Download or read book Improved Prediction of Performance of Asphalt Mixes Using a Creep Constitutive Model written by Lance Alan Roberts and published by . This book was released on 2014 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project investigated the application of the Brazilian indirect tension strength, constant mean stress, static triaxial compression, and static triaxial creep tests for testing asphalt mixes. Two different asphalt mixes, provided by the South Dakota Department of Transportation (SDDOT), were subjected to the laboratory testing program. Initially, the testing program was to provide the necessary data to conduct advanced viscoplastic modeling of asphalt pavement using finite element software. However, the time-dependent behavior of the asphalt mixes was more complex than anticipated and fitting of the creep test data to a constitutive model was not possible. Instead, the results of the testing program were used to demonstrate a qualitative approach to determine the potential performance of an asphalt mix. In addition, comparing the performance between the two asphalt mixes was accomplished. Recommendations are provided for conducting specific additional testing to further understand how such a program could be used to qualitatively predict asphalt pavement performance.
Download or read book Development and Validation of Performance Prediction Models and Specifications for Asphalt Binders and Paving Mixes written by Robert L. Lytton and published by Strategic Highway Research Program (Shrp). This book was released on 1993 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: A result of the Strategic Highway Research Program's asphalt research is the development of performance-based specifications for asphalt binders and mixtures to control 3 distress modes: rutting; fatigue cracking; and thermal cracking. The SHRP A-005 project developed detailed pavement performance models to support these binder and mixture specifications and performance-based mixture designs. This report documents the findings of this extensive research effort and provides supporting data for the performance-based specifications and mixture design procedure called SUPERPAVE. The A-005 contract developed and used a sophisticated, mechanistic-based pavement performance model to define the relationships between asphalt binder and mixture properties and pavement distress. A comprehensive pavement performance model was developed that predicts the amount of fatigue cracking, thermal cracking and rutting in asphalt concrete pavements with time, using results from the accelerated laboratory tests. The pavement performance models for each distress were also used to confirm the relevant binder and mixture properties established by other SHRP contractors. The model has 3 parts: a mixture evaluation model; a pavement response model; and a pavement distress model.
Download or read book Improving the Sustainability of Asphalt Pavements Through Developing a Predictive Model with Fundamental Material Properties written by Rashid Kamel Abu Al-Rub and published by . This book was released on 2009 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study presents the numerical implementation and validation of general constitutive relationships for describing the nonlinear behavior of asphalt concrete mixes. These constitutive relationships incorporate nonlinear viscoelasticity and viscoplasticity to predict the recoverable and irrecoverable responses, respectively. The nonlinear viscoelastic deformation is modeled using Schapery's model; while the irrecoverable component is represented using Perzyna's viscoplasticity theory with an extended Drucker-Prager yield surface and plastic potential that is modified to capture the distinction between the compressive and extension behavior of asphalt mixes. The nonlinear viscoelastic and viscoplastic model is represented in a numerical formulation and implemented in a finite element (FE) code using a recursive-iterative algorithm for nonlinear viscoelasticity and the radial return algorithm for viscoplasticity. Then, the model is used to analyze the nonlinear viscoelastic and viscoplastic behavior of asphalt mixtures subjected to single creep recovery tests at different stress levels and temperatures. This experimental analysis includes the separation of the viscoelastic and viscoplastic strain components. Based on this separation, a systematic procedure is presented for the identification of the material parameters associated with the nonlinear viscoelastic and viscoplastic constitutive equations. Finally, the model is applied and verified against a set of creep-recovery tests on hot mix asphalt at different stress levels and temperatures.
Download or read book Advances in Materials and Pavement Prediction written by Eyad Masad and published by CRC Press. This book was released on 2018-07-16 with total page 879 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Materials and Pavement Performance Prediction contains the papers presented at the International Conference on Advances in Materials and Pavement Performance Prediction (AM3P, Doha, Qatar, 16- 18 April 2018). There has been an increasing emphasis internationally in the design and construction of sustainable pavement systems. Advances in Materials and Pavement Prediction reflects this development highlighting various approaches to predict pavement performance. The contributions discuss links and interactions between material characterization methods, empirical predictions, mechanistic modeling, and statistically-sound calibration and validation methods. There is also emphasis on comparisons between modeling results and observed performance. The topics of the book include (but are not limited to): • Experimental laboratory material characterization • Field measurements and in situ material characterization • Constitutive modeling and simulation • Innovative pavement materials and interface systems • Non-destructive measurement techniques • Surface characterization, tire-surface interaction, pavement noise • Pavement rehabilitation • Case studies Advances in Materials and Pavement Performance Prediction will be of interest to academics and engineers involved in pavement engineering.
Download or read book Constitutive Modeling of Viscoelastic Behavior of Bituminous Materials written by Arash Motamed and published by . This book was released on 2012 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt mixtures are complex composites that comprise aggregate, asphalt binder, and air. Several research studies have shown that the mechanical behavior of the asphalt mixture is strongly influenced by the matrix, i.e. the asphalt binder. Therefore, accurate constitutive models for the asphalt binders are critical to ensure accurate performance predictions at a material and structural level. However, researchers who use computational methods to model the micromechanics of asphalt mixtures typically assume that (i) asphalt binders behave linearly in shear, and (ii) either bulk modulus or Poisson's ratio of asphalt binders is not time dependent. This research develops an approach to measure and model the shear and bulk behavior of asphalt binders at intermediate temperatures. First, this research presents the findings from a systematic investigation into the nature of the linear and nonlinear response of asphalt binders subjected to shear using a Dynamic Shear Rheometer (DSR). The DSR test results showed that under certain conditions a compressive normal force was generated in an axially constrained specimen subjected to cyclic torque histories. This normal force could not be solely attributed to the Poynting effect and was also related to the tendency of the asphalt binder to dilate when subjected to shear loads. The generated normal force changed the state of stress and interacted with the shear behavior of asphalt binder. This effect was considered to be an "interaction nonlinearity" or "three dimensional effect". A constitutive model was identified to accommodate this effect. The model was successfully validated for several different loading histories. Finally, this study investigated the time-dependence of the bulk modulus of asphalt binders. To this end, poker-chip geometries with high aspect ratios were used. The boundary value problem for the poker-chip geometry under step displacement loading was solved to determine the bulk modulus and Poisson's ratio of asphalt binders as a function of time. The findings from this research not only improve the understanding of asphaltic materials behavior, but also provide tools required to accurately predict pavement performance.
Download or read book Verification of Mechanistic Prediction Models for Permanent Deformation in Asphalt Mixes Using Accelerated Pavement Testing written by Mbakisya A. Onyango and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Permanent deformation (rutting) is the most critical load-associated distress that develops on asphalt pavements significantly affecting their performance. Past research work focused on estimating permanent deformation of asphalt mixes using empirical prediction models or prediction models based on linear elastic material models. In recent years, mechanistic and mechanistic-empirical prediction models have been developed to take into account the behavior of asphalt material (viscoelastic, viscoplastic or elasto-visco-plastic). This research project aims to evaluate existing mechanistic models that predict permanent deformation (rutting) in asphalt mixes by comparing computed permanent deformation to that measured in a full-scale accelerated pavement test. Six pavement sections were constructed in the Civil Infrastructure Systems Laboratory (CISL) of Kansas State University with six different asphalt mixes. The sections were loaded with up to 700,000 load repetitions of a 22,000lb single axle. The transverse profiles at the pavement surface were measured periodically. For material characterization, asphalt mix samples fabricated in the laboratory, were subjected to dynamic modulus (E*), static creep - flow time (Ft), dynamic creep - flow number (Fn), triaxial and uniaxial strength tests, repetitive shear at constant height (RSCH) and frequency sweep at constant height (FSCH). The finite element software, Abaqus, was used to simulate and evaluate four permanent deformation prediction models, which are: creep model, elasto-visco-plastic model, viscoelastic model and Drucker-Prager model. The predicted permanent deformation was then compared to permanent deformation measured in CISL for the six of asphalt pavement sections. It was found that, with some improvements, creep and elasto-visco-plastic models could be used to predict permanent deformation in asphalt mixes. The viscoelastic model greatly under-predict permanent deformation, and the Drucker-Prager model with hardening criteria over predicts permanent deformation as compared to values measured in CISL.
Download or read book The Development of Asphalt Mix Creep Parameters and Finite Element Modeling of Asphalt Rutting written by Ludomir Uzarowski and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Significant Findings from Full scale Accelerated Pavement Testing written by Wynand JvdM. Steyn and published by Transportation Research Board. This book was released on 2012 with total page 257 pages. Available in PDF, EPUB and Kindle. Book excerpt: "TRB's National Cooperative Highway Research Program (NCHRP) Synthesis 433: Significant Findings from Full-Scale Accelerated Pavement Testing documents and summarizes significant findings from the various experimental activities associated with full-scale accelerated pavement testing (f-sAPT) programs that have taken place between 2000 and 2011. The report also identifies gaps in knowledge related to f-sAPT and where future research may be needed. NCHRP Synthesis 433 is designed to expand the f-sAPT base of knowledge documented in NCHRP Syntheses 325 and 235, both with the same title of Significant Findings from Full-Scale Accelerated Pavement Testing. f-sAPT is the controlled application of a wheel loading, at or above the appropriate legal load limit, to a pavement system to determine pavement response in a compressed time period. The acceleration of damage is achieved by one or more of the following factors: increased repetitions, modified loading conditions, imposed climatic conditions, and thinner pavements with a decreased structural capacity which have shorter design lives"--
Download or read book Performance Prediction Models in the Superpave Mix Design System written by Harold L. Von Quintus and published by . This book was released on 1994 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Journal of Engineering Mechanics written by and published by . This book was released on 2005 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Using Image based Multi scale Finite Element Model to Predict Rutting Behavior of Asphalt Mixtures written by Cheng Ling and published by . This book was released on 2016 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rutting resistance is one of the essential needs in design of asphalt mixtures. Volumetric properties, and wheel tracking tests are used today to qualify the rutting resistance in practice. However, these tools are used on a trial and error basis and are mostly based on experience. With all the experience available today it is still not clear what is the contribution of aggregate structure and if plastomeric or elastomeric modifiers are preferred for better resistance. While expanding the types of aggregates and binders used in testing could help, a more fundamental understanding of how aggregate contacts are formed and how binders can contribute to actual mechanics of rutting resistance is a better path for designing of mixtures. In the last decade significant improvement in imaging and multi-scale modeling has been achieved, which allows looking closer at how binders and aggregates could affect rutting resistance. One of the most challenging aspects of this modeling effort is dealing with aggregates proximity zones and how response of mixture changes when aggregates come into contact. This dissertation includes a modification of an Image-based Finite Element model for addressing this challenge and provide a solution that is simple yet effective in better simulating of rutting resistance of asphalt mixtures. The dissertation also includes validation of the model to simulate measured performance of mixtures produced with plastomeric and elastomeric modifiers with different viscoelastic properties, as well as different aggregate gradations. Results indicate that predefined contact points are necessary for reliable prediction of rutting resistance of mixtures. The results also show that the non-recoverable creep compliance of binders plays a significant role, while elasticity of modified binder is not important. Further application of the model shows that it can be successfully used to simulate effects of mixture confining pressure to simulate pavement depth, and also to simulate effects of varying voids content and moisture damage due to the weakening of the interface bond between aggregates and binder. It is expected that the improved modeling of contact zones will allow a more rational selection of aggregates and modification techniques to enhance the rutting resistance of asphalt pavement.
Download or read book Modeling and Design of Flexible Pavements and Materials written by Dallas N. Little and published by Springer. This book was released on 2017-09-25 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook lays out the state of the art for modeling of asphalt concrete as the major structural component of flexible pavements. The text adopts a pedagogy in which a scientific approach, based on materials science and continuum mechanics, predicts the performance of any configuration of flexible roadways subjected to cyclic loadings. The authors incorporate state-of the-art computational mechanics to predict the evolution of material properties, stresses and strains, and roadway deterioration. Designed specifically for both students and practitioners, the book presents fundamentally complex concepts in a clear and concise way that aids the roadway design community to assimilate the tools for designing sustainable roadways using both traditional and innovative technologies.
Download or read book Efficient Transportation and Pavement Systems Characterization Mechanisms Simulation and Modeling written by Imad L. Al-Qadi and published by CRC Press. This book was released on 2008-11-01 with total page 924 pages. Available in PDF, EPUB and Kindle. Book excerpt: Internationally, significant attention is given to transport sustainability including planning, design, construction, evaluation, safety and durability of the road system. The 4th International Gulf Conference on Roads: Efficient Transportation and Pavement Systems - Characterization, Mechanisms, Simulation, and Modeling, hosted by the University o
Download or read book MODELING OF ASPHALT CONCRETE written by Y. Richard Kim and published by McGraw Hill Professional. This book was released on 2007-09-22 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt: An Expert Guide to Developing More-Durable and Cost-Effective Asphalt Pavements Written by distinguished experts from countries around the world, Modeling of Asphalt Concrete presents in-depth coverage of the current materials, methods, and models used for asphalt pavements. Included is state-of-the-art information on fundamental material properties and mechanisms affecting the performance of asphalt concrete, new rheological testing and analysis techniques, constitutive models, and performance prediction methodologies for asphalt concrete and asphalt pavements. Emphasis is placed on the modeling of asphalt mixes for specific geographic/climatic requirements. In light of America's crumbling infrastructure and our heavy usage of asphalt as a paving material, this timely reference is essential for the development of more-durable and cost-effective asphalt materials for both new construction and rehabilitation. Harness the Latest Breakthroughs in Asphalt Concrete Technology: • Asphalt Rheology • Constitutive Models • Stiffness Characterization • Models for Low-Temperature Cracking • Models for Fatigue Cracking and Moisture Damage • Models for Rutting and Aging
Download or read book Advanced Asphalt Materials and Paving Technologies written by Zhanping You and published by MDPI. This book was released on 2018-05-04 with total page 431 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Advanced Asphalt Materials and Paving Technologies" that was published in Applied Sciences
Download or read book Effect of Mixture Component Characteristics on Property and Performance of Superpave Mixtures written by Sanghyun Chun and published by . This book was released on 2012 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: Relationships able to predict initial fracture energy and creep rate, which are the properties known to govern the change in material property over time and are also required for performance model predictions, were developed in this study. Furthermore, conceptual relationships were identified to describe changes in these properties over time (aging) by including the effect of the non-healable permanent damage related to load and moisture. This can serve as the foundation for further development of improved models to predict mixture properties as a function of age in the field based on additional field data and laboratory studies using more advanced laboratory conditioning procedures. The verified relationships will also serve to provide reliable inputs for prediction of service life using pavement performance prediction models.
Download or read book Binder Characterization and Evaluation written by David A. Anderson and published by Strategic Highway Research Program (Shrp). This book was released on 1994 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
