WorldWideScience

Sample records for bituminous pavements

  1. Development of New Bituminous Pavement Design Method

    DEFF Research Database (Denmark)

    Ullidtz, Per

    The report and work of COST Action 333 sets in place the foundation for a coherent, cost-effective and harmonised European pavement design method. In order to do this, the work programme focused on information gathering, identification of requirements and the selection of the necessary design...

  2. A study of bituminous pavements to determine a correlation between pavement structure designs and tripping of asphalt cement

    Science.gov (United States)

    Barton, B. R.

    1984-03-01

    After detecting a few cases of stripping of asphalt cement from the aggregate in bituminous pavement, there was concern that stripping might be a widespread problem in the state. It is agreed that water is the cause of stripping, and it was the opinion of some that pavements on granular bases would be less likely to strip because of supposedly better drainage characteristics. Differently designed pavement structures in all areas of the state were investigated to determine if there is a correlation between base and pavement design and stripping. Stripping was not as widespread as had been feared and there was less stripping in fulldepth bituminous base and pavement constructed over a lime-treated subgrade than in pavements constructed oer granular bases. This was contrary to what some had theorized.

  3. A Method to Estimate the Dynamic Displacement and Stress of a Multi-layered Pavement with Bituminous or Concrete Materials

    OpenAIRE

    LU, ZHENG; Yao, Hailin; Zhang, JingBo

    2014-01-01

    In this research work, a method to estimate the dynamic characteristics of a multilayered pavement with bituminous or concrete materials is proposed. A mechanical model is established to investigate the dynamic displacement and stress of the multi-layered pavement structure. Both the flexible and the rigid pavements, corresponding to bituminous materials and concrete materials, respectively, are studied. The theoretical solutions of the multi-layered pavement structure are deduced considering...

  4. Locating the Drainage Layer for Bituminous Pavements in Indiana

    OpenAIRE

    Hassan, Hossam Farouk.; White, Thomas D.

    1996-01-01

    Pavement subsurface drainage and its effect on pavement performance has been a subject of interest since the 18th and 19th centuries. With no doubt the detrimental effects of heavy wheel loads on pavements with saturated base material is a significant factor. The consequence of subsurface water on pavement performance includes premature rutting, cracking, faulting, and increased roughness, all of which lead to a decrease in serviceability. This research study involves the evaluation of the...

  5. A Method to Estimate the Dynamic Displacement and Stress of a Multi-layered Pavement with Bituminous or Concrete Materials

    Directory of Open Access Journals (Sweden)

    Zheng LU

    2014-12-01

    Full Text Available In this research work, a method to estimate the dynamic characteristics of a multilayered pavement with bituminous or concrete materials is proposed. A mechanical model is established to investigate the dynamic displacement and stress of the multi-layered pavement structure. Both the flexible and the rigid pavements, corresponding to bituminous materials and concrete materials, respectively, are studied. The theoretical solutions of the multi-layered pavement structure are deduced considering the compatibility condition at the interface of the structural layers. By introducing FFT (Fast Fourier Transform algorithm, some numerical results are presented. Comparisons of the theoretical and experimental result implied that the proposed method is reasonable in predicting the stress and displacement of a multi-layered pavement with bituminous or concrete materials. DOI: http://dx.doi.org/10.5755/j01.ms.20.4.6071

  6. Effect of thickness variation of bituminous layer in the structural responses of flexible pavements

    Directory of Open Access Journals (Sweden)

    Juliana Pavan Vidotto

    2014-05-01

    Full Text Available In this work, a sensitivity analysis was performed to investigate the effect of thickness variation of bituminous layer in the structural responses of flexible pavements and, therefore in performance. For this, it used traffic data from a weigh station located at Km 28 of the Immigrants Highway, at state of Sao Paulo, whose data collection was realized in 2008. The loads deriving from traffic were applied to the computational program ELSYM5 to obtain structural responses related to damage such as fatigue cracks and rutting. With these values, the damage factors were calculated and then the sensitivity analysis related to the thickness variation of bituminous layer was performed. Through the obtained results was concluded that the variation of thickness of bituminous layer have an influence on structural responses, and that damage factors related to fatigue cracks were more sensitive than those factors related to rutting.

  7. Characterization and modelling of self healing of bituminous materials towards durable asphalt pavement

    NARCIS (Netherlands)

    Qiu, J.; Van de Ven, M.F.C.; Schlangen, H.E.J.G.; Wu, S.; Molenaar, A.A.A.

    2012-01-01

    The traffic volume and the number of heavy vehicles are growing enormously nowadays. There is a need for designing a durable asphalt pavement with innovative technologies. Pavement structures and materials with self healing and self repairing capability are believed to be very useful in such a syste

  8. Crumb Rubber in cold recycled bituminous mixes

    DEFF Research Database (Denmark)

    Dondi, Giulio; Tataranni, Piergiorgio; Pettinari, Matteo;

    2014-01-01

    Today recycling is one of the most innovative and interesting techniques for the rehabilitation of destressed road pavements. In recent years the increased interest in this process, has led to the development of various alternative methods for the recovery and the reuse of road bituminous materials....... Cold recycling is, among the recycling techniques, certainly the most studied and developed: it allows the recovering of bituminous material from an existing pavement without the addition of heat, whilst ensuring the creation of high quality bound base layers. A wide range of materials have been tested...... together with Reclaimed Asphalt Pavement (RAP) and, consequently, there is a large number of variables that can be considered in the mix-design process of new eco-friendly Cold Recycled Mixes. In particular, the present research involves the use of Crumb Rubber within a mixture containing 100% Reclaimed...

  9. Discussion on Overlaying Bituminous Concrete Pavement on the Old Cement Concrete Pavement Construction%旧水泥混凝土路面加铺沥青混凝土面层施工探讨

    Institute of Scientific and Technical Information of China (English)

    何拥宁

    2011-01-01

    近年来,随着交通量的剧增和汽车轴载日益重型化,原有的水泥混凝土路面已经出现露骨、开裂、断板、沉陷、错台、破碎、板底脱空等路面损坏,影响了道路的使用功能,面临着修复工作.本文结合了工程实际,对"刚改柔"的施工方法进行了总结.%In recent years, with the sharp increase in traffic and more heavy-duty vehicle axle load, the original cement concrete pavement has emerged cracking, breaking boards, subsidence, dislocation, broken and plate bottom gap which affects the function of road and faced with repair work.Combined with engineering practice, the construction method of changing rigid to flexible is summarized.

  10. Skid resistance of bituminous surfaces in Ohio

    Science.gov (United States)

    Colony, D. C.

    1984-03-01

    Statistical studies of skid number (SN) on the state highway system in Ohio reveal apparently systematic variations in distributions of SN among the twelve districts in the state. These variations appear to be significantly related to traffic and to geological characteristics of a given district. Regression calculations using traffic index, a function of ADT and age of the pavement surface in months, show a high correlation with SN, although standard errors of estimate were too large to make the equations useful for predicting SN from traffic variables. Similar results were obtained by elating SN to physiographic features in the state. Pavement surface type (bituminous or pcc) and coarse aggregate type (limestone, gravel or slag) are significantly related to SN.

  11. Bituminization plant Jaslovske Bohunice

    International Nuclear Information System (INIS)

    In this leaflet the principle of the bituminization plant for radioactive concentrate (the intermediate liquid radioactive waste generated during the NPP A1, V-1, V-2 operations) solidification used in the Bohunice Radwaste Treatment Centre (BSC RAO) is presented

  12. 8th RILEM International Symposium on Testing and Characterization of Sustainable and Innovative Bituminous Materials

    CERN Document Server

    Partl, Manfred

    2016-01-01

    This work presents the results of RILEM TC 237-SIB (Testing and characterization of sustainable innovative bituminous materials and systems). The papers have been selected for publication after a rigorous peer review process and will be an invaluable source to outline and clarify the main directions of present and future research and standardization for bituminous materials and pavements. The following topics are covered: - Characterization of binder-aggregate interaction - Innovative testing of bituminous binders, additives and modifiers - Durability and aging of asphalt pavements - Mixture design and compaction analysis - Environmentally sustainable materials and technologies - Advances in laboratory characterization of bituminous materials - Modeling of road materials and pavement performance prediction - Field measurement and in-situ characterization - Innovative materials for reinforcement and interlayer systems - Cracking and damage characterization of asphalt pavements - Rec...

  13. Reuse of steel slag in bituminous paving mixtures.

    Science.gov (United States)

    Sorlini, Sabrina; Sanzeni, Alex; Rondi, Luca

    2012-03-30

    This paper presents a comprehensive study to evaluate the mechanical properties and environmental suitability of electric arc furnace (EAF) steel slag in bituminous paving mixtures. A variety of tests were executed on samples of EAF slag to characterize the physical, geometrical, mechanical and chemical properties as required by UNI EN specifications, focusing additionally on the volumetric expansion associated with hydration of free CaO and MgO. Five bituminous mixtures of aggregates for flexible road pavement were designed containing up to 40% of EAF slag and were tested to determine Marshall stability and indirect tensile strength. The leaching behaviour of slag samples and bituminous mixtures was evaluated according to the UNI EN leaching test. The tested slag showed satisfactory physical and mechanical properties and a release of pollutants generally below the limits set by the Italian code. Tests on volume stability of fresh materials confirmed that a period of 2-3 months is necessary to reduce effects of oxides hydration. The results of tests performed on bituminous mixtures with EAF slag were comparable with the performance of mixtures containing natural aggregates and the leaching tests provided satisfactory results. PMID:22305201

  14. Cold bituminous mixes

    OpenAIRE

    Delak, Boštjan

    2012-01-01

    Asphalt mix (short also asphalt) can be obtained from nature (natural asphalt) or produced technically (artificial asphalt), i. e. as a mix of bituminous binder, stone grain, and other additives that improve the asphalt properties. The beginnings of the use of asphalt can be traced from 6,000 to 4,000 BC since people back then knew some materials that contained bitumen as a binder. A more frequent use of the natural asphalt, however, starts around 3,000 BC. Different peoples used it primar...

  15. A Study on Overlay Design of Repeatedly Deteriorating Flexible Pavement

    Directory of Open Access Journals (Sweden)

    Mahendrakar Kiran Kumar

    2015-06-01

    Full Text Available A factor, which causes further concern in India, is very high and very low pavement temperature in some parts of the country. Under these conditions, flexible pavements tend to become soft in summer and brittle in winter. Further increase in road traffic during the last one decade with an unduly low level of maintenance has contributed to accelerated deterioration of road surfacing. To prevent this deterioration process, several types of measures may be adopted effectively such as improved design, use of high performance materials and effective construction technologies. Over the last two decades, traffic volume and the percentage of heavy truck traffic have increased enormously on the National High Way No 18. This pavement is a Flexible pavement with bituminous surfacing. The high traffic intensity in terms of commercial vehicles, overloading of axles and significant variations in daily and seasonal temperature of the pavement have been always responsible for early development of distress symptoms like undulations, rutting, cracking, bleeding, raveling, shoving and potholing of bituminous surfacing.

  16. Pavement Subgrade Performance Study

    DEFF Research Database (Denmark)

    Zhang, Wei; Ullidtz, Per; Macdonald, Robin

    1998-01-01

    The report describes the second test in the Danish Road Testing Machine (RTM) under the International Pavement Subgrade Performance Study. Pavement response was measured in different layers, and compared to different theroretical values. Performance in terms of plastic strains, rutting...

  17. Permeable pavement study (Edison)

    Data.gov (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  18. Vehicle-Pavement Interaction

    OpenAIRE

    Khavassefat, Parisa

    2014-01-01

    Several aspects of vehicle-pavement interaction have been studied and discussed in this thesis. Initially the pavement response is studied through a quasi-static and a dynamic computationally efficient framework under moving traffic loads. Subsequently, a non-stationary stochastic solution has been developed in order to account for the effect of pavement surface deterioration on pavement service life.The quasi-static procedure is based on a superposition principle and is computationally favou...

  19. Noise Reduction Properties of an Experimental Bituminous Slurry with Crumb Rubber Incorporated by the Dry Process

    Directory of Open Access Journals (Sweden)

    Moisés Bueno

    2014-08-01

    Full Text Available Nowadays, cold technology for asphalt pavement in the field of road construction is considered as an alternative solution to conventional procedures from both an economic and environmental point of view. Among these techniques, bituminous slurry surfacing is obtaining an important role due to the properties of the obtained wearing course. The functional performance of this type of surfaces is directly related to its rough texture. Nevertheless, this parameter has a significant influence on the tire/road noise generation. To reduce this undesirable effect on the sound performance, new designs of elastic bituminous slurries have been developed. Within the FENIX project, this work presents the acoustical characterization of an experimental bituminous slurry with crumb rubber from wasted automobile tires incorporated by the dry process. The obtained results show that, under controlled operational parameters, the close proximity sound levels associated to the experimental slurry are considerably lower than those emitted by a conventional slurry wearing course. However, after one year of supporting traffic loads and different weather conditions, the evaluated bituminous slurry, although it conserves the original noise reduction properties in relation to the conventional one, noticeably increases the generated sound emission. Therefore, it is required to continue improving the design of experimental surfaces in order to enhance its long-term performance.

  20. Pavement Testing Facility

    Data.gov (United States)

    Federal Laboratory Consortium — Comprehensive Environmental and Structural Analyses The ERDC Pavement Testing Facility, located on the ERDC Vicksburg campus, was originally constructed to provide...

  1. Layered pavement systems

    Science.gov (United States)

    Numerous aspects of the mechanical and structural response of layered pavement systems are discussed. Subgrade moduli for soil that exhibits nonlinear behavior are predicted. The use of a pressure meter test to predict modulus is discussed. Load equivalency factors of triaxial loading for flexible pavements is discussed, as well as a constitutive equation for the permanent strain of sand subjected to cyclic loading.

  2. Asphalt in Pavement Maintenance.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

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

  3. Precast concrete pavements

    Science.gov (United States)

    Rollings, R. S.; Chou, Y. T.

    1981-11-01

    This report reviewed published literature on precast concrete pavements and found that precast concrete pavements have had some limited application in airfields, roads, and storage areas. This review of past experience and an analytical study of precast slabs concluded that existing design and construction techniques can be adapted for use with precast concrete pavements, but more work is needed to develop effective and easily constructed load transfer designs for slab joints. Precast concrete does not offer any advantage for conventional pavements due to its high cost and surface roughness, but it may find applications for special problems such as construction in adverse weather, subgrade settlement, temporary pavements that need to be relocated, and military operations.

  4. Asphalt pavement temperature prediction

    OpenAIRE

    Minhoto, Manuel; Pais, Jorge; Pereira, Paulo

    2006-01-01

    A 3-D finite element model (FEM) was developed to calculate the lemperature of an asphtalt rubber pavement localed in the Northeast of Portugal. The goal of the case study presented in this paper is to show the good accuracy temperature prediction tha can be obtained with this model when compared with the field pavement thermal condition obtained during a year. lnput data to the model are the hourly values for solar radiation and temperature and the mean daily value of wind speed obtained fr...

  5. DRAINAGE AND FLEXIBLE PAVEMENT PERFORMANCE

    Directory of Open Access Journals (Sweden)

    SIDDHARTHA ROKADE

    2012-04-01

    Full Text Available Providing adequate drainage to a pavement system has been considered as an important design consideration to prevent premature failures due to water related problems such as pumping action, loss of support, and rutting, among others. Most water in pavements is due to rainfall infiltration into unsaturated pavement layers, throughjoints, cracks, shoulder edges, and various other defects, especially in older deteriorated pavements. Water also seep upward from a high groundwater table due to capillary suction or vapour movements, or it may flow laterally from the pavement edges and side ditches. Providing adequate drainage to a pavement system has been considered as an important design consideration to ensure satisfactory performance of the pavement, particularly from the perspective of life cycle cost and serviceability. To minimize premature pavement distresses and to enhance the pavement performance, it is imperative to provide adequate drainage to allow infiltrated water to drain out from the base and sub-base, thus avoiding saturation of base and subgrade soils. This paper deals with the analysis of the impact of subsurface drainage on pavement system performance. The requirement ofeffective subsurface drainage for pavement performance is also discussed.

  6. Evaluation of a highway pavement using non destructive tests: Falling Weight Deflectometer and Ground Penetrating Radar

    Science.gov (United States)

    Marecos, Vania; Fontul, Simona; de Lurdes Antunes, Maria

    2015-04-01

    This paper presents the results of the application of Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) to assess the bearing capacity of a rehabilitated flexible highway pavement that began to show the occurrence of cracks in the surface layer, about one year after the improvement works. A visual inspection of the surface of the pavement was performed to identify and characterize the cracks. Several core drills were done to analyse the cracks propagation in depth, these cores were also used for GPR data calibration. From the visual inspection it was concluded that the development of the cracks were top-down and that the cracks were located predominantly in the wheel paths. To determine the thickness of the bituminous and granular layers GPR tests were carried out using two horn antennas of 1,0 GHz and 1,8 GHz and a radar control unit SIR-20, both from GSSI. FWD load tests were performed on the wheel paths and structural models were established, based on the deflections measured, through back calculation. The deformation modulus of the layers was calculated and the bearing capacity of the pavement was determined. Summing up, within this study the GPR was used to continuously detect the layer thickness and the GPR survey data was calibrated with core drills. The results showed variations in the bituminous layer thickness in comparison to project data. From the load tests it was concluded that the deformation modulus of the bituminous layers were also vary variable. Limitations on the pavement bearing capacity were detected in the areas with the lower deformation modulus. This abstract is of interest for COST Action TU1208 Civil Engineering Applications of Ground Penetrating Radar.

  7. Permeable Pavements at Purdue

    OpenAIRE

    Knapp, Jim

    2013-01-01

    Two case studies will be presented describing sustainable drainage alternatives. The processes used for the 2nd Street project in Seymour will provide a comparison of the design processes for conventional and green infrastructure solutions. Purdue University will discuss a number of permeable pavement installations on campus and provide a map for viewing. Asphalt, concrete, and permeable paver options will be discussed.

  8. Pervious Pavement System Evaluation

    Science.gov (United States)

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

  9. Comparative Study on Pavement Temperature Features of Bridge Deck and Road Pavement

    OpenAIRE

    Yueqin Hou; Nanxiang Zheng; Yiluo Zhang

    2013-01-01

    The objective of this study was to comparatively analyze the difference of pavement temperature of bride deck and road pavement. The asphalt pavement temperature of road pavement and bride deck were tested in Guozigou area of Xinjiang, China. And the air temperature, wind speed, humidness and sunlight radiation were collected. Further, the distribution features of asphalt pavement of bridge deck and road pavement were comparatively analyzed. At last, the predictive model of pavement temperatu...

  10. Time dependent viscoelastic rheological response of pure, modified and synthetic bituminous binders

    Science.gov (United States)

    Airey, G. D.; Grenfell, J. R. A.; Apeagyei, A.; Subhy, A.; Lo Presti, D.

    2016-08-01

    Bitumen is a viscoelastic material that exhibits both elastic and viscous components of response and displays both a temperature and time dependent relationship between applied stresses and resultant strains. In addition, as bitumen is responsible for the viscoelastic behaviour of all bituminous materials, it plays a dominant role in defining many of the aspects of asphalt road performance, such as strength and stiffness, permanent deformation and cracking. Although conventional bituminous materials perform satisfactorily in most highway pavement applications, there are situations that require the modification of the binder to enhance the properties of existing asphalt material. The best known form of modification is by means of polymer modification, traditionally used to improve the temperature and time susceptibility of bitumen. Tyre rubber modification is another form using recycled crumb tyre rubber to alter the properties of conventional bitumen. In addition, alternative binders (synthetic polymeric binders as well as renewable, environmental-friendly bio-binders) have entered the bitumen market over the last few years due to concerns over the continued availability of bitumen from current crudes and refinery processes. This paper provides a detailed rheological assessment, under both temperature and time regimes, of a range of conventional, modified and alternative binders in terms of the materials dynamic (oscillatory) viscoelastic response. The rheological results show the improved viscoelastic properties of polymer- and rubber-modified binders in terms of increased complex shear modulus and elastic response, particularly at high temperatures and low frequencies. The synthetic binders were found to demonstrate complex rheological behaviour relative to that seen for conventional bituminous binders.

  11. Time dependent viscoelastic rheological response of pure, modified and synthetic bituminous binders

    Science.gov (United States)

    Airey, G. D.; Grenfell, J. R. A.; Apeagyei, A.; Subhy, A.; Lo Presti, D.

    2016-04-01

    Bitumen is a viscoelastic material that exhibits both elastic and viscous components of response and displays both a temperature and time dependent relationship between applied stresses and resultant strains. In addition, as bitumen is responsible for the viscoelastic behaviour of all bituminous materials, it plays a dominant role in defining many of the aspects of asphalt road performance, such as strength and stiffness, permanent deformation and cracking. Although conventional bituminous materials perform satisfactorily in most highway pavement applications, there are situations that require the modification of the binder to enhance the properties of existing asphalt material. The best known form of modification is by means of polymer modification, traditionally used to improve the temperature and time susceptibility of bitumen. Tyre rubber modification is another form using recycled crumb tyre rubber to alter the properties of conventional bitumen. In addition, alternative binders (synthetic polymeric binders as well as renewable, environmental-friendly bio-binders) have entered the bitumen market over the last few years due to concerns over the continued availability of bitumen from current crudes and refinery processes. This paper provides a detailed rheological assessment, under both temperature and time regimes, of a range of conventional, modified and alternative binders in terms of the materials dynamic (oscillatory) viscoelastic response. The rheological results show the improved viscoelastic properties of polymer- and rubber-modified binders in terms of increased complex shear modulus and elastic response, particularly at high temperatures and low frequencies. The synthetic binders were found to demonstrate complex rheological behaviour relative to that seen for conventional bituminous binders.

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

    Science.gov (United States)

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

    2014-01-01

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

  13. Effects of using silica fume and polycarboxylate-type superplasticizer on physical properties of cementitious grout mixtures for semiflexible pavement surfacing.

    Science.gov (United States)

    Koting, Suhana; Karim, Mohamed Rehan; Mahmud, Hilmi; Mashaan, Nuha S; Ibrahim, Mohd Rasdan; Katman, Herdayati; Husain, Nadiah Md

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Suhana Koting

    2014-01-01

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

  15. Geotextiles in Flexible Pavement Construction

    Science.gov (United States)

    Alungbe, Gabriel D.

    2004-01-01

    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…

  16. Pavement roughness and skid properties

    Science.gov (United States)

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

  17. Procedures and Technologies for Pavement Monitoring

    OpenAIRE

    GEORGE, Luc Amaury; Brosseaud, Yves

    2009-01-01

    Pavement Monitoring (surface and structure). Surface characteristics - main indicators Pavement structures (non destructive testings). Monitoring objectives. Devices and indicators used in France Innovation & Research. Measurement's use by roads owners. Main road network (States & motorway concessionaires). Local and urban road networks. Some maintenance techniques. High modulus mixtures and very thin mixtures. Pavement in situ recycling Pavement in plan recycling. Low noise & coloured ...

  18. Response Modelling of Bitumen, Bituminous Mastic and Mortar

    NARCIS (Netherlands)

    Woldekidan, M.F.

    2011-01-01

    This research focuses on testing and modelling the viscoelastic response of bituminous binders. The main goal is to find an appropriate response model for bituminous binders. The desired model should allow implementation into numerical environments such as ABAQUS. On the basis of such numerical envi

  19. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    OpenAIRE

    Andrzej Plewa; Marta Wasilewska; Władysław Gardziejczyk; Paweł Gierasimiuk

    2015-01-01

    The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%). One should notice the influence of RAP on the performance and ...

  20. Permanent deformation of flexible pavements

    Science.gov (United States)

    Brown, S. F.; Broderick, B. V.; Pappin, J. W.

    1980-06-01

    Seven pairs of pavements with granular bases were tested under controlled conditions. One pavement in each pair contained fabric inclusions. An improved testing facility was developed, including: (1) servo-hydraulic system for the loading carriage; (2) amplification and read-out system for pressure cells; (3) linearizing unit for strain coils; (4) transducers for measuring vertical and resilient deflection; (5) techniques for measuring in situ strain on fabric inclusions; (6) extensive use of nuclear density meter to monitor pavement and foundation materials. The following conclusions are drawn: (1) No improvement in performance resulted from fabric inclusions. (2) No consistent reduction in in-situ stresses, resilient strains, or permanent strains was observed as a result of fabric inclusion. (3) No consistent improvement in densities resulted from fabric inclusions. (4) Some slip apparently occurred between fabric and soil on those pavements which involved large deformations. The slip occurred between fabric and crushed limestone base rather than between fabric and silty-clay subgrade.

  1. Pervious Pavement System Evaluation- Abstract

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  2. Radon concentration measurements in bituminous coal mines

    International Nuclear Information System (INIS)

    Radon measurements were carried out in Kozlu, Karadon and Uezuelmez underground coal mines of Zonguldak bituminous coal basin in Turkey. Passive-time integrating method, which is the most widely used technique for the measurement of radon concentration in air, was applied by using nuclear etched track detectors (CR-39) in the study area. The radon concentration measurements were performed on a total of 42 points in those three mines. The annual exposure, the annual effective dose and lifetime fatality risk, which are the important parameters for the health of workers, were estimated based on chronic occupational exposure to the radon gas, which is calculated using UNCEAR-2000 and ICRP-65 models. The radon concentrations at several coal production faces are higher than the action level of 1000 Bq m-3. It is suggested that the ventilation rates should be rearranged to reduce the radon concentration. (authors)

  3. Radon concentration measurements in bituminous coal mines.

    Science.gov (United States)

    Fisne, Abdullah; Okten, Gündüz; Celebi, Nilgün

    2005-01-01

    Radon measurements were carried out in Kozlu, Karadon and Uzülmez underground coal mines of Zonguldak bituminous coal basin in Turkey. Passive-time integrating method, which is the most widely used technique for the measurement of radon concentration in air, was applied by using nuclear etched track detectors (CR-39) in the study area. The radon concentration measurements were performed on a total of 42 points in those three mines. The annual exposure, the annual effective dose and lifetime fatality risk, which are the important parameters for the health of workers, were estimated based on chronic occupational exposure to the radon gas, which is calculated using UNCEAR-2000 and ICRP-65 models. The radon concentrations at several coal production faces are higher than the action level of 1000 Bq m(-3). It is suggested that the ventilation rates should be rearranged to reduce the radon concentration.

  4. Quantifying Evaporation in a Permeable Pavement System

    Science.gov (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  5. Dynamic contracting mechanism for pavement maintenance management

    NARCIS (Netherlands)

    Demirel, H.C.; De Ridder, H.A.J.

    2013-01-01

    Technological advances, financial possibilities and changes of demands have increasingly affected the pavement maintenance environment for outsourcing in recent years. This induces complexity in the contracting methods of pavement maintenance activities. Despite the fact that current contracting pra

  6. Pervious Pavement System Evaluation-Poster

    Science.gov (United States)

    Pervious pavement is a low impact development stormwater control. The Environmental Protection Agency's Urban Watershed Management Branch is evaluating interlocking concrete pavingstone pervious pavement systems. The pavingstones themselves are impermeable, but the spaces between...

  7. Deformation Properties and Fatigue of Bituminous Mixtures

    Directory of Open Access Journals (Sweden)

    Frantisek Schlosser

    2013-01-01

    Full Text Available Deformation properties and fatigue performance are important characteristics of asphalt bound materials which are used for construction of pavement layers. Viscoelastic asphalt mixtures are better characterized via dynamic tests. This type of tests allows us to collate materials with regard to axle vibrations which lie usually in the range of 6 Hz–25 Hz for standard conditions. Asphalt modified for heat sensitivity in the range from −20°C to +60°C has significant impact on the overall characteristics of the mixture. Deformation properties are used as inputs for empirical mixture design, and fatigue performance of asphalt mixtures reflects the parameters of functional tests. Master curves convey properties of asphalt mixtures for various conditions and allow us to evaluate them without the need of time expensive testing.

  8. Recycling of asphalt pavements with asphalt rubber

    OpenAIRE

    Pais, Jorge; Pereira, Paulo; Minhoto, Manuel; Baptista, António

    2008-01-01

    Pavement recycling has been an important rehabilitation technique to deal with reclaimed materials from old pavements which are usually sent to landfills. The application of this technique contributes to: i) the accomplishment of the requirements defined by the European legislation for the amount of material sent to landfills; ii) the reduction in the use of new raw materials used to produce pavement layers. The reduction of materials to be used in pavement rehabilitation has also been possib...

  9. Mechanical properties of hot bituminous mixes manufactured with recycled aggregate of Silestone® waste

    Directory of Open Access Journals (Sweden)

    Rubio, M. C.

    2011-03-01

    Full Text Available This article presents the results of a research project which analyzes the viability of incorporating waste material from decorative quartz solid surfacing in the manufacture of hot bituminous mixes. For this purpose, various bituminous mixes were manufactured with waste aggregate in different percentage. A set of tests were carried out that permitted the characterization of the mechanical behavior of these mixes. The results of these tests were similar to the results obtained when conventional mixes made from virgin quarry aggregate were tested. The results for moisture sensitivity as well as for wheel track rutting on mixes showed the optimal performance of this waste material even under very demanding traffic conditions. Laboratory studies showed that the use of this waste material in the manufacture of bituminous mixes is technically viable and can provide high-quality recycled aggregates at a very low cost, which can be used in the pavement of road.

    Este artículo muestra los resultados de un proyecto de investigación que tiene por objeto analizar la viabilidad de incorporación de residuos procedentes de piedra decorativa en la fabricación de mezclas bituminosas en caliente. Para ello se fabricaron mezclas con áridos reciclados de residuos procedentes de piedra decorativa en distintos porcentajes, realizando un conjunto de ensayos que posibilitaron caracterizar el comportamiento mecánico de dichas mezclas. Los resultados obtenidos fueron similares a los de las mezclas convencionales fabricadas con áridos vírgenes procedentes de cantera. Los valores de resistencia conservada ante la acción del agua y deformación en pista, pusieron de manifiesto la aptitud del residuo incluso ante las condiciones de tráfico más exigentes. Los trabajos realizados en el laboratorio indican que la utilización del residuo en la fabricación de mezclas bituminosas es técnicamente viable, pudiendo obtenerse áridos reciclados de gran calidad y

  10. Long-term properties of bituminized waste products

    International Nuclear Information System (INIS)

    This study is a survey of the factors of importance for long term behaviour of bituminized ion exchange resins. Phenomena occurring in bituminized waste products affected by the treatment, storage and disposal are identified. Test methods have been developed for characterizing product properties, which are important for the long-term behaviour. The long-term properties of bituminized ion-exchange resins are studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are ralated to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product. (author)

  11. Long-term properties of bituminized waste products

    International Nuclear Information System (INIS)

    This study is a survey of the factors of importance for the long term behaviour of bituminized ion exchange resins. Phenomena occurring in bituminized waste products affected by the treatment, storage and disposal are identified. Test methods have been developed for characterizing product properties, which are important for the long-term behaviour. The long-term properties of bituminized ion-exchange resins are studied in a repository environment with access of water equilibrated with concrete. In these circumstances the most important properties are related to the interactions of bituminized waste with the surrounding barriers. The most important phenomena are water uptake due to rehydration of the resins and subsequent swelling of the product

  12. Development of non-standard equipment of bituminization line

    International Nuclear Information System (INIS)

    A brief description is presented of some components of the bituminization line developed at the Research Institute of Chemical Installations in Brno. The film rotor evaporator has an evaporation area of 2 m2. The mixing tank is the main technological assembly for processing loose materials, i.e., sorbents and fly ash which it mixes with melted bitumen. The screw conveyor with a three-way valve is designed for batching the dried radioactive sorbent and fly ash into mixing tanks. Attention is also devoted to certain systems of measurement and control of the bituminization line, namely to measurement of the level of the bituminization product, the flow rate of bituminization emulsion and the water-sorbent mixture and to the diagnostics of failure and accident conditions of the film rotor evaporator. (Z.M.)

  13. EXPERIMENTAL STUDY ON HORIZONTAL COMBUSTION TECHNIQUE FOR BITUMINOUS COAL BRIQUET

    Institute of Scientific and Technical Information of China (English)

    路春美; 程世庆; 邵延玲; 张晔

    1997-01-01

    Through a lot of experiments, a new kind of stove using horizontal combustion technique for bituminous coal briquet has been developed. Making use of this stove, studies have been made on burning process of bituminous coal briquet, distribution of temperature field in the stove, the regularities of evolution and combustion of volatile matter, the burning rate and efficiency of bituminous coal briquet, characteristics of fire-sealing and sulfur-retention. The results show that, with the technique, some achievements can be obtained in combustion of bituminous coal briquet, such as lower pollution that the flue gas black degree is below 0.5R and dust concentration is below 90mg/m3 . The stove's combustion efficiency reaches 90%, sulfur fixing efficiency is 60%, and CO concentration is decreased by 40% compared with other traditional stoves. With so many advantages, the stove can be used extensively in civil stoves and smaller industrial boilers.

  14. Bituminous and asphaltic membranes for radioactive waste repositories on land

    International Nuclear Information System (INIS)

    The aim of the study has been to identify, within generic designs for waste facilities, areas where bituminous materials might be incorporated as a barrier. The report is presented in three sections: Part I - The properties of bitumen are described, with particular reference to the long-term behaviour of the material. The durability of bitumen is discussed, including aspects such as ageing, microbial degradation, chemical resistance and radiation resistance. Part II -The use of bituminous materials in hydraulic engineering is outlined. Much of this section of the report concentrates on the use of bituminous materials in embankment dams and reservoir construction. A review of material technology and construction techniques is presented and a detailed assessment made of the performance of the materials in service. Part III - Generic trench type radioactive waste repository designs incorporating bituminous materials are presented. Material and construction specifications for the designs are detailed, and a performance assessment presented. (author)

  15. Effects of bituminous layer as backfill material on mechanical behavior in tunnel model

    OpenAIRE

    Moriyoshi, Akihiro; Takano, Shin-ei; Urata, Hiroyuki; Suzuki, Tetsuya; Yoshida, Takaki

    2001-01-01

    This paper describes the effects of bituminous material as a backfill material on mechanical behavior in model tunnel in laboratory. It is known that load spreading and relaxation of bituminous material are good properties. Then if we use bituminous material as a backfill material of tunnel, the tunnel will have waterproof, good load spreading property. We used new bituminous material (Aquaphalt) which can solidify in water. We conducted relaxation test in tension for new bituminous mat...

  16. USE OF RECLAIMED ASPHALT PAVEMENT WITH MILLED ROAD PAVEMENT LAYERS

    Directory of Open Access Journals (Sweden)

    Andrzej Plewa

    2015-07-01

    Full Text Available The article presents the results of research on the functional properties of asphalt mixes using RAP obtained from milling asphalt road pavements. Asphalt concrete AC 22P with 0%, 10%, 15% and 20% addition of RAP used for base course of road pavements were designed. It was found that asphalt mixes with RAP characterized by comparable and in some cases better functional properties compared to the asphalt mixes without RAP (0%. One should notice the influence of RAP on the performance and durability of the asphalt mixtures, as compared to virgin asphalt mixtures (without RAP.

  17. The bituminous sands : a Canadian mirage?

    Energy Technology Data Exchange (ETDEWEB)

    Rousse, D.R. [Quebec Univ., Chicoutimi, PQ (Canada). Dept. des Sciences Appliquees; Nasr, G.J. [Lebanese Univ., Roumieh (Lebanon). Faculty of Engineering; Turcotte, S.F. [Quebec Univ., Montreal, PQ (Canada). Centre d' Etudes Internationales et Mondialisation; Salah, N.B. [Ecole Superieure des Sciences et Techniques De Tunis, Tunis (Tunisia). LMMP

    2009-07-01

    This paper examined the controversy about the potential role of a significant increase in Canadian oil sands production in order to bridge the upcoming gap between the world's increasing energy demand and the total recoverable oil supply. The paper presented the actual potential of different scenarios and considered the prediction cost forecasts. A brief overview of environmental impacts and the real return on investments were also provided. Environmental impacts that were considered included land degradation; water contamination; ecosystem damage; and air pollution. Nuclear energy was also presented as a possible solution. The paper demonstrated that even in a very optimistic scenario, Canada's oil sands accelerated production has a negligible effect on the aforementioned gap, has a considerable impact on environment that has yet to be accounted for. Energy ratios that were presented included energy return on energy investment; energy available on energy used; and energy payback. It was concluded that enhanced recovery techniques are clearly needed for future sustainable exploitation of these bituminous sands. 32 refs., 1 fig.

  18. Recycling of polyethylene terephthalate (PET plastic bottle wastes in bituminous asphaltic concrete

    Directory of Open Access Journals (Sweden)

    Adebayo Olatunbosun Sojobi

    2016-12-01

    Full Text Available This research sheds light on the concept of eco-friendly road construction which comprises eco-design, eco-extraction, eco-manufacturing, eco-construction, eco-rehabilitation, eco-maintenance, eco-demolition, and socioeconomic empowerment. It also revealed the challenges being faced in its adoption and the benefits derivable from its application. Furthermore, the effects of recycling PET plastic bottle wastes produced in North Central Nigeria in bituminous asphaltic concrete (BAC used in flexible pavement construction were also evaluated. The mix design consists of 60/70 penetration-grade asphaltic concrete (5%, 68% coarse aggregate, 6% fine aggregate, and 21% filler using the dry process at 170°C. The optimum bitumen content (OBC for conventional BAC was obtained as 4% by weight of total aggregates and filler. Polymer-coated aggregate (PCA-modified BAC seems preferable because it has the potential to utilize more plastic wastes with a higher optimum plastic content (OPC of 16.7% by weight of total aggregates and filler compared to that of 9% by weight of OBC achieved by PMB-BAC. For both PMB- and PCA-modified BAC, an increase in air void, void in mineral aggregate, and Marshall stability were observed. Eco-friendly road construction which recycles PET wastes should be encouraged by government considering its potential environmental and economic benefits.

  19. Analysis and modeling of 3D complex modulus tests on hot and warm bituminous mixtures

    Science.gov (United States)

    Pham, Nguyen Hoang; Sauzéat, Cédric; Di Benedetto, Hervé; González-León, Juan A.; Barreto, Gilles; Nicolaï, Aurélia; Jakubowski, Marc

    2015-05-01

    This paper presents the results of laboratory testing of hot and warm bituminous mixtures containing Reclaimed Asphalt Pavement (RAP). Complex modulus measurements, using the tension-compression test on cylindrical specimens, were conducted to determine linear viscoelastic (LVE) behavior. Sinusoidal cyclic loadings, with strain amplitude of approximately 50ṡ10-6, were applied at several temperatures (from -25 to +45 °C) and frequencies (from 0.03 Hz to 10 Hz). In addition to axial stresses and strains, radial strains were also measured. The complex modulus E ∗ and complex Poisson's ratios ν ∗ were then obtained in two perpendicular directions. Measured values in these two directions do not indicate anisotropy on Poisson's ratio. The time-temperature superposition principle (TTSP) was verified with good approximation in one-dimensional (1D) and three-dimensional (3D) conditions for the same values of shift factor. Experimental results were modeled using the 2S2P1D model previously developed at the University of Lyon/ENTPE. In addition, specific analysis showed that eventual damage created during complex modulus test is very small and is equivalent to the effect of an increase of temperature of about 0.25 °C.

  20. Teaching Methodology of Flexible Pavement Materials and Pavement Systems

    Science.gov (United States)

    Mehta, Yusuf; Najafi, Fazil

    2004-01-01

    Flexible pavement materials exhibit complex mechanical behavior, in the sense, that they not only show stress and temperature dependency but also are sensitive to moisture conditions. This complex behavior presents a great challenge to the faculty in bringing across the level of complexity and providing the concepts needed to understand them. The…

  1. G4高速公路湖南耒宜段大修工程路面结构方案设计%Pavement Structure Design of LeiYi Expressway Overhaul Engineering

    Institute of Scientific and Technical Information of China (English)

    吴超凡; 黄治湘; 张继森

    2014-01-01

    This paper introduces the original variety of Leiyi Expressway pavement structure,traf-fic flow and pavement damage.According to the pavement structure specific,traffic flow and axle load disparity of the road,using a technical and economical comparison,the original continuous reinforced concrete pavement overlay asphalt concrete pavement structure,the original ordinary cement concrete and reinforced concrete pavement overlay continuously reinforced concrete composite pavement,milling and overlay single or bunk asphalt pavement layer on the original asphalt pavement,the original asphalt pave-ment overlay situ thermal regeneration after single and double bituminous surface layer structure.%介绍了耒宜高速公路原路面的多种路面结构与交通流量及路面损害情况,针对具体的路面结构与左右幅交通流量与轴载的悬殊差异,经技术经济比较,采用了在原连续配筋混凝土路面上直接加铺沥青混凝土路面结构;在原普通水泥混凝土与钢筋混凝土路面上加铺连续配筋混凝土复合式路面;在原沥青路面上进行铣刨加铺单层沥青面层与双层沥青面层、对原沥青路面进行就地热再生后加铺单层与双层沥青面层结构。

  2. Tuning in to pavement radio

    NARCIS (Netherlands)

    Ellis, S.D.K.

    1989-01-01

    This article describes a phenomenon known all over Africa, for which there is no really satisfactory term in English but which is summed up in the French term 'radio trottoir', literally 'pavement radio'. It may be defined as the popular and unofficial discussion of current affairs in Africa, partic

  3. The Concrete and Pavement Challenge

    Science.gov (United States)

    Roman, Harry T.

    2012-01-01

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

  4. Bituminization of low- and intermediate-level radioactive concentrates

    International Nuclear Information System (INIS)

    The results and experiences are summed up from the research and development of the technology of bituminization of low- and intermediate-level radioactive concentrates generated in the operation of nuclear power plants with WWER-440 reactors. The experiments took place on a pilot plant bituminization line with various model solutions at an evaporator capacity of 70, 100 and 140 litres per hour. The composition of the solutions changed in dependence on the knowledge of the composition of actual concentrates in the V-1 nuclear power plant at Jaslovske Bohunice. The following factors were studied in the concentrate: the effect of its pH, its borate content and content of metal carbonates, the content of organic acid salts, the content of detergents, etc., on the process of bituminization. Physico-chemical conditions are described under which the operation of the evaporator was fail-safe and filling of the bituminization product with salts homogeneous. A low water content of up to 1% was achieved. The properties of the bituminization product were negatively affected by a high level of heavy metal oxides, surfactants, oxalates and citrates. In order to improve the properties of the product it will be necessary to replace bitumen emulsion Silembit-60 used as reinforcement matrix, by a different type of bitumen. (Z.M.)

  5. Simplified Pavement Design for LPAs: Introduction to PaveXpress

    OpenAIRE

    Bonte, Dudley

    2015-01-01

    Simplified Pavement Design for LPA's; An introduction to and use of PaveXpress, a simplified, free, web-based pavement design scoping tool for roadway and parking lot pavements. The system was developed by Pavia Systems in partnership with the National Asphalt Pavement Association. PaveXpress creates technical sound pavement structural designs for flexible and rigid pavements based on widely accepted industry standards from the Association of State Highway Officials (AASHTO). The simplified p...

  6. Pavement Preservation for Elected Officials: The Inside Story of Pavement Deterioration

    OpenAIRE

    Olson, Jim

    2012-01-01

    This session is intended to provide elected officials and practitioners with an introduction to the concept of pavement preservation and its applicability within public agencies. Topics include definitions, budget planning, pavement life, road networks, alternative strategies, pavement distresses, guidelines and preservation treatments.

  7. Impact of Overweight Traffic on Pavement Life Using Weigh-In-Motion Data and Mechanistic-Empirical Pavement Analysis

    OpenAIRE

    Wang, Hao; Zhao, Jingnan; Wang, Zilong

    2015-01-01

    The objective of this study is to evaluate the impact of overweight traffic on pavement life using mechanistic-empirical analysis approach. The state-of-practice mechanistic-empirical pavement design and analysis software (Pavement-ME) was used to predict pavement life under different traffic loading scenarios. Field performance data at the sites where the WIM data were collected were analyzed to estimate the pavement service life at field condition. The pavement structures considered in the ...

  8. Mechanical Response Analysis of Asphalt Pavement Structure

    Directory of Open Access Journals (Sweden)

    Yu Zhenqing

    2015-11-01

    Full Text Available Generally, the Chinese designed life of the high- grade asphalt concrete pavement is required 15 years, however, the designed life of the road in surface is often lower than the designed life, and even premature failure. Especially in heavy traffic conditions, the early damage of some high grade-asphalt pavement in China is serious. According to some investigations, we founded the main reason of the long-life asphalt pavement is to determine the function of each structure layer. According to the stress of pavement structure layer, so as to select the structure layer materials. Based on the viewpoint of mechanics, asphalt pavement damage mode is divided into three categories, such as top-down crack, fatigue cracking and rutting. Therefore, this paper uses ANSYS finite element software as calculation tool, the combination of road vehicle load and the primary influence on asphalt pavement structure mechanics response characteristics were analyzed. In this paper, the method of analysis is control variable: that means under different vehicle axle load, only change surface layer modulus and observe the pavement structure mechanical response trends to compare the effect. By using the same method, the response of the pavement base course parameters to the pavement mechanical structure is analyzed.

  9. Long Life Pavements; Firmes de larga duracion

    Energy Technology Data Exchange (ETDEWEB)

    Mateos Moreno, A.; Marron Fernandez, J. O.; Perez Ayuso, J.

    2009-07-01

    The existence of long-life pavements is not new; they have been built in Europe and the United States for decades. In fact, the concept arises from the observation of in-service roads; it was verified how particular pavements, initially designed for a 20-year service life, did not seem to have reduced the bearing capacity along the time, and its maintenance necessities had been exclusively focused on the wearing course. The base idea of long-life pavements is the existence of a fatigue threshold below which the damage produced by each load application is, in practice, zero or below the healing potential of the asphalt mix. The use practice of long-life pavements design considers a pavements constituted by three asphalt layers, each one with a very specific role: a wearing course that provides with the surface characteristics, an intermediate course that provides with most of the structural capacity and a base course that provides with the fatigue resistance. Furthermore, one of the particularities is the design against specific distress mechanisms. Maintenance strategy also presents specific particularities for long-life pavements. It is essentially focused on the detection of surface deterioration, and the appropriate and timely repair, before the damage extends beyond the wearing course, putting into risk the structural integrity of the pavement. Nowadays, this new way to conceive the design, the construction and the maintenance of road pavements, constitutes one of the main challenges for pavement engineering worldwide. (Author) 5 refs.

  10. Flexible pavement performance evaluation using deflection criteria

    Science.gov (United States)

    Wedner, R. J.

    1980-04-01

    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.

  11. Structural Evaluation for Maputo Airport Pavement

    Institute of Scientific and Technical Information of China (English)

    Jose F.R.Diogo; LU Yang; ZHANG Hua

    2007-01-01

    Maputo Airport was initially constructed to serve mixed traffic of light and medium aircrafts. With its opening to heavier aircrafts such as B727, DC10, Airbus 340, etc. , structural improvements have become necessary. For this purpose, structural evaluation were described and performed using falling weight deflectometer. Results show that while subgrade response to loads appears more consistent with depth, surface layer of the pavement is significantly influenced by the layer thickness as well as mechanical properties of pavement materials. Load magnitude also affects pavement performance. But loading conditions show an equivalent or even greater influence on pavement performance.

  12. Measurement of heat generation from simulated bituminized product

    International Nuclear Information System (INIS)

    The fire and explosion incident occurred at Bituminization Demonstration Facility of PNC Tokai Works on March 11, 1997. In order to ascertain the cause of incident, the investigation has been pushed forward. For the investigation, we prepared simulated bituminized product of measurement of heat generation in low temperature region less than 200degC. We used calvet Calorimeter MS80 for the heat generation measurement. Result of measurement, we were able to catch the feeble heat generation from bituminized product. The maximum calorific value that was able to detect it in isothermal measurement was approximately 1 mW/g in 160degC. It was approximately 2 mW/g in 200degC. And, as the another measurement, the measurement condition went heat rate by 0.01degC/minute, the highest temperature 190degC. As a result, the maximum generation of heat value that was able to detect it was approximately 0.5 mW/g. I changed simulated bituminized products and measured these. A difference of condition is salt particle size, salt content rate (45%, 60%), addition of the simulated precipitate. But there was not a difference in the generation of heat characteristic detected. (author)

  13. 30 CFR 716.4 - Special bituminous coal mines.

    Science.gov (United States)

    2010-07-01

    ... INTERIOR INITIAL PROGRAM REGULATIONS SPECIAL PERFORMANCE STANDARDS § 716.4 Special bituminous coal mines... may be used if necessary to prevent erosion. (3) Spoil piles will be graded and contoured with no more... of an amendment or revision to the State of Wyoming's regulatory program, regulations, or...

  14. The effect of Cryogenic Crumb Rubber in cold recycled mixes for road pavements

    DEFF Research Database (Denmark)

    Pettinari, Matteo; Dondi, Giulio; Sangiorgi, Cesare;

    2014-01-01

    Over recent years, the necessity of reducing the environmental mpact of building new infrastructures has increasingly directed research toward developing innovative manufacturing methods and materials that can satisfy these objectives. Cold recycling, widely used in renovating road pavements...... in Italy, is also moving in this direction, lowering the manufacturing temperatures of bituminous mixes and reducing or ultimately eliminating the use of virgin raw materials. Currently, a wide range of materials are used and, consequently, the number of variables to be considered in the mix-design process...... of cold recycled mixes for road bases is considerable. Furthermore, new products are continuously being introduced or developed for recycling purposes. The objective of this research project was to test the effects, both mechanically and environmentally, of crumb rubber included in 100% Reclaimed Asphalt...

  15. Modelling Flexible Pavement Response and Performance

    DEFF Research Database (Denmark)

    Ullidtz, Per

    This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods.......This textbook is primarily concerned with models for predicting the future condition of flexible pavements, as a function of traffic loading, climate, materials, etc., using analytical-empirical methods....

  16. Numerical Simulation of Tire-Pavement Interaction

    NARCIS (Netherlands)

    Srirangam, S.K.

    2015-01-01

    Good skid resistance of a pavement surface is essential for road safety. Loss of skid resistance can lead to property damage and loss of lives. Ever increasing need of driver safety poses challenges to the highway authorities to evaluate pavement conditions even more precisely under different condit

  17. Analysis and design optimization of flexible pavement

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-04-01

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

  18. Pervious Pavement System Evaluation-Paper

    Science.gov (United States)

    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...

  19. Pavement Crack Detection Using Spectral Clustering Method

    Directory of Open Access Journals (Sweden)

    Jin Huazhong

    2015-01-01

    Full Text Available Pavement crack detection plays an important role in pavement maintaining and management, nowadays, which could be performed through remote image analysis. Thus, edges of pavement crack should be extracted in advance; in general, traditional edge detection methods don’t consider phase information and the spatial relationship between the adjacent image areas to extract the edges. To overcome the deficiency of the traditional approaches, this paper proposes a pavement crack detection algorithm based on spectral clustering method. Firstly, a measure of similarity between pairs of pixels is taken into account through orientation energy. Then, spatial relationship is needed to find regions where similarity between pixels in a given region is high and similarity between pixels in different regions is low. After that, crack edge detection is completed with spectral clustering method. The presented method has been run on some real life images of pavement crack, experimental results display that the crack detection method of this paper could obtain ideal result.

  20. Improving Rutting Resistance of Pavement Structures Using Geosynthetics: An Overview

    Directory of Open Access Journals (Sweden)

    Sina Mirzapour Mounes

    2014-01-01

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

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

    Science.gov (United States)

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

    2014-01-01

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

  2. Theoretical Development and Engineering Practice of Pavements in China

    Institute of Scientific and Technical Information of China (English)

    QIU Yan-jun

    2008-01-01

    This paper presents a comprehensive review of historical theory development and current construction practice of pavement engineering in China. Mechanical models, design guides, construction techniques, evaluation methods and maintenance standards are elaborated for Portland cement concrete (PCC) pavements and asphalt concrete (AC) pavements. Differences in design methodology among pavements of rural highways, urban roads and airport fields are discussed based on service requirements.Lessons and experiences based on the past 20 years' construction practice and pavement performance are summarized. Current research areas in pavement engineering associated with unconventional geological and/or landscaping in China's highway construction and national strategic plan for pavement engineering are also covered.

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

    Science.gov (United States)

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

    2014-01-01

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

  4. Aircraf landing gear design in respect of pavement design

    OpenAIRE

    Fabre, C.; ALBIN, A; Balay, Jean Maurice

    2009-01-01

    This paper considers the close relationship between aircraft landing gear (LG) and pavement design in respect of airfield pavement compatibility. In pavement design and analysis, we usually deal with pavement structures, materials and design thickness procedure but rarely aircraft LG design This paper emphasizes key drivers, which must be considered for new aircraft LG design to achieve aircraft pavement compatibility. Several parameters such as number & size of wheels, type of gear, brakes, ...

  5. Amenability of Muzret bituminous coal to oil agglomeration

    Energy Technology Data Exchange (ETDEWEB)

    Sahinoglu, E.; Uslu, T. [Karadeniz Technical University, Department of Mining Engineering, 61080 Trabzon (Turkey)

    2008-12-15

    Laboratory scale agglomeration tests were undertaken to investigate the amenability of Muzret (Yusufeli-Artvin) bituminous coal to oil agglomeration. Kerosene was extensively used as oil in the tests. In addition, fuel oil, diesel oil, and hazelnut oil were also used in order to determine the effect of oil type. The effects of the parameters including coal content, kerosene content, agglomeration time, coal particle size, pH, oil type, and agitation rate, on the combustible matter recovery, ash reduction and pyritic sulphur reduction, were investigated. It was found that Muzret bituminous coal could be readily cleaned by oil agglomeration with substantial reductions in ash and pyritic sulphur content. Maximum combustible matter recovery, ash reduction and pyritic sulphur reduction were achieved to be 85.54%, 59.98%, and 85.17%, respectively. (author)

  6. Performance of PAHs emission from bituminous coal combustion

    Institute of Scientific and Technical Information of China (English)

    严建华; 尤孝方; 李晓东; 倪明江; 尹雪峰; 岑可法

    2004-01-01

    Carcinogenic and mutagenic polycyclic aromatic hydrocarbons (PAHs) generated in coal combustion have caused great environmental health concern. Seventeen PAHs (16 high priority PAHs recommended by USEPA plus Benzo[e]pyrene) present in five raw bituminous coals and released during bituminous coal combustion were studied. The effects of combustion temperature, gas atmosphere, and chlorine content of raw coal on PAHs formation were investigated. Two additives (copper and cupric oxide) were added when the coal was burned. The results indicated that significant quantities of PAHs were produced from incomplete combustion of coal pyrolysis products at high temperature, and that temperature is an important causative factor of PAHs formation. PAHs concentrations decrease with the increase of chlorine content in oxygen or in nitrogen atmosphere. Copper and cupric oxide additives can promote PAHs formation (especially the multi-ring PAHs) during coal combustion.

  7. Assessment of an action against environmental noise: Acoustic durability of a pavement surface with crumb rubber.

    Science.gov (United States)

    Vázquez, V F; Luong, J; Bueno, M; Terán, F; Paje, S E

    2016-01-15

    Environmental noise is a worldwide problem that has an adverse effect in the quality of life of urban population. Some work has shown that there is a correlation between environmental noise and health issues as sleep disturbance or annoyance. This study presents the time evolution of a test track fabricated with an asphalt mixture with 20% of crumb rubber by weight of bitumen, added by the wet process. A complete surface characterization has been performed by determining tire/pavement sound levels, road texture profiles, in-situ dynamic stiffness and sound absorption of compacted and extracted sample cores. Two measurement campaigns were performed: just after mixture laying and after 3 years in service. This study confirms that the use of crumb rubber as a modifier of bituminous binders (CRMB) can improve the pavement characteristics: gap-graded mixtures with crumb rubber can be used in the action plans as urban rehabilitation measure to fight noise pollution. However, this noise reduction seems to decrease with age at a rate of approximately 0.15 dB(A) per year. PMID:26519582

  8. Identification of aggregates for Tennessee bituminous surface courses

    Science.gov (United States)

    Sauter, Heather Jean

    Tennessee road construction is a major venue for federal and state spending. Tax dollars each year go to the maintenance and construction of roads. One aspect of highway construction that affects the public is the safety of its state roads. There are many factors that affect the safety of a given road. One factor that was focused on in this research was the polish resistance capabilities of aggregates. Several pre-evaluation methods have been used in the laboratory to predict what will happen in a field situation. A new pre-evaluation method was invented that utilized AASHTO T 304 procedure upscaled to accommodate surface bituminous aggregates. This new method, called the Tennessee Terminal Textural Condition Method (T3CM), was approved by Tennessee Department of Transportation to be used as a pre-evaluation method on bituminous surface courses. It was proven to be operator insensitive, repeatable, and an accurate indication of particle shape and texture. Further research was needed to correlate pre-evaluation methods to the current field method, ASTM E 274-85 Locked Wheel Skid Trailer. In this research, twenty-five in-place bituminous projects and eight source evaluations were investigated. The information gathered would further validate the T3CM and find the pre-evaluation method that best predicted the field method. In addition, new sources of aggregates for bituminous surface courses were revealed. The results of this research have shown T3CM to be highly repeatable with an overall coefficient of variation of 0.26% for an eight sample repeatability test. It was the best correlated pre-evaluation method with the locked wheel skid trailer method giving an R2 value of 0.3946 and a Pearson coefficient of 0.710. Being able to predict field performance of aggregates prior to construction is a powerful tool capable of saving time, money, labor, and possibly lives.

  9. Assessment of highway pavements using GPR

    Science.gov (United States)

    Plati, Christina; Loizos, Andreas

    2015-04-01

    Highway infrastructure is a prerequisite for a functioning economy and social life. Highways, often prone to congestion and disruption, are one of the aspects of a modern transport network that require maximum efficiency if an integrated transport network, and sustainable mobility, is to be achieved. Assessing the condition of highway structures, to plan subsequent maintenance, is essential to allow the long-term functioning of a road network. Optimizing the methods used for such assessment will lead to better information being obtained about the road and underlying ground conditions. The condition of highway structures will be affected by a number of factors, including the properties of the highway pavement, the supporting sub-base and the subgrade (natural ground), and the ability to obtain good information about the entire road structure, from pavement to subgrade, allows appropriate maintenance programs to be planned. The maintenance of highway pavements causes considerable cost and in many cases obstruction to traffic flow. In this situation, methods that provide information on the present condition of pavement structure non-destructively and economically are of great interest. It has been shown that Ground-Penetrating-Radar (GPR), which is a Non Destructive Technique (NDT), can deliver information that is useful for the planning of pavement maintenance activities. More specifically GPR is used by pavement engineers in order to determine physical properties and characteristics of the pavement structure, information that is valuable for the assessment of pavement condition. This work gives an overview on the practical application of GPR using examples from highway asphalt pavements monitoring. The presented individual applications of GPR pavement diagnostics concern structure homogeneity, thickness of pavement layers, dielectric properties of asphalt materials etc. It is worthwhile mentioning that a number of applications are standard procedures, either

  10. Mechanistic design concepts for conventional flexible pavements

    Science.gov (United States)

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

    1985-02-01

    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.

  11. Nonlinear Responses of a Two Dimensional Vehicle-pavement System

    Directory of Open Access Journals (Sweden)

    Shaohua Li

    2013-09-01

    Full Text Available The vehicle and pavement are usually investigated separately in vehicle dynamics and pavement dynamics. In this work, a new research scheme is proposed to link the vehicle and pavement model by tire loads and compute the nonlinear dynamic responses by analytical methods. A two-DOF nonlinear vehicle and a Bernoulli-Euler beam on a nonlinear elastic foundation with two simply supported ends compose the nonlinear vehicle-pavement system. The nonlinear tire loads are analytically gained using the averaging method. Then the nonlinear vibration equation of the pavement is obtained using Galerkin method and solved using the multiple scales method. The theoretical solutions are verified by numerical results and the effects of system parameters on pavement vibration are also studied. It is found that the pavement responses excited by tire loads attenuate quickly and small pavement mass, large foundation damping or foundation stiffness may decrease the pavement vibration.

  12. Permeable Pavement Research - Edison, New Jersey

    Science.gov (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  13. Pervious Pavement System Evaluation- Abstract 1

    Science.gov (United States)

    Porous pavement is a low impact development stormwater control. The Urban Watershed Management Branch is evaluating interlocking concrete pavers as a popular implementation. The pavers themselves are impermeable, but the spaces between the pavers are backfilled with washed, gra...

  14. Children, urban care, and everyday pavements

    OpenAIRE

    Kim Kullman

    2014-01-01

    This paper takes a mundane piece of urban infrastructure, the pavement, as a starting point, approaching it through the experiences of 7–12-year-old children who journey between home and school in Helsinki, Finland. In doing so, the paper argues that the children and their travel companions are employing pavements to cultivate the caring potential of their city, whether this entails patting dogs, picking up empty bottles, or checking the safety of zebra crossings. Inspired by recent work on t...

  15. Research on Fatigue Properties of Asphalt Pavement on Mix Base%混合式基层沥青路面的疲劳特性分析研究

    Institute of Scientific and Technical Information of China (English)

    彭宏图

    2013-01-01

    According to the 06 standard design methods,AASHTO experiment methods and actual interlayer bonding state,the fatigue properties of three different bituminous pavements of composite base are analyzed in this paper.The results reveal that with the same thickness,the mixed asphalt pavement has a better fatigue life than the semi-rigid base AC pavement.For the purpose of analyzing the sensitivity of the fatigue property,the thickness of the pavement and modulus of graded gravel are also taken into account in three different asphalt pavements of composite.%采用了06版规范方法、考虑实际层间粘接状态的规范方法以及AASH00经验方法对3种类型的混合式基层沥青路面的疲劳特性进行了分析研究,得出了相同厚度的混合式基层沥青路面比半刚性基层沥青路面具有更长的疲劳寿命的结论.并对不同结构层厚度、级配碎石模量对3种类型的混合式基层沥青路面的疲劳特性的敏感性进行了分析.

  16. Environmental interactions of Sulphlex pavement.

    Science.gov (United States)

    Ferenbaugh, R W; Gladney, E S; Soholt, L F; Lyall, K A; Kimber Wallwork-Barber, M; Herman, L E

    1992-01-01

    Sulphlex, a mixture of elemental sulfur and plasticizers, has been considered for use as an asphalt substitute in road construction. Because this material contains substantial quantities of elemental sulfur, it is a potential substrate for growth of sulfur-oxidising bacteria. Experiments, performed to determine the susceptibility of Sulphlex in Sulphlex-containing media to degradation by Thiobacillus thiooxidans, resulted in breakdown of the Sulphlex material and concomitant production of acid. In concurrent studies, plants were grown in Sulphlex-amended soils. These plants exhibited higher sulfur content and reduced productivity as compared with plants grown in unamended soils, indicating that Sulphlex was being broken down in the soil and that the breakdown products were apparently having a detrimental effect on plant productivity. These experiments indicate that naturally occurring sulfur-oxidising bacteria have the potential to break down Sulphlex paving material, resulting in adverse effects on both the structural integrity of the pavement and the local environment. PMID:15091995

  17. Pavement Performance Index for Indian rural roads

    Directory of Open Access Journals (Sweden)

    Abhay Tawalare

    2016-09-01

    Full Text Available The performance of a road is evaluated from time to time so as to improve its quality and helps in planning maintenance of roads. For this purpose various pavement deteriorating models as a decision tool are available. But they are not easy to use for field engineers due to either huge past data requirement or complicated calculations. Therefore, this paper presents a Pavement Performance Index for rural roads by using simple methodology. The distress parameters of rural roads were identified through literature review. Similarly rating criteria for each distress parameters were identified through literature. For final selection of distress parameters in context of Indian rural road, opinions of five highly experienced industrial experts were taken. After that the weightage for severity of each parameter causing distress of pavement is calculated by using data of questionnaire survey in which 117 professionals working in Pradhan Mantri Gram Sadak Yojana across the country were participated. The paper suggests a formula to decide Pavement Performance Index that depends on rating criterion and severity weightage of distress parameters of pavement performance. The study concluded that suggested Pavement Performance Index makes calculations easy for field engineers and will be useful to decide priority list of rural roads for repair and maintenance schedule.

  18. A STUDY OF BITUMINOUS SHUNGITE BINDER ON THE SCANNING MICROSCOPE

    OpenAIRE

    K. A. Andrianov; D V Ivanov; V. P. Yartsev

    2012-01-01

    Statement of the problem. It is possible to improve working conditions of road pavement and to use it more efficiently by regulating water-thermal conditions of the subgrade thereby reducing humidity in the design period and mitigating its seasonal changes.Results and conclusions. It is suggested to use extruded foam polystyrene as a heating layer. The thermal fluctuation approach was applied to failure and deformation processes. Physical constants for the analytical description of these proc...

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

    Science.gov (United States)

    Junwei, Zhang; Jinping, Li; Xiaojuan, Quan

    2013-01-01

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

  20. FLEXIBLE PAVEMENT REHABILITATION DESIGN BASED ON PAVEMENT SERVICE LIFE TIME SPAN LEFT

    OpenAIRE

    Gamelyak, I.; Shevchuk, V.

    2005-01-01

    The design of flexible pavement rehabilitation is analysed in terms of durability-cost. A notion of the remaining service life span is described. the model of rehabilitation strategy selection is presented for both design project and operation stages. the results can be used in the pavement management system.

  1. Improving a pavement-watering method on the basis of pavement surface temperature measurements

    CERN Document Server

    Hendel, Martin; Diab, Youssef; Royon, Laurent

    2014-01-01

    Pavement-watering has been studied since the 1990's and is currently considered a promising tool for urban heat island reduction and climate change adaptation. However, possible future water resource availability problems require that water consumption be optimized. Although pavement heat flux can be studied to improve pavement-watering methods (frequency and water consumption), these measurements are costly and require invasive construction work to install appropriate sensors in a dense urban environment. Therefore, we analyzed measurements of pavement surface temperatures in search of alternative information relevant to this goal. It was found that high frequency surface temperature measurements (more than every 5 minutes) made by an infrared camera can provide enough information to optimize the watering frequency. Furthermore, if the water retaining capacity of the studied pavement is known, optimization of total water consumption is possible on the sole basis of surface temperature measurements.

  2. Sorption of aqueous phosphorus onto bituminous and lignitous coal ashes

    Energy Technology Data Exchange (ETDEWEB)

    Yan Jinying; Kirk, Donald W. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada); Jia, Charles Q. [Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, M5S 3E5 (Canada)], E-mail: cqjia@chem-eng.toronto.edu; Liu Xinan [College of Chemical Engineering, Chongqing University, Chongqing (China)

    2007-09-05

    Aiming at the development of a phosphorus removal technology for waste water, phosphate (PO{sub 4}{sup 3-}) retention behavior of bituminous and lignitous coal ashes was investigated using a batch reactor. Ash samples, including fresh and weathered fly and bottom ashes, were studied for their sorption isotherms and reversibility. Fly ashes had a much higher phosphate retention capacity (4000-30,000 mg P/kg) than bottom ashes (15-600 mg P/kg). Lignitous coal ashes were more capable of retaining phosphate than bituminous coal ashes. The retention process was largely irreversible, and the irreversibility increased with the increase in the retention capacity. Weathering enlarged the retention capacity of the bituminous bottom ash, but substantially lowered that of the fly ash, likely due to the difference in the weather-induced changes between the fly and bottom ashes. Sorption isotherms of fly ashes were found to be adequately represented by the Langmuir model while those of bottom ashes fitted better to the Freundlich model. Concentrations of Ca{sup 2+} and PO{sub 4}{sup 3-} in the aqueous phase were measured at the end of sorption and desorption experiments, and were compared with solubilities of three calcium phosphate minerals. The aqueous solutions were saturated or super-saturated with respect to tricalcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}) and hydroxyapatite (Ca{sub 5}(PO{sub 4}){sub 3}OH), and slightly under-saturated with respect to amorphous calcium phosphate. It is concluded that precipitation of calcium phosphate is the predominant mechanism for phosphate retention by coal ash under the conditions studied. There is a strong and positive correlation between alkalinity and phosphate sorption capacity. Consequently, acid neutralization capacity (ANC) can be used as an indicator of phosphate sorption capacity of coal ashes.

  3. Porous Flame-retarded Asphalt Pavement for Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; HUANG Shaolong; Ding Qingjun

    2008-01-01

    A new way to improve the tunnel fire protection by using flame-retarded porous asphalt pavement containing ATH powders was introduced. Based on the miniature burning test designed and conducted, the burning time and temperature of porous asphalt (PA) and flame-retarded porous asphalt (FRPA) were studied comparing with cement concrete pavement, dense-graded HMA and S MA. Results of burning test and pavement performance test indicate that FRPA is appropriate and suitable as the pavement material of highway tunnel.

  4. Knowledge Discovery and Pavement Performance: Intelligent Data Mining

    NARCIS (Netherlands)

    Miradi, M.

    2009-01-01

    The main goal of the study was to discover knowledge from data about asphalt road pavement problems to achieve a better understanding of the behavior of them and via this understanding improve pavement quality and enhance its lifespan. Four pavement problems were chosen to be investigated; raveling

  5. Performance of pavements designed with low-cost materials

    Science.gov (United States)

    Grau, R. W.; Yrjanson, W. A.; Packard, R. G.; Barksdale, R. D.; Potts, C. F.; Ruth, B. E.; Smith, L. L.; Huddleston, I. J.; Vinson, T. S.; Hicks, R. G.

    1980-04-01

    The following areas are discussed. Utilization of marginal aggregate materials for secondary road surface layers; econocrete pavements; current practices; construction and performance of sand-asphalt bases and performance of sand-asphalt and limerock pavements in Florida. Cement stabilization of degrading aggregates use of crushed stone screenings in highway construction (abridgement); and sulfur-asphalt pavement technology are also reviewed.

  6. Effect of age of permeable pavements on their infiltration function

    NARCIS (Netherlands)

    Boogaard, Floris; Lucke, Terry; Beecham, Simon

    2013-01-01

    This study describes field investigations designed to compare the infiltration capacities of 55 permeable pavement systems installed in the Netherlands and in Australia. The ages of the pavements varied from 1 to 12 years. Using infiltrometer testing, the performance of the pavements has been compar

  7. Pavement Sealcoat, PAHs, and the Environment

    Science.gov (United States)

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

    2011-12-01

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

  8. A STUDY OF BITUMINOUS SHUNGITE BINDER ON THE SCANNING MICROSCOPE

    Directory of Open Access Journals (Sweden)

    K. A. Andrianov

    2012-07-01

    Full Text Available Statement of the problem. It is possible to improve working conditions of road pavement and to use it more efficiently by regulating water-thermal conditions of the subgrade thereby reducing humidity in the design period and mitigating its seasonal changes.Results and conclusions. It is suggested to use extruded foam polystyrene as a heating layer. The thermal fluctuation approach was applied to failure and deformation processes. Physical constants for the analytical description of these processes at varying temperatures and stresses are calculated. The technique for determining acting stresses and temperatures was described. The prediction of the durability of extruded foam polystyrene in road structure is presented.

  9. Design of airport pavements for expansive soils

    Science.gov (United States)

    McKeen, R. G.

    1981-01-01

    Expansive soil subgrades exhibit volume changes with variation in moisture condition. These changes result in differential movement of airport pavements resting on these soils. Special design procedures must be used to account for the expansive soil activity during equilibration. In addition, special precautions are required to protect the subgrade from moisture variation with climate. Measurement of soil suction is a key step in quantifying moisture-induced soil behavior. Procedures are outlined for suction characterization of the soil and for estimating the in situ differential movement likely to occur under the pavement. Once the wavelength and amplitude characteristics of the differential movement are obtained, design calculations to select the thickness and materials for the pavement may proceed.

  10. Construction of an experimental sulfur-extended-asphalt pavement

    Science.gov (United States)

    Dodge, K. S.

    1982-07-01

    The design, placement and collection of initial data from a sulfur extended asphalt (SEA) pavement and a conventional pavement used as a control is documented. The SEA pavement used 30 percent sulfur by total weight of the binder. Mix temperatures, hot bin gradations, and toxic emissions were monitored at the plant and the site throughout placement. Aggregates were collected from the hot bin during production of the control and SEA mixes for use in a Marshall mix design. Cores were extracted from both SEA and control pavements 1 month after placement for laboratory testing. Pavement surface properties were also examined after 1 month of service.

  11. Structural Design of Pavement Overlays Based on Functional Parameters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    This paper reports a practical pavement overlay design methodbased on PCI (Pavement Condition Index). Current pavement investigation method (JTJ 073-96) is compared to the ASTM D 5340, which is the standard test method for airport pavement condition evaluation initially developed for US Air Force. The deficiency in the calculation of PCI based on field data in JTJ 073 is discussed. The proposed design method is compared to AASHTO overlay design method with good agreement. The paper concludes with an example illustrating how the existing pavement structural capacity is related to pavement distress survey results. The presented design method can be used in the design for overlay rehabilitation of pavements of highways, urban streets and airports.

  12. Study of thermal reactivity during bituminization of radioactive waste

    International Nuclear Information System (INIS)

    This work deals with the study of chemical reactions and phases transitions which can occur between magnesium nitrate, sodium nitrate, cobalt sulphur product, and nickel potassium ferrocyanide, when they are heated together during bituminization process of nuclear waste. The applied methodology associates a few techniques: temperature, enthalpy, and kinetics of reaction are determined by calorimetry, reaction products are characterised by chemical analyses, mass spectrometry and XRD analysis. Three fields of temperature and energy are observed in function of composition (one compound or a mixture of compounds). The study of reactions between NaNO3 and cobalt sulphur product shows that the presence of water has got an effect on reaction temperature. The study of Mg(NO3)2, 6 H2O and CoS shows an overlapping of different signals, and that the reaction rate is very slow (a few hours). (author)

  13. Leaching tests of simulated Cogema bituminized waste form

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, S.; Akimoto, T.; Iida, Y.; Nagano, T. [Japan Atomic Energy Research Institute, Tokai, Ibaraki (Japan)

    2000-07-01

    The leaching behavior of COGEMA-type bituminized radioactive waste was studied for the atmospheric and anaerobic conditions. Active and inactive laboratory-scale bitumen samples, including two major salts of NaNO{sub 3} and BaSO{sub 4}, were contacted with deionized water, an alkaline solution (0.01 mol/L Ca(OH){sub 2} or 0.03 mol/L KOH), or a saline solution (0.5 mol/L KCl). It was found that the release of salt was reduced in the Ca(OH){sub 2} solution compared with deionized water under the atmospheric conditions. No significant difference in the concentrations of {sup 237}Np in leachants contacted with the samples for 7 days was observed between the atmospheric and the anaerobic conditions. (authors)

  14. Steam and air plasma gasification of bituminous coal and petrocoke

    Directory of Open Access Journals (Sweden)

    Vladimir Messerle

    2012-12-01

    Full Text Available This paper presents a numerical analysis and experimental investigation of two very different solid fuels, low-rank bituminous coal of 40 % ash content and petrocoke of 3 % ash content, gasification under steam and air plasma conditions with an aim of producing synthesis gas. Numerical analysis was fulfilled using the software package TERRA for equilibrium computation. Using the results of the numerical simulation, experiments on plasma steam gasification of the petrocoke and air and steam gasification of the coal were conducted in an original installation. Nominal power of the plasma installation is 100 kWe and sum consumption of the reagents is up to 20 kg/h. High quality synthesis gas was produced in the experiments on solid fuels plasma gasification. It has been found that the synthesis gas content at about 97.4 vol.% can be produced. Comparison between the numerical and experimental results showed satisfactory agreement. 

  15. 纤维沥青混合料的拌和成型工艺研究%Research on Mixing and Shaping Technology of Fiber Bituminous Mixture

    Institute of Scientific and Technical Information of China (English)

    程英伟; 何晓鸣

    2012-01-01

    利用正交试验对剑麻纤维沥青混凝土混合料的拌和成型工艺进行研究.在固定配合比的前题下,以拌和方案、沥青加热温度、集料加热温度和成型温度为试验因素,模拟路面施工的各种拌和成型情况设计了L9正交表分别进行马歇尔试验.运用极差分析法对试验结果进行分析,确定了纤维沥青混合料拌和成型的优选方案为“同步法拌和+沥青加热温度为175℃+集料加热温度为206℃+成型温度为165℃”.最后分析了几种试验因素对试验指标的影响机理.%In this paper, mixing and shaping technology of bituminous concrete mixture with sisal fiber is researched by orthogonal experiment. Under a fixed mix proportion, mixing solutions, asphalt heating temperature, aggregate heating temperature and shaping temperature are selected as test factors. The variety of mixing and shaping in pavement construction is simulated by designing a L9 orthogonal table for Marshall tests. Range Analysis Method is used to analyze test results, and then the optimal scheme of mixing and shaping for fiber bituminous concrete mixture is determined. The optimal scheme is "synchronization method of mixing+asphalt heating temperature of 175℃+aggregate heating temperature of 206℃ + shaping temperature of 165℃”. Last, the influence mechanism of test factors on test indicators is analyzed.

  16. Asphalt for draining pavement; Haisuisei hosoyo asphalt

    Energy Technology Data Exchange (ETDEWEB)

    Yamamori, H.; Nakamura, Y. [Mitsubishi Oil Co. Ltd., Tokyo (Japan)

    1994-12-28

    The effect and functions of draining pavement with a superb performance as a paved road were introduced. In the draining pavement, a porous asphalt mixture was used for the surface and base layers of the road and the remaining layers are not in water penetration property. It is necessary that void continues to prevent water film from being generated when rain falls and resistance against water flow is small but durability has problems when the void rate is large. According to the balance, the void rate ranges from 20 to 23 % for execution, thus preventing water splash on a rainy day, hydroplaning, and dazzlement, etc. due to reflection of light. The noise during driving due to the tire of an automobile is reduced by 5 to 6 dB owing to draining pavement. Also, engine noise is reduced to 40 - 60 % since the surface is porous. In the draining pavement, a high-viscosity asphalt is used for a binder and the void rate is large, thus preventing temperature to rise easily due to heat release and achieving an improved flow behavior. 6 refs., 11 figs., 14 tabs.

  17. Permeable pavement research – Edison, New Jersey

    Science.gov (United States)

    These are the slides for the New York City Concrete Promotional Council Pervious Concrete Seminar presentation. The basis for the project, the monitoring design and some preliminary monitoring data from the permeable pavement parking lot at the Edison Environmental Center are pre...

  18. Viscoelastic Pavement Modeling with a Spreadsheet

    DEFF Research Database (Denmark)

    Levenberg, Eyal

    2016-01-01

    The aim herein was to equip civil engineers and students with an advanced pavement modeling tool that is both easy to use and highly adaptive. To achieve this, a mathematical solution for a layered viscoelastic half-space subjected to a moving load was developed and subsequently implemented...

  19. Investigation of the combustion characteristics of Zonguldak bituminous coal using DTA and DTG

    Energy Technology Data Exchange (ETDEWEB)

    Haykiri-Acma, H.; Yaman, S.; Kucukbayrak, S.; Okutan, H. [Istanbul Technical University, Istanbul (Turkey). Dept. of Chemical Engineering

    2006-06-21

    Combustion characteristics of coking, semicoking, and noncoking Turkish bituminous coal samples from Zonguldak basin were investigated applying differential thermal analysis (DTA) and differential thermogravimetry (DTG) techniques. Results were compared with that of the coke from Zonguldak bituminous coal, a Turkish lignite sample from Soma, and a Siberian bituminous coal sample. The thermal data from both techniques showed some differences depending on the proximate analyses of the samples. Noncombustible components of the volatile matter led to important changes in thermal behavior. The data front both methods were, evaluated jointly, and some thermal properties were interpreted considering these methods in a complementary combination.

  20. Temperature induced healing in strained bituminous materials observed by atomic force microscopy

    NARCIS (Netherlands)

    Nahar, S.N.; Schmets, A.J.M.; Scarpas, A.; Schitter, G.

    2013-01-01

    Bitumen is the binder in the composite material named asphalt concrete. Under cyclic mechanical loading of traffic passing over the pavement, eventually damage will initiate in the pavement, leading to eventual structural failure. This damaging process is accelerated by time dependent change of the

  1. Effect of Cement on Properties of Over-Burnt Brick Bituminous Concrete Mixes

    Science.gov (United States)

    Sarkar, Dipankar; Pal, Manish

    2016-06-01

    The present investigation is carried out to propose the use of cement coated over burnt brick aggregate in the preparation of bituminous concrete mix. The effect of cement on various mechanical properties such as Marshall stability, flow, Marshall quotient (stability to flow ratio), indirect tensile strength, stripping, rutting and fatigue life of bituminous concrete overlay has been evaluated. In this study, different cement percentages such as 2, 3, 4 and 5 % by weight of aggregate have been mixed with Over Burnt Brick Aggregate (OBBA). The laboratory results indicate that bituminous concrete prepared by 4 % cement coated OBBA gives the highest Marshall stability. The bituminous concrete mix with 4 % cement shows considerable improvement in various mechanical properties of the mix compared to the plain OBBA concrete mix.

  2. State of the art report on bituminized waste forms of radioactive wastes

    International Nuclear Information System (INIS)

    In this report, research and development results on the bituminization of radioactive wastes are closely reviewed, especially those regarding waste treatment technologies, waste solidifying procedures and the characteristics of asphalt and solidified forms. A new concept of the bituminization method is suggested in this report which can improve the characteristics of solidified forms. Stable solid forms with high leach resistance, high thermal resistance and good compression strength were produced by the suggested bituminization method, in which spent polyethylene from agricultural farms was added. This report can help further research and development of improved bituminized forms of radioactive wastes that will maintain long term stabilities in disposal sites. (author). 59 refs., 19 tabs., 18 figs

  3. State of the art report on bituminized waste forms of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Kook; Shon, Jong Sik; Kim, Kil Jeong; Lee, Kang Moo; Jung, In Ha

    1998-03-01

    In this report, research and development results on the bituminization of radioactive wastes are closely reviewed, especially those regarding waste treatment technologies, waste solidifying procedures and the characteristics of asphalt and solidified forms. A new concept of the bituminization method is suggested in this report which can improve the characteristics of solidified forms. Stable solid forms with high leach resistance, high thermal resistance and good compression strength were produced by the suggested bituminization method, in which spent polyethylene from agricultural farms was added. This report can help further research and development of improved bituminized forms of radioactive wastes that will maintain long term stabilities in disposal sites. (author). 59 refs., 19 tabs., 18 figs

  4. MODELING PAVEMENT DETERIORATION PROCESSES BY POISSON HIDDEN MARKOV MODELS

    Science.gov (United States)

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

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

  5. An Airport Pavement Traffic Simulation Based on CPN

    OpenAIRE

    Heng Hong-jun; Yang Jue

    2014-01-01

    According to the characteristics of airport pavement traffic, we discuss a method of building an airport pavement traffic model which is based on CPN theory and simulate a practical situation as well. The method overcomes the shortage of modelling with normal Petri Net theory, solves the difficult problems of airport pavement traffic such as complex traffic nets, frequent road changing, etc., refines the process of the model, and will be good for the model’s analysis and simulation.

  6. Recent Developments in Pavement Management on Irish National Roads

    OpenAIRE

    Feighan, Kieran; McGowan, Ray; Casey, Tom; O’Sullivan, Andrew

    2015-01-01

    The Irish National pavement network is Ireland’s strategic road network consisting of over 5,300 centreline kilometres of road and is managed by the National Roads Authority (NRA). There is a very significant variation across the network under a variety of headings, including pavement construction, pavement age, carriageway width, lane width, geometric design and traffic volumes carried. A large proportion of the network consists of “legacy” roads that have evolved from historic routes that a...

  7. Permeability testing of drilling core sample from pavement

    Institute of Scientific and Technical Information of China (English)

    Suda WANG; Zhengguang TANG; Xiaojun NING; Peiguan WU; Pingyi XING

    2008-01-01

    The permeability coefficient of pavement material is a very important parameter in designing the drainage of pavement structures and is also used to evalu-ate the quality of road construction. New equipment is used to measure the permeability coefficient of the pave-ment drilling core sample and relevant testing methods are introduced. Testing drilling core samples from a certain highway of Yunnan province has been proven to be feas-ible. The test results are also analyzed.

  8. In-Situ Behavior of Geosynthetically Stabilized Flexible Pavement

    OpenAIRE

    Appea, Alexander Kwasi

    1997-01-01

    The purpose of a geotextile separator beneath a granular base, or subbase in a flexible pavement system is to prevent the road aggregate and the underlying subgrade from intermixing. It has been hypothesized that in the absence of a geotextile, intermixing between base course aggregate and soft subgrade occurs. Nine heavily instrumented flexible pavement test sections were built in Bedford County Virginia to investigate the benefits of geosynthetic stabilization in flexible pavements. ...

  9. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    OpenAIRE

    Arshad Ahmad Kamil; Haron Hairol Anuar; Abd Rahman Zanariah; Abdul Halim A.G.

    2016-01-01

    In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area) to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10...

  10. Long-Term Field Performance of Pervious Concrete Pavement

    OpenAIRE

    Aleksandra Radlińska; Andrea Welker; Kathryn Greising; Blake Campbell; David Littlewood

    2012-01-01

    The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and th...

  11. Environmentally friendly pavements: Results from noise measurements 2005-2008

    OpenAIRE

    Berge, Truls Svenn; Haukland, Frode; Ustad, Asbjørn

    2009-01-01

    CPX-measurements (tyre A) have been performed on a wide range of ordinary dense Norwegian road pavements and special test pavements, as part of the R&D project “Environmental friendly pavements” initiated by the Norwegian Public Roads Administration. The following conclusions can be made from the investigation:- New dense asphalt concrete pavements can give a tyre/road noise level (CPX) of 4-8 dB(A) lower noise level, compared to a chosen reference level for a pavement of type AC 0/11 and SMA...

  12. Hybrid green permeable pave with hexagonal modular pavement systems

    Science.gov (United States)

    Rashid, M. A.; Abustan, I.; Hamzah, M. O.

    2013-06-01

    Modular permeable pavements are alternatives to the traditional impervious asphalt and concrete pavements. Pervious pore spaces in the surface allow for water to infiltrate into the pavement during rainfall events. As of their ability to allow water to quickly infiltrate through the surface, modular permeable pavements allow for reductions in runoff quantity and peak runoff rates. Even in areas where the underlying soil is not ideal for modular permeable pavements, the installation of under drains has still been shown to reflect these reductions. Modular permeable pavements have been regarded as an effective tool in helping with stormwater control. It also affects the water quality of stormwater runoff. Places using modular permeable pavement has been shown to cause a significant decrease in several heavy metal concentrations as well as suspended solids. Removal rates are dependent upon the material used for the pavers and sub-base material, as well as the surface void space. Most heavy metals are captured in the top layers of the void space fill media. Permeable pavements are now considered an effective BMP for reducing stormwater runoff volume and peak flow. This study examines the extent to which such combined pavement systems are capable of handling load from the vehicles. Experimental investigation were undertaken to quantify the compressive characteristics of the modular. Results shows impressive results of achieving high safety factor for daily life vehicles.

  13. Study on Flexible Pavement Failures in Soft Soil Tropical Regions

    Science.gov (United States)

    Jayakumar, M.; Chee Soon, Lee

    2015-04-01

    Road network system experienced rapid upgrowth since ages ago and it started developing in Malaysia during the colonization of British due to its significant impacts in transportation field. Flexible pavement, the major road network in Malaysia, has been deteriorating by various types of distresses which cause descending serviceability of the pavement structure. This paper discusses the pavement condition assessment carried out in Sarawak and Sabah, Malaysia to have design solutions for flexible pavement failures. Field tests were conducted to examine the subgrade strength of existing roads in Sarawak at various failure locations, to assess the impact of subgrade strength on pavement failures. Research outcomes from field condition assessment and subgrade testing showed that the critical causes of pavement failures are inadequate design and maintenance of drainage system and shoulder cross fall, along with inadequate pavement thickness provided by may be assuming the conservative value of soil strength at optimum moisture content, whereas the exiting and expected subgrade strengths at equilibrium moisture content are far below. Our further research shows that stabilized existing recycled asphalt and base materials to use as a sub-base along with bitumen stabilized open graded base in the pavement composition may be a viable solution for pavement failures.

  14. Natural gas storage with activated carbon from a bituminous coal

    Science.gov (United States)

    Sun, Jielun; Rood, M.J.; Rostam-Abadi, M.; Lizzio, A.A.

    1996-01-01

    Granular activated carbons ( -20 + 100 mesh; 0.149-0.84 mm) were produced by physical activation and chemical activation with KOH from an Illinois bituminous coal (IBC-106) for natural gas storage. The products were characterized by BET surface area, micropore volume, bulk density, and methane adsorption capacities. Volumetric methane adsorption capacities (Vm/Vs) of some of the granular carbons produced by physical activation are about 70 cm3/cm3 which is comparable to that of BPL, a commercial activated carbon. Vm/Vs values above 100 cm3/cm3 are obtainable by grinding the granular products to - 325 mesh (adsorption capacity increases with increasing pore surface area and micropore volume when normalizing with respect to sample bulk volume. Compared with steam-activated carbons, granular carbons produced by KOH activation have higher micropore volume and higher methane adsorption capacities (g/g). Their volumetric methane adsorption capacities are lower due to their lower bulk densities. Copyright ?? 1996 Elsevier Science Ltd.

  15. Gasification of high ash, high ash fusion temperature bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Guohai; Vimalchand, Pannalal; Peng, WanWang

    2015-11-13

    This invention relates to gasification of high ash bituminous coals that have high ash fusion temperatures. The ash content can be in 15 to 45 weight percent range and ash fusion temperatures can be in 1150.degree. C. to 1500.degree. C. range as well as in excess of 1500.degree. C. In a preferred embodiment, such coals are dealt with a two stage gasification process--a relatively low temperature primary gasification step in a circulating fluidized bed transport gasifier followed by a high temperature partial oxidation step of residual char carbon and small quantities of tar. The system to process such coals further includes an internally circulating fluidized bed to effectively cool the high temperature syngas with the aid of an inert media and without the syngas contacting the heat transfer surfaces. A cyclone downstream of the syngas cooler, operating at relatively low temperatures, effectively reduces loading to a dust filtration unit. Nearly dust- and tar-free syngas for chemicals production or power generation and with over 90%, and preferably over about 98%, overall carbon conversion can be achieved with the preferred process, apparatus and methods outlined in this invention.

  16. The hydrogasification of lignite and sub-bituminous coals

    Science.gov (United States)

    Bhatt, B.; Fallon, P. T.; Steinberg, M.

    1981-02-01

    A North Dakota lignite and a New Mexico sub-bituminous coal have been hydrogenated at up to 900°C and 2500 psi hydrogen pressure. Yields of gaseous hydrocarbons and aromatic liquids have been studied as a function of temperature, pressure, residence time, feed rates and H2/coal ratio. Coal feed rates in excess of 10 lb/hr have been achieved in the 1 in. I. D.×8 ft reactor and methane concentration as high as 55% have been observed. A four-step reaction model was developed for the production and decomposition of the hydrocarbon products. A single object function formulated from the weighted errors for the four dependent process, variables, CH4, C2H6, BTX, and oil yields, was minimized using a program containing three independent iterative techniques. The results of the nonlinear regression analysis for lignite show that a first-order chemical reaction model with respect to C conversion satisfactorily describes the dilute phase hydrogenation. The activation energy for the initial products formation was estimated to be 42,700 cal/gmole and the power of hydrogen partial pressure was found to be +0.14. The overall correlation coefficient was 0.83. The mechanism, the rate expressions, and the design curves developed can be used for scale-up and reactor design.

  17. "Full-Scale Testing of Pavement Response"

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ekdahl, Peter

    1998-01-01

    -analysing FWD data and for calculating the stresses and the strains, the simple method based on Odemark's transformations and Boussinesq's equations appeared to be as good as, or better than, the more sophisticated methods using layered elastic theory or the Finite Element Method.......Three pavement sections in southern Sweden were instrumented in late 1991. Each section have instruments for measuring the strain at the bottom of the asphalt layer, vertical stress and strains in the subgrade and temperatures at different depths. The purpose was to evaluate different theoretical...... methods for determining stresses, strains and deflections in pavement structurers.Falling Weight Deflectometer (FWD) test were done on the test sections, and stresses and strains were measured both under FWD loading and under a rolling wheel load. Different back-analysis procedures were used to derive...

  18. 透水性铺装系统与大气间热水分传输过程实验方法及初期实验研究%Experimental Method and Initial Experimental Research on Permeable Pavement System and Heat Moisture Transmission Procedure in Atmosphere

    Institute of Scientific and Technical Information of China (English)

    李美玲; 刘京; 李彪; 敖靖

    2013-01-01

    城市透水性铺装材料与传统不透水性沥青路面相比具有良好的透水性能,并能随时间缓慢向附近局地大气蒸发散湿,达到改善城市热舒适环境的效果.本文首先针对实际城市交通透水性铺装系统制作了透水性铺装系统实验台,在实验台设计中创新提出了利用气体微压差变化量间接得到透水性铺装系统试样整体蒸发量变化的“差变单元”的实验方法,并利用此实验台在室外进行了典型透水性铺装系统与传统不透水性铺装系统内部各层热水分传输过程的对比实验,以研究和分析孔隙率大小对透水性铺装系统热水分传输效果的影响,进而归纳城市透水性沥青混凝土铺装系统对改善局地大气环境及地下水循环的优越性.%Compared with traditional impermeable bituminous pavement,urban permeable pavement materials have good permeability performances and can diffuse moisture through slow evaporation to nearby atmosphere,thus achieving the effect of improving thermal comfort environment in cities.In this paper,a test rig for permeable pavement system of urban transport was established,and an experimental method was innovatively brought forward that get indirectly "differential unit" of overall evaporation capacity variation of permeable pavement system samples through micro differential pressure variation of air during the design of test rig.And then,outdoor contrast experiments were carried out for heat moisture transmission procedure at respective layers inside typical permeable pavement system and traditional impermeable pavement system,so as to study and analyze the effect of porosity on heat moisture transmitting in permeable pavement system.Finally,the advantages of urban permeable bituminous concrete pavement system for improving partial atmosphere environment and underground water circulation were concluded.

  19. Towards noise classification of road pavements

    OpenAIRE

    Freitas, Elisabete F.; Paulo, Joel; Coelho, J. L. Bento; Pereira, Paulo A. A.

    2008-01-01

    Noise classification of road surfaces has been addressed in many European countries. This paper presents the first approach towards noise classification of Portuguese road pavements. In this early stage, it aims at establishing guidelines for decision makers to support their noise reduction policies and the development of a classification system adapted to the European recommendations. A ranking to provide guidance on tire-road noise emission levels for immediate use by decisio...

  20. Smart pavement sensor based on thermoelectricity power

    Science.gov (United States)

    Yu, Xiong; Zhang, Bin; Tao, Junliang; Liu, Zhen

    2010-04-01

    The aging infrastructure requires a proactive strategy to ensure their functionality and performance. Innovative sensors are needed to develop infrastructures that are intelligent and adaptive. A power supply strategy is among the crucial components to reduce the instrument cost and to ensure the long term function of these embedded sensors. This paper introduces the results of a preliminary study on using thermo-electricity generation to power sensors. This presents an innovative strategy for long term monitoring of pavement performance.

  1. COMPARISON OF PAVEMENT STRUCTURES IN TUNNELS

    OpenAIRE

    Rimac, Ivan; Šimun, Miroslav; Dimter, Sanja

    2014-01-01

    Tunnels pose many fire risks. It is difficult to fight fires in tunnels due to their limited accessibility, the quantity of smoke, and high thermal radiation. Temperatures in tunnel fires can reach 1000 °C, and these fires can spread quickly and persist for long periods, the longest recorded in Europe lasting 53 h. The main requirements of tunnel pavement structures are driving safety and comfort, as well as low construction and maintenance costs. Choosing between using concrete or asphalt pa...

  2. Performance of Drained and Undrained Flexible Pavement Structures Under Wet Conditions Test Data From Accelerated Pavement Test Section 543-Drained

    OpenAIRE

    Harvey, John; Bejarano, Manuel O.; Ali, Abdikarim; Russo, Mark; Mahama, David; Hung, Dave; Preedonant, Pitipat

    2004-01-01

    This report is the first in a series of four reports that describe the results of accelerated pavement tests on full-scale pavements with “wet†base conditions at the Pavement Research Center, located at the University of California Berkeley Richmond Field Station (RFS). The report contains a summary of the results and associated analysis of a pavement section comprised of three lifts of asphalt concrete, an asphalt treated permeable base (ATPB) layer, and untreated aggregate base layers o...

  3. Bituminous reference document: synthesis of knowledge on the long time behavior of bituminous packages; Dossier de reference bitume: synthese des connaissances sur le comportement a long terme des colis bitumes

    Energy Technology Data Exchange (ETDEWEB)

    Sercombe, J.; Adenot, F.; Vistoli, P.P.; Parraud, S.; Riglet-Martial, C.; Gwinner, B.; Felines, I.; Tiffreau, C.; Libert, M

    2004-07-01

    This document is a synthesis of the knowledge acquired at the CEA on the behavior of bituminous packages. In this framework, the CEA studied bituminous packages in generic conditions of a package lifetime. The main factors, the evolution mechanisms and influential parameters have been determined and quantitative s simulation have been developed. After a description of the main initial bituminous packages characterizations, the evolutions in saturated and un-saturated environment are exposed. (A.L.B.)

  4. New structural systems for zero-maintenance pavements. Volume 2: Analysis of anchored pavements using ANSYS

    Science.gov (United States)

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

    1980-08-01

    A set of procedures to evaluate the response of an anchored pavement subjected to vehicle static loads, moisture variation in the subgrade, and/or temperature variation through the surface of the pavement is presented. These procedures include two computer programs known as FEMESH and ANSYS. The FEMESH program generates rectangular meshes in either a two or three dimensional coordinate system for any prespecified number and spacing of nodes. The ANSYS program evaluates the stresses, strains, and the deflections at all elements in each material included in the analytical model.

  5. An analysis of pavement heat flux to optimize the water efficiency of a pavement-watering method

    International Nuclear Information System (INIS)

    Pavement-watering as a technique of cooling dense urban areas and reducing the urban heat island effect has been studied since the 1990's. The method is currently considered as a potential tool for and climate change adaptation against increasing heat wave intensity and frequency. However, although water consumption necessary to implement this technique is an important aspect for decision makers, optimization of possible watering methods has only rarely been conducted. An analysis of pavement heat flux at a depth of 5 cm and solar irradiance measurements is proposed to attempt to optimize the watering period, cycle frequency and water consumption rate of a pavement-watering method applied in Paris over the summer of 2013. While fine-tuning of the frequency can be conducted on the basis of pavement heat flux observations, the watering rate requires a heat transfer analysis based on a relation established between pavement heat flux and solar irradiance during pavement insolation. From this, it was found that watering conducted during pavement insolation could be optimized to 30-min cycles and water consumption could be reduced by more than 80% while reducing the cooling effect by less than 13%. - Highlights: • The thermal effects of pavement-watering were investigated in Paris, France. • Pavement-watering was found to significantly affect pavement heat flux 5 cm deep. • When insolated, a linear relation was found between heat flux and solar radiation. • Pavement-watering did not alter its slope, but introduced a negative intercept. • Subsequent improvements of the watering period, frequency and rate are proposed

  6. Modeling the Hydrologic Processes of a Permeable Pavement System

    Science.gov (United States)

    A permeable pavement system can capture stormwater to reduce runoff volume and flow rate, improve onsite groundwater recharge, and enhance pollutant controls within the site. A new unit process model for evaluating the hydrologic performance of a permeable pavement system has be...

  7. Nutrient Infiltrate Concentrations from Three Permeable Pavement Types

    Science.gov (United States)

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha...

  8. Full-Depth Asphalt Pavements for Parking Lots and Driveways.

    Science.gov (United States)

    Asphalt Inst., College Park, MD.

    The latest information for designing full-depth asphalt pavements for parking lots and driveways is covered in relationship to the continued increase in vehicle registration. It is based on The Asphalt Institute's Thickness Design Manual, Series No. 1 (MS-1), Seventh Edition, which covers all aspects of asphalt pavement thickness design in detail,…

  9. Research on pavement crack recognition methods based on image processing

    Science.gov (United States)

    Cai, Yingchun; Zhang, Yamin

    2011-06-01

    In order to overview and analysis briefly pavement crack recognition methods , then find the current existing problems in pavement crack image processing, the popular methods of crack image processing such as neural network method, morphology method, fuzzy logic method and traditional image processing .etc. are discussed, and some effective solutions to those problems are presented.

  10. Shakedown analysis of anisotropic asphalt concrete pavements with clay subgrade

    Energy Technology Data Exchange (ETDEWEB)

    Boulbibane, M.; Collins, I.F. [Auckland Univ., Auckland (New Zealand). Dept. of Engineering Science; Weichert, D. [RWTH-Aachen Inst. of General Mechanics, Aachen (Germany); Raad, L. [Alaska-Fairbanks Univ., Fairbanks, AK (United States). Transportation and Research Centre

    2000-08-04

    A mathematical model has been presented which can predict the effect of inherent anisotropic cohesion on the long-term behaviour of multilayered pavements. The model is based on the lower bound theorem of shakedown analysis and makes allowances for variations of soil strength with direction. Pavements operating above the critical shakedown load exhibit plastic strains under long term repeated loading conditions and eventually result in deep ruts. This model was used to examine the influence of subgrade properties on the shakedown behaviour of two-layer pavement systems consisting of an asphalt concrete layer and a granular base over a clay subgrade. The shakedown load for pavements under repeated loadings was estimated and the effects of variables such as temperature, asphalt thickness, stiffness and strength were determined. The materials in the various layers of the pavement were modeled as elastic-plastic Mohr-Coulomb materials. 38 refs., 3 tabs., 5 figs.

  11. Monitoring asphalt pavement damages using remote sensing techniques

    Science.gov (United States)

    Mettas, Christodoulos; Themistocleous, Kyriacos; Neocleous, Kyriacos; Christofe, Andreas; Pilakoutas, Kypros; Hadjimitsis, Diofantos

    2015-06-01

    One of the main issues in the maintenance plans of road agencies or governmental organizations is the early detection of damaged asphalt pavements. The development of a smart and non-destructive systematic technique for monitoring damaged asphalt pavements is considered a main priority to fill this gap. During the 1970's, remote sensing was used to map road surface distress, while during the last decade, remote sensing became more advanced, thereby assisting in the evolution of the identification and mapping of roads. Various techniques were used in order to explore condition, age, weaknesses and imperfections of asphalted pavements. These methods were fairly successful in the classification of asphalted surfaces and in the detection of some of their characteristics. This paper explores the state of the art of using remote sensing techniques for monitoring damaged pavements and some typical spectral profiles of various asphalt pavements in Cyprus area acquired using the SVC1024 field spectroradiometer.

  12. Pavement structure mechanics response of flexible on semi-flexible overlay that based on the old cement concrete pavement damage

    Directory of Open Access Journals (Sweden)

    Jiang Ruinan

    2015-01-01

    Full Text Available The old cement pavement damage status directly affect the design of the paving renovation. Based on the state of the old road investigation, combined with the research data at home and abroad, use the control index that average deflection, deflection value and CBR value to determine the reasonable time to overlay. Draw up the typical pavement structure according to the principle of combination of old cement pavement overlay structure design, and calculated that the tensile stress and shear stress in asphalt layer ,semi-flexible layer and the tensile in the old cement pavement adopting BISA3.0 statics finite element analysis model when modulus in the old road was diminishing. Use the computed result to analyses the influence of old road damage condition the influence of pavement structure.

  13. Pavement Pre- and Post-Treatment Performance Models Using LTPP Data

    OpenAIRE

    Lu, Pan; Tolliver, Denver

    2012-01-01

    This paper determines that pavement performance in International Roughness Index (IRI) is affected by exogenous interventions such as pavement age, precipitation level, freeze-thaw level, and lower level preservation maintenance strategies. An exponential function of pavement age was used to represent pavement IRI performance curves. Moreover, this paper demonstrates a method which calculates short-term post-pavement performance models from maintenance effect models and pre-treatment performa...

  14. Measurement of the Cooling Efficiency of Pavement-Watering as an Urban Heat Island Mitigation Technique

    Directory of Open Access Journals (Sweden)

    Martin Hendel

    2015-03-01

    Pavement watering was found to lower pavement surface temperatures by several degrees for several hours after watering, while also strongly reducing its cooling rate a few hours before and after sunset. Heat flux and storage at a depth of 5 cm in the pavement were also found to have been significantly reduced, especially during direct sunlight exposure, but also when the pavement was in the shade. Uninterrupted watering appears necessary during direct sunlight exposure of the pavement to maximize efficiency.

  15. Tire Footprint Affects Hydroplaning On Wet Pavement

    Science.gov (United States)

    Yager, Thomas J.

    1989-01-01

    Recent investigations of tire hydroplaning at highway speeds reveal, in addition to inflation pressure, tire-footprint aspect ratio (FAR), defined as width divided by length of tire surface in contact with pavement, significantly influences speed at which dynamic hydroplaning begins. Tire speeds and forces developed during tests of up to 65 mi/h (105 km/h) were monitored on flooded test surface to identify development of hydroplaning. Study focused on automotive tires because FAR's of automotive tires vary more than those of aircraft tires.

  16. Global market trade policy analysis for petroleum oils and oils obtained from bituminous minerals, crude

    Directory of Open Access Journals (Sweden)

    Bagheri, F.

    2012-01-01

    Full Text Available This article is based on surveying the custom tariffs imposed on the world export market of Petroleum Oils and Oils Obtained from Bituminous Minerals, Crude. We obtained the data according to the most updated available data provided online by UNCTAD and World Bank. The results indicate that none of the 142 countries in the world market of this product have imposed non-tariff trade barriers on the import of Petroleum Oils and Oils Obtained from Bituminous Minerals, Crude. The developed countries and the countries with transition economies are the main world import partners. European Union, United States, China, Japan, South Korea, Canada, Singapore, Taiwan, Thailand, South Africa, Australia, Turkey, Brazil, Sweden and Belarus are the examples and have imposed low custom tariffs on Petroleum Oils and Oils Obtained from Bituminous Minerals, Crude.

  17. Safety assessment for the bituminization facility of the medium-level waste

    International Nuclear Information System (INIS)

    The safety assessment for the home-made bituminization facility of the medium-level waste during hot test is made. The average external dose equivalent per month is 0.136 x 10-2 Sv. The radioactive substance released into the environment is much lower than the permissible limit. The danger of burning and exploding of the bituminized product is avoided because the operation temperature is controlled strictly below 170 C degree. The report also briefly describes the structural characteristic of the facility, the main process and radiation protection and safety measures

  18. Project and design of apparatus and equipment of pilot plant experimental bituminization line PS 44 EBO

    International Nuclear Information System (INIS)

    The modifications are described made in the design of major components of the pilot plant experimental bituminization line involving: the mixing equipment, the film rotor evaporator, the calciner, and various transport mechanisms for handling drums and containers. The difficulty and complexity of the problem which Kralovopolska strojirna Brno, the end supplier of the bituminization line, will have to tackle is evident mainly from the case of bridge cranes, which feed the line, and the full-portal gantry crane which handles the containers and drums at regional sites of radioactive waste disposal. (Z.M.)

  19. Installation in the A-1 plant of an experimental bituminization line by VUCHZ

    International Nuclear Information System (INIS)

    Following the termination of the experimental operation of the bituminization line at the Research Institute for Chemical Installations in Brno, the line was dismantled and transferred to the nucler power plant in Jaslovske Bohunice. The installation of the line, the layout of the assemblies are described and the results of tests with non-radioactive simulated wastes and actual radioactive wastes briefly described. An amount of 3.2 m3 of actual radioactive wastes from the V-1 nuclear power plant was processed in the tests. The results confirmed the suitability of bituminization for processing liquid radioactive wastes from WWER nuclear power plants. (Z.M.)

  20. Survival Analysis of Fatigue and Rutting Failures in Asphalt Pavements

    Directory of Open Access Journals (Sweden)

    Pabitra Rajbongshi

    2016-01-01

    Full Text Available Fatigue and rutting are two primary failure mechanisms in asphalt pavements. The evaluations of fatigue and rutting performances are significantly uncertain due to large uncertainties involved with the traffic and pavement life parameters. Therefore, deterministically it is inadequate to predict when an in-service pavement would fail. Thus, the deterministic failure time which is known as design life (yr of pavement becomes random in nature. Reliability analysis of such time (t dependent random variable is the survival analysis of the structure. This paper presents the survival analysis of fatigue and rutting failures in asphalt pavement structures. It is observed that the survival of pavements with time can be obtained using the bathtub concept that contains a constant failure rate period and an increasing failure rate period. The survival function (S(t, probability density function (pdf, and probability distribution function (PDF of failure time parameter are derived using bathtub analysis. It is seen that the distribution of failure time follows three parametric Weibull distributions. This paper also works out to find the most reliable life (YrR of pavement sections corresponding to any reliability level of survivability.

  1. An Innovative Strategy for Maintenance of Highway Pavement

    Directory of Open Access Journals (Sweden)

    Sandeep Choudhary, Dr. P. K. Agarwal

    2013-05-01

    Full Text Available Highway pavement are deteriorating fast due to lack of timely maintenance, leading to higher vehicle operating costs, increasing number of accidents etc. Thus, timely maintenance of the highway pavement is essential. Because, once pavements start to deteriorate; they deteriorate rapidly beyond the point where maintenance is effective. Thus, there is an urgent need to develop a strategy for maintenance of pavement in a huge highway network. In this study, an innovative strategy for maintenance of highway pavement is proposed. A two stage maintenance strategy is proposed. In stage I, it is proposed to determine priority of highway sections. In Stage II, priority of various maintenance activities to be carried out on various sections will be determined. Maintenance priority of the pavement is based on importance of the road sections, present road conditions, and future road conditions. The methodology proposed in this study is illustrated with the help of example of some hypothetical highway network consisting of 4 sections. Analysis results indicated that the proposed strategy is considered to be more rational, innovative & logical. Some strategies for maintenance of urban roads are also presented in this study. Therefore, it is expected that this study will be useful for maintenance of huge highway network in India and thus will be useful for preserving huge asset of pavement infrastructure.

  2. Evaluation of accelerated deterioration in NAPTF flexible test pavements

    Institute of Scientific and Technical Information of China (English)

    Kasthurirangan GOPALAKRISHNAN

    2008-01-01

    Previous research studies have successfully demonstrated the use of artificial neural network(ANN)models for predicting critical structural responses and layer moduli of highway flexible pavements.The primary objective of this study was to develop an ANN-based approach for backcalculation of pavement moduli based on heavy weight deflectometer(HWD)test data,especially in the analysis of airport flexible pavements subjected to new generation aircraft(NGA).Two medium-strength subgrade flexible test sections,at the National Airport Pavement Test Facility(NAPTF),were modeled using a finite element(FE) based pavement analysis program,which can consider the non-linear stress-dependent behavior of pavement geomaterials.A multi-layer,feed-forward network which uses an error-backpropagation algorithm was trained to approximate the HWD backcalculation function using the FE program generated synthetic database.At the NAPTF,test sections were subjected to Boeing 777 (B777)trafficking on one lane and Boeing 747(B747)trafficking on the other lane using a test machine.To monitor the effect of traffic and climatic variations on pavement structural responses.HWD tests were conducted on the traffieked lanes and on the untraffieked centerline of test sections as trafficking progressed.The trained ANN models were successfully applied on the actual HWD test data acquired at the NAPTF to predict the asphalt concrete moduli and non-1inear subgrade moduli of the medium-strength subgrade flexible test sections.

  3. Automated management for pavement inspection system (AMPIS)

    Science.gov (United States)

    Chung, Hung Chi; Girardello, Roberto; Soeller, Tony; Shinozuka, Masanobu

    2003-08-01

    An automated in-situ road surface distress surveying and management system, AMPIS, has been developed on the basis of video images within the framework of GIS software. Video image processing techniques are introduced to acquire, process and analyze the road surface images obtained from a moving vehicle. ArcGIS platform is used to integrate the routines of image processing and spatial analysis in handling the full-scale metropolitan highway surface distress detection and data fusion/management. This makes it possible to present user-friendly interfaces in GIS and to provide efficient visualizations of surveyed results not only for the use of transportation engineers to manage road surveying documentations, data acquisition, analysis and management, but also for financial officials to plan maintenance and repair programs and further evaluate the socio-economic impacts of highway degradation and deterioration. A review performed in this study on fundamental principle of Pavement Management System (PMS) and its implementation indicates that the proposed approach of using GIS concept and its tools for PMS application will reshape PMS into a new information technology-based system providing a convenient and efficient pavement inspection and management.

  4. Study on Asphalt Pavement Fatigue-Damage with Forecasting Axial Load Spectrum%按预测轴载谱分析沥青路面的疲劳损伤

    Institute of Scientific and Technical Information of China (English)

    马林; 葛折圣; 胡晓倩; 黄明波

    2011-01-01

    现行《公路沥青路面设计规范》(JTGG D50-2006)轴载等效换算方法难以反映超载、重载交通对路面结构的影响.结构层参数取值未考虑结构层在疲劳过程中的材料损伤,是重载交通沥青路面出现早期破坏的原因之一.采用预测轴载谱和Miner法则,计算分析了路面结构的疲劳损伤累积过程,并考虑不同使用阶段路面基层模量衰减对路面结构损伤进程的影响.结果表明,半刚性基层厚沥青面层路面结构的疲劳损伤累积进程明显优于目前国内较典型的半刚性基层沥青路面结构.研究结果为重载交通沥青路面结构设计指明了方向.%In Specifications for Design of Highway Asphalt Pavement (JTG D50-2006), the method of Equivalent Axle Loads could not reflect the influence on pavement structure by overload and heavy-load transportation. And the parameter of structural layers was no considering the material damage in the process of fatigue. It is one of the reasons why asphalt pavement is damaged early. The fatigue-damage accumulation in pavement structure was analyzed by using the forecasting axle load spectrum and Miner law. And the parameter of structural layers attenuated while the material damage in the process of fatigue. The results show that the fatigue damage accumulation process of semi-rigid base total thickness asphalt pavement structure is significantly better than the current domestic typical semi-rigid bituminous pavement structure. So this research results can help the development of structure design of heave-load asphalt pavement.

  5. Development of Improved Mechanistic Deterioration Models for Flexible Pavements

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman, Hans Larsen

    1998-01-01

    The paper describes a pilot study in Denmark with the main objective of developing improved mechanistic deterioration models for flexible pavements based on an accelerated full scale test on an instrumented pavement in the Danish Road Tessting Machine. The study was the first in "International...... Pavement Subgrade Performance Study" sponsored by the Federal Highway Administration (FHWA), USA. The paper describes in detail the data analysis and the resulting models for rutting, roughness, and a model for the plastic strain in the subgrade.The reader will get an understanding of the work needed...

  6. Adaptation of AASHTO Pavement Design Guide for Local Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Hajek, J.J. [Applied Research Associates Inc., Toronto, ON (Canada)

    2001-07-01

    The methodology used to adapt the 1993 AASHTO Guide for Design of Pavement Structures to Ontario conditions was described. The guide expresses the effect of traffic loads on pavement performance using the concept of axle Load Equivalency Factors (LEF). LEF is regarded as a pavement damage factor assigned to each specific load and axle configuration. The size of LEF is related to the damage that is expected to occur from a standard load of 80 kN carried by a single axle with dual tires. The factors are summarized to yield the number of Equivalent Single Axle Loads (ESALs) a pavement is expected to sustain during its life. A summary was also provided of the additional work done to prepare for the transition to the proposed mechanistically-based 2002 AASHTO Guide. The paper focused only on the design of flexible pavements in terms of load characterization using equivalent single axle loads along with axle load spectra, below grade and material characterization, plus initial and terminal serviceability and reliability. The AASHTO Guide uses two parameters to deal with design reliability: design reliability level and overall standard deviation. Data collected on Ontario highway pavements and materials was used for assessing the design inputs. Other data was also collected from research and development studies, laboratory experiments, and from a survey of experienced pavement design engineers. The end result was a new grouping of Ontario soils for pavement design, recommended values for the resilient modulus of below grade soils, recommendations for structural layer coefficients for Ontario pavement materials and recommendations for the initial pavement serviceability based on Ontario smoothness specifications. Results of calibration and verification processes indicate that for new flexible pavements, the AASHTO-Ontario model is in good agreement with the observed results. It was recommended that the calibration and verification of the AASHTO-Ontario model should be a

  7. Research on Alkaline Filler Flame-Retarded Asphalt Pavement

    Institute of Scientific and Technical Information of China (English)

    HU Shuguang; ZHANG Houji; WANG Jiaolan

    2006-01-01

    Used as flame retardant of tunnel asphalt pavement, organic bromides produce a large amount of poisons and smoke in construction and flame retardation stage. The alkaline filler was found to replace mineral filler, and the flame-retarded asphalt mixtures were produced. Experimental results show that these asphalt mixtures are smoke restrained; the performances and construction technology of asphalt pavement are not influenced; also the alkaline filler is of low-price. So this kind of flame-retarded asphalt mixtures is suitable for tunnel pavement.

  8. New approach for calculating permanent deformation in asphalt pavement

    Institute of Scientific and Technical Information of China (English)

    TAN Yi-qiu; CHEN Feng-chen; LIU Hao; SU Xin; DONG Ze-jiao; DONG Yu-ming

    2010-01-01

    A new approach using the Fiber Bragg Grating(FBG)sensor and viscoelastic model to monitor and analyze the internal strain and temperature of asphalt pavement is proposed.Some parameters including peak strain,temperature and loading time were calculated with the application of multi-dimensional sensors group.These parameters were incorporated with viscoelastic model of five units to evaluate the permanent deformation of pavement.An application example was conducted,and the results show that it is feasible to analyze and calculate the permanent deformation of pavement structures with FBG sensors.

  9. Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values

    OpenAIRE

    Noureldin, Menna; Fricker, Jon D; Sinha, Kumares C.

    2015-01-01

    Cost-Effective Pavement Performance Management of Indiana's Enhanced National Highway System through Strategic Modification of the Pavement Rehabilitation Treatment Trigger Values Presented during Session 3: Policy and Funding, moderated by Magdy Mikhail, at the 9th International Conference on Managing Pavement Assets (ICMPA9) in Alexandria, VA. Includes conference paper and PowerPoint slides.

  10. Development Of Optimum Maintenance amp Rehabilitation Strategies For Urban Bituminous Concrete Surfaced Roads

    Directory of Open Access Journals (Sweden)

    Dr Pardeep Kumar Gupta

    2015-02-01

    Full Text Available ABSTRACT In India the road traffic volume has increased manifolds during the post-independence period. The traffic axle loading may also in many cases be much heavier than the specified limit. As a result of which the existing road network has been subjected to severe deterioration leading to premature failure of the pavements.In such a scenario development of the effective pavement management strategies would furnish useful information to ensure the compatible and cost- effective decisions so as to keep the existing road network intact. The pavement deterioration models can prove to be an effective tool which can assist highway agencies to forecast economic and technical outcome of possible investment decisions regarding maintenance management of pavements. The optimum maintenance and rehabilitation strategies developed in this study would be useful in planning pavement maintenance strategies in a scientific manner and ensuring rational utilization of limited maintenance funds. Once this strategy for urban road network is implemented and made operational this would serve as window to the other urban road network of different regions.

  11. ANÁLISIS TÉRMICO DE GEOSINTÉTICOS UTILIZADOS EN LA REHABILITACIÓN DE PAVIMENTOS THERMAL ANALYSIS OF GEOSYNTHETICS USED IN THE REHABILITATION OF PAVEMENTS

    Directory of Open Access Journals (Sweden)

    José Norambuena-Contreras

    2009-04-01

    Full Text Available El crecimiento de la utilización de los geosintéticos en la rehabilitación de pavimentos flexibles se ha visto incrementado de forma considerable desde la década de los años setenta. Estos materiales presentan una serie de ventajas que motivan su gran demanda en la actualidad. La utilización de geosintéticos en la rehabilitación se basa en su capacidad de resistir deformaciones, atenuando las fisuras y grietas que pudiesen presentar los pavimentos flexibles. Se han realizado dos experiencias en laboratorio para simular el proceso de puesta en obra de los geosintéticos en la zona de intercapa. El procedimiento consiste en verter sobre el geosintético extendido, una capa de mezcla bituminosa en caliente comprendida entre 135 - 165 ºC. El análisis térmico de los resultados obtenidos avala significativamente al material poliéster (PS, con respecto al polipropileno (PP, en futuras aplicaciones de rehabilitación de pavimentos flexibles.The use of geosynthetics in rehabilitating flexible pavements has substantially expanded since the mid-seventies. These materials have a number of advantages that motivate their demand at present. The use of geosynthetics in rehabilitation is based on its ability to resist deformation, attenuating fissures and cracks that flexible pavements could present. Two experiments have been done to simulate the process of placing the geosynthetics in the interlayer area. The process consists of pouring on the spread geosynthetics a layer of hot bituminous mix between 135-165 °C. The thermal analysis of the results shows a significant performance of polyester (PS, compared to polypropylene (PP, in future applications for the rehabilitation of flexible pavements.

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

    Science.gov (United States)

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

    1980-08-01

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

  13. Towards an Accurate Stress Dependant Time & Frequency Domain VE Response Model for Bituminous Binders

    NARCIS (Netherlands)

    Woldekidan, M.F.; Huurman, M.; Pronk, A.C.

    2010-01-01

    Linear viscoelastic properties of bituminous binders for short loading times are analyzed using dynamic mechanical analysis methods. Dynamic Shear Rheometer (DSR) test with parallel plate (PP) configuration is widely used for this purpose. Due to the complex stress distribution over the cross-sectio

  14. Effect of Pavement Conditions on Rolling Resistance

    Directory of Open Access Journals (Sweden)

    Mr.Dipanjan Mukherjee

    2014-07-01

    Full Text Available Rolling resistance is the force acting on a vehicle over a full journey. It is generated by the hysteresis of tyre and pavement. Rolling resistance, sometimes called rolling friction or rolling drag, is the force resisting the motion when a body (such as a ball, tire, or wheel rolls on a surface. It is mainly caused by non-elastic effects; that is, not all the energy needed for deformation (or movement of the wheel, roadbed, etc. is recovered when the pressure is removed. A hysteresis phenomenon can be observed when viscoelastic materials undergo a load-then-unload process. A typical hysteresis curve of viscoelastic material can be found. The shadow area enclosed by the hysteresis loop represents energy loss. A characteristic of a deformable material such that the energy of deformation is greater than the energy of recovery. The rubber compound in a tire exhibits hysteresis. As the tire rotates under the weight of the vehicle, it experiences repeated cycles of deformation and recovery, and it dissipates the hysteresis energy loss as heat. Hysteresis is the main cause of energy loss associated with rolling resistance and is attributed to the viscoelastic characteristics of the rubber. Materials that have a large hysteresis effect, such as rubber, which bounce back slowly, exhibit more rolling resistance than materials with a small hysteresis effect that bounce back more quickly and more completely, such as steel or silica. Low rolling resistance tires typically incorporate silica in place of carbon black in their tread compounds to reduce low-frequency hysteresis without compromising traction. Note that railroads also have hysteresis in the roadbed structure. Like the fuel consumption, rolling resistance also has a significant relationship with velocity. experiment has shown that, for a 32-tonn goods vehicle, rolling resistance contributes about 70% of total drag when driven at 50km/h and about 37% at 100km/h. An important issue which should not

  15. Long-Term Field Performance of Pervious Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Aleksandra Radlińska

    2012-01-01

    Full Text Available The work described in this paper provides an evaluation of an aged pervious concrete pavement in the Northeastern United States to provide a better understanding of the long-lasting effects of placement techniques as well as the long-term field performance of porous pavement, specifically in areas susceptible to freezing and thawing. Multiple samples were taken from the existing pavement and were examined in terms of porosity and unit weight, compressive and splitting tensile strength, and the depth and degree of clogging. It was concluded that improper placement and curing led to uneven pavement thickness, irregular pore distribution within the pervious concrete, and highly variable strength values across the site, as well as sealed surfaces that prevented infiltration.

  16. Reliability-based Design Procedure for Flexible Pavements

    OpenAIRE

    Dinegdae, Yared Hailegiorgis

    2015-01-01

    Load induced top-down fatigue cracking has been recognized recently as a major distress phenomenon in asphalt pavements. This failure mode has been observed in many parts of the world, and in some regions, it was found to be more prevalent and a primary cause of pavements failure. The main factors which are identified as potential causes of top down fatigue cracking are primarily linked to age hardening, mixtures fracture resistance and unbound layers stiffness. Mechanistic Empirical analytic...

  17. Optical fiber feasibility study in Accelerated Pavement Testing facility

    OpenAIRE

    Bueche, N.; Rychen, P.; Dumont, A.-G.; Santagata, E.

    2009-01-01

    The presented research has been carried out within the European project Intelligent Roads (INTRO). The major objective followed was to assess the potential of optical fiber for pavement monitoring in comparison with classical strain gauges. Thus, both measurement devices have been tested under the same conditions in a full scale Accelerated Pavement Testing (APT) at LAVOC. This facility allows the user to control different parameters such as loading configuration and temperature and, as a mat...

  18. Evaluation of pavement skid resistance using high speed texture measurement

    Directory of Open Access Journals (Sweden)

    Jay N. Meegoda

    2015-12-01

    Full Text Available Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which also causes disruption of traffic in use. In this research skid numbers and MPD from 5 new asphalt pavements and 4 old asphalt pavements were collected using a locked wheel skid trailer and a vehicle mounted laser. Using the data collected, a correlation between the skid number (SN40R collected by locked wheel skid tester and the texture data or MPD collected by a vehicle mounted laser operating at highway speeds was developed. The proposed correlation for new pavements was positive for MPD values less than 0.75 mm to reach a peak SN40R value, then there was a negative correlation as the MPD increases until the MPD value was equal to 1.1 mm and beyond the MPD value of 1.1 mm to the maximum value of 1.4 mm, SN40R value remained almost constant. There were significant data scatter for the MPD value of 0.8 mm. To explain these results, water film thickness during the friction test was calculated and the critical MPD was defined. The effect of sealed water pool on the SN40R was discussed. The test result showed a similar trend for older asphalt pavements, but with lower SN40R values due to the polishing of pavement micro-texture by traffic. Hence, a reduction factor was proposed for older pavements based on cumulative traffic volume for the above correlation to predict the skid resistance of older pavements.

  19. Improvement of the functional pavement quality with asphalt rubber mixtures

    OpenAIRE

    Fontes, Liseane P. T. L.; Pereira, Paulo A. A.; Pais, Jorge C.; Trichês, Glicério

    2006-01-01

    Skid resistance and texture are important safety characteristics which need to be considered in flexible pavement design, maintenance and rehabilitation. The main objective of this paper is to optimize surface texture characteristics in asphalt rubber pavements, mainly macrotexture to reduce splash, spray and hydroplaning and microtexture to increase friction at low and high speeds. The objective was accomplished by measuring the friction surface with two different tests: (i) B...

  20. Visualizing Pavement Management Data at the Project Level

    OpenAIRE

    Rydholm, Timothy C.; Luhr, David R.

    2015-01-01

    As a Pavement Management System increases in maturity, so does the amount of information powering it. As the level of information grows, efficiently communicating the data becomes difficult. The Washington State Department of Transportation (WSDOT) has a long history of collecting and storing data that is electronically accessible and referenced against a Linear Referencing System (LRS). This data includes pavement surveys, contracts , capital projects, roadway configuration, maintenance acti...

  1. Field environmental evaluation plan for sulfur use in pavements

    Science.gov (United States)

    Saylak, D.; Deuel, L. E.; Izatt, J. O.; Jacobs, C.; Zahray, R.; Ham, S.

    1982-07-01

    The use of sulfur in highway paving mixtures is discussed. The evaluation procedures deal with the safety and environmental aspects of storage and handling, formulation, construction, operation and maintenance of highway pavements containing sulfur, including the possible generation of noxious and abnoxious fumes, dust and gases. Methods and equipment for monitoring potential emissions and pollutants are recommended and safety practices for the handling of sulfur and sulfur-modified asphalt mixtures and pavements are discussed.

  2. Application of surplus and waste materials in roads pavement making

    OpenAIRE

    S.M. Mousavi; Fazli, A. H.; Rouzmehr, F.

    2011-01-01

    Nowadays there are a lot of problems about surpluses and debris made by humans all around the world. Lots of these surpluses seriously harm our natural environment. Reuse of this kind of materials in other processes like building constructions or pavement help our natural environment in every aspect. Asphalt concrete is the main part of pavements in most parts of the world with an increasing rate of production in need of more ways and roads. In this paper we will provide...

  3. Use of lime cement stabilized pavement construction

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M.A.; Raju, G.V.R.P. [JNTU College of Engineering, Kakinada (India). Dept. of Civil Engineering

    2009-08-15

    Expansive clay is a major source of heave induced structural distress. Swelling of expansive soils causes serious problems and produce damages to many structures. Many research organizations are doing extensive work on waste materials concerning the feasibility and environmental suitability. Fly ash, a waste by product from coal burning in thermal power stations, is abundant in India causing severe health, environmental and disposal problems. Attempts are made to investigate the stabilization process with model test tracks over expansive subgrade in flexible pavements. Cyclic plate load tests are carried out on the tracks with chemicals like lime and cement introduced in fly ash subbase laid on sand and expansive subgrades. Test results show that maximum load carrying capacity is obtained for stabilized fly ash subbase compared to untreated fly ash subbase.

  4. Pavement Response to Variable Tyre Pressure of Heavy Vehicles

    Directory of Open Access Journals (Sweden)

    Arshad Ahmad Kamil

    2016-01-01

    Full Text Available In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

  5. Environmental assessment of pavement infrastructure: A systematic review.

    Science.gov (United States)

    Inyim, Peeraya; Pereyra, Jose; Bienvenu, Michael; Mostafavi, Ali

    2016-07-01

    Through a critical review and systematic analysis of pavement life cycle assessment (LCA) studies published over the past two decades, this study shows that the available information regarding the environmental impacts of pavement infrastructure is not sufficient to determine what pavement type is more environmentally sustainable. Limitations and uncertainties related to data, system boundary and functional unit definitions, consideration of use and maintenance phase impacts, are identified as the main reasons for inconsistency of reported results in pavement LCA studies. The study outcomes also highlight the need for advancement of knowledge pertaining to: (1) utilization of performance-adjusted functional units, (2) accurate estimation of use, maintenance, and end-of-life impacts, (3) incorporation of the dynamic and uncertain nature of pavement condition performance in impact assessment; (4) development of region-specific inventory data for impact estimation; and (5) consideration of a standard set of impact categories for comparison of environmental performance of different pavement types. Advancing the knowledge in these areas is critical in providing consistent and reliable results to inform decision-making toward more sustainable roadway infrastructure. PMID:27045541

  6. Noise emission of concrete pavement surfaces produced by diamond grinding

    Directory of Open Access Journals (Sweden)

    Jens Skarabis

    2015-04-01

    Full Text Available In Germany, diamond grinding is frequently used to improve the evenness and skid resistance of concrete pavement surfaces. Since diamond grinding has been observed to affect tyre/pavement noise emission favourably, the relationship among surface texture, concrete composition and noise emission of concrete pavement surfaces has been systematically investigated. The simulation program SPERoN was used in a parameter study to investigate the main factors which affect noise emission. Based on the results of the simulations, textured concrete surfaces were produced by using a laboratory grinding machine. As well as the composition of the concrete, the thickness and spacing of the diamond blades were varied. The ability of the textured surfaces to reduce noise emission was assessed from the texture characteristics and air flow resistance of textured surfaces measured in the laboratory. It was found that concrete composition and, in particular, the spacing of the blades affected the reduction in noise emission considerably. The noise emission behaviour of numerous road sections was also considered in field investigations. The pavement surfaces had been textured by diamond grinding during the last years or decades. The results show that diamond grinding is able to provide good, durable noise-reducing properties. Several new pavement sections were investigated using thicknesses and spacings of the blades similar to those used in the laboratory to optimize noise emission reduction. It is concluded that diamond grinding is a good alternative to exposed aggregate concrete for the production of low-noise pavement surfaces.

  7. Factors influencing PM 10 emissions from road pavement wear

    Science.gov (United States)

    Gustafsson, Mats; Blomqvist, Göran; Gudmundsson, Anders; Dahl, Andreas; Jonsson, Per; Swietlicki, Erik

    Accelerated pavement wear is one of the major environmental disadvantages of studded tyres in northern regions and results in increased levels of PM 10. Measurements of PM 10 in a road simulator hall have been used to study the influence of pavement properties, tyre type and vehicle speed on pavement wear. The test set-up included three different pavements (one granite and two quartzite with different aggregate sizes), three different tyre types (studded, non-studded, and summer tyres) and different speeds (30-70 km h -1). The results show that the granite pavement was more prone to PM 10 production compared to the quartzite pavements. Studded winter tyres yield tens of times higher PM 10 concentrations compared to non-studded winter tyres. Wear from summer tyres was negligible in comparison. It was also shown that wear is strongly dependent on speed; every 10 km h -1 increase yielded an increase of the PM 10 concentration of 680 μg m -3 in one of the simulator experiments.

  8. Numerical Analysis of Asphalt Pavements under Moving Wheel Loads

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The responses of the pavement in service are the basis for the design of the semi-rigid base course asphalt pavement.Due to the dynamic characteristics of wheel loads and the temperature loads,the dynamic response analysis is very significant.In this article, the dynamic analysis of asphalt pavement under moving wheel loads is carried out using finite element method coupled with non-reflective boundary method.The influences of the base modulus, thickness, the vehicle velocity, the tire pressure, and the contact condition at the interface are studied using parametric analysis.The results of numerical analysis show that it is not appropriate to simply increase the base modulus or thickness in the design.It would be beneficial if the base design is optimized synthetically.The increase of damping is also beneficial to the pavements because of the surface deflection and the stresses declination.Furthermore, the good contact condition at the interface results in good performance because it combines every layer of the pavement to work together.As overload aggravates the working condition of the pavement, it is not allowed.

  9. Urban pavement surface temperature. Comparison of numerical and statistical approach

    Science.gov (United States)

    Marchetti, Mario; Khalifa, Abderrahmen; Bues, Michel; Bouilloud, Ludovic; Martin, Eric; Chancibaut, Katia

    2015-04-01

    The forecast of pavement surface temperature is very specific in the context of urban winter maintenance. to manage snow plowing and salting of roads. Such forecast mainly relies on numerical models based on a description of the energy balance between the atmosphere, the buildings and the pavement, with a canyon configuration. Nevertheless, there is a specific need in the physical description and the numerical implementation of the traffic in the energy flux balance. This traffic was originally considered as a constant. Many changes were performed in a numerical model to describe as accurately as possible the traffic effects on this urban energy balance, such as tires friction, pavement-air exchange coefficient, and infrared flux neat balance. Some experiments based on infrared thermography and radiometry were then conducted to quantify the effect fo traffic on urban pavement surface. Based on meteorological data, corresponding pavement temperature forecast were calculated and were compared with fiels measurements. Results indicated a good agreement between the forecast from the numerical model based on this energy balance approach. A complementary forecast approach based on principal component analysis (PCA) and partial least-square regression (PLS) was also developed, with data from thermal mapping usng infrared radiometry. The forecast of pavement surface temperature with air temperature was obtained in the specific case of urban configurtation, and considering traffic into measurements used for the statistical analysis. A comparison between results from the numerical model based on energy balance, and PCA/PLS was then conducted, indicating the advantages and limits of each approach.

  10. 国外沥青路面纵向施工接缝技术的发展%Development of Longitudinal Construction Jointing Technology of Bituminous Pavement Abroad

    Institute of Scientific and Technical Information of China (English)

    许银行; 张迎菊; 胡成钢

    2006-01-01

    多车道沥青路面纵向接缝的裂缝和松散病害一直困扰着各国公路工作者,为此,文中主要介绍了国外8种不同的纵向接缝施工技术,以及尝试使用振荡压路机来处理纵向接缝.结果表明:使用橡胶改性沥青粘层处理的纵缝性能最好,没有明显裂缝,其次为切削盘.从热料车道距接缝152 mm处碾压和新泽西楔接两种方法处理的纵缝也有适当表现,且没有明显的裂缝出现.振荡压实对提高纵向接缝的密实度效果显著.

  11. Update to permeable pavement research at the Edison Environmental Center - slides

    Science.gov (United States)

    Abstract: The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable...

  12. Update to Permeable Pavement Research at the Edison Environmental Center - abstract

    Science.gov (United States)

    Abstract The EPA’s Urban Watershed Management Branch (UWMB) has been monitoring the permeable pavement demonstration site at the Edison Environmental Center, NJ since 2010. This site has three different types of permeable pavement including: interlocking concrete permeable ...

  13. Genetic Optimization Method of Asphalt Pavement Based on Rutting and Cracking Control

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Nowadays asphalt pavement structure bearing is not the main subject for pursuers to study.Comparatively,the pavement performance is more important and emphasized.Based on this,rutting and cracking analysis is introduced into pavement optimization.A optimization model based on these two considerations is also established.The genetic algorithms (GAs) is adopted to solve the model.It is an intellective method.This research provides a new idea and technique for asphalt pavement structure optimization.

  14. Implementation of the AASHTO pavement design procedures into MULTI-PAVE.

    OpenAIRE

    Bekele, Abiy

    2011-01-01

    This thesis implements the empirical pavement design procedures for flexible as well as rigid pavement by American Association of State Highways and Transportation Officials (AASHTO) into two MATLAB modules of MULTI-PAVE. MULTI-PAVE was developed as a teaching tool that performs pavement thickness design for multiple design procedures using a common input file and a common output format. The AASHTO components were developed in accordance with the 1993 AASHTO Pavement Design Guide, and verifie...

  15. Comparison of Surface Characteristics of Hot-Mix Asphalt Pavement Surfaces at the Virginia Smart Road

    OpenAIRE

    Davis, Robin Michelle

    2001-01-01

    Pavement surface characteristics are important to both the safety of the pavement surface and the comfort of the drivers. As of yet, texture and friction measurements have not been incorporated into the design of pavement surfaces. Seven different wearing surface mixtures, placed at the Virginia Smart Road pavement facility, were studied over a one year time period for both friction and texture properties. A locked wheel skid trailer and a laser profilometer were used to assess the pavemen...

  16. Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

    OpenAIRE

    Yingwei Ren; Jingsong Shan

    2014-01-01

    It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thickn...

  17. Transformism in Alberta: The Environmental Political Economy of the Bituminous Sands

    Science.gov (United States)

    Katz-Rosene, Ryan

    This thesis attempts to help establish environmental political economy as a viable academic field while providing an example of work in the discipline. It offers an analysis of societal processes resulting in the co-optation and/or neutralization of critical environmentalist ideas. Using Alberta's bituminous sands as a case study, and a Gramsci-influenced eco-Marxist theory as a foundation, the thesis argues that the term 'environmental transformism' (inspired by the Gramscian term trasformismo) is helpful in describing and framing such processes. Accordingly, the ensuing chapters provide an analysis of why environmental transformism is happening in Alberta, and demonstrate how this mechanism works at protecting the status quo from threatening ideologies, thereby consolidating neoliberal capitalism. A concluding argument discusses the inherent dangers posed to society by the transformism of certain environmental subjectivities. The thesis begins by introducing the contentious social and environmental issues surrounding the development of the bituminous sands.

  18. Prediction of IRI in short and long terms for flexible pavements: ANN and GMDH methods

    NARCIS (Netherlands)

    Ziari, H.; Sobhani, J.; Ayoubinejad, J.; Hartmann, T.

    2015-01-01

    Prediction of pavement condition is one of the most important issues in pavement management systems. In this paper, capabilities of artificial neural networks (ANNs) and group method of data handling (GMDH) methods in predicting flexible pavement conditions were analysed in three levels: in 1 year,

  19. 78 FR 26847 - Including Specific Pavement Types in Federal-aid Highway Traffic Noise Analyses

    Science.gov (United States)

    2013-05-08

    ... Federal Highway Administration Including Specific Pavement Types in Federal-aid Highway Traffic Noise...: The FHWA requests input from stakeholders and interested parties on expanding the specific pavement... data from three pavement types: dense-graded asphaltic concrete (DGAC), open-graded asphaltic...

  20. 23 CFR 972.208 - Federal lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ... “Pavement Management Guide,” AASHTO, 2001, is available for inspection as prescribed at 49 CFR part 7. It is... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands pavement management system (PMS). 972.208....208 Federal lands pavement management system (PMS). In addition to the requirements provided in §...

  1. 76 FR 67018 - Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather Information Systems

    Science.gov (United States)

    2011-10-28

    ... Federal Aviation Administration Notice to Manufacturers of Airport In-Pavement Stationary Runway Weather... of In-Pavement Stationary Runway Weather Information Systems. SUMMARY: Projects funded under the... Active or Passive In- Pavement Stationary Runway Weather Information Systems that meet the...

  2. 23 CFR 970.208 - Federal lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands pavement management system (PMS). 970.208... Federal lands pavement management system (PMS). In addition to the requirements provided in § 970.204, the...) An inventory of the physical pavement features including the number of lanes, length, width,...

  3. Development and evaluation of the model for the surface pavement temperature prediction

    Directory of Open Access Journals (Sweden)

    B. Matić

    2012-07-01

    Full Text Available This paper examines the existing models for predicting pavement temperatures and formulates a new one using a regression equation to predict the minimum and maximum pavement surface temperatures depending on the air temperature. Also, the paper presents a model for pavement temperature prediction according to the Superpave methodology and conducts the validation of the model for measured temperatures.

  4. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    Science.gov (United States)

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study.

  5. Stormwater quality of spring-summer-fall effluent from three partial-infiltration permeable pavement systems and conventional asphalt pavement.

    Science.gov (United States)

    Drake, Jennifer; Bradford, Andrea; Van Seters, Tim

    2014-06-15

    This study examined the spring, summer and fall water quality performance of three partial-infiltration permeable pavement (PP) systems and a conventional asphalt pavement in Ontario. The study, conducted between 2010 and 2012, compared the water quality of effluent from two Interlocking Permeable Concrete Pavements (AquaPave(®) and Eco-Optiloc(®)) and a Hydromedia(®) Pervious Concrete pavement with runoff from an Asphalt control pavement. The usage of permeable pavements can mitigate the impact of urbanization on receiving surface water systems through quantity control and stormwater treatment. The PP systems provided excellent stormwater treatment for petroleum hydrocarbons, total suspended solids, metals (copper, iron, manganese and zinc) and nutrients (total-nitrogen and total-phosphorus) by reducing event mean concentrations (EMC) as well as total pollutant loadings. The PPs significantly reduced the concentration and loading of ammonia (NH4(+)+NH3), nitrite (NO2(-)) and organic-nitrogen (Org-N) but increased the concentration and loading of nitrate (NO3(-)). The PP systems had mixed performances for the treatment of phosphate (PO4(3-)). The PP systems increased the concentration of sodium (Na) and chloride (Cl) but EMCs remained well below recommended levels for drinking water quality. Relative to the observed runoff, winter road salt was released more slowly from the PP systems resulting in elevated spring and early-summer Cl and Na concentrations in effluent. PP materials were found to introduce dissolved solids into the infiltrating stormwater. The release of these pollutants was verified by additional laboratory scale testing of the individual pavement and aggregate materials at the University of Guelph. Pollutant concentrations were greatest during the first few months after construction and declined rapidly over the course of the study. PMID:24681366

  6. The losing efficacy analysis and improving design on asphalt pavement planer cutter%沥青路面铣刨机刀具设计及失效分析

    Institute of Scientific and Technical Information of China (English)

    秦曼华; 杨贺来; 薛蛮

    2000-01-01

    Bituminous road asphalt pavement planer is.a kind of popular road maintenance equipment. Based on the investigation of the machine's actual performance,the reasons of the cutter's losing efficacy from wearing and tearing were analysed and the methods to improve the installment and angle of the cutter were proposed.%沥青珞面铣刨机是一种常用的路面养护机械.根据现场使用情况的调查,分析了铣刨机刀具发生磨损失效的原因和正确的刀具几何角度与安装角度设计.

  7. Study on Plastic Coated Overburnt Brick Aggregate as an Alternative Material for Bituminous Road Construction

    OpenAIRE

    Sarkar, Dipankar; Pal, Manish; Sarkar, Ashoke K.

    2016-01-01

    There are different places in India where natural stone aggregates are not available for constructional work. Plastic coated OBBA can solve the problem of shortage of stone aggregate to some extent. The engineers are always encouraged to use locally available materials. The present investigation is carried out to evaluate the plastic coated OBBA as an alternative material for bituminous road construction. Shredded waste plastics are mixed with OBBA in different percentages as 0.38, 0.42, 0.46...

  8. Modelling the quasi-static behaviour of bituminous material using a cohesive zone model

    OpenAIRE

    Tabakovic, Amir; Karac, Aleksandar; Ivankovic, Alojz; Gibney, Amanda; McNally, Ciaran; Gilchrist, M. D.

    2010-01-01

    This paper investigates the applicability of a cohesive zone model for simulating the performance of bituminous material subjected to quasistatic loading. The Dugdale traction law was implemented within a finite volume code in order to simulate the binder course mortar material response when subjected to indirect tensile loading. A uniaxial tensile test and a threepoint bend test were employed to determine initial stress-strain curves at different test rates and the cohesive zone parameters (...

  9. Modeling of unsaturated granular materials in flexible pavements

    Directory of Open Access Journals (Sweden)

    Gu Fan

    2016-01-01

    Full Text Available The unsaturated granular material (UGM is found to exhibit the moisture-sensitive and stress-dependent nonlinear cross-anisotropic behaviour in flexible pavements. This paper aims at developing a finite element (FE model for pavement structure, which takes into account this behaviour of UGM. First, the Lytton model is employed to characterize the moisture-sensitive and stress-dependent behaviour of UGM, which incorporated a matric suction term to the existing stress-dependent constitutive model. The Lytton model is validated by the laboratory resilient modulus tests on the selected UGMs at different moisture contents. Second, the nonlinear cross-anisotropic constitutive equation of UGM is derived from the generalized Hooke’s Law. The coefficients of the constitutive model are determined by the rapid triaxial test. Third, a User-Defined Material (UMAT subroutine is developed to characterize this constitutive behaviour in the FE software ABAQUS. The UMAT subroutine adopts the secant stiffness approach with multiple damping factors. The UMAT subroutine is then implemented in the FE model of flexible pavement structures. The FE simulation results indicate the nonlinear cross-anisotropic model predicts greater pavement responses than the isotropic model. When the UGM is suction sensitive, it is found that the moisture content of UGM significantly affects the moduli distribution of base layer and the critical strains (i.e., tensile strain at the bottom of asphalt concrete, and compressive strains in base and subgrade layers of pavement structures.

  10. Pavement Evaluation and Maintenance Decisions Based on Fuzzy Inference Systems

    Directory of Open Access Journals (Sweden)

    Beltrán-Calvo Gloria Inés

    2014-07-01

    Full Text Available The remaining service life and maintenance decisions of existing pavements are highly dependent on stiffness and deterioration conditions throughout their operation. A non-conventional fuzzy logic based methodology is proposed in this work to address the stiffness-deterioration condition and conservation decisions, by means of three Fuzzy Inference Systems. Analysis were conducted using a database gathered from field tests performed on three and four layer pavement systems, that included traditional layer structuring and pavements having a subbase stiffer than their granular base. Information about layer thicknesses, magnitude and severity of structural distresses, and parameters and indicators derived from deflection testing by impulse load devices were used. The developed systems, allowed representing expert knowledge and linguistic variables of subjective and qualitative nature, commonly used to describe the severity levels of deterioration; thus they can be involved into structural characterization of pavements. Results were also expressed linguistically, to facilitate their interpretation and understanding. Based on the high quality of results obtained, it seems reasonable to conclude that the proposed systems could be used confidently for assessing and making decisions about pavement conservation, with low computational cost.

  11. Study on Plastic Coated Overburnt Brick Aggregate as an Alternative Material for Bituminous Road Construction

    Directory of Open Access Journals (Sweden)

    Dipankar Sarkar

    2016-01-01

    Full Text Available There are different places in India where natural stone aggregates are not available for constructional work. Plastic coated OBBA can solve the problem of shortage of stone aggregate to some extent. The engineers are always encouraged to use locally available materials. The present investigation is carried out to evaluate the plastic coated OBBA as an alternative material for bituminous road construction. Shredded waste plastics are mixed with OBBA in different percentages as 0.38, 0.42, 0.46, 0.50, 0.54, and 0.60 of the weight of brick aggregates. Marshall Method of mix design is carried out to find the optimum bitumen content of such bituminous concrete mix prepared by plastic coated OBBA. Bulk density, Marshall Stability, flow, Marshall Quotient, ITS, TSR, stripping, fatigue life, and deformations have been determined accordingly. Marshall Stability value of 0.54 percent of plastic mix is comparatively higher than the other mixes except 0.60 percent of plastic mix. Test results are within the prescribed limit for 0.54 percent of plastic mix. There is a significant reduction in rutting characteristics of the same plastic mix. The fatigue life of the mix is also significantly higher. Thus plastic coated OBBA is found suitable in construction of bituminous concrete road.

  12. The microstructure of petroleum vacuum residue films for bituminous concrete: a microscopy approach.

    Science.gov (United States)

    Sourty, E D; Tamminga, A Y; Michels, M A J; Vellinga, W-P; Meijer, H E H

    2011-02-01

    Selected carbon-rich refinery residues ('binders') mixed with mineral particles can form composite materials ('bituminous concrete') with bulk mechanical properties comparable to those of cement concrete. The microstructural mechanism underlying the remarkable composite properties has been related to the appearance of a rigid percolating network consisting of asphaltenes and mineral particles [Wilbrink M. et al. (2005) Rigidity percolation in dispersions with a structured visco-elastic matrix. Phys. Rev. E71, 031402]. In this paper, we explore the microstructure of thin binder films of varying thickness with a number of microscopic characterization techniques, and attempt to relate the observed microstructure to the distinctive mechanical behaviour. Two binders, only one of which has been proven to be suitable for bituminous concrete were investigated, and their microstructure compared. Both binders show the formation of asphaltene aggregates. The binder suitable for bituminous concrete is distinguished by the fact that the asphaltenes show a stronger tendency towards such aggregation, due to a higher concentration and less stabilization in the maltene phase. They also show a clear affinity to other species (such as waxes) and may act as nucleation sites for crystals and aggregates of those species. PMID:21118207

  13. JV Task 126 - Mercury Control Technologies for Electric Utilities Burning Bituminous Coal

    Energy Technology Data Exchange (ETDEWEB)

    Jason Laumb; John Kay; Michael Jones; Brandon Pavlish; Nicholas Lentz; Donald McCollor; Kevin Galbreath

    2009-03-29

    The EERC developed an applied research consortium project to test cost-effective mercury (Hg) control technologies for utilities burning bituminous coals. The project goal was to test innovative Hg control technologies that have the potential to reduce Hg emissions from bituminous coal-fired power plants by {ge}90% at costs of one-half to three-quarters of current estimates for activated carbon injection (ACI). Hg control technology evaluations were performed using the EERC's combustion test facility (CTF). The CTF was fired on pulverized bituminous coals at 550,000 Btu/hr (580 MJ/hr). The CTF was configured with the following air pollution control devices (APCDs): selective catalytic reduction (SCR) unit, electrostatic precipitator (ESP), and wet flue gas desulfurization system (WFDS). The Hg control technologies investigated as part of this project included ACI (three Norit Americas, Inc., and eleven Envergex sorbents), elemental mercury (Hg{sup 0}) oxidation catalysts (i.e., the noble metals in Hitachi Zosen, Cormetech, and Hitachi SCR catalysts), sorbent enhancement additives (SEAs) (a proprietary EERC additive, trona, and limestone), and blending with a Powder River Basin (PRB) subbituminous coal. These Hg control technologies were evaluated separately, and many were also tested in combination.

  14. Continuous bench-scale slurry catalyst testing direct coal liquefaction rawhide sub-bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Bauman, R.F.; Coless, L.A.; Davis, S.M. [and others

    1995-12-31

    In 1992, the Department of Energy (DOE) sponsored research to demonstrate a dispersed catalyst system using a combination of molybdenum and iron precursors for direct coal liquefaction. This dispersed catalyst system was successfully demonstrated using Black Thunder sub-bituminous coal at Wilsonville, Alabama by Southern Electric International, Inc. The DOE sponsored research continues at Exxon Research and Development Laboratories (ERDL). A six month continuous bench-scale program using ERDL`s Recycle Coal Liquefaction Unit (RCLU) is planned, three months in 1994 and three months in 1995. The initial conditions in RCLU reflect experience gained from the Wilsonville facility in their Test Run 263. Rawhide sub-bituminous coal which is similar to the Black Thunder coal tested at Wilsonville was used as the feed coal. A slate of five dispersed catalysts for direct coal liquefaction of Rawhide sub-bituminous coal has been tested. Throughout the experiments, the molybdenum addition rate was held constant at 100 wppm while the iron oxide addition rate was varied from 0.25 to 1.0 weight percent (dry coal basis). This report covers the 1994 operations and accomplishments.

  15. Pavement Subgrade Performance Study in the Danish Road Testing Machine

    DEFF Research Database (Denmark)

    Ullidtz, Per; Ertman Larsen, Hans Jørgen

    1997-01-01

    Most existing pavement subgrade criteria are based on the AASHO Road Test, where only one material was tested and for only one climatic condition. To study the validity of these criteria and to refine the criteria a co-operative research program entitled the "International Pavement Subgrade...... Performance Study" was sponsored by the FHWA with American, Finnish and Danish partners. This paper describes the first test series which was carried out in the Danish Road Testing Machine (RTM).The first step in this program is a full scale test on an instrumented pavement in the Danish Road Testing Machine...... of elasticity to calculate the stresses and strains at the position of the gauges and to compare these values to the stresses and strains recorded under the rolling wheel load.Plastic strains resulting from 50 000 applications of each of two load levels (20 kN and 40 kN) were recorded, as well as the permanent...

  16. Determination of Pavement Rehabilitation Activities through a Permutation Algorithm

    Directory of Open Access Journals (Sweden)

    Sangyum Lee

    2013-01-01

    Full Text Available This paper presents a mathematical programming model for optimal pavement rehabilitation planning. The model maximized the rehabilitation area through a newly developed permutation algorithm, based on the procedures outlined in the harmony search (HS algorithm. Additionally, the proposed algorithm was based on an optimal solution method for the problem of multilocation rehabilitation activities on pavement structure, using empirical deterioration and rehabilitation effectiveness models, according to a limited maintenance budget. Thus, nonlinear pavement performance and rehabilitation activity decision models were used to maximize the objective functions of the rehabilitation area within a limited budget, through the permutation algorithm. Our results showed that the heuristic permutation algorithm provided a good optimum in terms of maximizing the rehabilitation area, compared with a method of the worst-first maintenance currently used in Seoul.

  17. Application of Artificial Intelligence for Optimization in Pavement Management

    Directory of Open Access Journals (Sweden)

    Reus Salini

    2015-07-01

    Full Text Available Artificial intelligence (AI is a group of techniques that have quite a potential to be applied to pavement engineering and management. In this study, we developed a practical, flexible and out of the box approach to apply genetic algorithms to optimizing the budget allocation and the road maintenance strategy selection for a road network. The aim is to provide an alternative to existing software and better fit the requirements of an important number of pavement managers. To meet the objectives, a new indicator, named Road Global Value Index (RGVI, was created to contemplate the pavement condition, the traffic and the economic and political importance for each and every road section. This paper describes the approach and its components by an example confirming that genetic algorithms are very effective for the intended purpose.

  18. Design prediction of pavement skid resistance from laboratory tests

    Science.gov (United States)

    Parcells, W. H.; Metheny, T. M.; Maag, R. G.

    1980-08-01

    Methods for preevaluating aggregates and paving mixtures so that predictions can be made covering skid resistance properties of proposed and in service pavement types are discussed. A correlation was established between the field testing using the data from the British Portable Tester and the Locked Wheel Pavement Friction Trailer at speeds of 40 and 55 mph. Core samples were extracted from the Locked Wheel Tester Skid Path and subjected to wear on the small wheel circular track with periodic surface friction testing. The final step was to remix and remold the cored pavement samples or make samples with new materials to obtain an 'as new' surface and again subject these samples to wear on the small wheel circular track with periodic testing.

  19. RAPID INSPECTION OF PAVEMENT MARKINGS USING MOBILE LIDAR POINT CLOUDS

    Directory of Open Access Journals (Sweden)

    H. Zhang

    2016-06-01

    Full Text Available This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu’s thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  20. Low cost pavement marking materials based on plasticized sulfur

    Science.gov (United States)

    Dale, J. M.

    1982-04-01

    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.

  1. Rapid Inspection of Pavement Markings Using Mobile LIDAR Point Clouds

    Science.gov (United States)

    Zhang, Haocheng; Li, Jonathan; Cheng, Ming; Wang, Cheng

    2016-06-01

    This study aims at building a robust semi-automated pavement marking extraction workflow based on the use of mobile LiDAR point clouds. The proposed workflow consists of three components: preprocessing, extraction, and classification. In preprocessing, the mobile LiDAR point clouds are converted into the radiometrically corrected intensity imagery of the road surface. Then the pavement markings are automatically extracted with the intensity using a set of algorithms, including Otsu's thresholding, neighbor-counting filtering, and region growing. Finally, the extracted pavement markings are classified with the geometric parameters using a manually defined decision tree. Case studies are conducted using the mobile LiDAR dataset acquired in Xiamen (Fujian, China) with different road environments by the RIEGL VMX-450 system. The results demonstrated that the proposed workflow and our software tool can achieve 93% in completeness, 95% in correctness, and 94% in F-score when using Xiamen dataset.

  2. Geo synthetic-reinforced Pavement systems; Sistemas de pavimentos reforzados con geosinteticos

    Energy Technology Data Exchange (ETDEWEB)

    Zornberg, J. G.

    2014-02-01

    Geo synthetics have been used as reinforcement inclusions to improve pavement performance. while there are clear field evidence of the benefit of using geo synthetic reinforcements, the specific conditions or mechanisms that govern the reinforcement of pavements are, at best, unclear and have remained largely unmeasured. Significant research has been recently conducted with the objectives of: (i) determining the relevant properties of geo synthetics that contribute to the enhanced performance of pavement systems, (ii) developing appropriate analytical, laboratory and field methods capable of quantifying the pavement performance, and (iii) enabling the prediction of pavement performance as a function of the properties of the various types of geo synthetics. (Author)

  3. Evaluation of Common Maintenance Methods for Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Asma T. Ibraheem

    2011-01-01

    Full Text Available Problem statement: With the increasing use and awareness of pavement management systems and the growing emphasis on asset management of pavement infrastructure, it is important to strengthen the maintenance components of these systems and particularly the preventive maintenance component. Iraqi Roads don’t receive an effective and proper maintenance during their service life until they reach the state of major failure that requires rehabilitation. Roads in Iraq are being lost. Approach: In this study, a study of the status of maintenance methods for road pavements in Iraq with special reference to flexible pavements is presented. For this purpose, open and closed questionnaires were executed in Baghdad to investigate the status of road pavement maintenance in Iraq. Road maintenance offices as (Ministry of construction and Housing, State Corporation for Roads and Bridges, Amanat Baghdad, Project office, were included in the questionnaire to arrive at the level of maintenance and techniques followed to maintain paved road in Iraq. Results: The interviews carried out reveal that maintenance in Iraq has secondary importance, apparently with no special budget allocated for such important works. In addition the maintenance methods and techniques followed do not comply the developments and modern techniques. Conclusion/Recommendations: Poor and miss-management of maintenance works and activities leading to delays and accumulation of failure in the highway network that require unusual expenditures to repair and maintain the accumulated damages. Also shortages in resources allocated for maintenance works and this leads to the diversion of significant portion of the allocated fund for maintenance works toward purchasing of new, or additional equipment to be used for the construction of new roads. It is strongly recommended to design a planning system for management pavement maintenance of road network in Iraq and develop a particular failure criterion

  4. Cold Region Pavements%寒区路面

    Institute of Scientific and Technical Information of China (English)

    GuyDore

    2002-01-01

    The article mainly discusses several essential problems of cold region pavement, including thermal cracking of asphalt concrete, cracking deterioration and heaving, frost heave, seasonal and long term roughness induced by different frost heave, frost heave cracking, bearing capacity loss during spring thaw. The reason for these problems is that cold region pavements are subjected to intense solicitation by climatic and environmental factors. The author offers several models corresponding to the solicitation. Furthermore in conclusion of the article the author indicates future research for cold region.

  5. Thin, applied surfacing for improving skid resistance of concrete pavements

    Science.gov (United States)

    Scholer, C. F.

    1980-12-01

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

  6. Deterioration modeling for condition assessment of flexible pavements considering extreme weather events

    Science.gov (United States)

    Hashemi Tari, Yasamin; Shahini Shamsabadi, Salar; Birken, Ralf; Wang, Ming

    2015-04-01

    Accurate pavement management systems are essential for states' Department Of Transportation and roadway agencies to plan for cost-effective maintenance and repair (M and R) strategies. Pavement deterioration model is an imperative component of any pavement management system since the future budget and M and R plans would be developed based on the predicted pavement performance measures. It is crucial for the pavement deterioration models to consider the factors that significantly aggravate the pavement condition. While many studies have highlighted the impact of different environmental, load, and pavement's structure on the life cycle of the pavement, effect of extreme weather events such as Floods and Snow Storms have often been overlooked. In this study, a pavement deterioration model is proposed which would consider the effect of traffic loads, climate conditions, and extreme weather events. Climate, load and performance data has been compiled for over twenty years and for eight states using the Long Term Pavement Performance (LTPP) and National Oceanic and Atmospheric Administration (NOAA) databases. A stepwise regression approach is undertaken to quantify the effect of the extreme weather events, along with other influential factors on pavement performance in terms of International Roughness Index (IRI). Final results rendered more than 90% correlation with the quantified impact values of extreme weather events.

  7. Tactile pavement for guiding walking direction: An assessment of heading direction and gait stability.

    Science.gov (United States)

    Pluijter, Nanda; de Wit, Lieke P W; Bruijn, Sjoerd M; Plaisier, Myrthe A

    2015-10-01

    For maintaining heading direction while walking we heavily rely on vision. Therefore, walking in the absence of vision or with visual attention directed elsewhere potentially leads to dangerous situations. Here we investigated whether tactile information from the feet can be used as a (partial) substitute for vision in maintaining a stable heading direction. If so, participants should be better able to keep a constant heading direction on tactile pavement that indicates directionality than on regular flat pavement. However, such a pavement may also be destabilizing. Thus we asked participants to walk straight ahead on regular pavement, and on tactile pavement (tiles with ridges along the walking direction) while varying the amount of vision. We assessed the effects of the type of pavement as well as the amount of vision on the variability of the heading direction as well as gait stability. Both of these measures were calculated from accelerations and angular velocities recorded from a smartphone attached to the participants trunk. Results showed that on tactile pavement participants had a less variations in their heading direction than on regular pavement. The drawback, however, was that the tactile pavement used in this study decreased gait stability. In sum, tactile pavement can be used as a partial substitute for vision in maintaining heading direction, but it can also decrease gait stability. Future work should focus on designing tactile pavement that does provided directional clues, but is less destabilizing. PMID:26344427

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

    Directory of Open Access Journals (Sweden)

    Huaping Wang

    2014-05-01

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

  9. Bearing capacity evaluation of rubblized concrete pavements

    Directory of Open Access Journals (Sweden)

    González, M.

    2009-03-01

    Full Text Available The paper presents the findings of a research work performed on a real scale concrete pavement project where Rubblizing technology was used for its structural rehabilitation. Rubblizing may be defined as a fracture technique in which a concrete pavement slab is transformed in a granular base with a very high Modulus. This technique, fractures the concrete slab in angular pieces by using a concentrated dynamic load of low amplitude and high frequency. The research work was based on field study on the rehabilitation of 5 km motorway. The structural evaluations where made, before, during and after one year construction. Measurements and site evaluation where made by using DCP, Light Weight Deflectometer and FWD (on top of asphalt layer and excavating inside pits. The structural capacity of the Rubblized layer was evaluated through theoretical analysis. Because of the anisotropic properties of the Rubblized layer the results are presented using AASHTO structural layer coefficient. The structural layer coefficients recommended are between the range of 0.25 and 0.30 for concrete slabs with thickness grater than 220 mm.El trabajo presenta los resultados de un estudio a escala real de la capacidad estructural de un firme de hormigón rehabilitado utilizando la técnica de Rubblizing. La técnica de Rubblizing ha sido traducida como el pulverizado del firme de hormigón pero, es más bien un efecto combinado de trituración y fracturación de la losa de hormigón en todo su espesor para convertir esta en una base granular de alto módulo. Esta tecnica fractura la losa de hormigón en trozos angulares y entrelazados empleando una carga dinámica concentrada, de baja amplitud y alta frecuencia. La investigación se basó en el estudio de la rehabilitación de 5 km de autopista. Los estudios de la capacidad estructural fueron realizados durante, al término y un año después de la construcción. Para las mediciones y evaluaciones de terreno se utilizó, el

  10. Calibrating mechanistic-empirical pavement performance models with an expert matrix

    Energy Technology Data Exchange (ETDEWEB)

    Tighe, S.; AlAssar, R.; Haas, R. [Waterloo Univ., ON (Canada). Dept. of Civil Engineering; Zhiwei, H. [Stantec Consulting Ltd., Cambridge, ON (Canada)

    2001-07-01

    Proper management of pavement infrastructure requires pavement performance modelling. For the past 20 years, the Ontario Ministry of Transportation has used the Ontario Pavement Analysis of Costs (OPAC) system for pavement design. Pavement needs, however, have changed substantially during that time. To address this need, a new research contract is underway to enhance the model and verify the predictions, particularly at extreme points such as low and high traffic volume pavement design. This initiative included a complete evaluation of the existing OPAC pavement design method, the construction of a new set of pavement performance prediction models, and the development of the flexible pavement design procedure that incorporates reliability analysis. The design was also expanded to include rigid pavement designs and modification of the existing life cycle cost analysis procedure which includes both the agency cost and road user cost. Performance prediction and life-cycle costs were developed based on several factors, including material properties, traffic loads and climate. Construction and maintenance schedules were also considered. The methodology for the calibration and validation of a mechanistic-empirical flexible pavement performance model was described. Mechanistic-empirical design methods combine theory based design such as calculated stresses, strains or deflections with empirical methods, where a measured response is associated with thickness and pavement performance. Elastic layer analysis was used to determine pavement response to determine the most effective design using cumulative Equivalent Single Axle Loads (ESALs), below grade type and layer thickness.The new mechanistic-empirical model separates the environment and traffic effects on performance. This makes it possible to quantify regional differences between Southern and Northern Ontario. In addition, roughness can be calculated in terms of the International Roughness Index or Riding comfort Index

  11. Rheological behaviour of polymer-modified bituminous mastics : a comparative analysis between physical and chemical modification

    OpenAIRE

    Shivokhin, Maxim; García Morales, Moisés; Partal López, Pedro; Cuadri Vega, Antonio Abad; Gallegos Montes, Críspulo

    2012-01-01

    Mastic, a bitumen/filler blend which naturally forms when bitumen is mixed with aggregates is the actual product used to bind coarse mineral particles in the asphalt mixtures. As a result, the characterisation of mastics is essential to improve the understanding of the response and performance of asphalt concrete pavements. On the other hand, the lack of experimental data concerning the behaviour of mastics and, above all, polymer-modified mastics has been lately claimed. In that sense, this ...

  12. Performance Evaluation of Flexible Pavements: A Case Study

    Directory of Open Access Journals (Sweden)

    V.K Chakravarthi1 ,

    2015-10-01

    Full Text Available : Flexible pavements get distress during their service life because of increase in traffic particularly commercial vehicles. The present study focuses on finding the increase of magnitude of deformations from 2008 to 2015 traffic data using ANSYS for which the BRTS stretch in Visakhapatnam is considering five locations along the stretch.

  13. Ground Penetrating Radar Assessment of Flexible Road Pavement Degradation

    Directory of Open Access Journals (Sweden)

    Sandro Colagrande

    2011-01-01

    Full Text Available GPR investigations were used to study degraded road pavements built in cutting sections. Road integrity was assessed via quantitative analysis of power curves. 1600 MHz and 600 MHz radar sections were collected in 40 damaged and undamaged road pavement sites. The collected data were processed as follows: (i linearisation with regression analysis of power curves; (ii assessment of absorption angle α′ which is directly proportional to absorption coefficient α (this was obtained by setting the e.m. propagation velocity to 10 cm/ns; (iii comparison of absorption coefficients in both damaged and undamaged zones with respect to road pavement degradation. If the absorption coefficients of damaged and undamaged road sections have nearly the same value, then the likely cause of degradation is the fatigue or the thermal shrinkage; if they are not, then road degradation is due to the different compactness of the soil caused by vehicular traffic load. In a considerable number of sites, the statistical comparison of damaged and undamaged zones through the absorption coefficient analysis shows that surface observations of road pavements are quite consistent with power curve analyses.

  14. A Detailed Study of Cbr Method for Flexible Pavement Design

    Directory of Open Access Journals (Sweden)

    Er. Devendra Kumar Choudhary

    2014-06-01

    Full Text Available As per IRC recommendation, California Bearing Ratio (CBR value of subgrade is used for design of flexible pavements. California Bearing Ratio (CBR value is an important soil parameter for design of flexible pavements and runway of air fields. It can also be used for determination of sub grade reaction of soil by using correlation. It is one of the most important engineering properties of soil for design of sub grade of roads. CBR value of soil may depends on many factors like maximum dry density (MDD, optimum moisture content (OMC, liquid limit (LL, plastic limit (PL, plasticity index (PI, type of soil, permeability of soil etc. Besides, soaked or unsoaked condition of soil also affects the value. These tests can easily be performed in the laboratory. the estimation of the CBR could be done on the basis of these tests which are quick to perform, less time consuming and cheap, then it will be easy to get the information about the strength of subgrade over the length of roads, By considering this aspect, a number of investigators in the past made their investigations in this field and designed different pavements by determining the CBR value on the basis of results of low cost, less time consuming and easy to perform tests. In this study, attempts have been made to seek the values of CBR of different soil samples and correlate their CBR values for the design purpose of flexible pavement as per guidelines of IRC: SP: 37-2001.

  15. Optimisation of the Crack Pattern in Continuously Reinforced Concrete Pavements

    NARCIS (Netherlands)

    Ren, D.

    2015-01-01

    Recent field investigations on several new Continuously Reinforced Concrete Pavements (CRCP) in Belgium indicate that its crack pattern is characterized by low mean crack spacing along with a high percentage of clusters of closely spaced cracks. Field surveys also indicate that it is difficult to si

  16. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

    Full Text Available Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  17. Nitrogen Transformations in Three Types of Permeable Pavement

    Science.gov (United States)

    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...

  18. Revised procedure for pavement design under seasonal frost conditions

    Science.gov (United States)

    Berg, R. L.; Johnson, T. C.

    1983-09-01

    This report presents engineering guidance and design criteria for pavements at Army and Air Force facilities in seasonal frost areas. Design methods for controlling surface roughness and loss of subgrade strength during thawing periods are provided. Criteria for using thermal insulating materials and membrane encapsulated soil layers in seasonal frost areas are presented. Six design examples are included.

  19. Monitoring pavement response and performance using in-situ instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Chen, D.H.; Bilyeu, J.; Hugo, F.

    1999-07-01

    The purpose of this paper is to present the effectiveness of in-situ instrumentation on diagnosing the pavement layer conditions under full-scale accelerated traffic loading. The test section is an in-service pavement (US281) in Jacksboro, Texas. Multi-Depth Deflectometers (MDDs) are used to measure both permanent deformations and transient deflections, caused by accelerated traffic loading and Falling Weight Deflectometers (MDDs) are used to measure both permanent deformations and transient deflections, caused by accelerated traffic loading and Falling Weight Deflectometer (FWD) tests. Four different FWD loads of 25, 40, 52, and 67 kN were applied in close proximity to the MDDs at various traffic loading intervals to determine pavement conditions. It was found that the majority of rutting occurred in the newly recycled asphalt mix. The aged ({gt}40 years) underlying base and subgrade layers contributed less than 30% to overall rutting. Only the top recycled Asphalt layer underwent notable deterioration due to traffic loading. Up to 1.5 million axle repetitions, the test pad responded to FWD load almost linearly, not only over the whole pavement system but also within individual layers. However, under higher FWD loads, the percentage of total deflection contributed by the subgrade increased.

  20. Prediction of subgrade moisture conditions for purposes of pavement design

    OpenAIRE

    Correia, A. Gomes

    1996-01-01

    The purpose of this paper is to summarize the procedures for determining moisture conditions in subgrade soils and make recommendations regarding the practical applications to pavement design. By using data from different moisture studies some moisture models were tested to demonstrate their capability of predicting ultimate moisture contents.

  1. Representative volume element of asphalt pavement for electromagnetic measurements

    Directory of Open Access Journals (Sweden)

    Terhi Pellinen

    2015-02-01

    Full Text Available The motivation for this study was to investigate the representative volume element (RVE needed to correlate the nondestructive electromagnetic (EM measurements with the conventional destructive asphalt pavement quality control measurements. A large pavement rehabilitation contract was used as the test site for the experiment. Pavement cores were drilled from the same locations where the stationary and continuous Ground Penetrating Radar (GPR measurements were obtained. Laboratory measurements included testing the bulk density of cores using two methods, the surface-saturated dry method and determining bulk density by dimensions. Also, Vector Network Analyzer (VNA and the through specimen transmission configuration were employed at microwave frequencies to measure the reference dielectric constant of cores using two different footprint areas and therefore volume elements. The RVE for EM measurements turns out to be frequency dependent; therefore in addition to being dependent on asphalt mixture type and method of obtaining bulk density, it is dependent on the resolution of the EM method used. Then, although the average bulk property results agreed with theoretical formulations of higher core air void content giving a lower dielectric constant, for the individual cores there was no correlation for the VNA measurements because the volume element seizes deviated. Similarly, GPR technique was unable to capture the spatial variation of pavement air voids measured from the 150-mm drill cores. More research is needed to determine the usable RVE for asphalt.

  2. Design Basis for Fibre Reinforced Concrete (FRC) Pavements

    DEFF Research Database (Denmark)

    Bendixen, Søren; Stang, Henrik

    1996-01-01

    -crack opening relationship can beused to descibe the properties of fibre reinforced concrete (FRC) intension and how the stress-crack opening relationship can beapplied in a simple design scheme for pavements. The projectincludes development of design tools, experiments to determine thestress-crack opening...

  3. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling

    Science.gov (United States)

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

  4. An Approach for Nonlinear Fatigue Damage Evaluation in Asphalt Pavements

    Science.gov (United States)

    Rajbongshi, Pabitra; Thongram, Sonika

    2016-08-01

    Fatigue due to vehicular loads is one of the primary distress mechanisms in asphalt pavements. It happens primarily due to deterioration in asphalt material with load repetitions. Degradation of asphalt material may be evaluated using different parameters. In view of degradation, the incremental damage in a given pavement section would be different for different repetitions, even with same loadings. Therefore, the damage progression becomes nonlinear with repetitions. Accounting such nonlinearity in damage accumulation, and based on different damage evaluation parameters, this paper presents an equivalent approach for fatigue damage evaluation in asphalt pavements. Traditional fatigue equation adopted in mechanistic-empirical pavement design has been used in the present work. Four different criteria, namely number of load repetitions, asphalt stiffness reduction, strain enhancement and fatigue life reduction with repetitions are considered for damage estimation. The proposed approach could estimate same value of nonlinear damage, irrespective of the criteria used. The simplest form of criterion i.e. the number of load repetitions can be used for fatigue performance evaluation. Probabilistically, the damage propagation is also correlated and assessed with the failure probability.

  5. Measuring Clogging with Pressure Transducers in Permeable Pavement Strips

    Science.gov (United States)

    Two issues that have a negative affect on the long term hydrologic performance of permeable pavement systems are surface clogging and clogging at the interface with the underlying soil. Surface clogging limits infiltration capacity and results in bypass if runoff rate exceeds in...

  6. Modeling Recycling Asphalt Pavement Processing Technologies in Asphalt Mixing Plants

    OpenAIRE

    Simonas Tamaliūnas; Henrikas Sivilevičius

    2011-01-01

    The article presents reclaimed asphalt pavement (RAP) processing technologies and equipment models used in the asphalt mixing plant (AMP). The schematic model indicating all possible ways to process RAP in AMP is shown. The model calculating the needed temperature of mineral materials used for heating RAP is given and an example of such calculation is provided.Article in Lithuanian

  7. Investigation of activity release from bituminized intermediate-level waste forms under thermal stresses

    International Nuclear Information System (INIS)

    To determine the consequences of a fire during fabrication, intermediate storage and transport of bituminized NaNO3 waste forms, the fractions of plutonium released from the waste forms were assessed. For this purpose, laboratory tests were made with PuO2-containing specimens as well as a field test with specimens containing Eu2O3. By the evaluation of plutonium release in the laboratory and by the determination of the total sodium release and the relative Eu/Na release in the field tests the plutonium release can be deduced from full-scale specimens. The results show that for bituminized waste forms with high NaNO3 contents (approx. 36 wt%) the average plutonium release obtained in laboratory testing is 15%. In the field tests (IAEA fire test conditions) an average Eu release of 8% was found. These results justify the statement that also for waste forms in open 175 L drum inserts a maximum plutonium release of about 15% can be expected. From the time-dependence of Eu/Na release in the field tests an induction period of 15-20 minutes between the start of testing and the first Na/Eu release can be derived. The maximum differential Na/Eu release occurs after a test period of 45 to 60 minutes duration and after 90 to 105 minutes (tests K2 and K4, respectively); after that time also the highest temperatures in the products are measured. The release values were determined for products in open 175 L drum inserts which in this form are not eligible for intermediate and ultimate storage. For bituminized waste forms in concrete packages (lost concrete shieldings) a delayed increase in temperature to only 70-80 deg. C takes place (4-5 hours after extinction of the fire) if the fire lasts 45 minutes. The concrete package remains intact under test conditions. This means that activity release from bituminized waste forms packaged in this way can be ruled out in the case under consideration. (author)

  8. Adsorption of SO2 on bituminous coal char and activated carbon fiber prepared from phenol formaldehyde

    Science.gov (United States)

    DeBarr, Joseph A.; Lizzio, Anthony A.; Daley, Michael A.

    1996-01-01

    Carbon-based materials are used commercially to remove SO2 from coal combustion flue gases. Historically, these materials have consisted of granular activated carbons prepared from lignite or bituminous coal. Recent studies have reported that activated carbon fibers (ACFs) may have potential in this application due to their relatively high SO2 adsorption capacity. In this paper, a comparison of SO2 adsorption for both coal-based carbons and ACFs is presented, as well as ideas on carbon properties that may influence SO2 adsorption

  9. NonPAS: A Program for Nonlinear Analysis of Flexible Pavements

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2015-06-01

    Full Text Available The primary step in design of a pavement using Mechanistic-Empirical (M-E method is the analysis of pavement and calculation of the critical responses of pavement under various loadings. This confirms the need for developing pavement analysis software as an analytical base of the M-E method. To this end, NonPAS program has been developed for linear and nonlinear analysis of flexible pavements. Developed program allows nonlinear analysis of flexible pavements using five nonlinear models, including K-θ, Uzan, Uzan-Witczak, MEPDG 2002 and Bilinear models. Nonlinear Analysis of flexible pavements by utilizing these constitutive models provides a more accurate modeling of granular material behavior. Developed program can be used to analyze a pavement system consists of maximum of 10 layers, which is subjected to a maximum of six circular loads. Developed program allows for calculating the responses at 400 different points of pavement. In order to validate the results of linear and nonlinear analysis, responses obtained from NonPAS have been compared with responses obtained using Kenlayer program. Results show very good agreement between responses, which are obtained using both linear and nonlinear analysis and approve that developed program can be used with high reliability for the purposes of pavement analysis and design.

  10. An assessment of the skid resistance effect on traffic safety under wet-pavement conditions.

    Science.gov (United States)

    Pardillo Mayora, José M; Jurado Piña, Rafael

    2009-07-01

    Pavement-tire friction provides the grip that is required for maintaining vehicle control and for stopping in emergency situations. Statistically significant negative correlations of skid resistance values and wet-pavement accident rates have been found in previous research. Skid resistance measured with SCRIM and crash data from over 1750km of two-lane rural roads in the Spanish National Road System were analyzed to determine the influence of pavement conditions on safety and to assess the effects of improving pavement friction on safety. Both wet- and dry-pavement crash rates presented a decreasing trend as skid resistance values increased. Thresholds in SCRIM coefficient values associated with significant decreases in wet-pavement crash rates were determined. Pavement friction improvement schemes were found to yield significant reductions in wet-pavement crash rates averaging 68%. The results confirm the importance of maintaining adequate levels of pavement friction to safeguard traffic safety as well as the potential of pavement friction improvement schemes to achieve significant crash reductions. PMID:19540980

  11. Effect Analysis of Vehicle System Parameters on Dynamic Response of Pavement

    Directory of Open Access Journals (Sweden)

    Rong-xia Xia

    2015-01-01

    Full Text Available In order to study the damage of a semirigid pavement under vehicle loads with varied parameters, the random dynamic loads applied on the pavement by a running vehicle were computed with two degrees of freedom, quarter-vehicle model, and then a three-dimensional finite element analysis model of semirigid asphalt pavement was established. With the peak stress index of each pavement layer, the effect of varied vehicle parameters on pavement response was studied. The results indicated that the stress wave frequency of each pavement layer was similar to that of the dynamic random load, and, with increased pavement depth, the wave effect decreased. The pavement response increased with increased suspension stiffness and tire stiffness and decreased with increased suspension damping and tire damping. Furthermore, compared to the stiffness, the response variation induced by the damping was orders of magnitude lower. Compared with the traditional time response analysis method, the peak response analysis of the pavement structure was more scientific, rational, and intuitive, which could be useful for the study of vehicle-pavement interaction and road damage.

  12. Assessing radioactive concentrates and waste vapor condensate in solidifying radioactive wastes by bituminization

    International Nuclear Information System (INIS)

    A brief overview is presented of chemical and radiochemical methods used in the world for the analysis of the concentrate of liquid radioactive wastes from nuclear power plants destined for bituminization. Most methods are also suitable for an analysis of the condensate of waste vapors produced in bituminization. The methods of analysis of the radioactive concentrate from the V-1 nuclear power plant in Jaslovske Bohunice and of the waste vapors condensate were developed and tested in practice. Gross gamma activity was measured using a well-type Na(Tl) scintillation detector, the content of radionuclides was determined using semiconductor Ge(Li) spectrometry. The concentration of boric acid in the concentrate was determined by titration with mannite; in the condensate, using spectrophotometry with curcumine. The content of nitrates in both the concentrate and the condensate was determined spectrophotometrically using salicylic acid, the content of nitrites was determined by spectrophotometry using sulfanilic acid and α-naphthylamine. Carbonates and chlorides were determined by titration, sodium and potassium by flame photometry. The content of organic acids was measured by gravimetry of extracted methyl esters, the content of surfactants by spectrophotometry. Infrared spectrophotometry was used in determining hydrocarbons in the waste vapor condensate. The measured value range and the measurement errors are shown for each method. (A.K.)

  13. Chemical activation of bituminous coal for hampering oligomerization of organic contaminants.

    Science.gov (United States)

    Yan, Liang; Sorial, George A

    2011-12-15

    Activated carbons prepared by KOH activation of bituminous coal were studied for hampering oligomerization of phenolic compounds on its surface. A total of 24 activated carbons with different microporosity and BET surface area were created. The effect of the different variables of the activation process (KOH/bituminous coal ratio, heating temperature, activation time, and flow rate of nitrogen gas) on critical carbon parameters was analyzed. The impact of activated carbon on oligomerization was examined by conducting isotherm experiments at a neutral pH on Carbon(exp) produced with optimal characteristics and granular activated carbon (GAC) F400 for phenol, 2-methylphenol and 2-ethylphenol. These isotherms were collected under anoxic (absence of molecular oxygen) and oxic (presence of molecular oxygen) conditions. The single solute adsorption of phenol, 2-methylphenol and 2-ethylphenol on Carbon(exp) showed no obvious differences between oxic and anoxic environment, which indicated that the Carbon(exp) sample is very effective in hampering the oligomerization of phenolic compounds under oxic conditions. On the other hand, F400, which have lower micropore percentage and BET surface area, significant increases in the adsorptive capacity had been observed when molecular oxygen was present. PMID:22004832

  14. THE HISTORY OF EXPLORATION AND EXPLOITATION OF BITUMINOUS AND KEROGENOUS DEPOSITS IN CROATIA

    Directory of Open Access Journals (Sweden)

    Berislav Šebečić

    1995-12-01

    Full Text Available It is assumed thal the first known sedimens of natural bitumen or asphalt in coastal Croatia were exploited as the early moddle ages. Yet authenticated written documents about Vinišće near Trogir derive from no earlier than 1628, about Vrgorac/Paklina from only 1753. By the end of the 18th century, many deposits were discovered in Dalmatia, but it was Škrip on the Island of Brač and Suhi Dolac that were important. The earliest known deposits and occurrences of kerogenous rocks, or bituminous or oil shales, are mentioned as stone or fossil coal in Sovinjak, in the upper course of the River Mirna, and in Rebići in Istria; near Sinj, Slivno not far from the River Neretva, Mirta and near Nerežišće on the Island uf Brač. All if these were well known and described in 1804, while Sovinjak was mentioned in the 16th century. In the article, some of new information derived from mining and geological research into bituminous and kerogenous sediments and deposits are provided (the paper is published in Croatian.

  15. Utilization of Waste Clay from Boron Production in Bituminous Geosynthetic Barrier (GBR-B) Production as Landfill Liner

    OpenAIRE

    Müfide Banar; Yücel Güney; Aysun Özkan; Zerrin Günkaya; Eren Bayrakcı; Derya Ulutaş

    2016-01-01

    Bituminous geomembranes, one type of geosynthetics, include a hot bituminous mixture with mineral filler and reinforcement. In this study, boron production waste clay (CW) was used as filler to produce a geosynthetic barrier with bentonite, waste tire, and bitumen. Bentonite and waste tires were used as auxiliary fillers and bitumen as the binder. CW/bitumen, CW/bentonite/bitumen, and CW/waste tire/bitumen mixtures were prepared by using a laboratory mixer at 100°C. Hot mixtures were extruded...

  16. Decision of National and Provincial Highway Asphalt Pavement Structure Based on Value Engineering

    Directory of Open Access Journals (Sweden)

    Yingwei Ren

    2014-01-01

    Full Text Available It is important that decision of asphalt pavement structure requires overall considerations of the performance and financial investment. To have asphalt pavement structure fulfilling good reliability, the asphalt pavement structure decision was researched based on value engineering theory. According to the national and provincial highway investigation data in Shandong Province during the last decade, the asphalt pavement performance attenuation rules of traffic levels and asphalt layer thicknesses were developed, and then the road performance evaluation method was presented. In addition, the initial investments, the costs of road maintenance, and middle-scale repair in a period were analyzed. For the light traffic and medium traffic example, using the value engineering method, the pavement performance and costs of which thickness varies from 6 cm to 10 cm were calculated and compared. It was concluded that value engineering was an effective method in deciding the asphalt pavement structure.

  17. COMPUTATIONAL INVESTIGATION OF COMPOSED MULTILAYERED HALF-SPACE STRENGTH UNDER PAVEMENT

    Directory of Open Access Journals (Sweden)

    Svetlana Talakh

    2015-10-01

    Full Text Available The article presents mathematical model of non-linear subgrade half-space on the basis of the von Mises advanced yieldcriterion. We have performed computational investigations of non-rigid pavement deflected mode in plane problem statement under simulation of subgrade half-space active zone including the layers of pavement. The results receiveds how the plastoelastic deformation development influences the strength of non-rigid pavement.

  18. Asphalt Materials Characterization in Support of Implementation of the Proposed Mechanistic-Empirical Pavement Design Guide

    OpenAIRE

    Flintsch, Gerardo W.; Loulizi, Amara; Stacey D. Diefenderfer; Khaled A. Galal; Diefenderfer, Brian K.

    2007-01-01

    The proposed Mechanistic-Empirical Pavement Design Guide (MEPDG) procedure is an improved methodology for pavement design and evaluation of paving materials. Since this new procedure depends heavily on the characterization of the fundamental engineering properties of paving materials, a thorough material characterization of mixes used in Virginia is needed to use the MEPDG to design new and rehabilitated flexible pavements. The primary objective of this project was to perform a full hot-mix a...

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

    OpenAIRE

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

    2014-01-01

    Pavements always play a predominant role in transportation. Health monitoring of pavements is becoming more and more significant, as frequently suffering from cracks, rutting, and slippage renders them prematurely out of service. Effective and reliable sensing elements are thus in high demand to make prognosis on the mechanical properties and occurrence of damage to pavements. Therefore, in this paper, various types of functionality enhancement of industrialized optical fiber sensors for pav...

  20. Biomarker geochemistry of bituminous shale sequence and crude oil in the Ereǧli-Bor Basin (Konya-Niǧde), Central Anatolia, Turkey

    Science.gov (United States)

    Kara-Gulbay, Reyhan; Erdogan, Mert; Korkmaz, Sadettin; Kadinkiz, Gökhan

    2016-04-01

    In the Ereǧli-Bor Basin (Konya-Niǧde), Central Anatolia, bituminous shale sequence with thickness ranging between 72 and 160 m occurs in lacustrine deposits of Upper Miocene-Pliocene age. The live oil has also been observed in this bituminous shale sequence. Rock-Eval/TOC, GC and GC-MS analyses were conducted on selected bituminous shale samples from four borehole (key-12/1, key-12/2, key-12/3 key-12/4) and one crude oil sample from a borehole (key-12/2) in the basin. In this study, organic matter type, maturity and depositional environment of bituminous shale are evaluated and the origin of crude oil is determined by the bituminous shale-crude oil correlation. The total organic carbon (TOC) values of the bituminous shale samples range from 1.21-13.98 wt% with an average TOC value of 4.75wt%. The bituminous shale sequence is characterized by high HI (127-662 mg HC/g TOC) and low OI (7-50 mgCO2/TOC). Tmax varies from 332-419ᵒC. Very low Pr/Ph ratios of bituminous shale (0.09-0.22) are indicative of anoxic depositional conditions. C27 is dominate sterane for bituminous shale and crude oil samples with C27>C29>C28. Normal steranes are more dominant compare to iso- and diasteranes. Ouite high sterane/hopane ratios (1.14-2.70) indicate dominant algal organic matter input for bituminous shale and source rock of crude oil. C31R/hopane ratio for bituminous shale and crude oil samples are very low (0.09-0.13) and these ratio show a lacustrine depositional envirronment for bituminous shale and source rock of crude oil. Sterane and terpane distributions of bituminous shale and crude oil are very similar. A very good correlation in terms of biomarker between bituminous shale and crude oil samples indicate that source rock of crude oil is bituminous shale. The 22S/(22R + 22S) C32 homohopane ratios of bituminous shale and crude oil samples are found to be 0.56 and 0.61, indicating that homohopane isomerization has attained equilibrium and bituminous shale and crude oil are

  1. Stress Analysis and Determination of Effective k-value for Rigid Pavement

    OpenAIRE

    Kundan Meshram; H.S. Goliya; Akhilesh Poddar

    2013-01-01

    EverFE is a user-friendly 3D finite-element analysis tool for simulating the response of jointed plain concrete pavement (JPCP) systems to axle loads and environmental effects. EverFE is useful for both concrete pavement researchers and designers who must perform either complex nonlinear or simple linear stress analyses of JPCP.With help of this develop any type of model of rigid pavement considering practical condition thus getting more accurate and advance analysis for rigid pavement. It ca...

  2. Investigations of the dynamics of road pavement reflectance

    Institute of Scientific and Technical Information of China (English)

    Kang Jiang; Kai Yu; Yongchao Zhao

    2012-01-01

    Road pavement reflectance is usually assumed to be invariant in short periods of time in some quantitative remote sensing applications. To examine its variability,reflectance sequences of concrete and asphalt pavement are measured in field for half a day in visible and near-infarecd (VNIR) spectral range using dual-beam method.As much as 20.7% and 3.52% of relative changes are found in asphalt and concrete reflectance data at 550 nm,and all VNIR bands demonstrate similar variations found to correlate with both illumination geometry and the relative portion of diffuse irradiance.In this letter,this effect is interpreted from a mathematic view.Further studies are needed to model the dynamics of reflectance physically.

  3. Mechanical Properties of Asphalt Pavement Structure in Highway Tunnel

    Institute of Scientific and Technical Information of China (English)

    SHI Chun-xiang; GUO Zhong-yin

    2008-01-01

    A linear full 3D finite element method (FEM) was performed in order to present the key design parameters of highway tunnel asphalt pavement under double-wheel load on rectangular loaded area considering horizontal contact stress induced by the acceleration/deceleration of vehicles. The key design parameters are the maximum horizontal tensile stresses at the surface of the asphalt layer, the maximum horizontal tensile stresses at the bottom of the asphalt layer and the maximum vertical shear stresses at the surface of the as- phalt layer were calculated. The influencing factors such as double-wheel weight; asphalt layer thickness; base course stiffness modulus and thickness; and the contact conditions among the structure layers on these key design parameters were also examined separately to propose construction procedures of highway tunnel asphalt pavement.

  4. Automatic Road Pavement Assessment with Image Processing: Review and Comparison

    Directory of Open Access Journals (Sweden)

    Sylvie Chambon

    2011-01-01

    Full Text Available In the field of noninvasive sensing techniques for civil infrastructures monitoring, this paper addresses the problem of crack detection, in the surface of the French national roads, by automatic analysis of optical images. The first contribution is a state of the art of the image-processing tools applied to civil engineering. The second contribution is about fine-defect detection in pavement surface. The approach is based on a multi-scale extraction and a Markovian segmentation. Third, an evaluation and comparison protocol which has been designed for evaluating this difficult task—the road pavement crack detection—is introduced. Finally, the proposed method is validated, analysed, and compared to a detection approach based on morphological tools.

  5. Use of Recycled Aggregate and Fly Ash in Concrete Pavement

    Directory of Open Access Journals (Sweden)

    Myle N. James

    2011-01-01

    Full Text Available Problem statement: Recycled materials aggregate from the demolished concrete structures and fly ash from burning coal shows the possible application as structural and non structural components in concrete structures. This research aims to evaluate the feasibility of using concrete containing recycled concrete aggregate and fly ash in concrete pavement. Approach: Two water cement ratio (0.45 and 0.55 the compressive strength, modulus of electricity and flexural strength for concrete with recycled aggregate and fly ash with 0, 25% replacing cement in mass were considered. Results: The material properties of recycled aggregate concrete with fly ash indicate comparable results with that of concrete with natural aggregate and without fly ash. Conclusion/Recommendations: The recycled materials could be used in concrete pavement and it will promote the sustainability of concrete.

  6. Kinect, a Novel Cutting Edge Tool in Pavement Data Collection

    Science.gov (United States)

    Mahmoudzadeh, A.; Firoozi Yeganeh, S.; Golroo, A.

    2015-12-01

    Pavement roughness and surface distress detection is of interest of decision makers due to vehicle safety, user satisfaction, and cost saving. Data collection, as a core of pavement management systems, is required for these detections. There are two major types of data collection: traditional/manual data collection and automated/semi-automated data collection. This paper study different non-destructive tools in detecting cracks and potholes. For this purpose, automated data collection tools, which have been utilized recently are discussed and their applications are criticized. The main issue is the significant amount of money as a capital investment needed to buy the vehicle. The main scope of this paper is to study the approach and related tools that not only are cost-effective but also precise and accurate. The new sensor called Kinect has all of these specifications. It can capture both RGB images and depth which are of significant use in measuring cracks and potholes. This sensor is able to take image of surfaces with adequate resolution to detect cracks along with measurement of distance between sensor and obstacles in front of it which results in depth of defects. This technology has been very recently studied by few researchers in different fields of studies such as project management, biomedical engineering, etc. Pavement management has not paid enough attention to use of Kinect in monitoring and detecting distresses. This paper is aimed at providing a thorough literature review on usage of Kinect in pavement management and finally proposing the best approach which is cost-effective and precise.

  7. Use of Recycled Aggregate and Fly Ash in Concrete Pavement

    OpenAIRE

    Myle N. James; Wonchang Choi; Taher Abu-Lebdeh

    2011-01-01

    Problem statement: Recycled materials aggregate from the demolished concrete structures and fly ash from burning coal shows the possible application as structural and non structural components in concrete structures. This research aims to evaluate the feasibility of using concrete containing recycled concrete aggregate and fly ash in concrete pavement. Approach: Two water cement ratio (0.45 and 0.55) the compressive strength, modulus of electricity and flexural streng...

  8. Influential Factors on Deicing Performance of Electrically Conductive Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    TANG Zuquan; QIAN Jueshi; LI Zhuoqiu; WU Chuanming

    2006-01-01

    The deicing experiment of carbon fiber reinforced electrically conductive concrete (CFRC) slab was conducted in laboratory at first, then the deicing process of CFRC pavement was analyzed by means of finite element method (FEM). At last, based on the energy conservation law and the computing results of finite element method, the influential factors including the setting of electric heating layer, environmental temperature, the thickness of ice, material parameters, and deicing power on deicing performance and energy consumption were discussed.

  9. Identifying Fine Aggregates Prone to Polishing in PCC Pavements

    OpenAIRE

    Fowler, David W; Rached, Marc M.

    2012-01-01

    Surface polishing in portland cement concrete (PCC) pavements leads to higher incidences of skid-related accidents on highways. This type of failure is often associated with the usage of softer fine aggregate such as limestone sands. To identify polish resistance aggregates, state agencies like TxDOT have adopted tests such as the acid insoluble residue test (AIR). Since calcium carbonate is soluble in acid, no carbonate sand passes the AIR test which has a minimum limit of 60% in Texas. This...

  10. Pavement wear and airborne dust pollution in Norway

    OpenAIRE

    Snilsberg, Brynhild

    2008-01-01

    In several large cities in Norway the traffic volume is high. The use of studded tires and other friction enhancing measures during winter leads to significant pavement wear, which in turn leads to an increase in the amount of airborne particulate matter, often exceeding the limits set in the ambient air regulation. This represents a nuisance or health risk for people being exposed to the pollution. According to regulations set by the European Union particulate matter is measured and regulate...

  11. DYNAMIC JOINT LOAD TRANSFER EFFICIENCY OF RIGID PAVEMENT

    Directory of Open Access Journals (Sweden)

    YU Xinhua

    2011-02-01

    Full Text Available the mechanistic analysis presented in this paper is only the beginning of new approach for understanding the real joint load transfer capability on airport and highway concrete pavements. It gives up the two major assumptions those have been popularly adopted by hundreds of published papers: the load is transferred under a wheel with zero speed and with fixed position. The real load transfer in field is always under wheels with non-zero speed and with varied position at any moment. The objective of this study focuses on quantifying the dynamic effects of a moving wheel while it is crossing a joint on a pavement. The analysis is conducted using a model of two-slab system on Kelvin foundation under a moving wheel with variable speed v, different pavement damping Cs, foundation reaction modulus k and foundation damping Ck. The dynamic joint load transfer efficiency is temporarily and empirically defined by the peak strain ratio LTE(S on the two sides of a joint. The primary findings include: (1 The higher speed of a moving wheel leads to the higher LTE(S;(2 The larger the pavement damping Cs leads to the higher LTE(S;(3 The numerical ratio c(=LTE(Sdynamic/ LTE(Sstatic varies in the range 1 to 2 mainly depending on speed v and damping Cs;(4 The LTE(Sdynamic is not sensitive to foundation reaction modulus k and foundation damping Ck. Further researches are needed for appropriate applications of the new model in practice.

  12. Development of a fiber optic pavement subgrade strain measurement system

    Science.gov (United States)

    Miller, Craig Emerson

    2000-11-01

    This dissertation describes the development of a fiber optic sensing system to measure strains within the soil subgrade of highway pavements resulting from traffic loads. The motivation to develop such a device include improvements to: (1)all phases of pavement design, (2)theoretical models used to predict pavement performance, and (3)pavement rehabilitation. The design of the sensing system encompasses selecting an appropriate transducer design as well as the development of optimal optical and demodulation systems. The first is spring based, which attempts to match its spring stiffness to that of the soil-data indicate it is not an optimal transducer design. The second transducer implements anchoring plates attached to two telescoping tubes which allows the soil to be compacted to a desired density between the plates to dictate the transducer's behavior. Both transducers include an extrinsic Fabry- Perot cavity to impose the soil strains onto a phase change of the optical signal propagating through the cavity. The optical system includes a low coherence source and allows phase modulation via path length stretching by adding a second interferometer in series with the transducer, resulting in a path matched differential interferometer. A digitally implemented synthetic heterodyne demodulator based on a four step phase stepping algorithm is used to obtain unambiguous soil strain information from the displacement of the Fabry-Perot cavity. The demodulator is calibrated and characterized by illuminating the transducer with a second long coherence source of different wavelength. The transducer using anchoring plates is embedded within cylindrical soil specimens of varying soil types and soil moisture contents. Loads are applied to the specimen and resulting strains are measured using the embedded fiber optic gage and LVDTs attached to the surface of the specimen. This experimental verification is substantiated using a finite element analysis to predict any differences

  13. Evaluation of pavement skid resistance using high speed texture measurement

    OpenAIRE

    Jay N. Meegoda; Shengyan Gao

    2015-01-01

    Skid resistance is an important parameter for highway designs, construction, management, maintenance and safety. The purpose of this manuscript is to propose the correlation between skid resistance, which is measured as skid resistance trailer, and mean profile depth (MPD) or the macro surface texture, which is measured by vehicle mounted laser, so that highway agencies can predict the skid resistance of pavement without the use of expensive and time consuming skid resistance trailer, which a...

  14. INVESTIGATION OF ASPHALT PAVEMENT WITH ADDED CRUMB RUBBER

    OpenAIRE

    Mandula, Jan; Olexa, Tomaš; Holubka, Mariya; Salaiova, Brigita

    2014-01-01

    Waste tires must be recycled in environmentally safe ways that meet civil engineering concerns while fulfilling standards for construction materials. Used tires can be processed into rubber powders with particle sizes of 0–2 mm, a suitable fine aggregate for mixing into road pavements. We tested asphalt mixtures with rubber added using the dry method, comparing their properties with a traditional mixture. We tested asphalt–rubber mixtures with rubber incorporated at either ambient temperature...

  15. Reinforcing Effects of Carbon Black on Asphalt Binder for Pavement

    OpenAIRE

    Yamaguchi, Katsuyuki; Sasaki, Iwao; Nishizaki, Itaru; Meiarashi, Seishi; Moriyoshi, Akihiro

    2005-01-01

    Carbon black, used as a reinforcing filler for rubber materials, was evaluated for asphalt binders in pavements. Carbon black added to straight asphalt within 20 wt% caused an increase in the elastic modulus and a decrease in the viscosity of the asphalt, especially at temperatures higher than room temperature. Addition of carbon black raised the maximum service temperature of asphalt in the category of the binder performance grade according to the SHRP (Strategic Highway Research Program) sp...

  16. The improvement of pavement performance using asphalt rubber hot mixes

    OpenAIRE

    Pais, Jorge C.; Pereira, Paulo A. A.

    2007-01-01

    The need of a better pavement performance has led researchers to develop new road materials, mainly for the asphalt layers, where the modification of the asphalt is the main example. This modification usually forces the use of polymers and fibers and, more recently, the use of crumb rubber from ground tires, where the modified asphalt is known as asphalt rubber. This asphalt rubber used in asphalt mixtures produces a superior performance if compared to the asphalt mixtures with...

  17. Structural Design of Asphalt Pavement for Low Cost Rural Roads

    Institute of Scientific and Technical Information of China (English)

    Yuan Goulin; Chen Rongshen

    2006-01-01

    On the basis of the equivalent axle load action frequency, the traffic classifications of rural roads as well as their corresponding types are classified. The asphalt pavement structure, road surface types and thickness of the rural roads are suggested for the various action frequency of the equivalent axle load. Furthermore, the roadbase thickness graphs are provided according to different equivalent axle load action frequency with different roadbed modulus and road surface modulus taken into account.

  18. Use of scrap rubber in asphalt pavement surfaces

    Science.gov (United States)

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

    1991-12-01

    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.

  19. Texture friction relationship: from texture empirical decomposition to pavement friction

    OpenAIRE

    Kane, Malal; RADO, Zoltan; CEREZO, Véronique; TIMMONS, Andrew; DO, Minh Tan

    2014-01-01

    This work investigates the friction-texture relationship: starting from a decomposition method of the pavement texture that is part of a new signal processing so called “Huang Hilbert Transformation” to texture parameters-friction relation. This method allows empirical decomposition of the texture profile to a set of basic profiles in a limited number, so called “Intrinsic Mode Functions” or IMF. From the obtained IMFs, a set of four new functions so called “Base...

  20. Integration of Sustainability Rating Tools in Contemporary Pavement Management Systems

    OpenAIRE

    Maher, Michael; Kazmierowski, Tom; Navarra, Michael

    2015-01-01

    There is growing demand around the world for public agencies to implement sustainable initiatives into public infrastructure projects. Sustainability principles need to be integrated seamlessly into all decision making processes, especially when it relates to public expenditures on vital infrastructure. While agreeing with the principles of sustainability, many agencies struggle with how to implement these objectives in a systematic manner. Pavement sustainability can be evaluated using sever...

  1. Osmosis-induced swelling of Eurobitum bituminized radioactive waste in constant total stress conditions

    Science.gov (United States)

    Valcke, E.; Marien, A.; Smets, S.; Li, X.; Mokni, N.; Olivella, S.; Sillen, X.

    2010-11-01

    In geological disposal conditions, contact of Eurobitum bituminized radioactive waste, which contains high amounts of the hygroscopic and highly soluble NaNO 3, with groundwater will result in water uptake and swelling of the waste, and in subsequent leaching of the embedded NaNO 3 and radionuclides. The swelling of and the NaNO 3 leaching from non-radioactive Eurobitum samples, comprised between two stainless steel filters and in contact with 0.1 M KOH, was studied in restricted (semi-confined) swelling conditions, i.e. under a constant total stress, or counterpressure, of 2.2, 3.3, or 4.4 MPa ( i.e. oedometer conditions). Four tests were stopped after hydration times between 800 and 1500 days, and the samples were analyzed by micro-focus X-ray Computer Tomography (μCT) and by Environmental Scanning Electron Microscopy (ESEM). The complete set of data enabled a consistent interpretation of the observations and lead to an improved understanding of the phenomenology of the water uptake, swelling, and NaNO 3 leaching in restricted swelling conditions. Under the studied conditions, the bituminous matrix surrounding the NaNO 3 crystals and pores with NaNO 3 solution behaved as a highly efficient semi-permeable membrane, i.e. osmotic processes occurred. In the main part of the leached layers, a high average NaNO 3 concentration and related to this a high osmotic pressure prevailed, explaining why in the studied range the swelling was not measurably affected by the counterpressure. At the interface with the stainless steel filters, a low permeable re-compressed bitumen layer was formed, contributing to the slow release of NaNO 3 compared to the water uptake rate. A fully coupled Chemo-Hydro-Mechanical (CHM) constitutive model has been developed that integrates the key processes involved and that reproduces satisfactorily the results; this is presented in another work. Combination of the experimental and the modelling study allow to conclude that under semi

  2. Reliability-based performance simulation for optimized pavement maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Jui-Sheng, E-mail: jschou@mail.ntust.edu.tw [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China); Le, Thanh-Son [Department of Construction Engineering, National Taiwan University of Science and Technology (Taiwan Tech), 43 Sec. 4, Keelung Rd., Taipei 106, Taiwan (China)

    2011-10-15

    Roadway pavement maintenance is essential for driver safety and highway infrastructure efficiency. However, regular preventive maintenance and rehabilitation (M and R) activities are extremely costly. Unfortunately, the funds available for the M and R of highway pavement are often given lower priority compared to other national development policies, therefore, available funds must be allocated wisely. Maintenance strategies are typically implemented by optimizing only the cost whilst the reliability of facility performance is neglected. This study proposes a novel algorithm using multi-objective particle swarm optimization (MOPSO) technique to evaluate the cost-reliability tradeoff in a flexible maintenance strategy based on non-dominant solutions. Moreover, a probabilistic model for regression parameters is employed to assess reliability-based performance. A numerical example of a highway pavement project is illustrated to demonstrate the efficacy of the proposed MOPSO algorithms. The analytical results show that the proposed approach can help decision makers to optimize roadway maintenance plans. - Highlights: > A novel algorithm using multi-objective particle swarm optimization technique. > Evaluation of the cost-reliability tradeoff in a flexible maintenance strategy. > A probabilistic model for regression parameters is employed to assess reliability-based performance. > The proposed approach can help decision makers to optimize roadway maintenance plans.

  3. Numerical Simulation of Moving Load on Concrete Pavements

    Directory of Open Access Journals (Sweden)

    Lajčáková Gabriela

    2015-06-01

    Full Text Available The knowledge of the development with time of the strain and stress states in pavement structures is needed in the solution of various engineering tasks as the design fatigue lifetime reliability maintenance and structure development. The space computing model of the truck TATRA 815 is introduced. The pavement computing model is created in the sense of Kirchhof theory of the thin slab on elastic foundation. The goal of the calculation is to obtain the vertical deflection in the middle of the slab and the time courses of vertical tire forces. The equations of motion are derived in the form of differential equations. The assumption about the shape of the slab deflection area is adopted. The equations of the motion are solved numerically in the environment of program system MATLAB. The dependences following the influence of various parameters (speed of vehicle motion, stiffness of subgrade, slab thickness, road profile on the pavement vertical deflections and the vertical tire forces are introduced. The results obtained from the plate computing model are compared with the results obtained by the FEM analysis. The outputs of the numerical solution in the time domain can be transformed into a frequency domain and subsequently used to solve various engineering tasks.

  4. EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

    Directory of Open Access Journals (Sweden)

    Rosa Cristina Cecche Lintz

    2009-12-01

    Full Text Available The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass.

  5. Study the Relationship between Pavement Surface Distress and Roughness Data

    Directory of Open Access Journals (Sweden)

    MubarakiMuhammad

    2016-01-01

    Full Text Available In this paper, pavement sections from the highway connected Jeddah to Jazan were selected and analyzed to investigate the relationship between International Roughness Index (IRI and pavement damage including; cracking, rutting, and raveling. The Ministry of Transport (MOT of Saudi Arabia has been collecting pavement condition data using the Road Surface Tester (RST vehicle. The MOT measures Roughness, Rutting (RUT, Cracking (CRA, raveling (RAV. Roughness measurements are calculated in terms of the International Roughness Index (IRI. The IRI is calculated over equally spaced intervals along the road profile. Roughness measurements are performed at speed between at 80 kilometers per hour. Thus RST vehicle has been used to evaluate highways across the country. The paper shows three relationships including; cracking (CRA verses roughness (IRI, rutting (RUT verses IRI, and raveling (RAV verses IRI. Also, the paper developed two models namely; model relates IRI to the three distress under study, and model relates IRI to ride quality. The results of the analysis claim at 95% confidence that a significant relationship exist between IRI and cracking, and raveling. It’s also shown that rutting did not show significant relationship to IRI values. That’s leads to conclude that the distresses types: cracking and raveling may possibly be described as ride quality distresses at different level of significant. Rutting distress described as non-ride quality type’s distresses.

  6. Performance of Recycled Asphalt Pavement as Coarse Aggregate in Concrete

    Directory of Open Access Journals (Sweden)

    Fidelis O. OKAFOR

    2010-12-01

    Full Text Available Recycled asphalt pavement (RAP is the reclaimed and reprocessed pavement material containing asphalt and aggregate. Most RAP is recycled back into pavements, and as a result there is a general lack of data pertaining to the mechanical properties for RAP in other possible applications such as Portland cement concrete. In the present study, some mechanical properties of Portland cement concrete containing RAP as coarse aggregate were investigated in the laboratory. Six concrete mixes of widely differing water/cement ratios and mix proportions were made using RAP as coarse aggregate. The properties tested include the physical properties of the RAP aggregate, the compressive and flexural strengths of the concrete. These properties were compared with those of similar concretes made with natural gravel aggregate. Results of the tests suggest that the strength of concrete made from RAP is dependent on the bond strength of the “asphalt-mortar” (asphalt binder-sand-filler matrix coatings on the aggregates and may not produce concrete with compressive strength above 25 MPa. However, for middle and low strength concrete, the material was found to compare favorably with natural gravel aggregate.

  7. Configurations Of Tire Pressure On The Pavement For Commercial Vehicles: Calculation Of The ‘N’ Number And The Consequences On Pavement Performance

    Directory of Open Access Journals (Sweden)

    Paulo Boulos Filho

    2016-07-01

    Full Text Available Road traffic has a high variety of types of vehicles and cargo transported. One of the main difficulties in pavement design is forecasting the changes in traffic over time and evaluating the comparative deterioration power of the various loads with axle and tire settings and different levels of repetition. The road environment in Brazil, as we know, is the main means of the country's cargo transportation. Throughout the 1990s and 2000s the road modal accounted for over 60% of the total cargo transported in the country leaving the unbalanced Brazilian transport matrix with almost exclusive investments in such means of transportation. According to CNT 2012, which conducted a survey in approximately 45% of the paved network, evaluating the pavement functional conditions, traffic signs and geometry, 46% of the country’s road network has some type of deficiency in the pavement. The goal of this work is to contribute to a better understanding of the complex influence of traffic in the design and service life of the pavement. The load pressure of commercial vehicle tires over the pavement has increased in recent decades. A more apparent effect of this increase in tire pressure would be the change in the pavement- tire contact area which in turn may result in an increase in the contact load between tire and pavement and other harmful effects on the structure. This study aims to determine the effect on the calculation of the N number, or the number of solicitations of the standard axle on the road pavement, measuring the overload as a percentage of the legal load indicated by a scale. In short, we calculate how an increase in the overload percentage in comparison with the allowable load will influence the decrease of the calculated durability of the pavement designed for the highway.

  8. GPR used in combination with other NDT methods for assessing pavements in PPP projects

    Science.gov (United States)

    Loizos, Andreas; Plati, Christina

    2014-05-01

    In the recent decades, Public-Private Partnerships (PPP) has been adopted for highway infrastructure procurement in many countries. PPP projects typically take the form of a section of highway and connecting roadways which are to be construction and managed for a given concession period. Over the course of the highway concession period, the private agency takes over the pavement maintenance and rehabilitation duties. On this purpose, it is critical to find the most cost effective way to maintain the infrastructure in compliance with the agreed upon performance measures and a Pavement Management Systems (PMS) is critical to the success of this process. For the prosperous operation of a PMS it is necessary to have appropriate procedures for pavement monitoring and evaluation, which is important in many areas of pavement engineering. Non Destructive Testing (NDT) has played a major role in pavement condition monitoring, assessments and evaluation accomplishing continuous and quick collection of pavement data. The analysis of this data can lead to indicators related to trigger values (criteria) that define the pavement condition based on which the pavement "health" is perceived helping decide whether there is the need or not to intervene in the pavement. The accomplished perception appoints required management activities for preserving pavements in favor not only of the involved highway/road agencies but also of users' service. Amongst NDT methods Ground Penetrating Radar (GPR) seems to be a very powerful toll, as it provides a range of condition and construction pavement information. It can support effectively the implementation of PMS activities in the framework of pavement monitoring and evaluation. Given that, the present work aims to the development and adaptation of a protocol for the use of GPR in combination with other NDT methods, such as Falling Weight Deflectometer (FWD), for assessing pavements in PPP projects. It is based on the experience of Laboratory of

  9. Physical properties of solid fuel briquettes from bituminous coal waste and biomass

    Institute of Scientific and Technical Information of China (English)

    ZARRINGHALAM-MOGHADDAM A; GHOLIPOUR-ZANJANI N; DOROSTIS; VAEZ M

    2011-01-01

    Biomass and bituminous coal fines from four different coalfields were used to produce fuel briquettes.Two physical properties of briquettes,water resistance index and compressive strength were analyzed.The influence of type and quantity of biomass on physical properties was also studied.The results reveal that depending on the mineral content of the coal,the physical properties of the briquettes differ noticeably.The comparison of briquettes with and without biomass showed that the presence of the beet pulp increased CS in all types of coal samples.Samples containing beet pulp had better physical properties than sawdust.Mezino Ⅱ coal briquettes had highest CS and WRI than the other ones.Calorific value of biomass/Mezino Ⅱ coal briquettes was lessened in comparison with raw coal,but it remained in an acceptable range.

  10. US bituminous coal test program in the British Gas/Lurgi (BGL) gasifier

    Energy Technology Data Exchange (ETDEWEB)

    de Souza, M.D.; Tart, K.R.; Eales, D.F. (British Gas plc, London (United Kingdom)); Turna, O. (Lurgi GmbH, Frankfurt am Main (Germany))

    1991-12-01

    The BGL moving-bed, slagging-gasification process is an extension of the commercially proven Lurgi dry-ash, moving-bed gasification process. British Gas and Lurgi have demonstrated the process over an 11-year period at the 350 and 500 t/d scale at British Gas' Westfield Development Center, Scotland, with a wide variety of US and British coals. British Gas also installed a gas purification and HICOM methanation plant at Westfield to treat approximately 190,000 sft{sup 3}/h of purified syngas. Objectives are: To demonstrate the suitability of US bituminous coals as feed-stocks in the BGL gasification process; to provide performance data for use in designing commercial-scale BGL-based gasification-combined-cycle (GCC) power plants; and to evaluate the performance of the British Gas HICOM process for methanation of US coal-derived syngas.

  11. Biological markers in bitumens and pyrolyzates of Upper Cretaceous bituminous chalks from the Ghareb Formation (Israel)

    Science.gov (United States)

    Rullkötter, Jürgen; Aizenshtat, Zeev; Spiro, Baruch

    1984-01-01

    The sterane and triterpane distributions of three bituminous chalks from the Upper Cretaceous Ghareb Formation (Israel) were investigated both in the original extractable bitumens and in extracts obtained after pyrolysis of whole rock and isolated kerogen samples at 450°C. Pyrolysis was performed in a closed system under hydrous (whole rock) and anhydrous conditions (isolated kerogens). The carbon number distributions of steranes and triterpanes differ significantly between original bitumen and pyrolyzates. Unlike the bitumens in which diasteranes were not detected, the anhydrous pyrolyzates contain small amounts of diasteranes. The presence of water during pyrolysis leads to an increase of sterane isomerization, the abundant formation of diasteranes and an increase of the 18α( H)- trisnorneohopane/17α( H)- trisnorhopane ratio. Sterane isomerization maturation parameters show a closer match between original bitumen and pyrolyzates after pyrolysis in a closed system when compared with an open system.

  12. STUDY ON EVOLUTION REGULARITIES AND ABSORPTION CHARACTERISTICS OF SULFIDE DURING BITUMINOUS BRIQUETTE HORIZONTAL COMBUSTION

    Institute of Scientific and Technical Information of China (English)

    路春美; 王永征

    1999-01-01

    This paper discusses the evolution regularity and the absorption characters of sulfide for bituminous briquette burned in a horizontal burning furnace. The evolution rate of sulphur is affected by some factors, such as the sulphur content in the burning coal, burning time and the meane excess air coefficient in the furnace. With processing the experimental result, the calculation related expression has been obtained to predict the evolution rate of sulfide. The sulphur absorption efficiency of briquette is affected by the factors such as the character of the sulphur sorbent, the type of the coal and the operating parameters. "By means of appropriately adjusting the calciumsulphur mole ratio, the mean excess air coefficient and the time-interval between pushing two layer briquettes, a high sulphur absorption efficiency (>74%) can be obtained.

  13. Examination and comparision of structure: lignite, bituminous and anthracite coal. [10 references

    Energy Technology Data Exchange (ETDEWEB)

    Winans, R.E.; Hayatsu, R.; Scott, R.G.; Moore, L.P.; Studier, M.H.

    1976-01-01

    Coal can be described as an amorphous mixture of macromolecules each made up of a complex array of organic molecules chemically linked together. Methods for breaking up these macromolecules in order to characterize the aromatic structural types have been explored. Pyrolysis is a common method for depolymerizing coal, but under the conditions necessary for pyrolysis much structural rearrangement occurs making a comparison of the products to the initial structural groups in coal difficult if not impossible. One approach has been to use a variety of selective oxidation methods. Aqueous sodium dichromate, aqueous air oxidation with uv light, and hydrogen peroxide in acetic acid have been used. Initial results of some of these studies have been published. This work has been extended to include characterization and comparison of a lignite, bituminous coal, and anthracite. Besides the oxidation products, the monomeric organic molecules trapped within the macromolecules are examined and the results interpreted in relation to coal structure and the coalification process.

  14. Using proximate analysis to characterize airborne dust generation from bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Page, S.J.; Organiscak, J.A. [NIOSH, Pittsburgh, PA (United States). Pittsburgh Research Lab.

    2002-06-01

    Laboratory crushing experiments were conducted on a range of low to high volatile bituminous coals to investigate the various factors influencing airborne respirable dust generation. Bituminous coal samples from 8 mines (5 U.S. and 3 Polish) were uniformly prepared and processed through a double roll crusher located in a low air velocity wind tunnel. Experimental factors studied included inherent coal seam constituents, specific energy of crushing, product size characteristics, dust cloud electrostatic field, and specific quantity of airborne respirable dust generated. A combination of factors is associated with the generation of airborne respirable dust. One factor involved is the effect of coal rank, described by the inherent moist fuel ratio, on the product size characteristics. However, since coals of high moist fuel ratio (high rank) are generally more extensively cleated, it is suggested that the degree of cleating is directly responsible for the quantity of respirable-sized particles produced in the crushed product material for eastern U.S. coals. This is implied by the relationship of ash content and at least one mineral constituent (pyrite, determined from pyritic sulfur analysis) to the percentage of airborne respirable dust. A clear delineation of coals, based on well-known proximate analysis characteristics, that generate the most respirable dust appears to be possible. It was also shown that the dust-generating characteristics of coals could be reasonably described by both the moist fuel ratio and the Hardgrove Grindability Index (HGI). These results show a clear distinction between eastern and western U.S. coals. However, no consistent distinction for Polish coal was observed.

  15. Uraniferous lignites and bituminous clays of the Serres Basin. Pt. A

    International Nuclear Information System (INIS)

    The lignites of the southern area (Christos-Vissiani-Lefkes-Perdikari) and the bituminous clay silts of the northern area (Maramena, Ano Metohi, Chrysopigi) are the main uraniferous beds in the Serres Basin. The sediments of the basin (Upper Miocene to recent) have been stratigraphically divided into three informal unities: the Lefkon, Georgios and Spilia formations. The uraniferous lignites pertaining to the Lefkon limnic-fluvial formation are developed into two discrete horizons, the upper Double Seam and the lower Main Seam. The bituminous clays are of the same age with the lignites, those of Maramena being, however, younger, equivalent to the marine and brackish Georgios formation. The continuity, thickness and dip of the strata reveal considerable regional changes resulting from the intense tectonism of the basin. Further to the surface works the upper lignites have been reached through small excavations and also about 100 boreholes totalling 10,000 m have been drilled. The composition of the organic constituents and the calorific value show a dull transitional to shiny hard lignite with ash rich in pyrite and sulphur. There have been no discrete U minerals detected, while the electron microprobe analysis showed that the uranium is uniformly disseminated into the lignite mass, mainly absorbed through its humic acids. More than 75% of the uranium is extractable, the control of its combustion conditions being, however, a major problem. The potential reserves have been up to date estimated to be of over 4,000 tons (uranium metal), this figure resulting mainly from data evaluated from the borehole γ-ray logs using the computer programmes LOGFILE and LOGPLOT developed at the Radioactive Raw Materials Dept. of the Greek AEC. (author)

  16. Distribution of inorganic and organic substances in the hydrocyclone separated Slovak sub-bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Anton Zubrik; Slavomir Hredzak; Ludmila Turcaniova; Michal Lovas; Ingo Bergmann; Klaus Dieter Becker; Maria Lukcova; Vladimir Sepelak [Slovak Academy of Sciences, Kosice (Slovakia). Institute of Geotechnics

    2010-08-15

    A low-rank Slovak sub-bituminous coal from the Handlova deposit was physically treated by washing in a water-only cyclone with the goal to find the separation effect for inorganic (mainly Fe-bearing minerals) and organic substances (humic acids, diterpanes). A high-quality coal product with the ash content in the dry matter of 9.02% and carbon content of C{sup d} = 68.12% at a mass yield of 29.51% was obtained using the water-only cyclone processing. At first, the physically treated coal samples were detailed characterized by XRD, {sup 57}Fe Moessbauer spectroscopy, FT-IR and HR-TEM. In addition to non-crystalline organic coal components, inorganic compounds belonging to silicate minerals (kaolinite, muscovite and quartz) as well as to Fe-bearing sulphide minerals (pyrite) were identified in the sub-bituminous coal by XRD. {sup 57}Fe Moessbauer spectroscopy detected the presence of iron carbonate (siderite), iron-containing clay mineral and two sulphur-containing minerals (pyrite, jarosite) in the untreated coal. On the other hand, only one Fe-bearing mineral, (pyrite) was found in the washed coal. Effect of the physical separation is also demonstrated in FT-IR spectra, where the peak at 1040 cm{sup -1} representing the silicate component in the untreated sample is not detectable in the washed coal sample. Presence of extractive organic substances, i.e. humic acids and tetracyclic diterpane (16a(H)-phyllocladane), in the hydrocyclone products is also evidenced. It was confirmed that the isolated diterpenoic compound is attendant in the washed product with the lowest ash content and it is assimilated with the organic part of coal. Surprisingly, humic acids were found in the highest concentration in the slurry that has the highest content of ash (63.14%). 54 refs., 8 figs., 5 tabs.

  17. Investigation of mechanical properties of pavement through electromagnetic techniques

    Science.gov (United States)

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

    2014-05-01

    Ground-penetrating radar (GPR) is considered as one of the most flexible geophysical tools that can be effectively and efficiently used in many different applications. In the field of pavement engineering, GPR can cover a wide range of uses, spanning from physical to geometrical inspections of pavements. Traditionally, such inferred information are integrated with mechanical measurements from other traditional (e.g. plate bearing test) or non-destructive (e.g. falling weight deflectometer) techniques, thereby resulting, respectively, in time-consuming and low-significant measurements, or in a high use of technological resources. In this regard, the new challenge of retrieving mechanical properties of road pavements and materials from electromagnetic measurements could represent a further step towards a greater saving of economic resources. As far as concerns unpaved and bound layers it is well-known that strength and deformation properties are mostly affected, respectively, by inter-particle friction and cohesion of soil particles and aggregates, and by bitumen adhesion, whose variability is expressed by the Young modulus of elasticity. In that respect, by assuming a relationship between electromagnetic response (e.g. signal amplitudes) and bulk density of materials, a reasonable correlation between mechanical and electric properties of substructure is therefore expected. In such framework, a pulse GPR system with ground-coupled antennae, 600 MHz and 1600 MHz centre frequencies was used over a 4-m×30-m test site composed by a flexible pavement structure. The horizontal sampling resolution amounted to 2.4×10-2 m. A square regular grid mesh of 836 nodes with a 0.40-m spacing between the GPR acquisition tracks was surveyed. Accordingly, a light falling weight deflectometer (LFWD) was used for measuring the elastic modulus of pavement at each node. The setup of such instrument consisted of a 10-kg falling mass and a 100-mm loading plate so that the influence domain

  18. Comparative study of test methods for bituminized and other low- and medium-level solidified waste materials

    International Nuclear Information System (INIS)

    Various aspects of the behaviour of bituminized or cemented simulated low- or medium-level radioactive waste in contact with water or salt solutions have been investigated. The solubility (approximately 0.5%) and the diffusion coefficient (approximately 5.10-8 cm2/sec) determining transort of water in pure bitumen have been measured for Mexphalte 40/50 at room temperature. A weighing method has been used to study water uptake and swelling of bituminized sodium nitrate, sodium sulphate or cation-exchange resin. The swelling of samples in contact with water was in some cases very pronounced. In strong salt solutions the tendency to swell is much less. The particle size of the embedded waste material is an important parameter. Thermal pre-treatment of cation-exchange resin before bituminization does not seem to improve the quality of the final product. The interaction between bituminized-exchange resin and concrete barrier materials has been studied. Microbial degradation of bitumen and bituminized waste under aerobic conditions has been investigated. It is probably of minor importance as far as leaching is concerned. A method for measuring leaching from a plane surface of cemented waste has been developed. The method avoids the problem of cracks between the sample and the container. Leaching from cemented sodium nitrate or sulphate was investigated. Absorption of CO2 from the atmosphere was found to have only minor effect on Cs- and Na-leaching but gave a pronounced decrease in Ca-leaching. The use of silica-fume as an additive to cemented sodium nitrate decreased the leach rate by a factor 4. (author)

  19. 23 CFR Appendix to Subpart F of... - Alternate Method of Determining the Color of Retroreflective Sign Materials and Pavement Marking...

    Science.gov (United States)

    2010-04-01

    ... Retroreflective Sign Materials and Pavement Marking Materials Appendix to Subpart F of Part 655 Highways FEDERAL... Pavement Marking Materials 1. Although the FHWA Color Tolerance Charts depreciate the use of... for Retroreflective Pavement Marking Material With CIE 2° Standard Observer and 45/0 (0/45)...

  20. FORECASTING OF DURABILITY OF ASPHALT PAVEMENT ON THE BASIS OF LEVELS OF THEIR VIBRATION LOADING

    Directory of Open Access Journals (Sweden)

    V. A. Osinovskaya

    2015-01-01

    Full Text Available The problem of low durability of flexible pavement is one of the most important problems of road economy. For example, the actual service life of asphalt pavement in Russia about 3 … 5 years. The bad condition of highways is an obstacle for the development of the national economy and leads to a significant annual economic losses.At present, this problem has no exact solution. Even at the seeming good road conditions of Europe and America the problem of low durability is no less important in these countries. And this problem becomes more and more actual every year.Our scientific researches allowed to make a hypothesis that the projected of pavements are not have the necessary durability yet not of a stage of designing because in strength calculations did not take into account the vibration of road constructions.Very actual the vibration loading becomes today as is now significantly changed the nature of loading of pavements. As a result the deflections of a pavements are reduced, but the increased vibration of pavements accelerated processes of destruction and significantly reduced durability.The theory of vibration destruction developed by the author allows to adjust the vibration, to form the vibration resistance pavements, and also to forecast a residual life of pavements that will more effectively develop repair actions.

  1. Design of Rigid and Flexible Pavements by Various Methods & Their Cost Analysis of Each Method

    Directory of Open Access Journals (Sweden)

    Saurabh Jain

    2013-09-01

    Full Text Available Highway and pavement design plays an important role in the DPR projects. The satisfactory performance of the pavement will result in higher savings in terms of vehicle operating costs and travel time, which has a bearing on the overall economic feasibility of the project. This paper discusses about the design methods that are traditionally being followed and examines the “Design of rigid and flexible pavements by various methods & their cost analysis by each method”. Flexible pavement are preferred over cement concrete roads as they have a great advantage that these can be strengthened and improved in stages with the growth of traffic and also their surfaces can be milled and recycled for rehabilitation. The flexible pavements are less expensive also with regard to initial investment and maintenance. Although Rigid pavement is expensive but have less maintenance and having good design period. The economic part are carried out for the design pavement of a section by using the result obtain by design method and their corresponding component layer thickness. It can be done by drawing comparisons with the standard way and practical way. This total work includes collection of data analysis various flexible and rigid pavement designs and their estimation procedure are very much useful to engineer who deals with highways.

  2. Quantifying Evaporation and Evaluating Runoff Estimation Methods in a Permeable Pavement System

    Science.gov (United States)

    The U.S. Environmental Protection Agency constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable pavement in the parking lanes which were designed to receive run-on from the impervious hot-mix asphalt driving lanes. Twelve lined permeable pavement sec...

  3. Active zone impact on deformation state of non-rigid pavement

    Science.gov (United States)

    Mandula, Ján

    2014-06-01

    The paper deals with the design of non-rigid pavement, with emphasis on the effect of active zone on its deformation state. The concepts of determination of active zone are described. The results of numerical modelling of pavement laying on elastic subgrade are presented in the paper

  4. Active zone impact on deformation state of non-rigid pavement

    Directory of Open Access Journals (Sweden)

    Mandula Ján

    2014-06-01

    Full Text Available The paper deals with the design of non-rigid pavement, with emphasis on the effect of active zone on its deformation state. The concepts of determination of active zone are described. The results of numerical modelling of pavement laying on elastic subgrade are presented in the paper

  5. 23 CFR 971.208 - Federal lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ...,” AASHTO, 2001, is available for inspection as prescribed at 49 CFR part 7. It is also available from the... 23 Highways 1 2010-04-01 2010-04-01 false Federal lands pavement management system (PMS). 971.208... lands pavement management system (PMS). In addition to the requirements provided in § 971.204, the...

  6. Evaluation of Surface and Subsurface Processes in Permeable Pavement Infiltration Trenches

    Science.gov (United States)

    The hydrologic performance of permeable pavement systems can be affected by clogging of the pavement surface and/or clogging at the interface where the subsurface storage layer meets the underlying soil. As infiltration and exfiltration are the primary functional mechanisms for ...

  7. Asphalt Pavement Aging and Temperature Dependent Properties Using Functionally Graded Viscoelastic Model

    Science.gov (United States)

    Dave, Eshan V.

    2009-01-01

    Asphalt concrete pavements are inherently graded viscoelastic structures. Oxidative aging of asphalt binder and temperature cycling due to climatic conditions being the major cause of non-homogeneity. Current pavement analysis and simulation procedures dwell on the use of layered approach to account for these non-homogeneities. The conventional…

  8. 23 CFR 973.208 - Indian lands pavement management system (PMS).

    Science.gov (United States)

    2010-04-01

    ..., 2001, is available for inspection as prescribed at 49 CFR part 7. It is also available from the... 23 Highways 1 2010-04-01 2010-04-01 false Indian lands pavement management system (PMS). 973.208... PROGRAM Bureau of Indian Affairs Management Systems § 973.208 Indian lands pavement management system...

  9. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    International Nuclear Information System (INIS)

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  10. Effects of reclaimed asphalt pavement on indirect tensile strength test of conditioned foamed asphalt mix

    Science.gov (United States)

    Yati Katman, Herda; Rasdan Ibrahim, Mohd; Yazip Matori, Mohd; Norhisham, Shuhairy; Ismail, Norlela

    2013-06-01

    This paper presents the results of Indirect Tensile Strength (ITS) Test for samples prepared with reclaimed asphalt pavement (RAP). Samples were conditioned in water at 25°C for 24 hours prior to testing. Results show that recycled aggregate from reclaimed asphalt pavement performs as well as virgin aggregate.

  11. RoADS: a road pavement monitoring system for anomaly detection using smart phones

    NARCIS (Netherlands)

    Seraj, Fatjon; Zwaag, van der Berend Jan; Dilo, Arta; Luarasi, Tamara; Havinga, Paul; Atzmueller, Martin; Chin, Alvin; Janssen, Frederik; Schweizer, Immanuel; Trattner, Christoph

    2016-01-01

    Monitoring the road pavement is a challenging task. Authorities spend time and finances to monitor the state and quality of the road pavement. This paper investigate road surface monitoring with smartphones equipped with GPS and inertial sensors: accelerometer and gyroscope. In this study we descri

  12. Integrated wave propagation devices for quality control or diagnostics of pavements

    Science.gov (United States)

    Nazarian, Soheil; Yuan, Deren; Baker, Mark R.; Crain, Kevin

    1996-11-01

    Seismic Pavement Analyzer and a portable version of it have been extensively used for quality control and monitoring the structural condition of pavements. With them, a pavement can be tested at closely spaced points and at a fraction of the cost and time of coring. The main tests used are the impact echo for determining the thickness of the slab, ultrasonic body wave and ultrasonic surface wave for determining the moduli of top layer, impulse response for determining the condition of subgrade, and SASW method for determining the modulus profile of pavement. Based on extensive field testing on numerous types of base and subgrade,the techniques in general, and the two devices in particular are quite suitable for many quality and pavement evaluation projects.

  13. Numerical simulation on the thermal response of heat-conducting asphalt pavements

    International Nuclear Information System (INIS)

    Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

  14. Numerical simulation on the thermal response of heat-conducting asphalt pavements

    Science.gov (United States)

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

    2010-05-01

    Using asphalt pavements as a solar collector is a subject of current interest all over the world because the sun provides a cheap and abundant source of clean and renewable energy, which can be captured by black asphalt pavements. A heat-conducting device is designed to absorb energy from the sun. In order to validate what parameters are critical in the asphalt collector, a finite element model is developed to predict the thermal response of the heat-conducting device compared to the conventional asphalt mixture. Some factors that may affect the asphalt pavement collector are considered, including the coefficient of heat conductivity of the asphalt pavement, the distance between pipes with the medium, water, and the pipe's diameter. Ultimately, the finite element model can provide pavement engineers with an efficient computational tool that can be a guide to the conductive asphalt solar collector's experiment in the laboratory.

  15. Use of Ground Penetrating Radar at the FAA's National Airport Pavement Test Facility

    Science.gov (United States)

    Injun, Song

    2015-04-01

    The Federal Aviation Administration (FAA) in the United States has used a ground-coupled Ground Penetrating Radar (GPR) at the National Airport Pavement Test Facility (NAPTF) since 2005. One of the primary objectives of the testing at the facility is to provide full-scale pavement response and failure information for use in airplane landing gear design and configuration studies. During the traffic testing at the facility, a GSSI GPR system was used to develop new procedures for monitoring Hot Mix Asphalt (HMA) pavement density changes that is directly related to pavement failure. After reviewing current setups for data acquisition software and procedures for identifying different pavement layers, dielectric constant and pavement thickness were selected as dominant parameters controlling HMA properties provided by GPR. A new methodology showing HMA density changes in terms of dielectric constant variations, called dielectric sweep test, was developed and applied in full-scale pavement test. The dielectric constant changes were successfully monitored with increasing airplane traffic numbers. The changes were compared to pavement performance data (permanent deformation). The measured dielectric constants based on the known HMA thicknesses were also compared with computed dielectric constants using an equation from ASTM D4748-98 Standard Test Method for Determining the Thickness of Bound Pavement Layers Using Short-Pulse Radar. Six inches diameter cylindrical cores were taken after construction and traffic testing for the HMA layer bulk specific gravity. The measured bulk specific gravity was also compared to monitor HMA density changes caused by aircraft traffic conditions. Additionally this presentation will review the applications of the FAA's ground-coupled GPR on embedded rebar identification in concrete pavement, sewer pipes in soil, and gage identifications in 3D plots.

  16. Solar Radiation effect on the bituminous binder; Efecto de la radiacion solar sobre el ligante bituminoso

    Energy Technology Data Exchange (ETDEWEB)

    Tadeo Rico, A.; Torres Perez, A.

    2010-07-01

    Asphalt, used as binder in road construction, becomes more brittle and harder during working life on the surface of the road pavement, conducting toward their deterioration. This is caused by the oxidation of the molecular functional groups of the asphalt molecular structure. Moreover, it is observed that ultraviolet radiation increases the oxidation process. However, the effect of solar light on the asphalt degradation has been poorly researched. The aim of this work is to study asphalt ageing caused by effect of solar radiation, by using standard test. Four commercial asphalts from different companies were selected: two with penetration number 50/70, and the other two polymer modified asphalts. From each of the asphalts forty samples were taken off and placed in four different aging conditions of temperature and radiation for a period ranging from 40 to 500 days. Ring and Ball test, and Fraass breaking Point test, were used to analyse the changes of asphalt properties after exposition to solar radiation. The results of the four analyzed asphalts showed a distinct behaviour; not only in the test temperature increase but also in the rate. Another experiment was carried out. Samples from a hot mix asphalt batch were placed under solar radiation, and were compacted by the Marshall procedure after increasing periods of time. Density and resistance to plastic flow using Marshall Apparatus were measured. Results showed an increase in the stability of samples under radiation. Both experiments show that the solar radiation is enough to cause changes in the asphalt molecular structure due to oxidation. So that, the study of the effect of the solar radiation on the asphalt properties could be a good tool to asses the performances of asphalt pavement. (Author) 26 refs.

  17. Application of matter-element analysis based on entropy right to evaluate the pavement condition in permafrost region

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Evaluation of pavement performance is one of the most important issues in a pavement-management system.By employing the concept of entropy,the matter-element model for evaluating pavement is established,and the weights of the evaluation indices are obtained from surveying data.By calculating the degree of dependence of the matter-element model,the pavement performance evaluation can be obtained by this method.The results show that the matter-element model based on entropy right has good performance for evaluating the pavement condition in permafrost region.

  18. Assessment of porous asphalt pavement performance: hydraulics and water quality

    Science.gov (United States)

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

    2005-05-01

    The objective of this study is to focus on the water quality treatment and hydraulic performance of a porous asphalt pavement parking lot in Durham, New Hampshire. The site was constructed in October 2004 to assess the suitability of porous asphalt pavement for stormwater management in cold climates. The facility consists of a 4-inch asphalt open-graded friction course layer overlying a high porosity sand and gravel base. This base serves as a storage reservoir in-between storms that can slowly infiltrate groundwater. Details on the design, construction, and cost of the facility will be presented. The porous asphalt pavements is qualitatively monitored for signs of distress, especially those due to cold climate stresses like plowing, sanding, salting, and freeze-thaw cycles. Life cycle predictions are discussed. Surface infiltration rates are measured with a constant head device built specifically to test high infiltration capacity pavements. The test measures infiltration rates in a single 4-inch diameter column temporarily sealed to the pavement at its base. A surface inundation test, as described by Bean, is also conducted as a basis for comparison of results (Bean, 2004). These tests assess infiltration rates soon after installation, throughout the winter, during snowmelt, after a winter of salting, sanding, and plowing, and after vacuuming in the spring. Frost penetration into the subsurface reservoir is monitored with a frost gauge. Hydrologic effects of the system are evaluated. Water levels are monitored in the facility and in surrounding wells with continuously logging pressure transducers. The 6-inch underdrain pipe that conveys excess water in the subsurface reservoir to a riprap pad is also continuously monitored for flow. Since porous asphalt pavement systems infiltrate surface water into the subsurface, it is important to assess whether water quality treatment performance in the subsurface reservoir is adequate. The assumed influent water quality is

  19. Numerical modeling of inelastic structures at loading of steady state rolling. Thermo-mechanical asphalt pavement computation

    Science.gov (United States)

    Wollny, Ines; Hartung, Felix; Kaliske, Michael

    2016-05-01

    In order to gain a deeper knowledge of the interactions in the coupled tire-pavement-system, e.g. for the future design of durable pavement structures, the paper presents recent results of research in the field of theoretical-numerical asphalt pavement modeling at material and structural level, whereby the focus is on a realistic and numerically efficient computation of pavements under rolling tire load by using the finite element method based on an Arbitrary Lagrangian Eulerian (ALE) formulation. Inelastic material descriptions are included into the ALE frame efficiently by a recently developed unsplit history update procedure. New is also the implementation of a viscoelastic cohesive zone model into the ALE pavement formulation to describe the interaction of the single pavement layers. The viscoelastic cohesive zone model is further extended to account for the normal pressure dependent shear behavior of the bonding layer. Another novelty is that thermo-mechanical effects are taken into account by a coupling of the mechanical ALE pavement computation to a transient thermal computation of the pavement cross-section to obtain the varying temperature distributions of the pavement due to climatic impact. Then, each ALE pavement simulation considers the temperature dependent asphalt material model that includes elastic, viscous and plastic behavior at finite strains and the temperature dependent viscoelastic cohesive zone formulation. The temperature dependent material parameters of the asphalt layers and the interfacial layers are fitted to experimental data. Results of coupled tire-pavement computations are presented to demonstrate potential fields of application.

  20. Asphaltic concrete overlays of rigid and flexible pavements

    Science.gov (United States)

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

    1980-10-01

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

  1. Synthesis report: D-cracking in portland cement concrete pavements

    Science.gov (United States)

    Thompson, S. R.; Olsen, M. P. J.; Dempsey, B. J.

    1980-06-01

    The mechanisms and testing procedures for D-cracking in portland cement concrete pavements are examined. Benefication procedures are also investigated. The three general responses to freezing in the aggregate/paste system include elastic accommodation, high internal pressure, and high external pressure. It is found that the critical aggregate parameters influencing D-cracking are degree of saturation, maximum particle size, permeability, porosity, and pore size distribution. Evaluation of present laboratory testing procedures indicated that the ASTM C666, VPI slow-cool, Mercury Porosimetry, and Iowa Pore Index Tests correlated the best with field performance of concrete with respect to D-cracking.

  2. Study on the cause of the fire and explosion incident at Bituminization Demonstration Facility of PNC Tokai Works

    International Nuclear Information System (INIS)

    On March 11, 1997, a fire and explosion incident occurred in Bituminization Demonstration Facility (BDF) at Tokai Reprocessing Plant (TRP). The cause of the incident was thoroughly investigated and after thirty meetings of 'Investigation Committee of Science and Technology Agency (STA)'. STA reported possible cause of this incident. Continually detailed investigation was discussed at 'Follow-up Committee of STA'. Based on the results of five meetings, JNC concluded that the main cause of fire was frictional heating and viscous heating in the extruder, which provided an unusually high temperature in the bituminized product at filling, since there was no chemical analysis data suggesting the generation of chemical heat. It is considered that these excessive heat generations were due to the decreased feed rate of liquid waste to the extruder. The Follow-up Committee almost agreed to this conclusion. This paper describes general information concerning the incident and details of the cause of the incident. (author)

  3. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Directory of Open Access Journals (Sweden)

    Rafiqul A. Tarefder

    2016-06-01

    Full Text Available Previous studies by the authors have determined pavement responses under dynamic loading considering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stress–strain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM technique. An instrumented pavement section on Interstate I-40 near Albuquerque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model parameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n < 1 (anisotropy to n=1 (isotropy. This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.

  4. Effects of cross-anisotropy and stress-dependency of pavement layers on pavement responses under dynamic truck loading

    Institute of Scientific and Technical Information of China (English)

    Rafiqul A. Tarefder; Mesbah U. Ahmed; Asifur Rahman

    2016-01-01

    Previous studies by the authors have determined pavement responses under dynamic loading consid-ering cross-anisotropy in one layer only, either the cross-anisotropic viscoelastic asphalt concrete (AC) layer or the cross-anisotropic stress-dependent base layer, but not both. This study evaluates pavement stressestrain responses considering cross-anisotropy in all layers, i.e. AC, base and subbase, using finite element modeling (FEM) technique. An instrumented pavement section on Interstate I-40 near Albu-querque, New Mexico was used in ABAQUS framework as model geometry. Field asphalt cores were collected and tested in the laboratory to determine the cross-anisotropy (n-values) defined by horizontal to vertical modulus ratio, and other viscoelastic parameters as inputs of the model incorporated through user defined material interface (UMAT) functionality in ABAQUS. Field base and subbase materials were also collected and tested in the laboratory to determine stress-dependent nonlinear elastic model pa-rameters, as inputs of the model, again incorporated through UMAT. The model validation task was carried out using field-measured deflections and strain values under falling weight deflectometer (FWD) loads at the instrumented section. The validated model was then subjected to an actual truck loading for studying cross-anisotropic effects. It was observed that horizontal tensile strain at the bottom of the AC layer and vertical strains in all layers decreased with an increase in n-value of the asphalt layer, from n<1 (anisotropy) to n ¼ 1 (isotropy). This indicates that the increase in horizontal modulus caused the decrease in layer strains. It was also observed that if the base and subbase layers were considered stress-dependent instead of linear elastic unbound layers, the horizontal tensile strain at the bottom of the asphalt layer increased and vertical strains on top of the base and subbase also increased.

  5. The bituminization in Marcoule and la Hague plants. Description of the processes and the fire risk prevention

    International Nuclear Information System (INIS)

    Chemical precipitation is an efficient process to decontaminate liquid effluents and has been selected as early as 1966 for the liquid waste treatment of MARCOULE. The process has been designed by the French CEA and improved along the time. The first implementation in LA HAGUE was for the STE 2 facility (Station de Traitement d'Effluents no 2). A new facility, STE 3, has been commissioned in 1989 in LA HAGUE, benefiting from these previous experience and therefore contributing into a drastic reduction of liquid discharges. The sludges coming from the treatment in MARCOULE and STE 3 are bituminized into continuous extruders. The resulting waste is kept in interim storage, waiting for final disposal. The industrial production, up to now, is close to 10000 drums (55 gallons) in LA HAGUE and 60000 drums in MARCOULE. A retrieval operation of the MARCOULE drums from the present storage has been launched to send them into a recently built interim storage operating since the beginning of 2000. At the present time, in LA HAGUE, evaporation has been preferred to chemical precipitation for the treatment of liquid effluents. After concentration, the effluents go to the vitrification and the volume of resulting waste is much smaller. However, bituminization is still the preferred option for the 10000 m3 of sludges resulting from the STE 2 operations which are being stored in tanks. A complete reevaluation of the operation safety measures of bituminization has been made lately in both plants following recent incidents on other installations. The paper describes the chemical precipitation and the bituminization processes and focuses on safety measures which are implemented for prevention, detection and fight. (authors)

  6. Assessing artificial neural network performance in estimating the layer properties of pavements

    Directory of Open Access Journals (Sweden)

    Gloria Inés Beltran

    2014-07-01

    Full Text Available A major concern in assessing the structural condition of existing flexible pavements is the estimation of the mechanical properties of constituent layers, which is useful for the design and decision-making process in road management systems. This parameter identification problem is truly complex due to the large number of variables involved in pavement behavior. To this end, non-conventional adaptive or approximate solutions via Artificial Neural Networks – ANNs – are considered to properly map pavement response field measurements. Previous investigations have demonstrated the exceptional ability of ANNs in layer moduli estimation from non-destructive deflection tests, but most of the reported cases were developed using synthetic deflection data or hypothetical pavement systems. This paper presents further attempts to back-calculate layer moduli via ANN modeling, using a database gathered from field tests performed on three- and four-layer pavement systems. Traditional layer structuring and pavements with a stabilized subbase were considered. A three-stage methodology is developed in this study to design and validate an “optimum” ANN-based model, i.e., the best architecture possible along with adequate learning rules. An assessment of the resulting ANN model demonstrates its forecasting capabilities and efficiency in solving a complex parameter identification problem concerning pavements.

  7. Solar-reflective coating as a cooling overlay for asphalt pavement

    Science.gov (United States)

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

    2012-04-01

    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.

  8. Analytical prediction and field validation of transient temperature field in asphalt pavements

    Institute of Scientific and Technical Information of China (English)

    陈嘉祺; 李亮; 汪浩

    2015-01-01

    This work presented the development and validation of an analytical method to predict the transient temperature field in the asphalt pavement. The governing equation for heat transfer was based on heat conduction radiation and convection. An innovative time-dependent function was proposed to predict the pavement surface temperature with solar radiation and air temperature using dimensional analysis in order to simplify the complex heat exchange on the pavement surface. The parameters for the time-dependent pavement surface temperature function were obtained through the regression analysis of field measurement data. Assuming that the initial pavement temperature distribution was linear and the influence of the base course materials on the temperature of the upper asphalt layers was negligible, a close-form analytical solution of the temperature in asphalt layers was derived using Green’s function. Finally, two numerical examples were presented to validate the model solutions with field temperature measurements. Analysis results show that the solution accuracy is in agreement with field data and the relative errors at a shallower depth are greater than those at a deeper one. Although the model is not sensitive to dramatic changes in climatic factors near the pavement surface, it is applicable for predicting pavement temperature field in cloudless days.

  9. Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

    2016-03-22

    In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase.

  10. Sustainable Development Factors in Pavement Life-Cycle: Highway/Airport Review

    Directory of Open Access Journals (Sweden)

    Peyman Babashamsi

    2016-03-01

    Full Text Available Sustainability has gained as much importance as management in business. Sustainable pavement development as a business practice should involve making evaluations according to the triple bottom line in the pavement life-cycle. Despite the current approaches to evaluating the social as well as economic and environmental feasibility of pavement projects (involving highway and airport infrastructure, there has recently been a lack of consensus on a methodology to guarantee sustainability upon assessment and analysis during the pavement life-cycle. As sustainability is a complex issue, this study intends to further explore sustainability and elaborate on its meaning. The second step involves a general depiction of the major sustainability appraisal tools, namely cost-benefit analysis, life-cycle cost analysis, life-cycle assessment, multi-criteria decision-making, environmental impact assessment and social life-cycle assessment, and an explanation of their cons and pros. Subsequently, the article addresses the application of an organized methodology to highlight the main factors or concepts that should be applied in sustainable pavement development and, more specifically, in sustainable pavement management. In the final step, research recommendations toward sustainability are given. This study is aimed to assist decision-makers in pavement management to plan sustainability frameworks in accordance with probable boundaries and restrictions.

  11. Determination of allowable subgrade frost heave with the pavement roughness index in numerical analysis

    Institute of Scientific and Technical Information of China (English)

    HongYan Ma; Feng Zhang; DeCheng Feng; Bo Lin

    2015-01-01

    Frost heave is an upward swelling of soil during cryogenic conditions in cold regions. It is caused by the accumulation of ice crystals in subgrade soil, which grow upwards when freezing temperatures penetrate into the subgrade. This study establishes the allowable soil subgrade frost heave based on the roughness standard of asphalt pavement in China, and aims to balance the pavement design and frost heave resistance of subgrades in cold regions. We formulated a mechanical model of pavement supported by the boundary conditions of differential frost heave, based on the elastic layered system theory. The differential soil subgrade frost heave was modeled as a sinusoidal function, and the allowable frost heave and the roughness index were modeled as the displacement boundaries for the top and bottom of the pavement structure. Then the allowable frost heave was back-calculated according to the roughness standard. Numerical results show that the allowable frost heave depends on the pavement structure, material properties, the highway grade, and other factors. In order to ensure that the actual soil subgrade frost heave is lower than the allowable frost heave, pavement structures and materials need to be selected and designed carefully. The numerical method proposed here can be applied to establish the frost heave re-sistance of subgrade when the pavement structure and materials are determined.

  12. An Optimization Model for Design of Asphalt Pavements Based on IHAP Code Number 234

    Directory of Open Access Journals (Sweden)

    Ali Reza Ghanizadeh

    2016-01-01

    Full Text Available Pavement construction is one of the most costly parts of transportation infrastructures. Incommensurate design and construction of pavements, in addition to the loss of the initial investment, would impose indirect costs to the road users and reduce road safety. This paper aims to propose an optimization model to determine the optimal configuration as well as the optimum thickness of different pavement layers based on the Iran Highway Asphalt Paving Code Number 234 (IHAP Code 234. After developing the optimization model, the optimum thickness of pavement layers for secondary rural roads, major rural roads, and freeways was determined based on the recommended prices in “Basic Price List for Road, Runway and Railway” of Iran in 2015 and several charts were developed to determine the optimum thickness of pavement layers including asphalt concrete, granular base, and granular subbase with respect to road classification, design traffic, and resilient modulus of subgrade. Design charts confirm that in the current situation (material prices in 2015, application of asphalt treated layer in pavement structure is not cost effective. Also it was shown that, with increasing the strength of subgrade soil, the subbase layer may be removed from the optimum structure of pavement.

  13. Greenhouse Gas Emissions from Asphalt Pavement Construction: A Case Study in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Lin, Ruiyu; Huang, Yue; Wang, Chao

    2016-03-01

    In China, the construction of asphalt pavement has a significant impact on the environment, and energy use and greenhouse gas (GHG) emissions from asphalt pavement construction have been receiving increasing attention in recent years. At present, there is no universal criterion for the evaluation of GHG emissions in asphalt pavement construction. This paper proposes to define the system boundaries for GHG emissions from asphalt pavement by using a process-based life cycle assessment method. A method for evaluating GHG emissions from asphalt pavement construction is suggested. The paper reports a case study of GHG emissions from a typical asphalt pavement construction project in China. The results show that the greenhouse gas emissions from the mixture mixing phase are the highest, and account for about 54% of the total amount. The second highest GHG emission phase is the production of raw materials. For GHG emissions of cement stabilized base/subbase, the production of raw materials emits the most, about 98%. The GHG emission for cement production alone is about 92%. The results indicate that any measures to reduce GHG emissions from asphalt pavement construction should be focused on the raw materials manufacturing stage. If the raw materials production phase is excluded, the measures to reduce GHG emissions should be aimed at the mixture mixing phase. PMID:27011196

  14. Investigation of the Permanent Deformation Characteristics of Overlaid Pavement Incorporating Stress Absorbing Membrane Interlayers

    Institute of Scientific and Technical Information of China (English)

    Olumide Moses Ogundipe[1; Nicholas H. Thom[2; Andrew C. Collop[3

    2014-01-01

    This study was carried out to evaluate the resistance of overlaid pavement incorporating stress absorbing membrane interlayers to permanent deformation. In this study, the permanent deformation of the interlayer mixtures was determined using the RLAT (repeated load axial text) carried out in the Nottingham Asphalt Tester. Also, a test pavement was constructed in the laboratory to assess the resistance to permanent deformation of overlaid pavement incorporating SAMIs (stress absorbing membrane interlayers). The test pavement was divided into two along the centre line. Each of the divisions has three sections--two having SAMIs and one without SAMIs. The pavement was instrumented and trafficked. Trafficking was stopped when the pavement was deemed to have failed. The results showed that the measured permanent deformation values of the control sections were less than the sections having SAMIs. The increased permanent deformation values indicate that the introduction of SAMIs causes more vertical/horizontal deformation of the pavement. It was also found that the permanent deformation values varied depending on the composition and thickness of the SAMIs.

  15. Effectiveness of pavement-solar energy system – An experimental study

    International Nuclear Information System (INIS)

    Highlights: • We built a small-scale pilot project of pavement-solar energy utilization. • Design an automatic monitoring system to record the operating data. • The average heat absorptivity of pavement-solar energy is 37%. • The average thermal storage effectiveness of the system is 17%. - Abstract: A small-scale pilot project was built for the pavement-solar energy utilization in this paper. An automatic data acquisition system was designed to measure the effectiveness of the pavement solar energy system based on the operation data of 24 h a day in both summer and winter. Through 69 days (1656 h) of operation in summer, 2821 kW h of heat energy were stored in soil underground. In the transitional season, 4598 kW h of heat energy were taken out from soil during 104 days (2496 h) of operation in winter. The analysis showed that in summer, solar heat collection of asphalt pavement could effectively reduce 7 °C of its temperature. Under conditions of natural radiation, the average heat absorptivity of pavement was 37% and the average thermal storage effectiveness of the system was 17%. The electrical energy consumed by the system is only 11% of stored heat. During the winter, the asphalt pavement absorbs heat from underground soil which effectively increases its temperature, cutting 32% days of surface temperature below the freezing point. This not only save the energy for ice/snow removal but also mitigate associated safety risks

  16. Utilization of Waste Clay from Boron Production in Bituminous Geosynthetic Barrier (GBR-B Production as Landfill Liner

    Directory of Open Access Journals (Sweden)

    Müfide Banar

    2016-01-01

    Full Text Available Bituminous geomembranes, one type of geosynthetics, include a hot bituminous mixture with mineral filler and reinforcement. In this study, boron production waste clay (CW was used as filler to produce a geosynthetic barrier with bentonite, waste tire, and bitumen. Bentonite and waste tires were used as auxiliary fillers and bitumen as the binder. CW/bitumen, CW/bentonite/bitumen, and CW/waste tire/bitumen mixtures were prepared by using a laboratory mixer at 100°C. Hot mixtures were extruded into strips by using a lab-scale corotating twin screw extruder (L/D: 40 followed by die casting (2 mm × 100 mm. Glass fleece or nonwoven polyester was used as reinforcement material and while die casting, both sides of the reinforcement materials were covered with bituminous mixture. Thickness, mass per unit area, tensile strength, elongation at yield, and hydraulic conductivity were used to characterize the geomembranes. Among all geomembranes, nonwoven polyester covered with 30% bitumen-70% boron waste clay mixture (PK-BTM30CW70 was found to be the most promising in terms of structure and mechanical behaviour. After that, consequences of its exposure to distilled water (DW, municipal solid waste landfill leachate (L-MSW, and hazardous waste landfill leachate (L-HW were examined to use for an innovative impermeable liner on solid waste landfills.

  17. Comparing potentials for gas outburst in a Chinese anthracite and an Australian bituminous coal mine

    Institute of Scientific and Technical Information of China (English)

    Li Guoqing; Saghafi Abouna

    2014-01-01

    Gas outbursts in underground mining occur under conditions of high gas desorption rate and gas content, combined with high stress regime, low coal strength and high Young’s modulus. This combination of gas and stress factors occurs more often in deep mining. Hence, as the depth of mining increases, the poten-tial for outburst increases. This study proposes a conceptual model to evaluate outburst potential in terms of an outburst indicator. The model was used to evaluate the potential for gas outburst in two mines, by comparing numerical simulations of gas flow behavior under typical stress regimes in an Australian gassy mine extracting a medium-volatile bituminous coal, and a Chinese gassy coal mine in Qinshui Basin (Shanxi province) extracting anthracite coal. We coupled the stress simulation program (FLAC3D) with the gas simulation program (SIMED II) to compute the stress and gas pressure and gas content distribution following development of a roadway into the targeted coal seams. The data from gas content and stress distribution were then used to quantify the intensity of energy release in the event of an outburst.

  18. Burnout behaviour of bituminous coals in air-staged combustion conditions

    Energy Technology Data Exchange (ETDEWEB)

    Kluger, F.; Spliethoff, H.; Hein, K.R.G. [University of Stuttgart, Stuttgart (Germany). Inst. of Process Engineering and Power Plant (IVD)

    2001-07-01

    In order to determine the influence on burnout by the combustion conditions and the coal preparation, three bituminous coals sold on the world market, from three different locations in Poland, South Africa, and Australia, were studied more closely. For this purpose, the coals were ground in two different particle size ranges, which, besides the influence of the combustion conditions, such a temperature, residence time, and stoichiometry, made it possible to also investigate the impact on burnout by the coal preparation. The experiments were carried out in an electrically heated entrained-flow reactor with a thermal input of 8.5 kW. The parameters for the experiments are wall temperature (1000-1350{degree}C), air ratio (0.6-1.15) and two particle sizes (70% {lt} 75 {mu}m, 90% {lt} 75 {mu}m). The results show that in general, for increasing temperatures, the burnout quality will improve. For the Australian Illawara coal, another outcome is increased NOx emissions. Lowering the air ratio in the reduction zone leads to less NOx emission but to increased unburnt matter in ash. For the smaller particle size fraction, the analysis of the different particle sizes shows an improvement of the burnout without a change in NOx emissions. 10 refs., 10 figs., 2 tabs.

  19. Using proximate analysis to characterize airborne dust generation from bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Page, S.J.; Organiscak, J.A.

    2005-11-01

    Prolonged exposure to airborne respirable coal dust is responsible for coal workers pneumoconiosis (CWP), commonly called black lung. Health research studies have identified that the prevalence and severity of CWP are directly related to both the amount of dust exposure and the coal rank. The amount of airborne respirable dust (ARD) smaller than 10 micrometers generated from breakage of different coals varies widely. To investigate the cause, researchers for the National Institute for Occupational Safety and Health (NIOSH) have conducted experiments to identify the causes of airborne respirable dust liberation. Laboratory crushing experiments were conducted on a range of low to high volatile bituminous coals from eight mines. The results indicate that the proximate analysis of a coal sample can provide a very good indicator of the potential for a dust problem. For application to the coal mining, processing, and utilization industries, data from 977 US coal seams compiled by the Department of Energy (DoE) has been used to calculate this dust generation potential from an equation based on the NIOSH measured data. A simple procedure for this calculation is provided. 1 fig.

  20. Experimental and modelling of the thermal regions of activity during pyrolysis of bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Strezov, Vladimir [Newbolds Applied Research, The University of Newcastle, Cnr Frith and Gavey Streets, Mayfield 2304, NSW (Australia); Lucas, John A. [Discipline of Chemical Engineering, Faculty of Engineering and Built Environment, The University of Newcastle, University Drive, Callaghan 2308, NSW (Australia); Strezov, Les [Strezov Consulting, 7 Marin Street, Adamstown 2289, NSW (Australia)

    2004-03-01

    Computer-aided thermal analysis technique, incorporated with thermogravimetric and Fourier transform infrared (TG-FTIR), and mass spectrometry, were employed in studying the devolatilisation of three thermal bituminous coals under packed bed pyrolysing conditions. The heats of reactions evolved during coal devolatilisation were determined by computational calorimetry and compared with the evolution rate of fourteen volatile species. The devolatilisation was classified into five major regions of thermal activity, according to the analysis, where the first was related to the dehydration of strongly bounded water. The second was the pre-plastic region with an endothermic prepyrolytic reaction, while the third was the exothermic plastic range with primarily evolution of tars and re-solidification reactions. The secondary devolatilisation was found to be endothermic and the major contributors were hydrocarbons, secondary water, CS{sub 2} and H{sub 2}S. The largest reaction was the contraction of carbon planes with evolution of hydrogen. Each reaction region was assumed to follow the first-order Arrhenius kinetic correlation and the activation energy was determined for each of the five regions. The activation energies were then incorporated into a simplified model for predicting the overall heats of reactions.

  1. Permeable pavement and stormwater management systems: a review.

    Science.gov (United States)

    Imran, H M; Akib, Shatirah; Karim, Mohamed Rehan

    2013-01-01

    Uncontrolled stormwater runoff not only creates drainage problems and flash floods but also presents a considerable threat to water quality and the environment. These problems can, to a large extent, be reduced by a type of stormwater management approach employing permeable pavement systems (PPS) in urban, industrial and commercial areas, where frequent problems are caused by intense undrained stormwater. PPS could be an efficient solution for sustainable drainage systems, and control water security as well as renewable energy in certain cases. Considerable research has been conducted on the function of PPS and their improvement to ensure sustainable drainage systems and water quality. This paper presents a review of the use of permeable pavement for different purposes. The paper focuses on drainage systems and stormwater runoff quality from roads, driveways, rooftops and parking lots. PPS are very effective for stormwater management and water reuse. Moreover, geotextiles provide additional facilities to reduce the pollutants from infiltrate runoff into the ground, creating a suitable environment for the biodegradation process. Furthermore, recently, ground source heat pumps and PPS have been found to be an excellent combination for sustainable renewable energy. In addition, this study has identified several gaps in the present state of knowledge on PPS and indicates some research needs for future consideration. PMID:24527626

  2. Finite Element Investigation of the Deterioration of Doweled Rigid Pavements

    CERN Document Server

    Ghauch, Ziad G

    2011-01-01

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

  3. ESTIMATION OF THE CONCRETE PAVEMENT TEMPERATURE FIELDS AND THEIR GRADIENTS

    Directory of Open Access Journals (Sweden)

    M. K. Pshembaev

    2015-01-01

    Full Text Available The heat fluxes impact on the road-dressing concrete surfacing under different regions climatic conditions of the construction and maintenance dramatically degrades their solidity, corroding-, shiftingand frost-resistance, and ultimately – the service durability. The source of deformation processes is the character of the gradient temperature fields in the road dressing materials developing with both protracted (static and short run (dynamic heat-and-mass impacts that forward destruction of the pavement surface layers being in contact with free air. In addition, pulsating hydrodynamic pressures appear in the pores of moisture-laden pavement as a result of the vehicular traffic that foster material structure disruption of the surface layers leading to irreversible deformation incipiency (cracks etc.. The authors report of developing a С++ computer program for temperature and gradient fields engineering evaluations of the road dressings made of materials with various surfacing and free-air thermophysical characteristics in line with boundary conditions of the 3rd kind for semi-bounded body. The paper presents the evaluation results in form of graphical curves of the temperature allocation along the surfacing thickness as function of its initial temperature and thermophysical characteristics of the concrete. 

  4. An Overview Of Pavement Management System For Industrial Areas

    Science.gov (United States)

    Hokam, Vivek S.

    2012-03-01

    ACT With the current surge in national economy the industrial traffic has increased many folds in terms of quantity of load and traffic volume. This results in early deterioration of the roads. Also the serviceability reduces hampering the industry's supply of raw material and transport of finished goods. An efficient road transportation system is of vitally important for smooth operations of industrial units. Construction of new roads needs an enormous investment. However, once constructed the road network system requires huge resources to maintain serviceability and to ensure safe passage at an appropriate speed and with low VOC (Vehicle Operating Cost). Road maintenance is therefore an essential function and should be carried out on a timely basis. The cost of providing and maintaining the roads for the industrial areas at an acceptable serviceability level is quite high. It is therefore essential for a transportation engineer to attempt establishing an acceptable pavement condition level from economic, safety and environmental point of view. In today's economic environment of constrained budgets, as the existing road infrastructure has aged, a more systematic approach towards determining maintenance and rehabilitation needs is necessary. The efficient pavement management system shall provide objective information and useful analysis to ensure consistent and cost effective decisions related to preservation of existing industrial road network in healthy condition.

  5. Sustainable Drainage Practices in Spain, Specially Focused on Pervious Pavements

    Directory of Open Access Journals (Sweden)

    Jorge Rodriguez-Hernandez

    2013-01-01

    Full Text Available The Spanish climate is full of contrasts, with torrential rains and long droughts; under these conditions, appropriate water management is essential. In Spain, until the end of the twentieth century, water management and legislative development lagged behind other more developed countries. Nowadays, great efforts are being made to reverse this situation and improve both water management and legislation in order to control the two main problems related to stormwater management in cities: floods and diffuse pollution. In this context, Sustainable Urban Drainage Systems (SUDS were developed as the main solution to these problems. The study of these techniques started in the 1970s in the USA, but they were not studied in Spain until 1993 when the University of Cantabria and CLABSA started to look into solutions for stormwater management. After 20 years of research and application, sustainable drainage in Spain is still behind other countries in spite of the efforts to change this situation, notably by the University of Cantabria with 10 years of experience in these techniques, mainly regarding pervious pavements, where more than 13 related research projects have been carried out. The future challenges focus on the application of pervious pavements for Urban Hydrological Rehabilitation.

  6. The effect of aggregate density on pavement performance of SMA-13 asphalt mixture

    Directory of Open Access Journals (Sweden)

    Qiao Yinping

    2016-05-01

    Full Text Available This paper chooses the top layer SMA-13 asphalt mixture material as the research object. Basalt was selected as pavement material, and modified SBS asphalt was used as a cementing material. Two basalt aggregates with different densities were used to carry out standard Marshall test in the laboratory.Aimed at the volume parameters of the asphalt mixture carry on anaiysis,and obtian the effect of aggregate density on pavement performance of SMA-13 asphalt mixture, which is that the density of aggregate has a significant effect on the void ratio, saturation, and the gap rate of the aggregate, thus affecting the pavement performance of the asphalt mixture

  7. The Dependence of Physical Mechanical Properties of Concrete Pavement Blocks on Coarse Aggregate Type

    Directory of Open Access Journals (Sweden)

    Malaiškienė Jurgita

    2014-12-01

    Full Text Available The aim of this research is to determine the dependences of the physical mechanical properties of vibropressed concrete (pavement blocks on the type of coarse aggregate used in the main layer. Sustainability of concrete pavement blocks is a really important matter. Five different batches of pavement blocks were produced, changing the consistence ratio of coarse aggregate in the main layer. There are two types of course aggregate: crushed gravel and granite. The consistence of a facing layer was not changed. All tests: density, tensile split strength, water absorption for vibro-pressed concrete units were made according to EN 1338:2003+AC2006.

  8. Waste to Wealth; The Utilization of Scrap Tyre as Aggregate in Bituminous Mixes for Road Construction

    Directory of Open Access Journals (Sweden)

    Oba, A. L.,

    2015-11-01

    Full Text Available The problem associated with solid waste management is on the increase both in the industries, urban cities and in the rural areas. In the United States of America, Asia and Europe, there are over hundreds of waste to wealth combustion plants from where solid wastes are incinerated. In Nigeria, amidst the increasing importation of vehicle tyre such plants are scarcely in existence to enhance generation of revenue from waste through the extraction of raw material for the production of light weight aggregates, printing ink, paints, shoe polish, dry cell and battery heads. This research paper seeks to utilize vehicle scrap tyre (VST as aggregates in asphaltic mixture by adopting the dry process to evaluate the effect of rubber-bitumen interaction on asphaltic concrete properties; laboratory investigation using 4.75mm, 2.36mm and 0.600mm chunk tyre particle size modified asphalt mixture containing 2%, 4%, 6%, 8% and 10% scrap tyre and 0% tyre content as control mixture. The mixtures were subjected to Marshall Tests where the stability, flow, percentage air void, unit weight, void mineral aggregate, height of specimen and specific gravity were determined. The results obtained shows that as tyre percentage increase the stability, unit weight and specific gravity value decreases. On the other hand, as the tyre content increases, the flow and height of specimen increases while as the tyre content increases the percentage air void and VMA increased for 4.75mm Tyre Particle Size (TPS and 2.36mm TPS while for 0.600mm TPS, reverse is the case. In summary and in comparism with standard specification for road construction material, the Marshall tests conducted on the tyre modified specimens remained intact and by interpretation; material possessing such property indicates good impact resistance when use as surface course in flexible pavement. Conclusively, the use of 10% 4.75mm, 4% 2.36mm or 4% 0.600mm TPS by weight of aggregate in asphaltic concrete is

  9. Preliminary evaluation of the lifecycle costs and market barriers of reflective pavements; TOPICAL

    International Nuclear Information System (INIS)

    The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher life cycle costs than conventional AC in parking lots, but several cost-saving features of porous pavements fell outside the boundaries of this study. Resin pavements were found to be only slightly more expensive than conventional AC, but the uncertainties in the cost and performance data were large. The use of light-colored additives in asphalt emulsion seal coats for parking lot pavements was found to be significantly more expensive than conventional AC, reflecting its current niche market of decorative applications. We also proposed two additional approaches to increasing the reflectivity of conventional AC

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2001-11-21

    The objective of this study is to evaluate the life cycle costs and market barriers associated with using reflective paving materials in streets and parking lots as a way to reduce the urban heat island effect. We calculated and compared the life cycle costs of conventional asphalt concrete (AC) pavements to those of other existing pavement technologies with higher reflectivity-portland cement concrete (PCC), porous pavements, resin pavements, AC pavements using light-colored chip seals, and AC pavements using light-colored asphalt emulsion additives. We found that for streets and parking lots, PCC can provide a cost-effective alternative to conventional AC when severely damaged pavements must be completely reconstructed. We also found that rehabilitating damaged AC streets and intersections with thin overlays of PCC (ultra-thin white topping) can often provide a cost-effective alternative to standard rehabilitation techniques using conventional AC. Chip sealing is a common maintenance treatment for low-volume streets which, when applied using light-colored chips, could provide a reflective pavement surface. If the incremental cost of using light-colored chips is low, this chip sealing method could also be cost-effective, but the incremental costs of light-colored chips are as of yet uncertain and expected to vary. Porous pavements were found to have higher life cycle costs than conventional AC in parking lots, but several cost-saving features of porous pavements fell outside the boundaries of this study. Resin pavements were found to be only slightly more expensive than conventional AC, but the uncertainties in the cost and performance data were large. The use of light-colored additives in asphalt emulsion seal coats for parking lot pavements was found to be significantly more expensive than conventional AC, reflecting its current niche market of decorative applications. We also proposed two additional approaches to increasing the reflectivity of conventional AC

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

    International Nuclear Information System (INIS)

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

  12. TPF 5(063) "Improving the Quality of Pavement Profile Measurement" Update

    OpenAIRE

    Mikhail, Magdy

    2014-01-01

    Functional Session 1: Longitudinal Profile Moderated by Magdy Mikhail This presentation was held at the Pavement Evaluation 2014 Conference, which took place from September 15-18, 2014 in Blacksburg, Virginia. Presentation only

  13. Theoretical analysis of piezoelectric energy harvesting from traffic induced deformation of pavements

    Science.gov (United States)

    Xiang, H. J.; Wang, J. J.; Shi, Z. F.; Zhang, Z. W.

    2013-09-01

    The problem of energy harvesting using piezoelectric transducers for pavement system applications is formulated with a focus on moving vehicle excitations. The pavement behavior is described by an infinite Bernoulli-Euler beam subjected to a moving line load and resting on a Winkler foundation. A closed-form dynamic response of the pavement is determined by a Fourier transform and the residue theorem. The voltage and power outputs of the piezoelectric harvester embedded in the pavements are then obtained by the direct piezoelectric effect. A comprehensive parametric study is conducted to show the effect of damping, the Winkler modulus, and the velocity of moving vehicles on the voltage and power output of the piezoelectric harvester. It is found that the output increases sharply when the velocity of the vehicle is close to the so-called critical velocity.

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

    Science.gov (United States)

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

    2013-01-01

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

  15. The Influence of Waste Carpet on the Structural Soil Characteristics in Pavement Granular Layer

    Directory of Open Access Journals (Sweden)

    Mohammad M. Khabiri

    2011-07-01

    Full Text Available Solid waste materials can be left out of environment in different ways or can be used again. As an example of waste fiber materials is the fibers reselling from producing carpet which are made in Iran in largest quantity. These materials are added to soil and granular materials and improve their various properties as compressive and tensile strengths. In present study, the result of previous researches are collected and presented, then, they are used to analyses the effect of using from waste materials in subgrade on highway pavement performance. By using analytical software and results of testing, tensile strain under asphalt layer and compressive strain on subgrade of pavement containing these materials are calculated and after that they are compared together. Next the allowable frequencies of loading for different pavement models are calculated by using existing formula. The results indicate that adding 1.5% of waste fiber to pavement subgrade increases the allowable frequency of loading to 15%.

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

    Science.gov (United States)

    Sneddon, R. V.

    1982-07-01

    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.

  17. Stress Analysis and Determination of Effective k-value for Rigid Pavement

    Directory of Open Access Journals (Sweden)

    Kundan Meshram

    2013-03-01

    Full Text Available EverFE is a user-friendly 3D finite-element analysis tool for simulating the response of jointed plain concrete pavement (JPCP systems to axle loads and environmental effects. EverFE is useful for both concrete pavement researchers and designers who must perform either complex nonlinear or simple linear stress analyses of JPCP.With help of this develop any type of model of rigid pavement considering practical condition thus getting more accurate and advance analysis for rigid pavement. It can also determine effective k-values for different combination of granular sub-base and dry lean concrete. A comparative study is done for two types of loading i.e. single and tandem axle. Edge and Corner stresses are also calculated for Class-AA of loading. Also calculate moment and shear force transfer by dowel bar by EverFE.

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

    Science.gov (United States)

    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...

  19. Assessment of Clogging Dynamics in Permeable Pavement Systems with Time Domain Reflectometers

    Science.gov (United States)

    Infiltration is a primary functional mechanism in green infrastructure stormwater controls. This study used time domain reflectometers (TDRs) to measure spatial infiltration and assess clogging dynamics of permeable pavement systems in Edison, NJ, and Louisville, KY. In 2009, t...

  20. Generating enhanced site topography data to improve permeable pavement performance assessment methods - presentation

    Science.gov (United States)

    Permeable pavement surfaces are infiltration based stormwater control measures (SCM) commonly applied in parking lots to decrease impervious area and reduce runoff volume. Many are not optimally designed however, as little attention is given to draining a large enough contributin...

  1. Techniques to Determine Maintenace Frequency of Permeable Pavement Systems with Time Domain Reflectometers (TDRs

    Science.gov (United States)

    As the surface clogs in permeable pavement systems, they lose effectiveness and require maintenance. There is limited direct guidance for determining when maintenance is needed to prevent surface runoff bypass. Research is being conducted using multiple time domain reflectomete...

  2. Microsurfacing – An Eco-Efficient Tool for Road Safety and Pavement Maintenance

    Directory of Open Access Journals (Sweden)

    Rajesh S. Gujar

    2013-11-01

    Full Text Available With the development of infrastructure, in rapidly developing modern era, frequent maintenance of existing infrastructure, especially roads is of prime importance.  Microsurfacing is a preventive maintenance technique (preventative maintenance strategy aims at producing the most cost-effective improvements in pavement quality and life involving three to six millimeter sized bitumen aggregate treated with a special emulsion.  The layer is neatly laid down on road section requiring maintenance.  This paper aims at focusing on the contributions made by researchers on Microsurfacing as a tool for pavement maintenance and repair.  Although the technique is finding its place in Indian sub-continents little late, but nevertheless it is universally considered as an inevitable tool as far as preventive pavement maintenance is concerned and should be used to extend life of the underlying pavement

  3. The Effect of Cement Stabilized Subgrade on Cost of the Flexible Pavement

    Directory of Open Access Journals (Sweden)

    Baha Vural Kök

    2012-03-01

    Full Text Available The road authorities aim roads that are resistant, with less maintenance, with high traffic security, with long life and economic. It is difficult to have an economic pavement construction on the subgrade with weak bearing capacity. In this study the effect of the cement stabilization on the weak subgrade and pavement costs has been studied. For this purpose the California Bearing Ratio (CBR of a weak subgrade that has been stabilized with 4% - 16% cement have been determined. The effect of the increase in the CBR on the pavement costs has been determined thanks to MATLAB program by considering thousands of alternatives. Consequently, the optimum cement content between the decrease on the pavement costs with increase on subgrade' CBR value and the additional costs spent to increase the CBR value has been determined.

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

    Energy Technology Data Exchange (ETDEWEB)

    Loh, S.W.; Olek, J.

    1999-05-01

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

  5. Investigating In Situ Properties of Recycled Asphalt Pavement with Foamed Asphalt as Base Stabilizer

    Directory of Open Access Journals (Sweden)

    Christina Plati

    2010-01-01

    Full Text Available The objective of the present study was to conduct a comprehensive field experiment for the in situ assessment of in-depth recycled asphalt pavement using foamed asphalt as a stabilization treatment for base works. For this purpose Nondestructive Testing (NDT data collected using the Falling Weight Deflectometer (FWD and Ground Penetrating Radar (GPR along a foamed asphalt recycled pavement section was thoroughly analysed. Critical issues including the stabilized material curing and the contribution of the asphalt layers to the structural properties of the in-depth recycled pavement are discussed. In addition, recommendations concerning the improvement of the structural condition of the in-depth recycled pavement are developed based on this practical approach of investigation using NDT.

  6. Mechanical Behavior and Failure Mechanism of Recycled Semi-lfexible Pavement Material

    Institute of Scientific and Technical Information of China (English)

    DING Qingjun; ZHAO Mingyu; SHEN Fan; ZHANG Xiaoqiang

    2015-01-01

    The mechanical behavior and failure mechanism of recycled semi-lfexible pavement material were investigated by different scales method. The macroscopic mechanical behavior of samples was studied by static and dynamic splitting tensile tests on mechanics testing system (MTS). The mechanical analysis in micro scale was carried out by material image analysis method and ifnite element analysis system. The strains of recycled semi-lfexible pavement material on samples surface and in each phase materials were obtained. The test results reveal that the performance of recovered asphalt binder was the major determinant on the structural stability of recycled semi-lfexible pavement material. The asphalt binder with high viscoelasticity could delay the initial cracking time and reduce the residual strain under cyclic loading conditions. The failure possibility order of each phase in recycled semi-flexible pavement material was asphalt binder, reclaimed aggregate, cement paste and virgin aggregate.

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

    Science.gov (United States)

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

    2014-05-01

    Desert pavements are recognized in arid landscapes around the world, developing via diminution of constructional/depositional landform relief and creating a 1-2 stone thick armor over a "stone free" layer. Surface exposure dating demonstrates that clasts forming the desert pavements are maintained at the land surface over hundreds of thousands of years, as aeolian fines are deposited on the land surface, transported into the underlying parent material and incorporated into accretionary soil horizons (e.g., the stone free or vesicular [Av] horizon). This surface armor provides long-term stability over extensive regions of the landscape. Over shorter time periods and at the landform-element scale, dynamic surficial processes (i.e., weathering, runoff) continue to modify the pavement form. Clast size reduction in comparison to underlying parent material, along with armoring and packing of clasts in pavements contribute to their persistence, and studies of crack orientations in pavement clasts indicate physical weathering and diminution of particle size are driven by diurnal solar insolation. Over geologic time, cracks form and propagate from tensile stresses related to temporal and spatial gradients in temperature that evolve and rotate in alignment with the sun's rays. Observed multimodal nature of crack orientations appear related to seasonally varying, latitude-dependent temperature fields resulting from solar angle and weather conditions. Surface properties and their underlying soil profiles vary across pavement surfaces, forming a landscape mosaic and controlling surface hydrology, ecosystem function and the ultimate life-cycle of arid landscapes. In areas of well-developed pavements, surface infiltration and soluble salt concentrations indicate that saturated hydraulic conductivity of Av horizons decline on progressively older alluvial fan surfaces. Field observations and measurements from well-developed desert pavement surfaces landforms also yield

  8. Study on the submicron and micron morphology and the properties of poor bituminous coal burnout

    Energy Technology Data Exchange (ETDEWEB)

    Pei-Fang Fu; Huai-Chun Zhou; Qing-Yan Fang; Hai Yao; Jianrong Qiu; Minghou Xu [Huazhong University of Science and Technology, Wuhan (China). State Key Laboratory of Coal Combustion

    2007-05-15

    Carbon burnout and its reaction mechanism have been widely focused on in the past decades. The properties of burnout, submicron and micron morphology and the reaction mechanism of poor bituminous coal/char (PBC) in a W-shaped power plant boiler was studied and was compared with those in DTF and in TGA, which showed that the degree of PBC burnout in TGA at 1450{sup o}C was greater than or approximately equal to that in a W-shaped boiler, and that the complexity of the reactions among residual char, oxygen and SiO{sub 2} did not seem to result in mass loss in TGA, although the weight percentage of the residual char in ash decreased from 33% ad (air dry basis) at 900{sup o}C to 9% and at 1450{sup o}C. According to the distribution of pores and the properties of the char burnout, the char can be simply categorized into three classes: char burnout easy, char burnout difficult and char burnout very difficult. The differences of the reaction mechanism must be considered while predicting the burning rate and degree of char burnout in a full-scale boiler by making use of experimental results from TGA and DTF. A different char particle contains markedly different amount of carbons, but for a special char particle, the ratio of carbon to ash is generally constant, and an ash shell does not exist on the char surface. The fusion mineral matter composing of C-O-Si-Al is amorphous, not in the form of Al{sub 2}O{sub 3} and SiO{sub 2} above 1450{sup o}C.

  9. Variations in pore characteristics in high volatile bituminous coals: Implications for coal bed gas content

    Science.gov (United States)

    Mastalerz, Maria; Drobniak, A.; Strapoc, D.; Solano-Acosta, W.; Rupp, J.

    2008-01-01

    The Seelyville Coal Member of the Linton Formation (Pennsylvanian) in Indiana was studied to: 1) understand variations in pore characteristics within a coal seam at a single location and compare these variations with changes occurring between the same coal at different locations, 2) elaborate on the influence of mineral-matter and maceral composition on mesopore and micropore characteristics, and 3) discuss implications of these variations for coal bed gas content. The coal is high volatile bituminous rank with R0 ranging from 0.57% to 0.60%. BET specific surface areas (determined by nitrogen adsorption) of the coals samples studied range from 1.8 to 22.9??m2/g, BJH adsorption mesopore volumes from 0.0041 to 0.0339??cm3/g, and micropore volumes (determined by carbon dioxide adsorption) from 0.0315 to 0.0540??cm3/g. The coals that had the largest specific surface areas and largest mesopore volumes occur at the shallowest depths, whereas the smallest values for these two parameters occur in the deepest coals. Micropore volumes, in contrast, are not depth-dependent. In the coal samples examined for this study, mineral-matter content influenced both specific surface area as well as mesopore and micropore volumes. It is especially clear in the case of micropores, where an increase in mineral-matter content parallels the decrease of micropore volume of the coal. No obvious relationships were observed between the total vitrinite content and pore characteristics but, after splitting vitrinite into individual macerals, we see that collotelinite influences both meso- and micropore volume positively, whereas collodetrinite contributes to the reduction of mesopore and micropore volumes. There are large variations in gas content within a single coal at a single location. Because of this variability, the entire thickness of the coal must be desorbed in order to determine gas content reliably and to accurately calculate the level of gas saturation. ?? 2008 Elsevier B.V. All

  10. Long-Term Pavement Performance (LTPP) InfoPave: Extracting Practical Information out of the Data

    OpenAIRE

    Ahmad, Riaz; Daleiden, Jerome; Kargah-Ostadi, Nima

    2015-01-01

    Long-Term Pavement Performance (LTPP) InfoPave is the web interface for the world's largest pavement performance database. This web interface is being developed under the Federal Highway Administration (FHWA) LTPP program to achieve the strategic goal of utilizing LTPP data effectively. An effective web interface helps reach users crossing all levels of expertise and geographical boundaries and helps information sharing which adds value to tax payers' dollars. To overcome the hurdles for easy...

  11. Runoff on Pavements of Soil-Cement Blocks – an Experimental Boarding

    Directory of Open Access Journals (Sweden)

    Zegarra-Tarqui Jorge Luis

    2015-01-01

    Full Text Available The article evaluates the reduction of runoff in pavements constructed with rectangular blocks of soil-cement. The tests were conducted in a pilot pavement built with soil-cement blocks, seated in a metal box of 50 cm × 50 cm (area = 2500 cm2, with declivities of 1%, 3% and 5%. Mean intensities of 76.9 mm / I 117.7 mm / h were used, values close to the intensities calculated by intensity-frequency-duration (i-f- -d equation of the city of Salvador, Brazil, for return periods of 2 and 5 years, respectively. The medium runoff coefficient was C = 0.61, this value is close to the coefficient of pavement with rectangular blocks (C = 0.6 and it has a lower value than the coefficient for concrete block pavement (C = 0.78. On the other hand, considering that areas with more than 2500 cm2 are constituted by coupling of area units of 50 cm × 50 cm, the splash losses are part of the runoff, obtaining the coefficient Csuperficial + splashing, which showed values in the 0.74 to 0.89 range, these values were found close to the coefficient of concrete block pavement (C = 0.78 and below the concrete pavement (C = 0.95, respectively, but factors such as displacement time of runoff on surface, depressions on the surface, roughness of pavement, evaporation and others, should reduce this value. Then, the pavement of soil-cement blocks can be considered in the category of semi-permeable for the area size used.

  12. The Effect of Cement Stabilized Subgrade on Cost of the Flexible Pavement

    OpenAIRE

    Baha Vural Kök; Mehmet Yılmaz; Alaaddin Geçkil

    2012-01-01

    The road authorities aim roads that are resistant, with less maintenance, with high traffic security, with long life and economic. It is difficult to have an economic pavement construction on the subgrade with weak bearing capacity. In this study the effect of the cement stabilization on the weak subgrade and pavement costs has been studied. For this purpose the California Bearing Ratio (CBR) of a weak subgrade that has been stabilized with 4% - 16% cement have been determined. The effect of ...

  13. 投稿须知%Construction Technology for Fast-Track Concrete Pavement

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In this paper, one of new contents: construction technology for fast-track concrete pavement is introduced in 《Technical Specification for Construction of Highway Cement Concrete Pavements》 (JTG F30) which is revised in 2010 in order to not only provide high-quality and long-lasting life, but also reduce the time of engineering in the new construction, reconstruction and resurfacing maintain of cement concrete pavements, to quickly and early open public traffic, and to reduce traffic interruptions.

  14. INVESTIGATION OF SKID RESISTANCE PROPERTIES OF AGGREGATES USED IN AFYONKARAHISAR CITY PAVEMENTS

    OpenAIRE

    Gürer, Cahit; AKBULUT, Hüseyin; ÇETİN, Sedat

    2007-01-01

    For a safe driving, pavement surface aggregates must have superior physical and mechanical properties. Although high rate of accidents is mainly due to drivers errors, pavement surface properties affect significantly occurance of traffic accidents. The most important factor in the highways leading to traffic accidents are the skid resistance. In this study, adherence test with Vialit plate, Nicholson stripping test, accelerated polishing test (PSV) were carried out on four aggregate samples w...

  15. Assessing the Impacts of Pavement Surface Condition on the Performance of Signalized Intersections

    OpenAIRE

    Hussein, Nasreen A.; Hassan, Rayya A.; Evans, Robert

    2015-01-01

    Signalized intersections are one of the most dangerous places on the road network as they carry a very high crash risk. This may be exacerbated by inadequate pavement surface condition. The main objective of this study was to assess the effect of pavement surface condition (in terms of skid resistance, roughness and rutting) at intersections and approaches on users' safety. In particular, this paper studied the change in crash frequency for numerous signalized intersections before and after s...

  16. Determination Of Correlation Between Road Pavement Skid Resistance And Braking Deceleration

    OpenAIRE

    KOKOT, D; Rijavec, R.; Ambroz, M.

    2012-01-01

    There are many situations when road pavement surface skid resistance drops to unacceptable levels. Skid resistance is an essential pavement property for road safety, but drivers are not able to assess its degree by visual means, although in the end they must be able to stop their vehicles safely within the stopping sight distance. In our research normalized braking deceleration was related to SCRIMTEX SFC values and analyzed for different driving conditions (wet/dry), vehicle systems, skid re...

  17. Laser Scanning on Road Pavements: A New Approach for Characterizing Surface Texture

    OpenAIRE

    Gabriele Bitelli; Andrea Simone; Fabrizio Girardi; Claudio Lantieri

    2012-01-01

    The surface layer of road pavement has a particular importance in relation to the satisfaction of the primary demands of locomotion, such as security and eco-compatibility. Among those pavement surface characteristics, the “texture” appears to be one of the most interesting with regard to the attainment of skid resistance. Specifications and regulations, providing a wide range of functional indicators, act as guidelines to satisfy the performance requirements. This paper describes an experime...

  18. Research on the relationship between water stability and aggregate gradation of asphalt pavement

    OpenAIRE

    Zhao Bing; Zhao Bo

    2015-01-01

    In the early destruction of asphalt pavement, water damage is the most major form.In this paper, experimental study was conducted on the composition of asphalt concrete,Marshall specimens were made in different types of aggregate gradation with the same kind of asphalt. Water immersion tests were conducted in order to analysis the relationship between the water stability and aggregate gradation of asphalt pavement.

  19. Investigating In Situ Properties of Recycled Asphalt Pavement with Foamed Asphalt as Base Stabilizer

    OpenAIRE

    Antonis Kaltsounis; Vasilis Papavasiliou; Andreas Loizos; Christina Plati

    2010-01-01

    The objective of the present study was to conduct a comprehensive field experiment for the in situ assessment of in-depth recycled asphalt pavement using foamed asphalt as a stabilization treatment for base works. For this purpose Nondestructive Testing (NDT) data collected using the Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) along a foamed asphalt recycled pavement section was thoroughly analysed. Critical issues including the stabilized material curing and the con...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-06-01

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

  1. The Effect of Alternative Heavy Truck Suspensions on Flexible Pavement Response

    OpenAIRE

    Hedrick, J. K.; Yi, K.

    1991-01-01

    In this paper, the dynamic effects of heavy vehicle suspensions are investigated by analyzing parametric studies performed using previously developed simulation tools. In particular, the truck simulation package, VESYM, and the flexible pavement simulation package. VESYS, are used to look at the influence of alternative suspension types, e.g., walking beam, leaf spring/short rocker, air spring and semi-active shock absorbers on pavement response. The intent of the study is to determi...

  2. The influence of recycled asphalt pavement on 20mm binder course mix performance

    OpenAIRE

    Tabakovic, Amir; Gibney, Amanda; Gilchrist, M. D.; McNally, Ciaran

    2006-01-01

    This paper presents the results of ongoing research on the mechanical performance of a 20mm binder course asphalt pavement mix incorporating recycled asphalt pavement (RAP). A series of binder course mixes were designed containing varying percentages of RAP. A mix made only from virgin material was selected as the control mix for the investigation. The effect of introducing RAP into the binder course mix was evaluated through a series of laboratory tests including the Marshall Test, Indire...

  3. Calculating rutting of some thin flexible pavements from repeated load triaxial test data

    OpenAIRE

    Qiao, Yaning; Dawson, Andrew; Huvstig, Anders; Korkiala-Tanttu, Leena

    2015-01-01

    This paper describes parts of a Nordic pavement performance prediction model study (at the project level of the NordFoU project) where a material performance model, developed at VTT research centre in Finland, has been selected as a mean of calculating the permanently accumulated (plastic) deformation (i.e. rutting) of unbound granular materials (UGMs) in flexible pavements subjected to trafficking. The paper aims to assess the suitability of this VTT model application to Swedish roads compri...

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

    OpenAIRE

    Sañudo Fontaneda, Luis Ángel; Charlesworth, Susanne M.; Castro Fresno, Daniel; Andrés Valeri, Valero Carlos Alessio; Rodríguez Hernández, Jorge

    2014-01-01

    Pervious pavements have become one of the most used sustainable urban drainage system (SUDS) techniques in car parks. This research paper presents the results of monitoring water quality from several experimental car park areas designed and constructed in Spain with bays made of interlocking concrete block pavement, porous asphalt, polymer-modified porous concrete and reinforced grass with plastic and concrete cells. Moreover, two different sub-base materials were used (limestone aggregates a...

  5. Infrastructure Pavement Assessment & Management Applications Enabled by the Connected Vehicles Environment – Proof-of-Concept

    OpenAIRE

    Flintsch, Gerardo; Smith, Brian

    2015-01-01

    The objective of this project was to develop prototypes and conduct a field test of system level applications of a connected vehicle pavement condition measurement system. This allowed the research team to: (1) investigate different approaches to a connected vehicle pavement measurement system; and (2) determine the optimum procedures for collecting, processing, aggregating, and storing the data to support engineering and management decisions. The study found that roughness measures obtain...

  6. Modelling of Mechanical Properties of Cement Concrete Incorporating Reclaimed Asphalt Pavement

    OpenAIRE

    MATHIAS, Vincent; SEDRAN, Thierry; De Larrard, François

    2009-01-01

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

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

    International Nuclear Information System (INIS)

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

  8. Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas

    Energy Technology Data Exchange (ETDEWEB)

    Carl Richardson; Katherine Dombrowski; Douglas Orr

    2006-12-31

    This project Final Report is submitted to the U.S. Department of Energy (DOE) as part of Cooperative Agreement DE-FC26-03NT41987, 'Sorbent Injection for Small ESP Mercury Control in Low Sulfur Eastern Bituminous Coal Flue Gas.' Sorbent injection technology is targeted as the primary mercury control process on plants burning low/medium sulfur bituminous coals equipped with ESP and ESP/FGD systems. About 70% of the ESPs used in the utility industry have SCAs less than 300 ft2/1000 acfm. Prior to this test program, previous sorbent injection tests had focused on large-SCA ESPs. This DOE-NETL program was designed to generate data to evaluate the performance and economic feasibility of sorbent injection for mercury control at power plants that fire bituminous coal and are configured with small-sized electrostatic precipitators and/or an ESP-flue gas desulfurization (FGD) configuration. EPRI and Southern Company were co-funders for the test program. Southern Company and Reliant Energy provided host sites for testing and technical input to the project. URS Group was the prime contractor to NETL. ADA-ES and Apogee Scientific Inc. were sub-contractors to URS and was responsible for all aspects of the sorbent injection systems design, installation and operation at the different host sites. Full-scale sorbent injection for mercury control was evaluated at three sites: Georgia Power's Plant Yates Units 1 and 2 [Georgia Power is a subsidiary of the Southern Company] and Reliant Energy's Shawville Unit 3. Georgia Power's Plant Yates Unit 1 has an existing small-SCA cold-side ESP followed by a Chiyoda CT-121 wet scrubber. Yates Unit 2 is also equipped with a small-SCA ESP and a dual flue gas conditioning system. Unit 2 has no SO2 control system. Shawville Unit 3 is equipped with two small-SCA cold-side ESPs operated in series. All ESP systems tested in this program had SCAs less than 250 ft2/1000 acfm. Short-term parametric tests were conducted on Yates

  9. The design and analysis on asphalt concrete pavement%沥青混凝土路面设计分析

    Institute of Scientific and Technical Information of China (English)

    王星茹

    2016-01-01

    This paper introduced the design process of urban road asphalt pavement,discussed the material and type of asphalt concrete pave-ment,from the pavement structure combination design,pavement design index,pavement structure layer calculation and other aspects,elabora-ted the design method of asphalt concrete pavement,made the asphalt pavement meet the structure strength and stability requirements.%介绍了城市道路沥青路面设计的流程,论述了沥青混凝土面层的材料与类型,从路面结构组合设计、路面设计指标、路面结构层计算等方面,阐述了沥青混凝土路面的设计方法,使沥青路面满足结构强度和稳定性的要求.

  10. Applying AHP—Based CBR to Estimate Pavement Maintenance Cost

    Institute of Scientific and Technical Information of China (English)

    Jui-Sheng Chou

    2008-01-01

    The cost-efficacy control of maintenance operations in developing countries has become critical to the infrastructure asset management after highway construction.To effectively manage numerous projects annually with limited resources,it is necessary to reasonably estimate costs during the process of making maintenance project selection decisions.This study outlines the modeling of case-based reasoning (CBR) estimation that compares and retrieves the most similar instance across the case library.Four CBR ap- proaches were presented and assessed in terms of their mean absolute prediction error rates.The resulting model demonstrates the ability of estimating the pavement maintenance project costs with the satisfactory accuracy at the early stages.

  11. Dynamic Modeling of Pavements with Application to Deflection Measurements

    DEFF Research Database (Denmark)

    Madsen, Stine Skov

    with different speeds is needed. In this thesis a new Finite Element formulation for transient dynamic loading of a layered half space is developed. Equations are derived in 2D and 3D and include efficient absorbing boundary conditions in the form of the Perfectly Matched Layer (PML) which ensures capability...... Deflectometer (RWD) type of device due to its ability to measure deflections continuously while driving at traffic speed. To be able to properly interpret deflection measurements from an RWD device, more knowledge about the structural behavior of a pavement when subjected to transient dynamic loads moving...... of long time simulations without disruptions from the boundaries. The equations are formulated in a moving frame of reference such that the domain is following the load, which ensures that the size of the model is kept small regardless of simulation time frame. A parametric study for finding optimal PML...

  12. Validation of theoretical models through measured pavement response

    DEFF Research Database (Denmark)

    Ullidtz, Per

    1999-01-01

    performance. The analytical models are based on a number of simplifications with respect to reality and must be verified experimentally.Different pressure gauges were installed in a sand, assumed to be a semi-infinite halfspace. The surface of the sand was loaded by a Falling Weight Deflectometer (FWD......) at different lateral positions with respect to the gauges. An integration of the stresses measured at the plane of the gauges showed that the total load recorded by the gauges was close to the loade imposed by the FWD, cofirming the reliability of the gauges. The theoretical stress calculated using continuum...... then used to derive the elastic parameters of the pavement layeres, that would produce deflections matching the measured deflections. Stresses and strains were then calculated at the position of the gauges and compared to the measured values. It was found that all analytical models would predict the tensile...

  13. Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

    Institute of Scientific and Technical Information of China (English)

    PENG; Miaojuan; XU; Zhihong

    2006-01-01

    To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pavements is presented.The model combines a generalized Maxwell model with an elastoplastic one.Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained.From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained.And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN.The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN.This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective.The properties,such as nonlinear elasticity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model.And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

  14. Pavement response to vehicular loads: a mechanistic approach involving nondestructive evaluation techniques

    Science.gov (United States)

    Kennedy, James C., Jr.

    1996-11-01

    The need for effective design in the nation's highways is greater now, more than ever, due to shrinking funds for new construction and rehabilitation/maintenance practices and the need to preserve the lands that are not now part of the roadway system. Most of the nation's highways were constructed within the last 30 years and many of these are due for significant rehabilitation and even reconstruction. Thus, the need to infuse robust design methods into these rehabilitation and reconstruction strategies is paramount. Currently, methods for cost allocation for pavement rehabilitation/maintenance activities and pavement management estimations are based on empirical and semi- empirical founded predictions that come up short, particularly when the roadway i subjected to multi-axle, heavy weight vehicles. Additionally, materials currently used int he construction of the pavement structure do not always behave in an elastic manner and the ability to predict the pavement response in the presence of other than elastic material behavior is essential. Finally, prediction of pavement states of distress based on empirical methods and elastic material behavior are inadequate, particularly when heavy weight vehicular traffic is involved. This paper includes descriptions of the overall methodology for pavement design and the unique requirements for the design and implementation of the structural and environmental sensing elements. Description of the mechanistic aspects in the software for the structural and material models is discussed and comparison of predicted and field measured results are presented.

  15. Thermal Behavior of an Asphalt Pavement in the Laboratory and in the Parking Lot

    Directory of Open Access Journals (Sweden)

    J. B. Martinkauppi

    2015-01-01

    Full Text Available The urban, constructed areas are full of buildings and different kinds of pavements and have a noticeable lack of trees and flora. These areas are accumulating the heat from the Sun, people, vehicles, and constructions. One interesting heat collector is the asphalt pavement. How does the heat transfer to different layers under the pavement or does it? What are the temperatures under the pavement in Finland where the winter can be pretty hard? How can those temperatures be measured accurately? These are the main questions this paper gives the preliminary answers to. First the thermal behavior of asphalt and the layers beneath are researched in the laboratory and then the measurement field is bored and dug in the parking in the Western coast of Finland, 63°5′45′′ N. Distributed temperature sensing method was found to be a good choice for temperature measurements. Thermal behavior of pavement has been monitored in different layers and the preliminary results have been published here. The goal of this research is to assess the applicability of asphalt pavements for heat energy collection.

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

    Science.gov (United States)

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

    2013-03-30

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

  17. Study of the Effect of Temperature Changes on the Elastic Modulus of Flexible Pavement Layers

    Directory of Open Access Journals (Sweden)

    Mohd Raihan Taha

    2013-02-01

    Full Text Available In general, the stiffness of flexible pavement is influenced by environmental changes, whereby temperature and rainfall affect the asphalt layer and non-asphalt layer, such as the subgrade, respectively. Normally, the effect of temperature on flexible pavement can be measured using two methods. The first is a destructive test whereby core samples are tested in a laboratory using a Universal Testing Machine (UTM. The second is a non-destructive in situ test using equipment such as a Falling Weight Deflectometer (FWD and Spectral Analysis of Surface Waves (SASW. This study was conducted to investigate the effect of temperature at different tensile levels on the Soekarno-Hatta and Purwakarta Cikampek roads in Bandung, West Java, Indonesia. It is observed that different tensile levels and testing methods result in various elastic modulus values of flexible pavement. The higher the temperature applied to the flexible pavement layer, the more the elastic modulus values decrease. In contrast, the lower the temperature imposed on the flexible pavement layer, the more the elastic modulus values increase. Different testing methods (FWD, UTM and SASW on the flexible pavement layer are also affected by temperature changes.

  18. Sensitivity analysis of asphalt-pavement structure dynamic responses under heavy load

    Directory of Open Access Journals (Sweden)

    ZHANG Lijuan

    2015-04-01

    Full Text Available With the 3-Dimensional finite-element dynamic model,the influence of axis-load,axis-speed,and pavement structure parameters on dynamic performance of pavement structure is studied.The results show that with the increase in load,the dynamic response of pavement is nearly proportional to axis-load and increases noticeably;Axis-speed influences the dynamic response to some extent.With the increase of axis-speed,dynamic response of pavement structure increases firstly.With axis-speed further increasing,dynamic response of pavement structure then decreases gradually.For fatigue failure,the influence of heavy-load with common moving speed is much greater than that of static load.Among the pavement structure parameters,thickness of surface-layer has a significant effect on shear stress and the compression stress at road surface.Subgrade modulus has a significant effect on road surface deflection,tensile stress at the bottom of subbase,and compression-strain at the top of subgrade.

  19. Field validation of road roughness evaluation using in-pavement strain sensors

    Science.gov (United States)

    Zhang, Z.; Deng, F.; Huang, Y.; Bridgelall, R.

    2016-04-01

    Most transportation agencies now collect pavement roughness data using the inertial profilers, which requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor requirements of the profiling activities limit data collection for portions of the national highway system to at most once per year, resulting in outdated roughness data for decision making of maintenance needs. In this paper, a real-time roughness evaluation method was developed by linking the output of durable in-pavement strain sensors to road roughness level. The durable in-pavement sensors will continuously provide information of road roughness in real time after they are installed and calibrated during the road construction until the service life of the associated pavement. Field tests validated the developed strain method by comparison with standard inertial profiling method and the connected-vehicle method. The comparison of the results from the field tests approves the effectiveness of the developed road roughness evaluation method using in-pavement strain sensors, which can be further applied practically for needed concrete pavements.

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

    Science.gov (United States)

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

    2013-03-30

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

  1. New Asphalt Pavement Failure Criterion Based on Unifi ed Strength Theory

    Institute of Scientific and Technical Information of China (English)

    YANG Qun; CHEN Lu; WANG Ping; DAI Jingwang

    2015-01-01

    This study aims to introduce an appropriate analytical method for asphalt pavement based upon unified strength theory (UST). The traditional maximum shear stress strength theory (MSST) cannot describe the marked difference between tension strength and compressive strength or variable intermediate principal stress, which significantly affects the geotechnical materials. Our studies try to find a new asphalt pavement failure criterion that considers the influence of both tension-compression strength ratio and intermediate principal stress of asphalt mixture. In order to select a suitable theory on pavement material, the UST is introduced and compared with the traditional theory. Results show that the tension-compression strength ratio of asphalt mixture, which is used as a material parameter, dramatically affects the stress and stress distribution law in pavement; the pavement stress level increases dramatically after considering the intermediate principal stresses. Therefore, the UST which considers both tension-compression strength ratio and intermediate principal stress is more in line with the material characteristics of asphalt pavement.

  2. Synthesis Study on Use of Concrete Recycled from Pavement and Building Rubble in the Indiana Highway System

    OpenAIRE

    Burke, Thomas T.; Cohen, Menashi D.; Scholer, Charles F.

    1992-01-01

    The demolition of buildings and highway pavements in the State of Indiana generates a considerable amount of waste materials. The disposal of these materials causes strain on the existing landfills which are rapidly approaching their full capacity. This study is a synthesis of the information on the use of concrete recycled from pavements and building rubble for use in the Indiana highway system. Test results have shown that recycled pavement concrete made chiefly from broken-up and crushed o...

  3. Traffic noise abatement : how different pavements, vehicle speeds and traffic densities affect annoyance levels

    OpenAIRE

    Freitas, Elisabete F.; Mendonça, Catarina; Santos, Jorge A.; Murteira, Carla; Ferreira, João Amaro Oliveira

    2012-01-01

    In this paper, annoyance ratings from traffic noise recorded on cobblestones, dense asphalt, and open asphalt rubber pavements are assessed with regard to car speeds and traffic den- sities. It was found that cobblestones pavements are the most annoying; also while open asphalt rubber pavement imposes less annoyance than dense asphalt it is not significantly different. Higher car speeds always lead to greater annoyance, as does higher traffic densi- ties. LAeq and LAmax correl...

  4. Evaluation of a new experimental test procedure to more accurately determine the surface infiltration rate of permeable pavement systems

    OpenAIRE

    Lucke, T.; Boogaard, F.; Van den Ven, F.

    2014-01-01

    Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over time and this reduces their infiltration capacity. In order to assess the infiltration of permeable pavements, a variety of infiltration test procedures have been utilised in the past. However, the ...

  5. Organic petrology and geochemistry of Eocene Suzak bituminous marl, north-central Afghanistan: Depositional environment and source rock potential

    Science.gov (United States)

    Hackley, Paul C.; Sanfilipo, John

    2016-01-01

    Organic geochemistry and petrology of Eocene Suzak bituminous marl outcrop samples from Madr village in north-central Afghanistan were characterized via an integrated analytical approach to evaluate depositional environment and source rock potential. Multiple proxies suggest the organic-rich (TOC ∼6 wt.%) bituminous marls are ‘immature’ for oil generation (e.g., vitrinite Ro  1) indicating organic input from marine algae and/or bacterial biomass, and sterane/hopane ratios are low (0.12–0.14). Monoaromatic steroids are dominated by C28clearly indicating a marine setting. High gammacerane index values (∼0.9) are consistent with anoxia stratification and may indicate intermittent saline-hypersaline conditions. Stable C isotope ratios also suggest a marine depositional scenario for the Suzak samples, consistent with the presence of marine foraminifera including abundant planktic globigerinida(?) and rare benthic discocyclina(?) and nummulites(?). Biomarker 2α-methylhopane for photosynthetic cyanobacteria implies shallow photic zone deposition of Madr marls and 3β-methylhopane indicates presence of methanotrophic archaea in the microbial consortium. The data presented herein are consistent with deposition of Suzak bituminous marls in shallow stratified waters of a restricted marine basin associated with the southeastern incipient or proto-Paratethys. Geochemical proxies from Suzak rock extracts (S content, high polar content, C isotopes, normal (αααR) C27–29 steranes, and C29/C30 and C26/C25 hopane ratios) are similar to extant data from Paleogene oils produced to the north in the Afghan-Tajik Basin. This observation may indicate laterally equivalent strata are effective source rocks as suggested by previous workers; however, further work is needed to strengthen oil-source correlations.

  6. Petrographic and Vitrinite Reflectance Analyses of a Suite of High Volatile Bituminous Coal Samples from the United States and Venezuela

    Science.gov (United States)

    Hackley, Paul C.; Kolak, Jonathan J.

    2008-01-01

    This report presents vitrinite reflectance and detailed organic composition data for nine high volatile bituminous coal samples. These samples were selected to provide a single, internally consistent set of reflectance and composition analyses to facilitate the study of linkages among coal composition, bitumen generation during thermal maturation, and geochemical characteristics of generated hydrocarbons. Understanding these linkages is important for addressing several issues, including: the role of coal as a source rock within a petroleum system, the potential for conversion of coal resources to liquid hydrocarbon fuels, and the interactions between coal and carbon dioxide during enhanced coalbed methane recovery and(or) carbon dioxide sequestration in coal beds.

  7. Behaviour of bituminized waste under gamma irradiation. Effect of STE3 decontamination process components

    International Nuclear Information System (INIS)

    Liquid wastes of light and medium activity are treated by chemical co-precipitation and sludge are mixed with bitumen. Irradiation is responsible of gas production and potential swelling of the embedded. It prevails on limitation of filling of storage containers and activity to 140 Ci. The aim of this work is the study of influence of the components of the decontamination process on the behaviour of bituminous wastes, in order to control swelling and to state radiolysis mechanisms, both for production and storage of wastes. For pure bitumen, mechanism of production of H2 and CH4 are specified. Oxygen consumption, localised on the surface of samples, leads to conversion of aromatic oils and resins to asphaltenes, by a chain reaction mechanism. CO2 et CO are reaction products of gaseous oxygen, respectively with bitumen and light hydrocarbons. The composition of bitumen is slightly modified to heavier and higher polarity products, with parallel hardening. NaNO3, Na2SO4, BaSO4, PPFNi, K2SO4, NiSO4, et diatoms DIT3R et DIC3 have strictly a dilution effect towards gas generation. CoS, above 1% embedded, strongly inhibits production of H2, CH4 and light hydrocarbons. Degradation of bitumen being reduced, a radical mechanism with both radicals H· et R· might exist. Kinetic shows that a bi-radicals mechanism (or more) is probable. In the same way, Raney's nickel induces a important decrease of production of H2, CH4 et C2, with a capacity of 7,7 ml/g. Swelling depends on dimension of sample gas production and dose rate. Solid content and particle size are not determining parameters. Low swelling is obtained for penetrability higher than 70 1/10 mm, This can be realised by addition of a solvent as TBP and by increasing temperature above 40 deg C. Rheological characterizations (oscillation and creeping mode) have not been successful to correlate swelling with a physical parameter. (author)

  8. Mechanical, sorption and transport experiments on a German high volatile bituminous coal

    Energy Technology Data Exchange (ETDEWEB)

    Gensterblum, Y.; Krooss, B.M. [RWTH Aachen Univ. (Germany). Inst. of Geology and Geochemistry of Petroleum and Coal; Massarotto, Paul [Queensland Univ., Brisbane, St Lucia, QLD (Australia). School of Engineering

    2013-08-01

    A high volatile bituminous coal (vitrinite reflectance: 0.93%, carbon content: 83%) from the Prosper-Haniel mine, North Rhine-Westphalia has been studied using a comprehensive set of measurements and experimental procedures at RWTH Aachen University and the University of Queensland. Using the True Triaxial Stress Coal Permeameter (TTSCP) (Massarotto 2003) of the University of Queensland, permeability and gas displacement tests were performed on an 80 mm cube of the Prosper-Haniel coal. Extensive data sets were recorded to assess the effects of stress changes on gas transport and the impact of nitrogen, methane and CO{sub 2} sorption on the mechanical properties. We investigate the permeability coefficients for helium, nitrogen, methane and carbon dioxide measured on this sample as a function of net stress. As expected, permeability values decrease with increasing stress. Methane and nitrogen have nearly identical permeability coefficients throughout the entire net stress range, while permeability coefficients measured with helium are higher and those measured with CO{sub 2} significantly lower. During the permeability measurements with CO{sub 2} an anisotropic swelling of the coal cube by about 0.19% to 0.23% was observed. The volumetric effect (swelling) is 100 times slower than gas displacement. Simultaneous mechanical tests indicated a softening of the coal block upon exposure to CO{sub 2}. Thus, a decrease of Young's modulus (YM) of the coal cube during the CO{sub 2} flow test was observed as compared to the methane and nitrogen tests. High-pressure sorption isotherms with CH{sub 4} and CO{sub 2} were determined on different grain-size fractions of the Prosper-Haniel coal at 318K and different moisture contents. Methane sorption capacity decreases by 29% with increasing moisture content. Also, a decrease of sorption rate was observed with increasing moisture content. While sorption rates are generally faster for CO{sub 2} than for CH{sub 4}, the sorption

  9. Organic geochemistry of Upper Carboniferous bituminous coals and clastic sediments from the Lublin Coal Basin

    Science.gov (United States)

    Gola, Marek R.; Karger, Michał; Gazda, Lucjan; Grafka, Oliwia

    2013-09-01

    Bituminous coals and clastic rocks from the Lublin Formation (Pennsylvanian, Westphalian B) were subjected to detailed biomarker and Rock-Eval analyses. The investigation of aliphatic and aromatic fractions and Rock-Eval Tmax suggests that the Carboniferous deposits attained relatively low levels of thermal maturity, at the end of the microbial processes/initial phase of the oil window. Somewhat higher values of maturity in the clastic sediments were caused by postdiagenetic biodegradation of organic matter. The dominance of the odd carbon-numbered n-alkanes in the range n-C25 to n-C31 , high concentrations of moretanes and a predominance of C 28 and C29 steranes are indicative of a terrigenous origin of the organic matter in the study material. This is supported by the presence of eudesmane, bisabolane, dihydro-ar-curcumene and cadalene, found mainly in the coal samples. In addition, tri- and tetracyclic diterpanes, e. g. 16β(H)-kaurane, 16β(H)-phyllocladane, 16α(H)-kaurane and norisopimarane, were identified, suggesting an admixture of conifer ancestors among the deposited higher plants. Parameters Pr/n-C17 and Rdit in the coal samples show deposition of organic matter from peat swamp environments, with the water levels varying from high (water-logged swamp) to very low (ephemeral swamp). Clastic deposits were accumulated in a flood plain environment with local small ponds/lakes. In pond/lake sediments, apart from the dominant terrigenous organic matter, research also revealed a certain quantity of algal matter, indicated, i.a., by the presence of tricyclic triterpanes C28 and C29 and elevated concentrations of steranes. The Paq parameter can prove to be a useful tool in the identification of organic matter, but the processes of organic matter biodegradation observed in clastic rocks most likely influence the value of the parameter, at the same time lowering the interpretation potential of these compounds. The value of Pr/Ph varies from 0.93 to 5.24 and from 3

  10. Influence of mixture composition on the noise and frictional characteristics of flexible pavements

    Science.gov (United States)

    Kowalski, Karol J.

    Both traffic noise and wet pavement-tire friction are mainly affected by the tire/pavement interaction. Existing laboratory test methods allow for evaluation of polishing resistance of the aggregates only. Currently, there is no generally accepted standardized laboratory test method to address noise related issues and the overall frictional properties of pavements (including macrotexture). In this research, which included both laboratory and field components, friction and noise properties of the flexible (asphalt) pavements were investigated. As a part of this study, a laboratory device to polish asphalt specimens was developed and the procedure to evaluate mixture frictional properties was proposed. Following this procedure, forty-six different Superpave mixtures (each utilizing a different aggregate blends), one stone matrix asphalt (SMA) mixture and one porous friction course (PFC) mixture were tested. Six of the above mixes (four Superpave mixtures, SMA mixture and PFC mixture) were selected for laboratory noise testing. This testing was performed using a one-of-a-kind tester called the Tire/Pavement Test Apparatus (TPTA). In addition, the field sections constructed using Superpave, SMA and PFC mixtures were also periodically tested for friction and noise. Field measurements included testing of total of 23 different asphalt and two concrete pavements. The field friction testing was performed using both portable CTM and DFT devices and the (ASTM E 274) locked wheel friction trailer. The laboratory friction testing was performed using CTM and DFT devices only. The results of both field and laboratory friction measurements were used to develop an International Friction Index (IFI)-based frictional requirement for laboratory friction measurements. The results collected in the course of the study indicate that the IFI-based flag values could be successfully used in place of SN-based flag values to characterize frictional characteristics of pavements.

  11. Numerical analysis of applying special pavements to solve the frost heave diseases of high-speed railway roadbeds in seasonally frozen ground regions

    Institute of Scientific and Technical Information of China (English)

    Chang Yuan; FuJun Niu; QiHao Yu; XinBin Wang; Lei Guo; YanHui You

    2015-01-01

    The Haerbin-Dalian Passenger Dedicated Line is the first high-speed railway constructed in the seasonally frozen ground regions of northeastern China. Frost heave diseases occurred in the first winter of its operation (between October 2012 and January 2013), and frost heave was observed mainly in the roadbed fills that were considered not susceptible to frost heave. This paper proposes applying two special pavements — black pavement and insulation-black pavement — to improve the thermal regime of the roadbed. Three numerical models of the roadbed temperature field were built based on the field con-ditions of the Changchun section (D3K692+840 to D3K692+860). The results show that: (1) Compared with cement pave-ment, black pavement and insulation-black pavement could reduce the freezing index at the roadbed surface by 37% and 64%, respectively, which could influence the maximum frozen depth; (2) the maximum frozen depths under the black pavement and insulation-black pavement were respectively 1.3–1.4 m and 1 m. Compared with cement pavement, they could reduce the maximum frozen depth by 0.4 m and 0.7–0.8 m, respectively, which would reduce the permitted amount of frost heave by 4 mm and 7–8 mm, which would meet the deformation limit established by theCode for Design on Special Subgrade of Railway; (3) the freezing periods of the black pavement and the insulation-black pavement were, respectively, approximately four months and two months. Compared with cement pavement, they could reduce the freezing period by approximately 19 days and 40 days, respectively, and delay the initial freezing time by 9 days and 18 days; and (4) compared with cement pavement, black pavement and black-insulation pavement could reduce the frozen areas of roadbeds in the cold season, which suggests that these two special pavements could provide better thermal stability for roadbeds.

  12. On-site inspections of pavement damages evolution using GPR

    Science.gov (United States)

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

    2014-05-01

    Ground-penetrating radar (GPR) is being increasingly used for pavements maintenance due to the wide range of applications spanning from physical to geometrical inspections, thereby allowing for a reliable diagnosis of the main causes of road structural damages. In this work, an off-ground GPR system was used to investigate a large-scale rural road network. Two sets of surveys were carried out in different time periods, with the main goals to i) localize the most critical sections; ii) monitor the evolution of previous damages and localize newborn deep faults, although not revealed at the pavement surface level; iii) analyze the causes of both evolution and emergence of faults by considering environmental and human factors. A 1-GHz GPR air-launched antenna was linked to an instrumented van for collecting data at traffic speed. Other support techniques (e.g. GPS data logger, odometer, HD video camera) were used for cross-checking,. Such centre frequency of investigation along with a 25-ns time window allow for a signal penetration of 900 mm, consistent with the deepest layer interfaces. The bottom of the array was 400 mm over the surface, with a minimum distance of 1200 mm from the van body. Scan length of maximum 10 km were provided for avoiding heavy computational loads. The rural road network was located in the District of Rieti, 100 km north from Rome, Italy, and mostly develops in a hilly and mountainous landscape. In most of the investigated roads, the carriageway consists in two lanes of 3.75 meters wide and two shoulders of 0.50 meters wide. A typical road section includes a HMA layer (65 mm average thickness), a base layer (100 mm average thickness), and a subbase layer (300 mm average thickness), as described by pavement design charts. The first set of surveys was carried out in two days at the beginning of spring in moderately dry conditions. Overall, 320-km-long inspections were performed in both travel directions, thereby showing a productivity of

  13. Effect of Pre-oxidation on the Properties of Crushed Bituminous Coal and Activated Carbon Prepared Therefrom

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of a pre-oxidation process on the chemical properties of crushed bituminous coal and on adsorption properties of the subsequently formed char and activated carbon is discussed in this paper.Datong bituminous coal samples sized 6 mm were oxidized at different temperatures and for different times and then carbonized and activated by steam to obtain activated carbons.A Uniform Design method was used to arrange the experiments, IR and adsorption experiments were used to characterize these oxidized coals, chars and activated carbon samples.The results show that the carboxyl group disappeared and α-CH2 groups joined to alkenes decreased dramatically but the carbonyl group clearly increased in the coal sample oxidized at 543 K; The chemical composition of coal samples oxidized at lower temperature is different from that of coal oxidized at 543 K.Oxidizing coal samples at higher temperatures for a short time or at lower temperatures for a longer time resulted in activated carbon samples that tended toward the same adsorption properties: Iodine number 1100 mg/g and Methylene blue value 252 mg/g.The yield of activated carbon obtained from the pre-oxidized coal is 10% higher than the yield from parent coal but the activated carbons have the same adsorption properties.

  14. Characterization of burning and CO2 gasification of chars from mixtures of Zonguldak (Turkey) and Australian bituminous coals

    International Nuclear Information System (INIS)

    In this study, different mixtures (30 wt.% + 70 wt.% and 50 wt.% + 50 wt.%, respectively) of Zonguldak bituminous coal (Turkey) and an Australian bituminous coal are carbonized to obtain char samples. The ignition temperatures of the samples are determined by sending O2 onto the samples in a system designed for determining the ignition temperature. The gasification reactivity of the chars in a CO2 atmosphere is also measured at temperatures between 800 deg. C and 1050 deg. C. The relationship between the ignition temperature and the burning character of the same samples is investigated thermogravimetrically. The moisture, ash and volatile matter analyses are also performed. An increase in carbonization temperature leads to a decrease in the amount of volatile matter. The differences between the effects of volatile matter on the ignition temperature and the gasification reactivity of the samples with CO2 might be explained by the change in pore structure and the varying catalytic effect of mineral components in the structure. It is also seen that there is a good correlation between the thermal analysis and the complete analysis results of the samples

  15. Quantitative Analysis of Carbon Content in Bituminous Coal by Laser-Induced Breakdown Spectroscopy Using UV Laser Radiation

    Science.gov (United States)

    Li, Xiongwei; Mao, Xianglei; Wang, Zhe; Richard, E. Russo

    2015-11-01

    The carbon content of bituminous coal samples was analyzed by laser-induced breakdown spectroscopy. The 266 nm laser radiation was utilized for laser ablation and plasma generation in air. The partial least square method and the dominant factor based PLS method were used to improve the measurement accuracy of the carbon content of coal. The results showed that the PLS model could achieve good measurement accuracy, and the dominant factor based PLS model could further improve the measurement accuracy. The coefficient of determination and the root-mean-square error of prediction of the PLS model were 0.97 and 2.19%, respectively; and those values for the dominant factor based PLS model were 0.99 and 1.51%, respectively. The results demonstrated that the 266 nm wavelength could accurately measure the carbon content of bituminous coal. supported by National Natural Science Foundation of China (No. 51276100) and the National Basic Research Program of China (973 Program) (No. 2013CB228501). The authors also thank the financial funding from the U. S. Department of Energy, Office of Basic Energy Sciences, Chemical Science Division at Lawrence Berkeley National Laboratory (No. 2013CB228501)

  16. Evaluation of the fatigue macro-cracking behavior of crumb rubber modified bituminous mixes

    Directory of Open Access Journals (Sweden)

    Moreno-Navarro, F.

    2014-09-01

    Full Text Available The use of crumb rubber modified bitumen (CRMB in asphalt mixes is a road engineering technology that has become increasingly important in recent years. Given the many economic and environmental benefits of this type of binder, the goal is to give CRMB the same level of performance as conventional polymer-modified bitumen. The appearance and propagation of cracks due to fatigue phenomena is one of the most common distresses affecting road pavements. Since crumb rubber enhances the mechanical properties of asphalt mixes, it can provide a viable solution for fatigue cracking. This paper presents the results of a comparative analysis of the fatigue-cracking behavior of asphalt mixtures manufactured with crumb rubber modified bitumen and polymer-modified bitumen.El empleo de betunes modificados con polvo de neumático usado en la fabricación de mezclas bituminosas es una de las técnicas que mayor auge está teniendo en los últimos años en la ingeniería de carreteras. Dadas sus grandes ventajas económicas y ambientales, este tipo de ligantes pretende conseguir prestaciones similares a la de los betunes modificados con polímeros utilizados habitualmente. La aparición de fisuras debido a fenómenos de fatiga es una de las patologías más comunes en firmes de carretera. Debido a las mejoras de las propiedades mecánicas del betún aportadas tras la incorporación de polvo de neumático, las mezclas fabricadas con estos ligantes se postulan como una posible solución a dicho problema. En este artículo se lleva a cabo un análisis comparativo del comportamiento a fisuración por fatiga realizado sobre mezclas bituminosas fabricadas con betún modificado con polvo de neumático y con polímeros.

  17. Reuse of Lathe Waste Steel Scrap in Concrete Pavements

    Directory of Open Access Journals (Sweden)

    Pooja Shrivastavaa

    2014-12-01

    Full Text Available These project works assess on the study of the workability and mechanical strength properties of the concrete reinforced with industrialized waste fibers or the recycled fibers. In each lathe industries wastes are available in form of steel scraps are yield by the lathe machines in process of finishing of different machines parts and dumping of these wastes in the barren soil contaminating the soil and ground water that builds an unhealthy environment. Now a day’s these steel scraps as a waste products used by innovative construction industry and also in transportation and highway industry. In addition to get sustainable progress and environmental remuneration, lathe scrap as worn-recycle fibers with concrete are likely to be used. When the steel scrap reinforced in concrete it acquire a term; fiber reinforced concrete and steel fibers in concrete defined as steel fiber reinforced concrete (SFRC.Different experimental studies are done to identify about fresh and hardened concrete properties of steel scrap fiber reinforced concrete (SSFRC and their mechanical properties are found to be increase due to the addition of steel scrap in concrete i.e. compressive strength, flexural strength, impact strength, fatigue strength and split tensile strength were increased but up to 0.5-2% scrap content . When compared with usual concrete to SSFRC, flexural strength increases by 40% and considerable increases in tensile and compressive strength. These steel scrap also aid to improve the shrinkage reduction, cracking resistance i.e. preventing crack propagation and modulus of elasticity. The workability of fresh SSFRC are carried out by using slump test but it restricted to less scrap contents. This work focuses on the enhancement of structural strength and improvement in fatigue life of concrete pavements by reuse of scrap steel in concrete. These concrete roads with SSFRC promises an appreciably eminent design life, offer superior serviceability and

  18. Use of accelerated aging to predict behavior of recycled materials in concrete pavements. Physical and environmental comparison of laboratory-aged samples with field pavements

    Energy Technology Data Exchange (ETDEWEB)

    Van der Sloot, H.A. [ECN Clean Fossil Fuels, Petten (Netherlands); Eighmy, T.T.; Cook, R.A.; Gress, D.L.; Coviello, A.; Spear, J.C.M. [University of New Hampshire, Durham, NH (United States); Hover, K.; Pinto, R.; Hobbs, S. [Cornell University, Ithaca, NY (United States); Kosson, D.S.; Sanchez, F. [Vanderbilt University, Nashville, TN (United States); Korhonen, C. [US Army Corps of Engineers Cold Regions Research and Engineering Laboratory, Hanover, NH (United States); Simon, M. [Turner-Fairbank Highway Research Center, McLean, VA (United States)

    2002-11-01

    Future behavior of recycled materials in highway applications is often difficult to predict. Accelerated aging is one means of exploring the long-term physical and environmental performance. Coal fly ash (CFA), routinely used as a cementitious replacement in portland cement concrete pavement, was selected as a model system in an accelerated aging approach. US-20 near Fort Dodge, Iowa, was used as a source of field-aged pavement slab material and concrete mixture proportions. This pavement, constructed in 1987, experienced early failure and distress. The role of CFA, if any, in the failure is not known. Three types of accelerated aging treatments were chosen and applied on laboratory prisms made with the US-20 mixture proportions: arrhenius ageing (AA), cyclic loading, and freeze-thaw exposure. Physical and environmental response variables were used to examine the pavement slab and the aged laboratory prisms. The aging protocol affected both physical and chemical properties of the monoliths. It took about 9 months of elapsed time to age specimens to an equivalent age of about 4 years. The equivalent ages matched well with the time frame seen in the field for the onset of early distress. Most response variables for the aged laboratory prisms and the field samples were similar, suggesting that the aging method reasonably produced a pavement of similar age and distress. The AA treatment produced an unexpected loss of strength, suggesting that the accelerated aging promoted the onset of a deleterious reaction. Distinguishing the source of trace metals in leachates was difficult, for all components (CFA, aggregates, cement) had similar elemental compositions and leachability. The use of both physical and environmental response variables showed linkages between compressive strength, microcracking, fine pore structure, Cl diffusive leaching (efflux related to road slating that increases the concentration of Cl in the monolith), and Ca diffusive leaching (related to change

  19. Network level pavement evaluation with 1 mm 3D survey system

    Directory of Open Access Journals (Sweden)

    Kelvin C.P. Wang

    2015-12-01

    Full Text Available The latest iteration of PaveVision3D Ultra can obtain true 1 mm resolution 3D data at full-lane coverage in all 3 directions at highway speed up to 60 mph. This paper introduces the PaveVision3D Ultra technology for rapid network level pavement survey on approximately 1280 center miles of Oklahoma interstate highways. With sophisticated automated distress analyzer (ADA software interface, the collected 1 mm 3D data provide Oklahoma Department of Transportation (ODOT with comprehensive solutions for automated evaluation of pavement surface including longitudinal profile for roughness, transverse profile for rutting, predicted hydroplaning speed for safety analysis, and cracking and various surface defects for distresses. The pruned exact linear time (PELT method, an optimal partitioning algorithm, is implemented to identify change points and dynamically determine homogeneous segments so as to assist ODOT effectively using the available 1 mm 3D pavement surface condition data for decision-making. The application of 1 mm 3D laser imaging technology for network survey is unprecedented. This innovative technology allows highway agencies to access its options in using the 1 mm 3D system for its design and management purposes, particularly to meet the data needs for pavement management system (PMS, pavement ME design and highway performance monitoring system (HPMS.

  20. State-of-the-art review of the applications of nanotechnology in pavement materials

    Science.gov (United States)

    Castillo, Luis, Jr.

    The use of nanotechnology in pavement materials is one main area that shows great promise and has the potential to change commonly used materials. This will develop more effective solutions to achieve the desired performance. The overall objective of this work is to present a state-of-the-art literature review of nano-science-based principles to improve the performance and, ultimately, the life cycle of transportation construction materials. This work will be organized into two different parts. The first part will consist of six sections: applications of nanotechnology in concrete pavements, applications of nanotechnology in asphalt pavement, application of nanotechnology in general soils, cost-benefit analysis, challenges, and trends to the future. In addition, a current practice review was performed from a literature review that included a questionnaire of the knowledge and opinion about nanotechnology, which included students, general contractors, teachers, engineers, and architects. The second part will deal with the advancement of the application of nanotechnology in pavement materials for different developed countries. Because nanotechnology is relatively a young field in pavement materials, limited research has been conducted in North America, Europe, and Asia. A comparison of the advancement of nano-science-based principles, as applied to the performance and life cycle of transportation materials, for the three continents will be carried out in a summarized manner.

  1. Application of viscoelastic continuum damage approach to predict fatigue performance of Binzhou perpetual pavements

    Directory of Open Access Journals (Sweden)

    Wei Cao

    2016-04-01

    Full Text Available For this study, the Binzhou perpetual pavement test sections constructed in Shandong Province, China, were simulated for long-term fatigue performance using the layered viscoelastic pavement analysis for critical distresses (LVECD finite element software package. In this framework, asphalt concrete was treated in the context of linear viscoelastic continuum damage theory. A recently developed unified fatigue failure criterion that defined the boundaries of the applicable region of the theory was also incorporated. The mechanistic modeling of the fatigue mechanisms was able to accommodate the complex temperature variations and loading conditions of the field pavements in a rigorous manner. All of the material models were conveniently characterized by dynamic modulus tests and direct tension cyclic fatigue tests in the laboratory using cylindrical specimens. By comparing the obtained damage characteristic curves and failure criteria, it is found that mixtures with small aggregate particle sizes, a dense gradation, and modified asphalt binder tended to exhibit the best fatigue resistance at the material level. The 15-year finite element structural simulation results for all the test sections indicate that fatigue performance has a strong dependence on the thickness of the asphalt pavements. Based on the predicted location and severity of the fatigue damage, it is recommended that Sections 1 and 3 of the Binzhou test sections be employed for perpetual pavement design.

  2. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States.

    Science.gov (United States)

    Van Metre, Peter C; Mahler, Barbara J; Wilson, Jennifer T

    2009-01-01

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SigmaPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo[a]pyrene in dustfrom coal-tarsealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. PMID:19209579

  3. PAHs underfoot: contaminated dust from coal-tar sealcoated pavement is widespread in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Van Metre; Barbara J. Mahler; Jennifer T. Wilson [U.S. Geological Survey, Austin, TX (USA)

    2009-01-15

    We reported in 2005 that runoff from parking lots treated with coal-tar-based sealcoat was a major source of polycyclic aromatic hydrocarbons (PAHs) to streams in Austin, Texas. Here we present new data from nine U.S. cities that show nationwide patterns in concentrations of {Sigma}PAHs associated with sealcoat. Dust was swept from parking lots in six cities in the central and eastern U.S., where coal-tar-based sealcoat dominates use, and three cities in the western U.S., where asphalt-based sealcoat dominates use. For six central and eastern cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are 2200 and 27 mg/kg, respectively. For three western cities, median SPAH concentrations in dust from sealcoated and unsealcoated pavement are similar and very low (2.1 and 0.8 mg/kg, respectively). Lakes in the central and eastern cities where pavement was sampled have bottom sediments with higher PAH concentrations than do those in the western cities relative to degree of urbanization. Bottom-sediment PAH assemblages are similar to those of sealcoated pavement dust regionally, implicating coal-tar-based sealcoat as a PAH source to the central and eastern lakes. Concentrations of benzo(a)pyrene in dust from coal-tar sealcoated pavement and adjacent soils greatly exceed generic soil screening levels, suggesting that research on human-health risk is warranted. 30 refs., 4 figs., 2 tabs.

  4. Effects on evaporation rates from different water-permeable pavement designs.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2011-01-01

    The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate.

  5. Impact of Vehicle Class and Tire Pressure on Pavement Performance in MEPDG

    Directory of Open Access Journals (Sweden)

    Mohamed I. E. Attia

    2014-10-01

    Full Text Available The new Mechanistic-Empirical Pavement Design Guide (MEPDG design and analysis procedures defines the exact traffic loading by defining the specific number of each vehicle class and the use of axle load distribution factors instead of the equivalent single axle load (ESAL. The number of traffic inputs (parameters in MEPDG was found to be 17024. This research aimed to evaluate the sensitivity of the predicted flexible pavement distress to vehicle class and tire pressure in MEPDG. To evaluate the impact of vehicle (truck class on pavement sections, different cases of loading were analyzed. For each case, the MEPDG Ver. 1.1 was used to evaluate the effect of tire pressure by solving each case for a tire pressure of 120 and 140 psi. The effect of the traffic parameters on asphalt pavement (AC rutting, base rutting, subgrade rutting, international roughness index (IRI, longitudinal cracking and fatigue (alligator cracking were investigated. It was found that vehicle class distribution (VCD would cause clear impact (comparable to the effect of AADTT level only if the major traffic is of specific class (very light or very heavy. If this is not the case, the vehicle class distribution will not be a significant factor that affects the final design because most of the trucks had similar impact on flexible pavement distresses. The impact of tire pressure is clear on longitudinal cracking, fatigue cracking and AC rutting, and have no significant impact on both base and subgrade rutting.

  6. The Greenhouse Gas Emission from Portland Cement Concrete Pavement Construction in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Yang, Panpan; Huang, Yue

    2016-01-01

    This study proposes an inventory analysis method to evaluate the greenhouse gas (GHG) emissions from Portland cement concrete pavement construction, based on a case project in the west of China. The concrete pavement construction process was divided into three phases, namely raw material production, concrete manufacture and pavement onsite construction. The GHG emissions of the three phases are analyzed by a life cycle inventory method. The CO₂e is used to indicate the GHG emissions. The results show that for 1 km Portland cement concrete pavement construction, the total CO₂e is 8215.31 tons. Based on the evaluation results, the CO₂e of the raw material production phase is 7617.27 tons, accounting for 92.7% of the total GHG emissions; the CO₂e of the concrete manufacture phase is 598,033.10 kg, accounting for 7.2% of the total GHG emissions. Lastly, the CO₂e of the pavement onsite construction phase is 8396.59 kg, accounting for only 0.1% of the total GHG emissions. The main greenhouse gas is CO₂ in each phase, which accounts for more than 98% of total emissions. N₂O and CH₄ emissions are relatively insignificant. PMID:27347987

  7. Development of Performance Models for a Typical Flexible Road Pavement in Nigeria

    Directory of Open Access Journals (Sweden)

    Adebayo Oladipo Owolabi

    2012-09-01

    Full Text Available The results of a study conducted to facilitate the development of road pavement performance models that are appropriate for Nigeria and similar developing countries andcould predict the rate of deterioration over their lifespan have been presented. Comprehensive investigations were carried out on the expressway linking Lagos (the economic nerve centre of Nigeria with Ibadan (the largest city in West Africa - apparently one of the most heavily trafficked roads in the country. Data relating to traffic characteristics, pavement condition ratings, distress types, pavement thickness, roughness index, rainfall and temperature, were collected. Models were developed to determine Pavement Condition Score (PCS and International Roughness Index (IRI. Stepwise Regression was used to analyse the data and quantify the impact of key input parameters on the PCS and IRI. Parameters such as depth of ruts and area of pot holes were found to be statistically significant in predicting PCS while number of patches, length of longitudinal cracks and depth of ruts were statistically significant in predicting IRI. The models can be used for planning road maintenance programs, thus minimizing the need for comprehensive data collection on pavement condition before the maintenance exercise, which is costly and time consuming.

  8. The Greenhouse Gas Emission from Portland Cement Concrete Pavement Construction in China

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Yang, Panpan; Huang, Yue

    2016-01-01

    This study proposes an inventory analysis method to evaluate the greenhouse gas (GHG) emissions from Portland cement concrete pavement construction, based on a case project in the west of China. The concrete pavement construction process was divided into three phases, namely raw material production, concrete manufacture and pavement onsite construction. The GHG emissions of the three phases are analyzed by a life cycle inventory method. The CO2e is used to indicate the GHG emissions. The results show that for 1 km Portland cement concrete pavement construction, the total CO2e is 8215.31 tons. Based on the evaluation results, the CO2e of the raw material production phase is 7617.27 tons, accounting for 92.7% of the total GHG emissions; the CO2e of the concrete manufacture phase is 598,033.10 kg, accounting for 7.2% of the total GHG emissions. Lastly, the CO2e of the pavement onsite construction phase is 8396.59 kg, accounting for only 0.1% of the total GHG emissions. The main greenhouse gas is CO2 in each phase, which accounts for more than 98% of total emissions. N2O and CH4 emissions are relatively insignificant. PMID:27347987

  9. Effects on evaporation rates from different water-permeable pavement designs.

    Science.gov (United States)

    Starke, P; Göbel, P; Coldewey, W G

    2011-01-01

    The urban water balance can be attenuated to the natural by water-permeable pavements (WPPs). Furthermore, WPPs have a 16% higher evaporation rate than impermeable pavements, which can lead to a better urban climate. Evaporation rates from pavements are influenced by the pavement surface and by the deeper layers. By a compared evaporation measurement between different WPP designs, the grain size distribution of the sub-base shows no influence on the evaporation rates in a significant way. On the contrary, a sub-base made of a twin-layer decreases the evaporation by 16% compared to a homogeneous sub-base. By a change in the colour of the paving stone, 19% higher evaporation rates could be achieved. A further comparison shows that the transpiration-effect of the grass in grass pavers increases the evaporation rates more than threefold to pervious concrete pavements. These high evapotranspiration rates can not be achieved with a pervious concrete paving stone. In spite of this, the broad field of application of the pervious concrete paving stone increases the importance in regard to the urban climate. PMID:22049757

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

    Energy Technology Data Exchange (ETDEWEB)

    Santero, Nicholas; Masanet, Eric; Horvath, Arpad

    2010-04-20

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

  11. The Greenhouse Gas Emission from Portland Cement Concrete Pavement Construction in China.

    Science.gov (United States)

    Ma, Feng; Sha, Aimin; Yang, Panpan; Huang, Yue

    2016-06-24

    This study proposes an inventory analysis method to evaluate the greenhouse gas (GHG) emissions from Portland cement concrete pavement construction, based on a case project in the west of China. The concrete pavement construction process was divided into three phases, namely raw material production, concrete manufacture and pavement onsite construction. The GHG emissions of the three phases are analyzed by a life cycle inventory method. The CO₂e is used to indicate the GHG emissions. The results show that for 1 km Portland cement concrete pavement construction, the total CO₂e is 8215.31 tons. Based on the evaluation results, the CO₂e of the raw material production phase is 7617.27 tons, accounting for 92.7% of the total GHG emissions; the CO₂e of the concrete manufacture phase is 598,033.10 kg, accounting for 7.2% of the total GHG emissions. Lastly, the CO₂e of the pavement onsite construction phase is 8396.59 kg, accounting for only 0.1% of the total GHG emissions. The main greenhouse gas is CO₂ in each phase, which accounts for more than 98% of total emissions. N₂O and CH₄ emissions are relatively insignificant.

  12. 公路路面扩宽中新老路面拼接的施工技术%Construction Technology of New and Old Pavement Splicing in Highway Pavement Widening

    Institute of Scientific and Technical Information of China (English)

    涂序广

    2014-01-01

    本文首先分析公路旧路面中存在的病害,然后分析在新旧路面拼接前对旧路面的处理,最后分析新老路面拼接施工技术在公路路面扩宽中的应用,供相关人员参考。%This paper firstly analyzes the existing diseases in old highway pavement, then analyzes the treatment of old pav-ement before the splicing of old and new pavement, final y an-alyzes the application of construction technology of new and old pavement splicing in highway pavement widening, to pro-vide a reference for the related personnel.

  13. 30 Years – 20 State DOTs: Trends in Pavement Management observed through real world Implementation at the State DOT Level

    OpenAIRE

    Zavitski, Jeffrey L.; Piane, Robert R.

    2013-01-01

    Since the first International Conference on Managing Pavement Assets 30 years ago in 1985, there has been continuous enhancement and evolution of pavement management system (PMS) technology to produce more effective recommendations coming out of an agency's PMS. Improvements in data collection, performance measures, deterioration modeling, dynamic segmentation, treatment algorithms, triggering mechanisms and optimization technologies have led to significant improvements in PMS strategy recomm...

  14. Evaluation of a new experimental test procedure to more accurately determine the surface infiltration rate of permeable pavement systems

    NARCIS (Netherlands)

    Lucke, T.; Boogaard, F.; Van den Ven, F.

    2014-01-01

    Permeable pavements are specifically designed to promote the infiltration of stormwater through the paving surface in order to reduce run-off volumes and to improve water quality by removing sediment and other pollutants. However, research has shown that permeable pavements can become clogged over t

  15. Analysing the accuracy of pavement performance models in the short and long terms: GMDH and ANFIS methods

    NARCIS (Netherlands)

    Ziari, H.; Sobhani, J.; Ayoubinejad, J.; Hartmann, T.

    2016-01-01

    The accuracy of pavement performance prediction is a critical part of pavement management and directly influences maintenance and rehabilitation strategies. Many models with various specifications have been proposed by researchers and used by agencies. This study presents nine variables affecting pa

  16. Mechanics based model for predicting structure-induced rolling resistance (SRR) of the tire-pavement system

    Science.gov (United States)

    Shakiba, Maryam; Ozer, Hasan; Ziyadi, Mojtaba; Al-Qadi, Imad L.

    2016-05-01

    The structure-induced rolling resistance of pavements, and its impact on vehicle fuel consumption, is investigated in this study. The structural response of pavement causes additional rolling resistance and fuel consumption of vehicles through deformation of pavement and various dissipation mechanisms associated with inelastic material properties and damping. Accurate and computationally efficient models are required to capture these mechanisms and obtain realistic estimates of changes in vehicle fuel consumption. Two mechanistic-based approaches are currently used to calculate vehicle fuel consumption as related to structural rolling resistance: dissipation-induced and deflection-induced methods. The deflection-induced approach is adopted in this study, and realistic representation of pavement-vehicle interactions (PVIs) is incorporated. In addition to considering viscoelastic behavior of asphalt concrete layers, the realistic representation of PVIs in this study includes non-uniform three-dimensional tire contact stresses and dynamic analysis in pavement simulations. The effects of analysis type, tire contact stresses, pavement viscoelastic properties, pavement damping coefficients, vehicle speed, and pavement temperature are then investigated.

  17. Recycling of radioactive oil sludge waste into pavement brick

    International Nuclear Information System (INIS)

    Malaysia produces about 1450 tons of radioactive oil sludge waste per year and there is an urgent need to find a permanent solution to the storage and disposal of this radioactive waste problem. Several treatment methods such bacteria farming, ultracentrifuge, steam reforming and incineration are currently being used but the core issue of the radioactive material in the oil sludge had not been solved. The paper relates a study on utilizing the radioactive component of the oil sludge and turning them into pavement brick. Characteristic study of this radioactive component by XRD and XRF show that it mainly comprised of quartz and anorthite minerals. While the radioactivity analysis by gamma technique shows that more than 90 % of this radioactivity comes from this soil component with Ra-226 and Ra-228 as the main radionuclides. A vitrified brick was then produced from this sediment by mixing it with low radioactive local red clay. The result also shows that the formation of the vitrified layer may be due high content of K in the red clay. Tensile test on the brick shows that it has more than four times the strength of commercial clay brick. Long duration leaching test on the brick also shows that there is no dissolution of radionuclide from the brick. (author)

  18. Road roughness evaluation using in-pavement strain sensors

    Science.gov (United States)

    Zhang, Zhiming; Deng, Fodan; Huang, Ying; Bridgelall, Raj

    2015-11-01

    The international roughness index (IRI) is a characterization of road roughness or ride quality that transportation agencies most often report. The prevalent method of acquiring IRI data requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor and high cost requirements associated with the existing approaches limit data collection to at most once per year for portions of the national highway system. Agencies characterize roughness only for some secondary roads but much less frequently, such as once every five years, resulting in outdated roughness information. This research developed a real-time roughness evaluation approach that links the output of durable in-pavement strain sensors to prevailing indices that summarize road roughness. Field experiments validated the high consistency of the approach by showing that it is within 3.3% of relative IRI estimates. After their installation and calibration during road construction, the ruggedized strain sensors will report road roughness continuously. Thus, the solution will provide agencies a real-time roughness monitoring solution over the remaining service life of road assets.

  19. Effects of conductive fillers on temperature distribution of asphalt pavements

    International Nuclear Information System (INIS)

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

  20. Effects of conductive fillers on temperature distribution of asphalt pavements

    Science.gov (United States)

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

    2010-05-01

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

  1. Road dust from pavement wear and traction sanding

    Energy Technology Data Exchange (ETDEWEB)

    Kupiainen, K.

    2007-07-01

    Vehicles affect the concentrations of ambient airborne particles through exhaust emissions, but particles are also formed in the mechanical processes in the tire-road interface, brakes, and engine. Particles deposited on or in the vicinity of the road may be re-entrained, or resuspended, into air through vehicle-induced turbulence and shearing stress of the tires. A commonly used term for these particles is 'road dust'. The processes affecting road dust emissions are complex and currently not well known. Road dust has been acknowledged as a dominant source of PM10 especially during spring in the sub-arctic urban areas, e.g. in Scandinavia, Finland, North America and Japan. The high proportion of road dust in sub-arctic regions of the world has been linked to the snowy winter conditions that make it necessary to use traction control methods. Traction control methods include dispersion of traction sand, melting of ice with brine solutions, and equipping the tires with either metal studs (studded winter tires), snow chains, or special tire design (friction tires). Several of these methods enhance the formation of mineral particles from pavement wear and/or from traction sand that accumulate in the road environment during winter. When snow and ice melt and surfaces dry out, traffic-induced turbulence makes some of the particles airborne. A general aim of this study was to study processes and factors underlying and affecting the formation and emissions of road dust from paved road surfaces. Special emphasis was placed on studying particle formation and sources during tire road interaction, especially when different applications of traction control, namely traction sanding and/or winter tires were in use. Respirable particles with aerodynamic diameter below 10 micrometers (PM10) have been the main concern, but other size ranges and particle size distributions were also studied. The following specific research questions were addressed: (i) How do traction

  2. Cytokinin signaling regulates pavement cell morphogenesis in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    Hongjiang Li; Tongda Xu; Deshu Lin; Mingzhang Wen; Mingtang Xie; Jér(o)me Duclercq; Agnieszka Bielach

    2013-01-01

    The puzzle piece-shaped Arabidopsis leaf pavement cells (PCs) with interdigitated lobes and indents is a good model system to investigate the mechanisms that coordinate cell polarity and shape formation within a tissue.Auxin has been shown to coordinate the interdigitation by activating ROP GTPase-dependent signaling pathways.To identify additional components or mechanisms,we screened for mutants with abnormal PC morphogenesis and found that cytokinin signaling regulates the PC interdigitation pattern.Reduction in cytokinin accumulation and defects in cytokinin signaling (such as in ARR7-over-expressing lines,the ahk3cre1 cytokinin receptor mutant,and the ahp12345 cytokinin signaling mutant) enhanced PC interdigitation,whereas over-production of cytokinin and over-activation of cytokinin signaling in an ARR20 over-expression line delayed or abolished PC interdigitation throughout the cotyledon.Genetic and biochemical analyses suggest that cytokinin signaling acts upstream of ROPs to suppress the formation of interdigitated pattern.Our results provide novel mechanistic understanding of the pathways controlling PC shape and uncover a new role for cytokinin signaling in cell morphogenesis.

  3. 沥青路面施工技术浅谈%On construction technology of asphalt pavement

    Institute of Scientific and Technical Information of China (English)

    李伟勇

    2009-01-01

    Combined with wide application of asphalt pavement the reasons caused the premature failure of asphalt pavement axe analyzed, at the same time corresponding key points for asphalt pavement construction are presented. Meanwhile, technological research and innovation prospect of asphalt pavement are elaborated, in order to increase construction quality and prolong the service life of asphalt pavement to ensure investment benefits.%结合沥青路面的广泛应用,分析了沥青路面早期损害形成的原因,提出了沥青路面施工要领,阐述了沥青路面的技术研究和创新前景,以提高沥青路面的质量,延长沥青路面的使用周期,从而提高投资效益.

  4. Modelling of composite concrete block pavement systems applying a cohesive zone model

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    This paper presents a numerical analysis of the fracture behaviour of the cement bound base material in composite concrete block pavement systems, using a cohesive zone model. The functionality of the proposed model is tested on experimental and numerical investigations of beam bending tests...... that the cohesive model is suitable for simulation of crack propagation in cement bound materials subjected to monotonic loading. The methodology implemented gives a new understanding of the mechanical behaviour of cement bound materials which can be used in further refinements of mechanical models for composite...... block pavements. It is envisaged that the methodology implemented in this study can be extended and thereby contribute to the ongoing development of rational failure criteria that can replace the empirical formulas currently used in pavement engineering....

  5. 3-D cohesive finite element model for application in structural analysis of heavy duty composite pavements

    DEFF Research Database (Denmark)

    Skar, Asmus; Poulsen, Peter Noe

    2015-01-01

    The problem of stiffness degradation in composite pavement systems from localised fracture damage in the quasibrittle cement bound granular mixture are today taken into account only by empirical formulas. These formulas deals with a limited number of materials in a restricted range of design...... this paper presents a numerical analysis of the fracture behaviour of cement bound granular mixtures in composite concrete block pavement systems applying a cohesive model. The functionality of the proposed model is compared to experimental investigations of beam bending tests. The pavement is modelled...... as a slab on grade and parameters influencing the response such as geometry, material parameters and loading position are studied and compared to experimental results. It is found that a cohesive model is suitable for the description of the fracture behaviour of cement bound granular mixtures. Moreover...

  6. Monitoring the performance of geosynthetic materials within pavement systems using MEMS

    Science.gov (United States)

    Attoh-Okine, Nii O.; Ayenu-Prah, Albert Y.; Mensah, Stephen A.

    2005-05-01

    Geosynthetic materials have found useful applications when unbound aggregates have been placed on cohesive soil with very weak subgrade. They have also been successfully used in retarding reflective cracking in both flexible and composite pavements. There are many applications of geosynthetics in pavement engineering yet there is considerable lack of understanding in the behavior of the material. Geosynthetic materials exhibit very peculiar properties in the area of tensile strength and reinforcement. MEMS are miniature sensing or actuating devices that can interact with other environments (provided no adverse reaction occurs) to either obtain information or alter it. With remote query capability, it appears such devices can be embedded in pavement systems as testing and monitoring tools. The aim of this paper is to propose both field and laboratory methods for monitoring geotextile performance using MEMS.

  7. Research on segregation evaluation methods of asphalt pavement based on air voids distribution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Eye observation was used to evaluate the segregation degree of asphalt pavement, which was not much creditable. To the asphalt pavement, road surface texture measuring method which has appeared recently can identify gradational segregation; but it can't reflect the influence of the temperature segregation. However,using infrared temperature detector to evaluate the segregation must be taken during paving, which brings much inconvenience. In this paper, measuring the air voids distribution using non-nuclear density gauge to evaluate asphalt pavement segregation was introduced. Result shows that this method can directly reflect the comprehensive results of the two types of segregation in a high efficient and accurate way. Moreover, using the sketch map of segregation area can help to analyze the segregation reason visually.

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

    CERN Document Server

    Chabot, Armelle; Deloffre, Lydie; Duhamel, Denis

    2010-01-01

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

  9. New Technology and Experimental Study on Snow-Melting Heated Pavement System in Tunnel Portal

    Directory of Open Access Journals (Sweden)

    Jinxing Lai

    2015-01-01

    Full Text Available In recent years, with the rapid growth of economy and sharp rise of motor vehicles in China, the pavement skid resistance in tunnel portals has become increasingly important in cold region. However, the deicing salt, snow removal with machine, and other antiskid measures adopted by highway maintenance division have many limitations. To improve the treatment effect, we proposed a new snow-melting approach employing electric heat tracing, in which heating cables are installed in the structural layer of road. Through the field experiment, laboratory experiment, and numerical investigation, structure type, heating power, and preheating time of the flexible pavement heating system in tunnel portal were systematically analyzed, and advantages of electric heat tracing technology in improving the pavement skid resistance in tunnel portal were also presented. Therefore, such new technology, which offers new snow-melting methods for tunnel portal, bridge, mountainous area, and large longitudinal slope in cold region, has promising prospect for extensive application.

  10. Analysis of asphalt pavement structural response from an accelerated loading test

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    This study was to compare theoretical calculation and practical measurement structure response of asphalt pavement. Analysis of the pavement layer moduli was determined from a Back-calculation of Falling Weight Deflectometer (FWD) data and the measured stiffness moduli of asphalt layer cores. The pavement response was calculated using a theoretical model and the measured strain response at the bottom different layers.Layered elastic theory was used to back-calculate the layer moduli and three different theory models were used to forward calculate the strain and deflection. The models were: Layered Elastic Theory (LET), the Method of Equivalent Thicknesses (MET) with linear elastic and the Finite Element Method (FEM) where asphalt layer may be viscoelastic. The results showed that the calculation structure response from FEM was consistent with measured results.

  11. Plastic Damage Model to Evaluate the Fracture Size of Semi-Rigid Base Pavement

    Directory of Open Access Journals (Sweden)

    Cao Peng

    2013-01-01

    Full Text Available A simple supported beam model has been presented to simulate the response of semi-rigid pavement structure, which are consistent of the upper layer, middle layer, bottom layer, base and sub base course, during the cycle vehicle loading. This mechanics model coupled with plastic-damage mechanics model could simulate the limit broken of the pavement structure in condition that soil base layer losing bearing capacity gradually. In the meanwhile, numerical calculations based on preceding mechanics model, using the FEM software ABAQUS, have been used to define the broken size of beam. The results indicated that: when the size of simple supported beam expanded to 10 m, brittle damage could happen immediately, Just the standard vehicle loading (about 0.7 Mpa has been implement once. Objective of this study is to provide a physical and rather concrete explanation for the style and concept of the semi-rigid pavement brittle broken.

  12. Application of cluster analysis to preventive maintenance scheme design of pavement

    Institute of Scientific and Technical Information of China (English)

    ZENG Feng; ZHANG Xiao-ning

    2009-01-01

    To quantitatively identify the maintenance demand for each highway segments in the pavement main-tenance scheme design, a mathematical model of uniform segment division was established and an approach of applying cluster analysis theory to the uniform segment division and evaluation of pavement maintenance demand was proposed.The actual maintenance project of a highway carried out in Guangdong province was cited as an example to demonstrate the validity of the proposed method.It is proved that the cluster analysis can eliminate human factors in classification without being constrained by the quantities of samples, considering muhiple pavement distress indexes and the continuity of samples.Thus it is evident that cluster analysis is an efficient analytical tool in uniform segment division and evaluation of maintenance demand.

  13. The use of reflective and permeable pavements as a potential practice for heat island mitigation and stormwater management

    International Nuclear Information System (INIS)

    To help address the built environmental issues of both heat island and stormwater runoff, strategies that make pavements cooler and permeable have been investigated through measurements and modeling of a set of pavement test sections. The investigation included the hydraulic and thermal performance of the pavements. The permeability results showed that permeable interlocking concrete pavers have the highest permeability (or infiltration rate, ∼0.5 cm s−1). The two permeable asphalt pavements showed the lowest permeability, but still had an infiltration rate of ∼0.1 cm s−1, which is adequate to drain rainwater without generating surface runoff during most typical rain events in central California. An increase in albedo can significantly reduce the daytime high surface temperature in summer. Permeable pavements under wet conditions could give lower surface temperatures than impermeable pavements. The cooling effect highly depends on the availability of moisture near the surface layer and the evaporation rate. The peak cooling effect of watering for the test sections was approximately 15–35 °C on the pavement surface temperature in the early afternoon during summer in central California. The evaporative cooling effect on the pavement surface temperature at 4:00 pm on the third day (25 h after watering) was still 2–7 °C lower compared to that on the second day, without considering the higher air temperature on the third day. A separate and related simulation study performed by UCPRC showed that full depth permeable pavements, if designed properly, can carry both light-duty traffic and certain heavy-duty vehicles while retaining the runoff volume captured from an average California storm event. These preliminarily results indicated the technical feasibility of combined reflective and permeable pavements for addressing the built environment issues related to both heat island mitigation and stormwater runoff management. (letter)

  14. Selected annotated bibliography of the geology of uraniferous and radioactive native bituminous substances, exclusive of coals, in the United States

    Science.gov (United States)

    Jones, Harriet Nell

    1956-01-01

    Native bituminous substances are divided into two groups, 1) bitumens and, 2) pyrobitumens. Bitumens are composed principally of hydrocarbons substantially free from oxygenated bodies, are fusible, and are soluble in carbon disulfide. Native bitumens occur in liquid and solid forms. The native liquid bitumens include all petroleums or crude oils. Native solid bitumens include native waxes such as ozocerite, asphalts or petroleum tars, and asphaltites such as gilsonite and grahamite. Pyrobitumens are composed principally of hydrocarbons which may contain oxygenated bodies. They are infusible and are insoluble, or nearly insoluble, in carbon disulfide. Native pyrobitumens are divided into an oxygen-containing group including peats, lignites, and coals, and an essentially oxygen-free, asphaltic group including such substances as wurtzilite, albertite, impsonite, and ingramite. Thucholites, which are carbonaceous substances that may contain uranium, thorium, and rare earths, commonly are considered to be pyrobitumens. Their compositions are variable and may fall into either the oxygen-containing or oxygen-free group. All varieties of native bituminous substances may be associated with mineral matter. The nomenclature of bitumens and pyrobitumens is used very loosely in the literature. This circumstance arises from the difficulty in recognizing many of these substances by visual examination, and because many of them can be identified accurately only by chemical methods. Inasmuch as some of the chemical procedures are time-consuming and satisfactory analytical methods have not been devised for all these substances, geologists generally have not obtained precise identifications but rather have used names that appeared most appropriate to the circumstances. It is expected that future research will show many substances called "asphaltite," "thucholite," etc., to be incorrectly identified. The nomenclature used by the authors of the various references of this bibliography is

  15. Petrography and geochemistry of Oligocene bituminous coal from the Jiu Valley, Petrosani basin (southern Carpathian Mountains), Romania

    Energy Technology Data Exchange (ETDEWEB)

    Belkin, Harvey E.; Tewalt, Susan J. [U.S. Geological Survey, 956 National Center, Reston, VA 20192 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Stucker, J.D. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); University of Kentucky Department of Earth and Environmental Sciences, Lexington, KY 40506 (United States); O' Keefe, Jennifer M.K. [Morehead State University, Morehead, KY, 40351 (United States); Tatu, Calin A. [University of Medicine and Pharmacy, Department of Immunology, Clinical Laboratory No. 1, Pta. E. Murgu No. 2, RO-1900 Timisoara (Romania); Buia, Grigore [University of Petrosani, Department of Geology, University St. 20, RO-2675 Petrosani (Romania)

    2010-05-01

    Belt samples of Oligocene (Chattian) bituminous coal from 10 underground mines located in the Jiu Valley, Hunedoara County, Petrosani basin, Romania, have been examined and analyzed for proximate and ultimate analysis, major-, minor- and trace-element chemistry, organic petrography, and vitrinite reflectance. The mineral chemistry and mode of occurrence of trace elements also have been investigated using SEM and electron microprobe techniques. Twenty coal beds occur in the Jiu Valley and most of the samples are from bed no. 3, the most productive bed of the Dilja-Uricani Formation of Oligocene age. The Petrosani basin, oriented SW-NE, is 48-km long, 10-km wide at the eastern part and 2-km wide at the western part. The coal mines are distributed along the center of the valley generally following the Jiu de Vest River. Reflectance measurements indicate that the rank of the coals ranges from high-volatile B to high-volatile A bituminous. Overall, rank decreases from the southwest to the northeast. In bed no. 3, R{sub max} varies from 0.75% in the northeast to 0.93% in the southwest. Although, most Oligocene coals in Romania and adjacent countries are lignite in rank, the Jiu Valley bituminous coals have been affected by regional metamorphism and attending hydrothermal fluids related to the Alpine orogenic event. The coals are all dominated by vitrinite; resinite and funginite are important minor macerals in most of the coals. Pyrite and carbonate generally dominate the mineral assemblages with carbonate more abundant in the northwest. Siderite occurs as nodules and masses within the macerals (generally vitrinite). Dolomite and calcite occur as fracture fillings, plant-cell fillings, and in other authigenic forms. Late-stage fracture fillings are siderite, dolomite, calcite, and ankerite. In one instance, two populations of siderite ({proportional_to} 35 and {proportional_to} 45 wt.% FeO) plus ankerite fill a large fracture. Late-stage pyrite framboid alteration is Ni

  16. The Effect of Slope Geometry and Shoulder on Rutting Depth of Flexible Pavement

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Khabiri

    2015-05-01

    Full Text Available The slope and width of the road shoulder are important parameters in geometry of the road pavement. Therefore, it is important to comply with the requirements relating to the slope and width of the shoulders. So that by using the minimum width and slope of the shoulders according to regulations not only stresses and strains transferred to the lower layers will decrease, but also reduces damages in asphalt layers, base, and sub-base. Therefore, it is vital to conduct analyses which can bring good amount of accuracy in assessment of the stress and settlement due to shoulder width and slope. The aim of this study is to investigate the effect of geometry of the shoulder on the performance and behavior of weak or strong pavement. For this purpose, numerical two-dimensional modeling of the road pavement (asphalt،base،sub-base on which the axel load is placed was done using finite element method, ABAQUS, and the effect of the shoulder width and slope on the stresses and settlements caused by the strong and weak pavement have been studied. Also for verification of the software, several obtained field values are compared to each other. The results indicate that the increase in the width of the shoulders and the decrease in the slope will cause in decrease of the stress and settlements in different layers of the roadways. Thus, creating less steeper shoulder and wider pavement can reduce damages and will contribute to the increased safety and sustained life of the pavement.

  17. How to transform an asphalt concrete pavement into a solar turbine

    International Nuclear Information System (INIS)

    Highlights: • We create a system for harvesting energy from asphalt concrete. • We create an artificial porosity in the asphalt concrete. • We connect a chimney to this porosity. • Differences in temperature produce an air flow. • This air flow serves also for cooling down the pavement. - Abstract: Asphalt concrete can absorb a considerable amount of the incident solar radiation. For this reason asphalt roads could be used as solar collectors. There have been different attempts to achieve this goal. All of them have been done by integrating pipes conducting liquid, through the structure of the asphalt concrete. The problem of this system is that all pipes need to be interconnected: if one is broken, the liquid will come out and damage the asphalt concrete. To overcome these limitations, in this article, an alternative concept is proposed:parallel air conduits, where air can circulate will be integrated in the pavement structure. The idea is to connect these artificial pore volumes in the pavement to an updraft or to a downdraft chimney. Differences of temperature between the pavement and the environment can be used to create an air flow, which would allow wind turbines to produce an amount of energy and that would cool the pavement down in summer or even warm it up in winter. To demonstrate that this is possible, an asphalt concrete prototype has been created and basics calculations on the parameters affecting the system have been done. It has been found that different temperatures, volumes of air inside the asphalt and the difference of temperature between the asphalt concrete and the environment are critical to maximize the air flow through the pavement. Moreover, it has been found that this system can be also used to reduce the heat island effect

  18. Comparative Evaluation of Pavement Crack Detection Using Kernel-Based Techniques in Asphalt Road Surfaces

    Science.gov (United States)

    Miraliakbari, A.; Sok, S.; Ouma, Y. O.; Hahn, M.

    2016-06-01

    With the increasing demand for the digital survey and acquisition of road pavement conditions, there is also the parallel growing need for the development of automated techniques for the analysis and evaluation of the actual road conditions. This is due in part to the resulting large volumes of road pavement data captured through digital surveys, and also to the requirements for rapid data processing and evaluations. In this study, the Canon 5D Mark II RGB camera with a resolution of 21 megapixels is used for the road pavement condition mapping. Even though many imaging and mapping sensors are available, the development of automated pavement distress detection, recognition and extraction systems for pavement condition is still a challenge. In order to detect and extract pavement cracks, a comparative evaluation of kernel-based segmentation methods comprising line filtering (LF), local binary pattern (LBP) and high-pass filtering (HPF) is carried out. While the LF and LBP methods are based on the principle of rotation-invariance for pattern matching, the HPF applies the same principle for filtering, but with a rotational invariant matrix. With respect to the processing speeds, HPF is fastest due to the fact that it is based on a single kernel, as compared to LF and LBP which are based on several kernels. Experiments with 20 sample images which contain linear, block and alligator cracks are carried out. On an average a completeness of distress extraction with values of 81.2%, 76.2% and 81.1% have been found for LF, HPF and LBP respectively.

  19. Oxygen demand of aircraft and airfield pavement deicers and alternative freezing point depressants

    Science.gov (United States)

    Corsi, Steven R.; Mericas, Dean; Bowman, George

    2012-01-01

    Aircraft and pavement deicing formulations and other potential freezing point depressants were tested for biochemical oxygen demand (BOD) and chemical oxygen demand (COD). Propylene glycol-based aircraft deicers exhibited greater BOD5 than ethylene glycol-based aircraft deicers, and ethylene glycol-based products had lower degradation rates than propylene glycol-based products. Sodium formate pavement deicers had lower COD than acetate-based pavement deicers. The BOD and COD results for acetate-based pavement deicers (PDMs) were consistently lower than those for aircraft deicers, but degradation rates were greater in the acetate-based PDM than in aircraft deicers. In a 40-day testing of aircraft and pavement deicers, BOD results at 20°C (standard) were consistently greater than the results from 5°C (low) tests. The degree of difference between standard and low temperature BOD results varied among tested products. Freshwater BOD test results were not substantially different from marine water tests at 20°C, but glycols degraded slower in marine water than in fresh water for low temperature tests. Acetate-based products had greater percentage degradation than glycols at both temperatures. An additive component of the sodium formate pavement deicer exhibited toxicity to the microorganisms, so BOD testing did not work properly for this formulation. BOD testing of alternative freezing point depressants worked well for some, there was little response for some, and for others there was a lag in response while microorganisms acclimated to the freezing point depressant as a food source. Where the traditional BOD5 test performed adequately, values ranged from 251 to 1,580 g/kg. Where the modified test performed adequately, values of BOD28 ranged from 242 to 1,540 g/kg.

  20. Effect of structural alteration on the macromolecular properties of brown and bituminous coals, quantitative relationships to the hydrogenation reactivity with tetralin

    Energy Technology Data Exchange (ETDEWEB)

    Kuznetsov, P.N.; Kuznetsova, L.I. [Inst. of Chemistry and Chemico-Metallurgical Processes, Krasnoyarsk (Russian Federation); Bimer, J.; Salbut, P.D. [Inst. of Organic Chemistry, Warszawa (Poland); Gruber, R. [Univ. de Metz (France)

    1996-12-31

    The mobility of macromolecular network has been found to be the fundamental property of both brown and bituminous coals governing the reactivity for hydrogenation with tetralin. In Kansk-Achinsk brown coal, this was primarily affected by carboxylate cross-linking via polyvalent cations like Ca.

  1. Building Asphalt Pavement with SBS-based Compound Added Using a Dry Process in Greenland

    DEFF Research Database (Denmark)

    Lee, Hosin; Kim, Yongjoo; Geisler, Nivi;

    2009-01-01

    -based compound seemed to affect the asphalt mix to become more flexible under the heavy loads. By adding SBS-based compound to asphalt mixtures using a “dry” process, it is expected that the pavement would become more resistant to rutting than a typical asphalt mixture used in Greenland while enduring its arctic...... PMA where it is formulated to melt and blend with asphalt quickly during a batch mixing process. The main objectives of this study are to (1) build asphalt pavement using asphalt mixtures with SBS-based compound added using a “dry” process at the batch plant and (2) evaluate its performance under...

  2. Thermal and Mechanical Properties of Glass Cullet Mixed with Asphalt as Low-Exothermic Pavement Material

    OpenAIRE

    Gotoh, Keinosuke; Yamanaka, Minoru; Saruwatari, Motoki; Mochishita, Teruo

    2001-01-01

    The asphalt pavement contributes to the heat island phenomenon of the city. Thus in order to decrease the temperature of asphalt pavement and to utilize glass cullet as a recycling material as an aggregate, some tests were carried out. In this study the specimen in which the cullet was entrapped in cold-laid paving materials and non-mixing specimen are made respectively, and the surface temperature of each specimen is measured by the thermal video camera. A set of tests have been conducted an...

  3. System Identification Method for Evaluating the Effect of Thickness Error on Backcalculated Pavement Layer Moduli

    Institute of Scientific and Technical Information of China (English)

    ZHONG Yan-hui; WANG Fu-ming; ZHANG Bei; CAI Ying-chun

    2004-01-01

    Based on system identification theory and FWD testing data, the effect of thickness error on backcalculating pavement layer moduli is studied and the method of singular value decomposition (SVD) is presented to solve the morbidity problem of sensitivity matrix in this paper.The results show that the thickness error has great effects on the backcalculated pavement layer moduli. The error of backcalculated moduli can be controlled within the range of ±15% by limiting the thickness error within the range of ±5%.

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

    Science.gov (United States)

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

    2011-11-01

    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.

  5. LOW-NOISE PAVEMENT AS A WAY OF LIMITATION OF TRAFFIC NOISE LEVEL

    Directory of Open Access Journals (Sweden)

    Władysław Gardziejczyk

    2014-11-01

    Full Text Available Road surface can significantlyreduce the trafficnoise level. Depending on the characteristic of the upper surface layers the differences between the maximum rolling noise levels from passing vehicles to reach values about 10 dB (A. A special group is low-noise pavements characterized by the presence of voids above 15%. Application the porous asphalt layers or asphalt mixture type BBTM affects a significantreduction the width of land surrounded the roads where permissible equivalent sound level is exceeded. Such solutions in some cases can replace acoustic barriers. Road pavements with a higher content of voids require proper maintenance because their acoustic performances are reduced during operation.

  6. Construction and Preliminary HVS Tests of Pre-Cast Concrete Pavement Slabs

    OpenAIRE

    Kohler, Erwin R.; du Plessis, Louw; Theyse, Hechter

    2008-01-01

    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) Preparation of a sand bedding layer, (c) Placement of the pre-cast slabs, (d) Application of grout materi...

  7. Influence of High Water Contents on Pavement Layers Stiffness Caused by Flooding

    Directory of Open Access Journals (Sweden)

    Rokitowski Przemysław

    2016-03-01

    Full Text Available Moisture inside the construction of road pavements is the problem for road engineers all around the world. This issue is mentioned in many European or the US papers and studies, but still it needs to be developed. From the road engineers’ point of view, very important for solving above problems are the studies on the influence of water and moisture inside the construction of road pavement during deflection measurements using Falling Weight Deflectometer (FWD. The paper raises this issue by showing a short review of Polish and foreign literature and presenting the first step of research work at the test site on Voivodeship Road 933 in Poland.

  8. Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA).

    Science.gov (United States)

    Idris, Siti Shawalliah; Rahman, Norazah Abd; Ismail, Khudzir

    2012-11-01

    The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value. PMID:22944493

  9. Comparative study of thermal properties of bio-coal from aromatic spent with low rank sub-bituminous coals.

    Science.gov (United States)

    Yadav, Vineet; Baruah, B P; Khare, Puja

    2013-06-01

    In present investigation, biocoal samples were prepared from aromatic plant waste of two perennial grasses, i.e. Cymbopogon flexuosus (lemongrass) and Vetiveria zizanioides (khus) after oil extraction, root of Rosa damascene (rose), bark of Eucalyptus citriodora. These biocoals were characterized by proximate, ultimate, metal, thermogravimetric analysis (TGA), Fourier Transform Infra Red (FTIR) spectroscopy and ash analyses. Activation energies, initial temperature of devolatilization, maximum rate of weight loss (Rmax), fouling, slagging and alkali index were determined on the basis of TGA and ash analysis. These biocoals have good calorific values. There is possibility of slagging and fouling in combustion system but it is not severe. Owing to their similar fuel properties as high sulphur sub-bituminous coal, they can be good candidates for co-firing. Blending of these biocoals with high sulphur coals will serve dual purpose as (i) alternate fuel, and (ii) reduction in SO2 emission. PMID:23603187

  10. Structural characterization of vitrinite-rich and inertinite-rich Permian-aged South African bituminous coals

    Energy Technology Data Exchange (ETDEWEB)

    Van Niekerk, Daniel; Mathews, Jonathan P. [Energy and Mineral Engineering and the EMS Energy Institute, Pennsylvania State University, Hosler Building, University Park, PA 16802 (United States); Pugmire, Ronald J. [Department of Chemical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 (United States); Solum, Mark S. [Department of Chemistry, University of Utah, Salt Lake City, Utah 84112 (United States); Painter, Paul C. [Department of Materials Science and Engineering, Pennsylvania State University, 320 Steidle Building, University Park, PA 16802 (United States)

    2008-12-01

    Two South African coals of the same rank and age, but different in maceral composition were subjected to extensive structural analyses. Inertinite-rich Highveld coal (dominated by semifusinite) and vitrinite-rich Waterberg coal were studied to determine structural differences and similarities. The two coals had similar carbon content ({proportional_to} 84%, dmmf) and vitrinite reflectance (mean-maximum 0.71% for vitrinite-rich vs. 0.75% for inertinite-rich), but differed in hydrogen content (6.23% for vitrinite-rich and 4.53% for inertinite-rich). The inertinite-rich coal was more aromatic (86% for inertinite-rich and 76% for vitrinite-rich) and more polycondensed (indicated by a higher bridgehead carbon content). The inertinite-rich coal was structurally more ordered, with a higher degree of crystalline stacking. Both coals had similar average aromatic cluster sizes (16 carbons for vitrinite-rich and 18 carbons for inertinite-rich) and number of cluster attachments (6 attachments for vitrinite-rich and 5 attachments for inertinite-rich). Mass spectrometry showed that both coals consist of similar molecular weight distributions; ranging to approximately 1700 m/z with a maximum abundance of {proportional_to} 450 m/z for the vitrinite-rich coal and {proportional_to} 550 m/z for the inertinite-rich coal. Compared to the Argonne Premium coals the South African vitrinite-rich Waterberg coal was comparable to the coals in the high-volatile bituminous range and inertinite-rich Highveld was closer to the medium- to low-volatile bituminous range. Both coals were surprisingly similar in bulk characterization, although inertinite-rich Highveld coal was structurally more ordered, hydrogen deficient, and more aromatic. (author)

  11. Enhancing the resolution of gpr spectra for pavement engineering applications

    Science.gov (United States)

    Benedetto, F.; Benedetto, A.

    2012-04-01

    Ground Penetrating Radar (GPR) is a geophysical method that uses radar pulses to image the subsurface. This non-destructive method uses electromagnetic radiation and detects the reflected signals from subsurface structures. It can detect objects, changes in material, and voids and cracks. GPR has many applications in a number of fields. In the field of civil engineering one of the most advanced technologies used for road pavement monitoring is based on the deployment of advanced GPR systems. One of the most relevant causes of road pavement damage is often referable to water intrusion in structural layers. In this context, GPR has been recently proposed as a method to estimate moisture content in a porous medium without preventive calibration. Hence, the development of methods to obtain an estimate of the moisture content is a crucial research field involving economic, social and strategic aspects in road safety for a great number of public and private Agencies. In particular, a recent new approach was proposed to estimate moisture content in a porous medium basing on the theory of Rayleigh scattering, showing a shift of the frequency peak of the GPR spectrum towards lower frequencies as the moisture content increases in the soil. The weakness characterizing this approach is represented by the needs of high resolution signals, whereas GPR spectra are affected by low resolution. Hence, the rising requirement for high resolution leads to specific demands for improved prediction methods. Recently, a new technique combining the response of the conventional fast Fourier transform (FFT, well known for its high-precision receiving signal level) with that of the MUSIC (multiple signal classification) algorithm, well known for its super-resolution capacity has been proposed. This combined method has been proved to obtain a high precision level in quantifying the shift of the frequency peak of the GPR spectrum. This combined method can perform a reliable coarse estimate of

  12. Comparison of Fuzzy AHP and Fuzzy TOPSIS for Road Pavement Maintenance Prioritization: Methodological Exposition and Case Study

    Directory of Open Access Journals (Sweden)

    Yashon O. Ouma

    2015-01-01

    Full Text Available For road pavement maintenance and repairs prioritization, a multiattribute approach that compares fuzzy Analytical Hierarchy Process (AHP and fuzzy Technique for Order Preference by Ideal Situation (TOPSIS is evaluated. The pavement distress data was collected through empirical condition surveys and rating by pavement experts. In comparison to the crisp AHP, the fuzzy AHP and fuzzy TOPSIS pairwise comparison techniques are considered to be more suitable for the subjective analysis of the pavement conditions for automated maintenance prioritization. From the case study results, four pavement maintenance objectives were determined as road safety, pavement surface preservation, road operational status and standards, and road aesthetics, with corresponding depreciating significance weights of W=0.37,0.31,0.22,0.10T. The top three maintenance functions were identified as Thin Hot Mix Asphalt (HMA overlays, resurfacing and slurry seals, which were a result of pavement cracking, potholes, raveling, and patching, while the bottom three were cape seal, micro surfacing, and fog seal. The two methods gave nearly the same prioritization ranking. In general, the fuzzy AHP approach tended to overestimate the maintenance prioritization ranking as compared to the fuzzy TOPSIS.

  13. Discussion on pavement preventive maintenance technology of asphalt pavement%沥青路面预防性养护技术探讨

    Institute of Scientific and Technical Information of China (English)

    胡逢新; 孙奕; 陈培松

    2014-01-01

    Based on analyzing the importance of preventive maintenance concept of asphalt pavement,this paper put forward the methods and steps of preventive maintenance plan selection of asphalt pavement,including preventive maintenance sections divided,preventive maintenance measures selection and preventive maintenance time determination,provided reference for preventive maintenance of asphalt pavement for high-way maintenance management department.%在分析沥青路面预防性养护理念及重要性的基础上,提出了沥青路面预防性养护方案选择的方法和步骤,包括预防性养护路段划分、预防性养护措施选择和预防性养护时机确定,为高速公路养护管理部门进行沥青路面预防性养护提供了参考。

  14. EVALUATION OF RUTTING DEPTH IN FLEXIBLE PAVEMENTS BY USING FINITE ELEMENT ANALYSIS AND LOCAL EMPIRICAL MODEL

    Directory of Open Access Journals (Sweden)

    Alaa H. Abed

    2012-01-01

    Full Text Available The objective of this research is to predict rut depth in local flexible pavements. Predication model in pavement performance is the process that used to estimate the parameter values which related to pavement structure, environmental condition and traffic loading. The different local empirical models have been used to calculate permanent deformation which include environmental and traffic conditions. Finite element analysis through ANSYS computer software is used to analyze two dimensional linear elastic plane strain problem through (Plane 82 elements. Standard Axle Load (ESAL of 18 kip (80 kN loading on an axle with dual set of tires, the wheel spacing is 13.5 in (343 mm with tire contact pressure of 87 psi (0.6 MPa is used. The pavement system is assumed to be an elastic multi-layers system with each layer being isotropic, homogeneous with specified resilient modulus and Poisson ratio. Each layer is to extend to infinity in the horizontal direction and have a finite thickness except the bottom layer. The analysis of results show that, although, the stress level decrease 14% in the leveling course and 27% in the base course, the rut depth is increased by 12 and 28% in that layers respectively because the material properties is changed.

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

    Science.gov (United States)

    Tiğdemir, Mesut

    2014-01-01

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

  16. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    YANG ShaoPu; LI ShaoHua; LU YongJie

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi-cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin's and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  17. Quantifying Evaporation and Evaluating Runoff Estimation Methods in a Permeable Pavement System - abstract

    Science.gov (United States)

    Studies on quantifying evaporation in permeable pavement systems are limited to few laboratory studies that used a scale to weigh evaporative losses and a field application with a tunnel-evaporation gauge. A primary objective of this research was to quantify evaporation for a la...

  18. Reducing greenhouse gas emissions through strategic management of highway pavement roughness

    International Nuclear Information System (INIS)

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

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

    Directory of Open Access Journals (Sweden)

    Halsey Leah E

    2011-02-01

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

  20. Analysis and design of a stabilized fly ash as pavement base material

    Energy Technology Data Exchange (ETDEWEB)

    A. Hilmi Lav; M. Aysen Lav; A. Burak Goktepe [Istanbul Technical University, Istanbul (Turkey). Faculty of Civil Engineering

    2006-11-15

    The main objective of this study is to utilize a class F fly ash as base material in road pavements. Since class F fly ashes do not manifest desirable engineering properties for this purpose, it was decided to stabilize the material with cement. Fly ash may be utilized with or without aggregate as a pavement layer. It should be noted that, in this research only aggregate free stabilized mixtures (fly ash and cement only) were used since the aim was to utilize high volumes of this waste material. Cement content in the stabilized, laboratory prepared samples were between 2%, 4%, 8%, and 10% by total weight. Initially, Texas triaxial test was carried out to justify the suitability of the fly ash as pavement material. Then, mechanical tests were performed to obtain the fundamental properties of the cement stabilized material in order to analyze the pavement structure. Under repeated wheel loading, fatigue cracking is the primary mode of failure of stabilized materials in which cracks initiate due to the repeated tensile stresses. Utilizing an accelerated full scale road test data for the fatigue performance of cement stabilized fly ash and performing a mechanistic-empirical design procedure, required layer thickness for different lives were obtained for different amount of cement content. 32 refs., 13 figs., 3 tabs.

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

    Science.gov (United States)

    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...

  2. Methods to Use Surface Infiltration Tests in Permeable Pavement Systems to Determine Maintenance Frequency

    Science.gov (United States)

    Currently, there is limited guidance on selecting test sites to measure surface infiltration rates in permeable pavement systems to determine maintenance frequency. The ASTM method (ASTM C1701) for measuring infiltration rate of in-place pervious concrete suggest to either (1) p...

  3. Response of pavement to freeze-thaw cycles: Lebanon, New Hampshire, regional airport

    Science.gov (United States)

    Allen, Wendy L.; Quinn, William F.; Keller, Donald; Eaton, Robert A.

    1989-01-01

    In 1978 reconstruction was begun on the runway of the Lebanon Regional Airport, Lebanon, New Hampshire. The runway had experienced severe differential frost heaving and cracking during the previous three winters, which had resulted in closure of the facility during periods of extreme roughness. Temperature sensors were placed within the newly constructed pavement sections, and during the winters of 1979, 1980, and 1982 temperature data were recorded, and level surveys and repeated plate bearing tests were performed in order to provide data for the investigation. The three pavement sections were constructed to investigate the effect of section thickness on the level of frost protection provided. The sections consisted of 4 in. of asphalt concrete, 6 in. of crushed gravel and 22,30 dn 38 in. of well-graded sand subbase material. The 48-in section provided the highest level of frost protection to the subgrade. However, all three pavement sections maintained resilient stiffness values during the spring thaw period on the order of two to three times that of the pavement before reconstruction. Also, frost heave in all sections was reduced to levels that would not cause difficulty for aircraft using the facility.

  4. Dynamic Response of a Rigid Pavement Plate Based on an Inertial Soil.

    Science.gov (United States)

    Gibigaye, Mohamed; Yabi, Crespin Prudence; Alloba, I Ezéchiel

    2016-01-01

    This work presents the dynamic response of a pavement plate resting on a soil whose inertia is taken into account in the design of pavements by rational methods. Thus, the pavement is modeled as a thin plate with finite dimensions, supported longitudinally by dowels and laterally by tie bars. The subgrade is modeled via Pasternak-Vlasov type (three-parameter type) foundation models and the moving traffic load is expressed as a concentrated dynamic load of harmonically varying magnitude, moving straight along the plate with a constant acceleration. The governing equation of the problem is solved using the modified Bolotin method for determining the natural frequencies and the wavenumbers of the system. The orthogonal properties of eigenfunctions are used to find the general solution of the problem. Considering the load over the center of the plate, the results showed that the deflections of the plate are maximum about the middle of the plate but are not null at its edges. It is therefore observed that the deflection decreased 18.33 percent when the inertia of the soil is taken into account. This result shows the possible economic gain when taking into account the inertia of soil in pavement dynamic design. PMID:27382639

  5. Automatic processing and modeling of GPR data for pavement thickness and properties

    Science.gov (United States)

    Olhoeft, Gary R.; Smith, Stanley S., III

    2000-04-01

    A GSSI SIR-8 with 1 GHz air-launched horn antennas has been modified to acquire data from a moving vehicle. Algorithms have been developed to acquire the data, and to automatically calibrate, position, process, and full waveform model it without operator intervention. Vehicle suspension system bounce is automatically compensated (for varying antenna height). Multiple scans are modeled by full waveform inversion that is remarkably robust and relatively insensitive to noise. Statistical parameters and histograms are generated for the thickness and dielectric permittivity of concrete or asphalt pavements. The statistical uncertainty with which the thickness is determined is given with each thickness measurement, along with the dielectric permittivity of the pavement material and of the subgrade material at each location. Permittivities are then converted into equivalent density and water content. Typical statistical uncertainties in thickness are better than 0.4 cm in 20 cm thick pavement. On a Pentium laptop computer, the data may be processed and modeled to have cross-sectional images and computed pavement thickness displayed in real time at highway speeds.

  6. Arabidopsis FH1 Formin Affects Cotyledon Pavement Cell Shape by Modulating Cytoskeleton Dynamics.

    Science.gov (United States)

    Rosero, Amparo; Oulehlová, Denisa; Stillerová, Lenka; Schiebertová, Petra; Grunt, Michal; Žárský, Viktor; Cvrčková, Fatima

    2016-03-01

    Plant cell morphogenesis involves concerted rearrangements of microtubules and actin microfilaments. We previously reported that FH1, the main Arabidopsis thaliana housekeeping Class I membrane-anchored formin, contributes to actin dynamics and microtubule stability in rhizodermis cells. Here we examine the effects of mutations affecting FH1 (At3g25500) on cell morphogenesis and above-ground organ development in seedlings, as well as on cytoskeletal organization and dynamics, using a combination of confocal and variable angle epifluorescence microscopy with a pharmacological approach. Homozygous fh1 mutants exhibited cotyledon epinasty and had larger cotyledon pavement cells with more pronounced lobes than the wild type. The pavement cell shape alterations were enhanced by expression of the fluorescent microtubule marker GFP-microtubule-associated protein 4 (MAP4). Mutant cotyledon pavement cells exhibited reduced density and increased stability of microfilament bundles, as well as enhanced dynamics of microtubules. Analogous results were also obtained upon treatments with the formin inhibitor SMIFH2 (small molecule inhibitor of formin homology 2 domains). Pavement cell shape in wild-type (wt) and fh1 plants in some situations exhibited a differential response towards anti-cytoskeletal drugs, especially the microtubule disruptor oryzalin. Our observations indicate that FH1 participates in the control of microtubule dynamics, possibly via its effects on actin, subsequently influencing cell morphogenesis and macroscopic organ development. PMID:26738547

  7. Monitoring Strategies in Permeable Pavement Systems to Optimize Maintenance Scheduling - abstract

    Science.gov (United States)

    As the surface in a permeable pavement system clogs and performance decreases, maintenance is required to preserve the design function. Currently, guidance is limited for scheduling maintenance on an as needed basis. Previous research has shown that surface clogging in a permea...

  8. Internal hydrological mechanism of permeable pavement and interaction with subsurface water - slides

    Science.gov (United States)

    A permeable pavement site located at the Seitz Elementary School on Fort Riley, Kansas was selected for this study. An 80-space parking lot was built behind the school as part of an EPA ORD collaboration with the U.S. Army under the Net Zero program. The parking lot design includ...

  9. Internal hydrological mechanism of permeable pavement and interaction with subsurface water

    Science.gov (United States)

    Many communities are implementing green infrastructure stormwater control measures (SCMs) in urban environments across the U.S. to mimic pre-urban, natural hydrology more closely. Permeable pavement is one SCM infrastructure that has been commonly selected for both new and retro...

  10. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Directory of Open Access Journals (Sweden)

    Mesut Tiğdemir

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

  11. Re-evaluation of the AASHTO-flexible pavement design equation with neural network modeling.

    Science.gov (United States)

    Tiğdemir, Mesut

    2014-01-01

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

  12. Dynamics of vehicle-pavement coupled system based on a revised flexible roller contact tire model

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A revised flexible roller contact tire model (RFRC tire model) is proposed, which considers not only the geometric and flexible filtering effect, but also tire damping and pavement displacement. A vehi- cle-pavement coupled system is modeled as a two DOF oscillator moving along a simply supported beam on a linear viscoelastic foundation. By using the Galerkin’s and Direct Integral method, dynamical responses of the vehicle-pavement coupled system are obtained based on the RFRC tire model and the traditional single point contact tire model (SPC tire model). The simulation results are compared with test data and the validity of the proposed RFRC tire model is verified. Differences between the two models are also investigated. It is found that the dynamical behaviors for both models agree with each other quite well when road surface roughness is a long harmonic wave. On the other hand, they are different under short harmonic wave or impulse road excitation. Thus the RFRC tire model should be used to compute the tire force and investigate dynamical responses of vehicle and pavement.

  13. A mathematical model for the distribution of heat through pavement layers in Makkah roads

    Directory of Open Access Journals (Sweden)

    Mohammad H. Alawi

    2014-01-01

    Full Text Available Pavement layers are the predominant type used in Saudi Arabian roads, it is necessary to have roads with excellent pavements from the structural and functional points of view. The heat distribution is highly influential in the pavement’s structural design and has a large effect on indirect tensile stiffness modulus (ITSM. In this study, heat distribution through all the layers of the pavement will be studied. The mathematical technique used in the present analysis is the parameter-group transformation, the linear transformation group approach is developed to solve the heat diffusion problems in the presence of thermal conductivity and heat capacity. These problems obeyed an unusual power law relation, subject to nonlinear boundary conditions due to radiation exchange at the interface according to the fourth power law. The group theoretic approach shrinks the number of independent variables by one, therefore a nonlinear ordinary differential equation is obtained instead of the given nonlinear partial differential. The Runge–Kutta shooting method is used to solve the resulting nonlinear ordinary differential equation to determine heat distribution in the pavement layers of “Makkah” roads.

  14. Agency and Design: Pavement Failure in the Transmilenio Project, Bogotá, Colombia

    DEFF Research Database (Denmark)

    Pineda, Andres Felipe Valderrama

    Transmilenio is the world’s first mass rapid bus transit system designed and built for the city of Bogotá, Colombia. Its first phase was developed and built during the years 1998-2000. The concrete pavement of the cities main corridor, Avenida Caracas and Autopista Norte, was designed and re...

  15. A hybrid strategy in selecting diverse combinations of innovative sustainable materials for asphalt pavements

    Directory of Open Access Journals (Sweden)

    Baron Colbert

    2016-04-01

    Full Text Available This project integrates recent innovations of recycled materials used in designing and building sustainable pavements. An increasing environmental awareness and the demand for improving economic and construction efficiencies, through measures such as construction warrantees and goals to reduce air pollution under the Kyoto Protocol, have increased the efforts to implement sustainable materials in roadways. The objective of this research is to develop a systematic approach toward selecting optimum combinations of sustainable materials for the construction of asphalt pavements. The selected materials, warm mix asphalt (WMA, recycled asphalt shingles (RAS, and reclaimed asphalt pavement (RAP were incorporated in this study. The results of this research are intended to serve as guidelines in the selection of the mixed sustainable materials for asphalt pavements. The approach developed from this project draws upon previous research efforts integrating graphical modeling with optimizing the amount of sustainable materials based on the performance. With regard to moisture susceptibility and rutting potential test results, as well as the MIM analysis based on a 95% confidence interval, the rutting performance and moisture susceptibility of asphalt mixtures are not significantly different regardless of the percentages of RAS, RAP, or WMA. The optimum mixture choices could be made by the plant emission rankings with consideration of the optimal WMA types, percentages of RAS/RAP, and WMA production temperatures. The WMA mixtures prepared with 75% RAP and Advera® WMA have produced the lowest CO2 emissions among the investigated mixture types.

  16. International study on the long-term efficiency of stormwater infiltration by permeable pavements

    NARCIS (Netherlands)

    Boogaard, Floris; Lucke, T.; Wentink, R.; Dierkes, C.; Akkerman, O.

    2015-01-01

    Although permeable pavements have been used all over the world in recent years to infiltrate and treat stormwater, only limited research has been undertaken to investigate and compare the long-term performance of these sustainable urban drainage system devices. This paper presents the results of an

  17. Reducing greenhouse gas emissions through strategic management of highway pavement roughness

    Science.gov (United States)

    Wang, Ting; Harvey, John; Kendall, Alissa

    2014-03-01

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

  18. Dynamic Response of a Rigid Pavement Plate Based on an Inertial Soil

    Science.gov (United States)

    Gibigaye, Mohamed; Yabi, Crespin Prudence; Alloba, I. Ezéchiel

    2016-01-01

    This work presents the dynamic response of a pavement plate resting on a soil whose inertia is taken into account in the design of pavements by rational methods. Thus, the pavement is modeled as a thin plate with finite dimensions, supported longitudinally by dowels and laterally by tie bars. The subgrade is modeled via Pasternak-Vlasov type (three-parameter type) foundation models and the moving traffic load is expressed as a concentrated dynamic load of harmonically varying magnitude, moving straight along the plate with a constant acceleration. The governing equation of the problem is solved using the modified Bolotin method for determining the natural frequencies and the wavenumbers of the system. The orthogonal properties of eigenfunctions are used to find the general solution of the problem. Considering the load over the center of the plate, the results showed that the deflections of the plate are maximum about the middle of the plate but are not null at its edges. It is therefore observed that the deflection decreased 18.33 percent when the inertia of the soil is taken into account. This result shows the possible economic gain when taking into account the inertia of soil in pavement dynamic design. PMID:27382639

  19. 高寒地区沥青路面设计%Asphalt Pavement Design in High Latitudeand Cold Regions

    Institute of Scientific and Technical Information of China (English)

    程军勤

    2015-01-01

    Combining with the development of highway pavement and key factors in pavement design,the selection of pavement structural layers in high latitude and cold regions is discussed in this paper,which can be seen as preference to similar projects.%从青海省公路路面设计的发展及设计中的关键要素等方面入手,探讨了高寒地区路面各结构层的选择,为同类地区的路面设计提供参考。

  20. Characterization of pavement texture by means of height difference correlation and relation to wet skid resistance

    Directory of Open Access Journals (Sweden)

    Stefan Torbruegge

    2015-04-01

    We deduce within this article the correlation between classical surface roughness parameters and the parameter set of self-affine surfaces. These parameters allow for a detailed understanding of the relationship between pavement texture and its wet skid resistance. We present wet skid resistance measurements with the British pendulum and a linear friction tester device on different pavement textures. We demonstrate that the so-called estimated texture depth does not correlate to the surface skid resistance measured with the British pendulum. Finally, we deduce a dependency of wet skid resistance on pavement texture which is supported by current models for hysteresis friction.