Download or read book Characterization of Healing of Asphalt Mixtures Using Creep and Step Loading Recovery Test written by Xue Luo and published by . This book was released on 2015 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: Healing of asphalt mixtures has been proven to be significant, and different approaches exist to characterize it, such as the phenomenological methods, mechanism-based, and mechanics-based methods. To target the actual causal relationship for healing in asphalt mixtures, a new test called the creep and step-loading recovery (CSR) test, along with a new mechanistic method termed the energy-based mechanistic (EBM) approach, was previously developed by the authors. This paper aimed at examining the applicability of the CSR test with the EBM approach in characterizing healing of asphalt mixtures. A variety of asphalt mixtures were selected and subjected to the CSR test in this study. The internal stress measured by the CSR test was used in the EBM approach to generate a damage density progression curve, which directly reflected how the damage developed and healed in the tested material. Based on this curve, the normalized extent of healing was defined as a direct measure of healing, and the healing curve (the normalized extent of healing versus the rest time) was defined as a straightforward tool to qualitatively evaluate the healing ability of asphalt mixtures. To further achieve a quantitative description of the healing ability, a healing model based on the Ramberg-Osgood equation was developed to simulate the healing curve. The parameters in the healing model represent the healing speed at different stages of healing (the initial healing rate and ultimate healing rate) and the overall ability of the material to heal (the healing scale). Both the healing curves and healing parameters can discern the difference in the healing ability caused by the air void content, aging, temperature, and the type of asphalt binder. In other words, the CSR test, along with the EBM approach, was able to produce a reasonable and consistent prediction of healing for asphalt mixtures.
Download or read book Characterization of Fatigue Cracking and Healing of Asphalt Mixtures written by Xue Luo and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue cracking is one of the most common distresses of asphalt pavements, whereas healing is a counter process to cracking which alleviates cracking damage and extends fatigue life of asphalt pavements. Most of existing methods to characterize fatigue cracking and healing are generally empirical or phenomenological in nature, which does not satisfy the need to develop mechanistic-based pavement design methods. The objective of this study is to characterize fatigue cracking and healing of asphalt mixtures using an energy-based mechanistic approach. A controlled-strain repeated direct tension (RDT) test is selected to generate both fatigue cracking and permanent deformation in an asphalt mixture specimen. Fatigue cracking is separated from permanent deformation from a mechanical viewpoint. The development of fatigue cracking is described by the evolution of the damage density and the increase of the average crack size with the increase of loading cycles. A creep and step-loading recovery (CSR) test is designed to measure the internal stress in the recovery phase of an asphalt mixture specimen. The internal stress and the strain measured in the recovery phase are used to conduct the mechanistic analysis of recovery and healing of the asphalt mixture specimen. Then healing is described using the decrease of the damage density and average crack size with time. Different types of asphalt mixtures produce distinctly different fatigue cracking and healing characteristics. The effect of mixture composition, temperature, and aging are evaluated using the approach above. The entire series of tests for fatigue, permanent deformation and healing can be completed in one day, with the healing part requiring only a matter of minutes. The methods proposed in this study characterize fatigue cracking and healing of asphalt mixtures using its essential cause and effect relationship.
Download or read book Advances in Asphalt Materials written by Shin-Che Huang and published by Woodhead Publishing. This book was released on 2015-04-08 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: The urgent need for infrastructure rehabilitation and maintenance has led to a rise in the levels of research into bituminous materials. Breakthroughs in sustainable and environmentally friendly bituminous materials are certain to have a significant impact on national economies and energy sustainability. This book will provide a comprehensive review on recent advances in research and technological developments in bituminous materials. Opening with an introductory chapter on asphalt materials and a section on the perspective of bituminous binder specifications, Part One covers the physiochemical characterisation and analysis of asphalt materials. Part Two reviews the range of distress (damage) mechanisms in asphalt materials, with chapters covering cracking, deformation, fatigue cracking and healing of asphalt mixtures, as well as moisture damage and the multiscale oxidative aging modelling approach for asphalt concrete. The final section of this book investigates alternative asphalt materials. Chapters within this section review such aspects as alternative binders for asphalt pavements such as bio binders and RAP, paving with asphalt emulsions and aggregate grading optimization. Provides an insight into advances and techniques for bituminous materials Comprehensively reviews the physicochemical characteristics of bituminous materials Investigate asphalt materials on the nano-scale, including how RAP/RAS materials can be recycled and how asphalt materials can self-heal and rejuvenator selection
Download or read book Long and Deep Tunnels written by Vittorio Guglielmetti and published by CRC Press. This book was released on 2016-04-15 with total page 1336 pages. Available in PDF, EPUB and Kindle. Book excerpt: The design and construction of “long and deep” tunnels, i.e. tunnels under mountains, characterised by either considerable length and/or overburden, represent a considerable challenge. The scope of this book is not to instruct how to design and construct such tunnels but to share a method to identify the potential hazards related to the process of designing and constructing long and deep tunnels, to produce a relevant comprehensive analysis and listing, to quantify the probability and consequences, and to design proper mitigation measures and countermeasures. The design, developed using probabilistic methods, is verified during execution by means of the so called Plan for Advance of the Tunnel (PAT) method, which allows adapting the design and control parameters of the future stretches of the tunnel to the results of the stretches already finished, using the monitoring data base. Numerous criteria are given to identify the key parameters, necessary for the PAT procedure. Best practices of excavation management with the help of real time monitoring and control are also provided. Furthermore cost and time evaluation systems are analysed. Finally, contractual aspects related to construction by contract are investigated, for best development and application of models more appropriate for tunnelling-construction contracts. The work will be of interest to practising engineers, designers, consultants and students in mining, underground, tunnelling, transportation and construction engineering, as well as to foundation and geological engineers, urban planners/developers and architects.
Download or read book Response Behavior of Asphalt Mixtures at Low Temperatures Under Varying Indirect Tensile Test Loading Conditions written by Xinjun Li and published by . This book was released on 2011 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper investigates the effect of loading level and loading rate on the damage development and strength of asphalt mixtures. Indirect tensile creep tests with different loading levels and strength tests with three loading rates were performed at three low temperatures for ten mixtures. An acoustic emission (AE) system with eight recording channels was used to monitor the development of micro cracking in the specimens for both tests for one mixture. The experimental results show that test temperature has a significant effect on the behavior of the material. Data analysis from the creep test indicates that the creep loading level significantly affects the response of the tested material. The AE rate analysis shows that no actual damage develops when a creep load is less than 20 % of the strength and significant micro damage accumulates when the applied creep load is more than 30 % of the strength value. The loading rate was found to have a significant effect on the measured tensile strength even at a relatively low temperature, and the measured tensile strength increases with the increase of the loading rate for all the test temperatures considered in this study. However, this effect was found to be diluted with the decrease of the test temperature. The AE analysis indicates that a damage zone develops in both the creep and strength tests. The damage zone decreases with temperature decrease and increases with the increase of the loading level applied during the creep test. The damage zone obtained from the strength test was approximately equal to that from the creep testing with a loading level about 25-50 % of the strength value.
Download or read book Journal of Testing and Evaluation written by and published by . This book was released on 1985 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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:
Download or read book Asphalt Mix Materials and Mixtures 1990 written by National Research Council (U.S.). Transportation Research Board and published by Transportation Research Board National Research. This book was released on 1990 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Characteristics of Asphalt Binders written by and published by . This book was released on 1996 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Proceedings of the 5th International Symposium on Asphalt Pavements Environment APE written by Marco Pasetto and published by Springer Nature. This book was released on 2019-08-29 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume highlights the latest advances, innovations, and applications in the field of asphalt pavement technology, as presented by leading international researchers and engineers at the 5th International Symposium on Asphalt Pavements & Environment (ISAP 2019 APE Symposium), held in Padua, Italy on September 11-13, 2019. It covers a diverse range of topics concerning materials and technologies for asphalt pavements, designed for sustainability and environmental compatibility: sustainable pavement materials, marginal materials for asphalt pavements, pavement structures, testing methods and performance, maintenance and management methods, urban heat island mitigation, energy harvesting, and Life Cycle Assessment. The contributions, which were selected by means of a rigorous international peer-review process, present a wealth of exciting ideas that will open novel research directions and foster multidisciplinary collaboration among different specialists.
Download or read book Sustainable Winter Road Operations written by Xianming Shi and published by John Wiley & Sons. This book was released on 2018-08-27 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first and only comprehensive guide to best practices in winter road operations Winter maintenance operations are essential to ensure the safety, mobility, and productivity of transportation systems, especially in cold-weather climates, and responsible agencies are continually challenged to provide a high level of service in a fiscally and environmentally responsible manner. Sustainable Winter Road Operations bridges the knowledge gaps, providing the first up-to-date, authoritative, single-source overview and guide to best practices in winter road operations that considers the triple bottom line of sustainability. With contributions from experts in the field from around the world, this book takes a holistic approach to the subject. The authors address the many negative impacts on regional economies and the environment of poorly planned and inadequate winter road operations, and they make a strong case for the myriad benefits of environmentally sustainable concepts and practices. Best practice applications of materials, processes, equipment, and associated technologies and how they can improve the effectiveness and efficiency of winter operations, optimize materials usage, and minimize cost, corrosion, and environmental impacts are all covered in depth. Provides the first up-to-date, authoritative and comprehensive overview of best practices in sustainable winter road operations currently in use around the world Covers materials, processes, equipment, and associated technologies for sustainable winter road operations Brings together contributions by an international all-star team of experts with extensive experience in designing, implementing, and managing sustainable winter road operations Designed to bring professionals involved in transportation and highway maintenance and control up to speed with current best practice Sustainable Winter Road Operations is essential reading for maintenance professionals dealing with snow and ice control operations on highways, motorways and local roads. It is a valuable source of information and guidance for decision makers, researchers, and engineers in transportation engineering involved in transportation and highway maintenance. And it is an ideal textbook for advanced-level courses in transportation engineering.
Download or read book Asphalt Pavements written by Y. Richard Kim and published by CRC Press. This book was released on 2014-11-06 with total page 1966 pages. Available in PDF, EPUB and Kindle. Book excerpt: Asphalt Pavements contains the proceedings of the International Conference on Asphalt Pavements (Raleigh, North Carolina, USA, 1-5 June 2014), and discusses recent advances in theory and practice in asphalt materials and pavements. The contributions cover a wide range of topics:- Environmental protection and socio-economic impacts- Additives and mo
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 Self Healing Materials written by S. van der Zwaag and published by IOS Press. This book was released on 2015-11 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2006 the Dutch government funded an 8 year and 20 million euro research program on Self Healing Materials. The research was not to be restricted to one material class or one particular healing approach. It was to explore all opportunities to create self healing behavior in engineering and functional materials and to bring the new materials to a level where they could be tested in real life applications. At its launch, the IOP program was the very first integrated multi-material approach to this field in the world. The research was to be conducted at Dutch universities working in collaboration with industry. With the IOP Self Healing Materials program coming to an end, this book presents the highlights of the pioneering research in the field of self healing materials in the Netherlands. Given the diversity of topics addressed, the book will be of value to all materials scientists working in the field of materials and materials by design in particular, as well as industrial engineers and developers with an interest in increasing the reliability and reducing the maintenance of their products. The book will also be an inspiration to students and show them how an unspecified concept of self healing can be translated to new materials with exceptional behavior.
Download or read book Physical Principles of Electron Microscopy written by R.F. Egerton and published by Springer Science & Business Media. This book was released on 2006-04-28 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scanning and stationary-beam electron microscopes are indispensable tools for both research and routine evaluation in materials science, the semiconductor industry, nanotechnology and the biological, forensic, and medical sciences. This book introduces current theory and practice of electron microscopy, primarily for undergraduates who need to understand how the principles of physics apply in an area of technology that has contributed greatly to our understanding of life processes and "inner space." Physical Principles of Electron Microscopy will appeal to technologists who use electron microscopes and to graduate students, university teachers and researchers who need a concise reference on the basic principles of microscopy.
