transport, and laydown of the asphalt mixture. Sometimes segregation may result from a single source or from ...

G. R. Duncan R. C. Williams T. D. White

1996-01-01

452

Use of Time Domain Reflectometers (TDRs) in Permeable Pavement Systems to Predict Maintenance Needs and Effectiveness  

EPA Science Inventory

As the surface in permeable pavement systems clogs, infiltration capacity decreases, so maintenance is required to maintain hydrologic performance. There is limited direct guidance for determining when maintenance is needed to prevent surface runoff bypass. Research is being co...

453

Comparative Field Study of Permastripe(Trademark) Polymer Concrete and Waterborne Airfield Pavement Markings.  

National Technical Information Service (NTIS)

The study reported herein compared polymer concrete pavement markings (Permastripe) to Federal specification waterborne airfield marking paint for field durability and retroreflectivity. The markings were placed at Tyndall Air Force Base (AFB) (hot, wet c...

B. Hudson D. Speidel J. K. Newman R. Boeger

2007-01-01

454

Automated Survey of Pavement Distress based on 2D and 3D Laser Images.  

National Technical Information Service (NTIS)

Despite numerous efforts in recent decades, currently most information on pavement surface distresses cannot be obtained automatically, at high-speed, and at acceptable precision and bias levels. This research provided seed funding to produce a functional...

K. Wang

2011-01-01

455

Influence of Three Permeable Pavement Surfaces on Nitrogen Treatment  

EPA Science Inventory

Nitrogen is a stressor of concern in many nutrient sensitive watersheds often associated with algal blooms and resulting fish kills. Communities are increasingly installing green infrastructure stormwater control measures (SCMs) to reduce pollutant loads associated with stormwat...

456

PERFORMANCE OF WATERBOUND MACADAM PAVEMENTS CONSTRUCTED LABOUR INTENSIVELY: CASE STUDY  

Microsoft Academic Search

Waterbound Macadam (WM) layers were used extensively during the first half of the previous century and have been reintroduced in the 1980's, focusing on re-engineering labour-intensive construction techniques during the 1990's. In 1994 and 1995 the former Johannesburg Transitional Metropolitan Council (TMC) in consultation with AFRICON and the University of the Witwatersrand constructed two pilot projects in Johannesburg with a

R. J. Moloisane; W. A. van Wyngaard

457

Nanoparticles-modified polymer-based solar-reflective coating as a cooling overlay for asphalt pavement  

Microsoft Academic Search

The phenomenon of rutting is one of the most serious problems on asphalt pavements. Decreasing the surface temperature of the asphalt pavement is an effective method to solve the rutting problem on asphalt pavements. In this study, a nano-sized-particles-filled polymer composite was developed as an overlay to reflect solar energy and decrease the surface temperature of asphalt pavements. The overlay

He Wang; Jing Zhong; Decheng Feng; Jing Meng; Ning Xie

2012-01-01

458

Evaluation of Selected Softening Agents Used in Flexible Pavement Recycling.  

National Technical Information Service (NTIS)

Twenty-three softening agents were tested for physical and chemical properties. The agents were very low in viscosity, which seemed to correspond to a low asphaltenes content. Four of these softening agents were selected for detailed evaluation on two pav...

D. I. Anderson D. E. Peterson M. L. Wiley W. B. Betenson

1978-01-01

459

Development of a Viscoelastic Finite Element Tool for Asphalt Pavement Low Temperature Cracking Analysis  

Microsoft Academic Search

This paper proposed and developed a tailored tool, “VE2D” for pavement low temperature cracking analysis based on viscoelastic two-dimensional (2D) finite element (FE) method. The tool can provide accurate thermal stress evaluation and thermal cracking prediction while considering the entire pavement structure rather than just the asphalt concrete layer. Also, this tool has four innovative features: Firstly, it incorporates the

Sheng Hu; Fujie Zhou; Lubinda F. Walubita

2009-01-01

460

SOURCE CONTROL FOR WATERSHED PROTECTION: PERMEABLE PAVEMENT TECHNOLOGY  

Microsoft Academic Search

Permeable pavement systems remain largely unutilised in the Auckland, New Zealand region as outstanding questions regarding performance benefit versus long term cost and maintenance obligations have yet to be answered under local conditions. In response, a comprehensive field monitoring study is currently being conducted by the University of Auckland in conjunction with the North Shore City Council, the Auckland Regional

Elizabeth A. Fassman; Sam Blackbourn

2007-01-01

461

Alternative modeling framework for pervious concrete pavement condition analysis  

Microsoft Academic Search

Pervious concrete pavement (PCP) is listed as one of the best stormwater management practices by the Environmental Protection Agency (EPA) due to its capacity to reduce impervious areas, capability to improve water quality, reduce runoff quantity, eliminate the need for detention basins, protect downstream channels, and reduce flooding (save lives and properties). Moreover, it is designated a “Green Asset” since

Amir Golroo; Susan L. Tighe

2011-01-01

462

Performance Assessment of Portland Cement Pervious Pavement. Report 3 of 4: Compressive Strength of Pervious Concrete Pavements.  

National Technical Information Service (NTIS)

The pervious concrete system and its corresponding strength are as important as its permeability characteristics. The strength of the system not only relies on the compressive strength of the pervious concrete but also on the strength of the soil beneath ...

A. M. Mulligan M. Chopra M. Wanielista

2006-01-01

463

Deterioration of insulating materials by internal discharge  

Microsoft Academic Search

Various round-robin tests have been made to investigate degradation phenomena of insulating materials by corona discharges which take place in a cavity inside specimens composed of three thin films adhered with each other. For specimens made of several kinds of materials such as polyethylene, ac voltages of 3 to 8 kV are applied under conditions of different frequencies and film

H. Okamoto; M. Kanazashi; T. Tanaka

1977-01-01

464

Aircraft Tire/Pavement Pressure Distribution.  

National Technical Information Service (NTIS)

This report presents tire/pavement pressure distributions calculated for seven different aircraft tires. The tires are main gear equipment on a variety of Air Force aircraft. The calculations were made with a finite element tire model developed previously...

J. T. Tielking

1989-01-01

465

Classification of Crystal Defects in Diamond-Type Material.  

National Technical Information Service (NTIS)

Investigations of native defects in diamond-type lattices were concentrated on two major subjects: (1) rigid-sphere geometry of interstitial sites in the diamond, sphalerite and wurtzite lattice, and (2) structural analysis of a typical low-energy grain b...

E. Sirtl O. Spindler

1982-01-01

466

Performance Assessment of Portland Cement Pervious Pavement. Report 2 of 4: Construction and Maintenance Assessment of Pervious Concrete Pavements.  

National Technical Information Service (NTIS)

The information of the report focused on the construction and maintenance activities for Portland cement pervious concrete as used in selected sites in Florida, Georgia, and South Carolina. Construction specifications were suggested for Portland cement pe...

C. Ballock J. Spence M. Chopra M. Wanielista

2007-01-01

467

Alternative aircraft loading index for pavement structural analysis  

SciTech Connect

The most common practical way to simplify the structural analysis of airfield pavements is the use of equivalent single wheel load models instead of the actual gear of the aircrafts. As the accuracy and reliability of these models strongly affects the design and evaluation of airfield pavements, there is considerable need to investigate both system approaches. The first one, which uses a constant value for the pressure while the radius is variable, is currently under use by the aircraft classification number-pavement classification number method of the International Civil Aviation Organization, but despite this fact it proved to be inadequate to express the aircraft loading in many situations. On the contrary, according to this study, the second model, which has a constant value for the radius while the pressure varies, is more reliable, and it can be an interesting alternative. Thus, based on this model, an aircraft loading index is introduced, which aims to be a simple and reliable factor for expressing the severity of the loading of the aircrafts and a utility for several matters related to the airfield pavement applications.

Loizos, A.; Charonitis, G. [National Technical Univ. of Athens (Greece)

1999-05-01

468

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

469

Investigation of Hydrated Lime-Asphalt and Aggregate interactions.  

National Technical Information Service (NTIS)

Serviceability of bituminous materials is a desirable asset in the design and construction of highway pavements. Some characteristics of asphalts - aggregates or their mixtures that have an effect on the useful service life of a highway pavement include: ...

B. H. Welch M. L. Wiley

1977-01-01

470

Staged heating by oxidation of carbonaceous material  

DOEpatents

A carbonaceous material is pyrolyzed in the presence of a particulate source of heat obtained by the partial oxidation of a carbon containing solid residue of the carbonaceous material. The heat obtained from the oxidation of the carbon containing solid residue is maximized by preheating the carbon containing solid residue with a hot gas stream obtained by oxidizing the gaseous combustion products of the carbon containing solid residue.

Knell, Everett W. (Los Alamitos, CA); Green, Norman W. (Upland, CA)

1978-01-31

471

MgSrSi-Type Compounds as a Possible New Family of Thermoelectric Materials  

NASA Astrophysics Data System (ADS)

We calculated electronic structures and transport properties of 33 Zintl phase compounds M1M2X (M1, M2 = Li, Na, Mg, K, Ca, Rb, Sr, Ba; X = Si, Ge, As, Se, Sn, Sb, Te, Pb, Bi) having orthorhombic MgSrSi-type (PbCl2-type) structure. These compounds were calculated to be narrow-gap semiconductors or semimetals. By comparison with known thermoelectric materials, our analysis showed that these compounds are promising candidate new thermoelectric materials, when heavily doped with holes or electrons. The weak chemical bonds and the variety in constituent elements indicate the possibility to achieve high thermoelectric figure of merit.

Katsura, Yukari; Takagi, Hidenori

2013-07-01

472

Joining of advanced materials by superplastic deformation  

DOEpatents

A method for utilizing superplastic deformation with or without a novel joint compound that leads to the joining of advanced ceramic materials, intermetallics, and cermets. A joint formed by this approach is as strong as or stronger than the materials joined. The method does not require elaborate surface preparation or application techniques.

Goretta, Kenneth C. (Downers Grove, IL); Routbort, Jules L. (Hinsdale, IL); Gutierrez-Mora, Felipe (Woodridge, IL)

2008-08-19

473

A Design Model for Geosynthetic-reinforced Pavements  

Microsoft Academic Search

The first paper to this companion series of articles [Perkins, S.W and Edens, M.Q. (2003) “Finite elements and distress models for geosynthetic-reinforced pavements”, International Journal of Pavement Engineering, 3(4), 239–250] described a finite element response model and empirical damage models that were combined to form a mechanistic–empirical (M–E) for geosynthetic-reinforced flexible pavement systems. The model provides predictions of an extension

S. W. Perkins; M. Q. Edens

2003-01-01

474

Covariance matrix adaptation evolution strategy for pavement backcalculation  

Microsoft Academic Search

The falling weight deflectometer (FWD) is the foremost and widely accepted tool for characterizing the deflection basins of pavements in a non-destructive manner. The FWD pavement deflection data are used to determine the in situ mechanical properties (elastic moduli) of the pavement layers through inverse analysis, a process commonly referred to as backcalculation (B\\/C). Several B\\/C methodologies have been proposed

Kasthurirangan Gopalakrishnan; Anshu Manik

2010-01-01

475

Framework for incorporating nondestructive evaluation (NDE) into pavement and bridge management systems  

NASA Astrophysics Data System (ADS)

One of the major components of an infrastructure management system is the condition assessment or deterioration modeling. With application to highway pavements and bridges, this paper presents conceptually how nondestructive evaluation (NDE) results can be utilized to provide a quantitative assessment of the infrastructure condition in a format usable for network-level pavement management systems and bridge management systems. NDE techniques typically applied to pavements include Visual Rating, Falling Weight Deflectometer, Dynaflect, Seismic Pavement Analyzer, and the Ground Penetrating Radar (GPR). Bridges can also be evaluated using the GPR. NDE is particularly useful at the network level of infrastructure management because of the mobility of conducting the tests. Detailed mechanistic methods have been suggested for NDE interpretation but this method may not be practical at network level. Interpretation of NDE results, through knowledge-based systems and intelligent databases indicate the defects and residual capacity of infrastructures. Measured physical properties and defects in the infrastructure component materials can be correlated to existing scales of condition assessment such as in the NBI and PONTIS formats for bridge management and also to an index or rating such as the PSI in highway pavements.

Sobanjo, John O.; Tawfiq, Kamal S.

1999-02-01

476

Study of Material Science by Neutron Scattering.  

National Technical Information Service (NTIS)

To develop accurate methods of texture measurement in metallic materials by neutron diffraction, (100),(200),(111) and (310) pole figures have been measured for the oriented silicon steel sheet, and currently study of correction methods for neutron absorp...

H. J. Kim B. K. Yoon B. C. Cheon C. Y. Lee C. S. Kim

1980-01-01

477

Use of Cement Kiln Dust for Subgrade Stabilization.  

National Technical Information Service (NTIS)

Poor subgrade soil conditions can result in inadequate pavement support and reduce pavement life. Soils may be improved through the addition of chemical or cementitious additives. These chemical additives range from waste products to manufactured material...

R. L. Parsons E. Kneebone J. P. Milburn

2004-01-01

478

Study of Material Science by Neutron Scattering.  

National Technical Information Service (NTIS)

To develop accurate methods of texture measurement in metallic materials by neutron diffraction, (100), (200), (111) and (310) pole figures were measured for the oriented silicon steel sheet. Correction methods for neutron absorption and extinction effect...

H. J. Kim B. K. Yoon B. C. Cheon C. Y. Lee C. S. Kim

1980-01-01

479

Determining the material type of man-made orbiting objects using low-resolution reflectance spectroscopy  

Microsoft Academic Search

The purpose of this research is to improve the knowledge of the physical properties of orbital debris, specifically the material type. Combining the use of the fast-tracking United States Air Force Research Laboratory (AFRL) telescopes with a common astronomical technique, spectroscopy, and NASA resources was a natural step toward determining the material type of orbiting objects remotely. Currently operating at

Kira Jorgensen; John L. Africano; Eugene G. Stansbery; Paul W. Kervin; Kris M. Hamada; Paul F. Sydney

2001-01-01

480

Analysis of Instrumentation Selection and Placement to Monitor the Hydrologic Performance of Permeable Pavement Systems and Bioinfiltration Areas at the Edison Environmental Center in New Jersey  

EPA Science Inventory

In 2009, the U.S. Environmental Protection Agency constructed a 0.4-ha (1-ac) parking lot surfaced with three different permeable pavement types (interlocking concrete pavers, porous concrete, and porous asphalt) and six bioinfiltration areas with three different drainage area to...