Global ETD Search

1	A case study of pavement failures in Central Texas due to expansive soils Jouben, Andrew James 02 February 2015 (has links) The volumetric strains induced in the subgrade of a pavement or light foundation by the swelling and shrinking of expansive soils routinely cause distress, and ultimately failure of the structure. Additionally, shallow embankment slope failures have also been shown to cause damage to pavements throughout Central Texas. As such, the main objective of this project was to correlate observed field pavement distresses, attributed to expansive soil movement, to results obtained from laboratory forced ventilated swell-shrink tests. Additionally, the author wished to analyze if edge distresses could be attributed to shallow slope stability failures. This research was conducted with the cooperation of the Capital Area Pavement Engineering Council (CAPEC); a multi-agency entity with the goal of mitigating or eliminating historical pavement distresses with roadways constructed over highly expansive soils. Forced ventilated swell-shrink tests were conducted on specimens from six specific test section locations. In general, the magnitude of shrinkage strains measured in the laboratory were larger for specimens obtained from severely distressed roadway sections. / text Expansive soil Pavement distresses
2	Estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner e validação de resultados. / Research on the applicability of the functional inventory of rigid pavements with the use of Pavement Scanner equipment and results validation. Scabello, Daniel Torres 20 April 2018 (has links) O gerenciamento de uma malha rodoviária engloba avaliações constantes das condições estruturais e, principalmente, funcionais. Assim sendo, uma forma de coleta automatizada, realizada em velocidades de tráfego, em que a influência humana possa ser desconsiderada, está em desenvolvimento na engenharia rodoviária brasileira, assim como é visto internacionalmente. O presente trabalho tem como objetivo a contribuição para o processo de avaliação funcional de pavimentos através do estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner. Para tanto, após a revisão bibliográfica sobre a sistemática de inventário de pavimentos rígidos e também sobre o equipamento Pavement Scanner, seções testes foram definidas e avaliadas de acordo com o método tradicional de levantamento da superfície do pavimento (ICP - DNIT 062/PRO, DNIT 060/PRO), o método volumétrico tradicional de mancha de areia para avaliação de macrotextura (ASTM E 965/96), através de imageamento com análise de imagens obtidas no trecho e sob a utilização do equipamento Pavement Scanner. Com os resultados foi realizada uma análise estatística destas técnicas utilizadas, demonstrando a viabilidade de utilização do equipamento e do procedimento de análise adotado. / The management of a road network encompasses constant assessments of structural conditions and, above all, functional conditions. Thus, a form of automated survey, carried out at traffic speeds, in which human influence can be unconsidered, is under development in Brazilian road engineering, as it is seen internationally. This present work aims to contribute to the process of functional assessment of pavements through the study of applicability of the functional inventory process of rigid pavements with the use of Pavement Scanner equipment. In order to do so, after the literature review of rigid pavement inventory and Pavement Scanner equipment, test sections were defined and evaluated according to the traditional method of surface survey (ICP - DNIT 062 / PRO, DNIT 060 / PRO), the traditional sand patch volumetric method for the evaluation of macrotexture (ASTM E 965/96), through imaging analysis from the test sections and under the use of Pavement Scanner equipment. With the results, a statistical analysis of these techniques were performed, demonstrating the feasibility of using the equipment and the analysis procedure adopted. Cimento Portland Concrete pavement distresses Equipment for functional assessment Functional evaluation of pavements Macrotexture Pavement distresses Pavement Scanner Pavimentação de concreto (Defeito) Pavimentos rígidos Portland Cement
3	Estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner e validação de resultados. / Research on the applicability of the functional inventory of rigid pavements with the use of Pavement Scanner equipment and results validation. Daniel Torres Scabello 20 April 2018 (has links) O gerenciamento de uma malha rodoviária engloba avaliações constantes das condições estruturais e, principalmente, funcionais. Assim sendo, uma forma de coleta automatizada, realizada em velocidades de tráfego, em que a influência humana possa ser desconsiderada, está em desenvolvimento na engenharia rodoviária brasileira, assim como é visto internacionalmente. O presente trabalho tem como objetivo a contribuição para o processo de avaliação funcional de pavimentos através do estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner. Para tanto, após a revisão bibliográfica sobre a sistemática de inventário de pavimentos rígidos e também sobre o equipamento Pavement Scanner, seções testes foram definidas e avaliadas de acordo com o método tradicional de levantamento da superfície do pavimento (ICP - DNIT 062/PRO, DNIT 060/PRO), o método volumétrico tradicional de mancha de areia para avaliação de macrotextura (ASTM E 965/96), através de imageamento com análise de imagens obtidas no trecho e sob a utilização do equipamento Pavement Scanner. Com os resultados foi realizada uma análise estatística destas técnicas utilizadas, demonstrando a viabilidade de utilização do equipamento e do procedimento de análise adotado. / The management of a road network encompasses constant assessments of structural conditions and, above all, functional conditions. Thus, a form of automated survey, carried out at traffic speeds, in which human influence can be unconsidered, is under development in Brazilian road engineering, as it is seen internationally. This present work aims to contribute to the process of functional assessment of pavements through the study of applicability of the functional inventory process of rigid pavements with the use of Pavement Scanner equipment. In order to do so, after the literature review of rigid pavement inventory and Pavement Scanner equipment, test sections were defined and evaluated according to the traditional method of surface survey (ICP - DNIT 062 / PRO, DNIT 060 / PRO), the traditional sand patch volumetric method for the evaluation of macrotexture (ASTM E 965/96), through imaging analysis from the test sections and under the use of Pavement Scanner equipment. With the results, a statistical analysis of these techniques were performed, demonstrating the feasibility of using the equipment and the analysis procedure adopted. Cimento Portland Pavimentação de concreto (Defeito) Pavimentos rígidos Concrete pavement distresses Equipment for functional assessment Functional evaluation of pavements Macrotexture Pavement distresses Pavement Scanner Portland Cement
4	Using Mixture Design Data and Existing Prediction Models to Evaluate the Potential Performance of Asphalt Pavements January 2020 (has links) abstract: Several ways exist to improve pavement performance over time. One suggestion is to tailor the asphalt pavement mix design according to certain specified specifications, set up by each state agency. Another option suggests the addition of modifiers that are known to improve pavement performance, such as crumb rubber and fibers. Nowadays, improving asphalt pavement structures to meet specific climate conditions is a must. In addition, time and cost are two crucial settings and are very important to consider; these factors sometimes play a huge role in modifying the asphalt mix design needed to be set into place, and therefore alter the desired pavement performance over the expected life span of the structure. In recent studies, some methods refer to predicting pavement performance based on the asphalt mixtures volumetric properties. In this research, an effort was undertaken to gather and collect most recent asphalt mixtures’ design data and compare it to historical data such as those available in the Long-Term Pavement Performance (LTPP), maintained by the Federal Highway Administration (FHWA). The new asphalt mixture design data was collected from 25 states within the United States and separated according to the four suggested climatic regions. The previously designed asphalt mixture designs in the 1960’s present in the LTPP Database implemented for the test sections were compared with the recently designed pavement mixtures gathered, and pavement performance was assessed using predictive models. Three predictive models were studied in this research. The models were related to three major asphalt pavement distresses: Rutting, Fatigue Cracking and Thermal Cracking. Once the performance of the asphalt mixtures was assessed, four ranking criteria were developed to support the assessment of the mix designs quality at hand; namely, Low, Satisfactory, Good or Excellent. The evaluation results were reasonable and deemed acceptable. Out of the 48 asphalt mixtures design evaluated, the majority were between Satisfactory and Good. The evaluation methodology and criteria developed are helpful tools in determining the quality of asphalt mixtures produced by the different agencies. They provide a quick insight on the needed improvement/modification against the potential development of distress during the lifespan of the pavement structure. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2020 Transportation Materials Science Asphalt pavements database HMA LTPP pavement distresses predictive models
5	Verification of Mechanistic-Empirical Pavement Deterioration Models Based on Field Evaluation of In-Service Pavements Gramajo, Carlos Rafael 15 July 2005 (has links) This thesis focused on using a detailed structural evaluation of seven (three flexible and four composite) high performance in-service pavements designated as high-priority routes to verify the applicability of the Mechanistic Empirical (M-E) models to high performance pavements in the Commonwealth of Virginia. The structural evaluation included: determination of layer thicknesses (from cores, GPR and historical data), pavement condition assessment based on visual survey, estimation of layer moduli from FWD analysis as well as material characterization. One of the main objectives of this study was to utilize the results from the backcalculated moduli in order to predict the performance of this group of pavement structures using the M-E Design Guide Software. This allowed a quick verification of the performance prediction models used by comparing their outcome with the current condition. The in-depth structural evaluation of the three flexible and four composite pavements showed that all the sites are structurally sound. The investigation also confirmed that the use of GPR to determine layer thicknesses and the comparison with a minimum number of cores is a helpful tool for pavement structural evaluation. Despite some difficulties performing the backcalculation analysis for complex structures, the obtained results were considered reasonable and were useful in estimating the current structural adequacy of the evaluated structures. The comparison of the measured distresses with those predicted by the M-E Design Guide software showed poor agreement. In general, the predicted distresses were higher than the distresses actually measured. However, there was not enough evidence to determine whether this is due to errors in the prediction models or software, or because of the use of defaults material properties, specially for the AC layers. It must be noted that although an in-depth field evaluation was performed, only Level 3 data was available for many of the input parameters. The results suggest that significant calibration and validation will be required before implementation of the M-E Design Guide. / Master of Science backcalculation pavement evaluation pavement structural capacity mechanistic-empirical design pavement distresses performance prediction
6	A Pavement Structural Capacity Index for Use in Network-level Evaluation of Asphalt Pavements Bryce, James Matthew 05 April 2012 (has links) The objective of this research was to develop a structural index for use in network-level pavement evaluation, which facilitates the inclusion of the pavements structural condition in many pavement management applications. The primary goal of network-level pavement management is to maintain an acceptable condition of the pavements within the network using available, and often limited, resources. Pavement condition is described in terms of functional and structural condition, and the current widespread practice is to only consider the functional condition during network-level evaluation. This practice results in treatments that are often under-designed or over-designed when considered in more detail at the project-level. The disagreement may be reduced by considering the structural capacity of the pavements as part of the network-level decision process. This research was conducted by identifying various structural indices, choosing an appropriate index, and then applying data from the state of Virginia to modify the index and show example application for the index. It was concluded that the Modified Structural Index best met the research objectives. Project-level and network level data were used to conduct a sensitivity analysis on the index, and example applications were presented. The results indicated that the inclusion of the Modified Structural Index into the network-level decision process minimized the errors between network-level and project-level decisions, when compared to the current network-level decision making process. Furthermore, the Modified Structural Index could be used in various pavement management applications, such as network-level structural screening, and developing structural performance measures. / Master of Science pavement structural capacity Pavement evaluation performance prediction pavement distresses pavement management
7	Evaluation of the Automated Laser Rut Measurement System Used by the Ohio Department of Transportation Hoffman, Bradley R. January 2011 (has links) No description available. Civil Engineering Engineering Transportation Transportation Planning LRMS laser measurement profiler profilometer pavement ODOT rut rutting pavement distresses laser rut measurement system INO
8	Response of concrete pavements under moving vehicular loads and environmental effects Darestani, Mostafa Yousefi January 2007 (has links) The need for modern transportation systems together with the high demand for sustainable pavements under applied loads have led to a great deal of research on concrete pavements worldwide. Development of finite element techniques enabled researchers to analyse the concrete pavement under a combination of axle group loadings and environmental effects. Consequently, mechanistic approaches for designing of concrete pavements were developed based on results of finite element analyses. However, unpredictable failure modes of concrete pavements associated with expensive maintenance and rehabilitation costs have led to the use of empiricalmechanistic approach in concrete pavement design. Despite progressive knowledge of concrete pavement behaviour under applied loads, concrete pavements still suffer from deterioration due to crack initiation and propagation, indicating the need for further research. Cracks can be related to fatigue of the concrete and/or erosion of materials in sub-layers. Although longitudinal, midedge and corner cracks are the most common damage modes in concrete pavements, Austroads method for concrete pavement design was developed based on traditional mid-edge bottom-up transverse cracking introduced by Packard and Tayabji (1985). Research presented in this thesis aims to address the most common fatigue related distresses in concrete pavements. It uses comprehensive finite element models and analyses to determine the structural behaviour of concrete pavements under vehicular loads and environmental effects. Results of this research are supported by laboratory tests and an experimental field test. Results of this research indicate that the induced tensile stresses within the concrete pavement are significantly affected by vehicle speed, differential temperature gradient and loss of moisture content. Subsequently, the interaction between the above mentioned factors and concrete damage modes are discussed. Typical dynamic amplifications of different axle groups are presented. A new fatigue test setup is also developed to take into consideration effects of pavement curvature on fatigue life of the concrete. Ultimately, results of the research presented in this thesis are employed to develop a new guide for designing concrete pavements with zero maintenance of fatigue damage. dynamic analysis dynamic amplification finite element analysis finite element model static analysis axle group loads critical axle group configuration critical position of axle groups tyre pavement interaction stress distribution fatigue failure concrete pavement distresses corner cracking longitudinal cracking transverse cracking top-down cracking bottom-up cracking boundary conditions debonding layer temperature effects loss of moisture contents shrinkage effects curling induced stress warping stress pavement curvature field test laboratory text experimental study truck load JPCP JRCP CRCP SAST SADT TAST TADT TRDT QADT

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