Download or read book Laboratory Fatigue and Its Relationship to Pavement Performance written by R. Ian Kingham and published by . This book was released on 1972 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pavement Performance Models written by Matthew W. Witczak and published by . This book was released on 1976 with total page 202 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Principles of Pavement Design written by E. J. Yoder and published by John Wiley & Sons. This book was released on 1991-01-08 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presents a complete coverage of all aspects of the theory and practice of pavement design including the latest concepts.
Download or read book Development of a New Fatigue Performance Test Using the Hamburg Wheel Tracking Device written by Ali Sahraei Joubani and published by . This book was released on 2024 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main objective of this study was to develop a new test that would be simple to conduct and analyze for evaluating resistance of asphalt mixtures to fatigue cracking. For this purpose, a piece of equipment known as the Hamburg Wheel Tracking Test (HWTT) was used. HWTT has been widely accepted as a reasonable and reliable test to evaluate the rutting and moisture damage performance of asphalt mixtures but its use for evaluating fatigue resistance of asphalt mixtures is relatively a new concept. Its use as a fatigue test is advantages over current laboratory fatigue tests because of the possibility of considering various underlying support layers when the specimen is subjected to repeated loading. Ability to assess the asphalt mixture fatigue resistance in a layered system under repeated loading and in a laboratory environment provides the opportunity to integrate material design and pavement structural design for optimum performance. In addition, this test is practically feasible as a routine test method in terms of reliability, equipment availability, and data processing efficiency. The tests were conducted on a two-layer structure with the asphalt concrete slab as the top layer and the neoprene or an unbound aggregate base as the underlying layer. Based on the numerical analysis, a width of 6 inches was selected as the optimum width for this study. However, the experiment also included the 4-inch width for comparison. The thickness of the slab was selected at three levels: 1.0, 1.5, and 2.0 inches, with the 1.5-inch thickness being the main thickness applied to most of the slabs. In an asphalt pavement structure, the surface layer is often designed at a thickness of 1.5 to 2.0 inches. These tests were based on strain amplitude growth corresponding to three defined stages during the test (Early, Middle, Late). The impact of several factors on the test results was investigated. Those factors included the slab width and thickness, the underlying support type and condition, temperature of the test, the speed of tracking, and the type of asphalt mixture. The experiment showed that as the slab thickness become smaller, the strain amplitude and its corresponding growth rate become larger, exhibiting a relatively higher rate of fatigue damage. Using the unbound aggregate base proved to be challenging because of difficulty in achieving a smooth, even surface. A smooth surface was required to ensure proper bond of the gauges and collection of the data. Using synthetic rubber neoprene provided a smooth base and delivered a more reliable dataset compared to the aggregate base in this study. As expected, temperature played a significant role in the experiment, as a higher initial strain amplitude was observed at elevated temperatures. A higher strain and increased strain growth rate were observed at lower loading speeds. After determining the appropriate dimensions, temperature, and underlying support, tests were conducted on six different asphalt mixes. Strain development was monitored at the bottom of the slab for each mix. From the data collected, a new fatigue life model was developed to evaluate the fatigue performance of asphalt pavements when tested under the conditions explored in this research. The fatigue life in this model is defined as the number of HWTT load cycles at which the strain amplitude doubles, or equivalently, when the stiffness is reduced to half. This determination is made under the premise that the test operates in stress control mode. It was found that the rate of growth in strain amplitude during the test increased considerably when the binder content in the mix was decreased, validating the importance of ensuring adequate binder content in the asphalt mix. The SMA mixture demonstrated a higher rate of strain amplitude increase compared to the dense-graded mixtures. The mix with 35% RAP content and a PG 64-22 binder delivered lower growth in strain amplitude compared with other mixes. The IDEAL-CT test was also performed to draw comparisons. However, based on the outcomes, it showed no correlation with the results of the newly developed fatigue test. Based on the growth of strain amplitude throughout the test, a fatigue life model was developed. The fatigue life can be determined using this model, based on the number of cycles, with a criterion of either a 50% reduction in stiffness or a doubling of the strain amplitude. Finally, a numerical model was developed, and the observed strain response demonstrated that this model is capable of predicting both the type of response and the magnitude of strain amplitude with relative accuracy.
Download or read book Fatigue Life Characterization of Superpave Mixtures at the Virginia Smart Road written by Imad L. Al-Qadi and published by . This book was released on 2005 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory fatigue testing was performed on six Superpave HMA mixtures in use at the Virginia Smart Road. Evaluation of the applied strain and resulting fatigue life was performed to fit regressions to predict the fatigue performance of each mixture. Differences in fatigue performance due to field and laboratory production and compaction methods were investigated. Also, in-situ mixtures were compared to mixtures produced accurately from the job mix formula to determine if changes occurring between the laboratory and batch plant significantly affected fatigue life. Results from the fatigue evaluation allowed verification of several hypotheses related to mixture production and compaction and fatigue performance. It was determined that location within the pavement surface, such as inner or outer wheelpath or center-of-lane, did not significantly affect laboratory fatigue test results, although the location will have significant effects on in-situ fatigue life. Also the orientation of samples cut from an in-situ pavement (parallel or perpendicular to the direction of traffic) had only a minor effect on the laboratory fatigue life, because the variability inherent in the pavement due to material variability is greater than the variability induced by compaction. Fatigue life of laboratory-compacted samples was found to be greater than fatigue life of field-compacted samples; additionally, the variability of the laboratory compacted mixture was found to be less than that of the field-compacted samples. However, it was also found that batch-plant production significantly reduces specimen variability as compared to small-batch laboratory production when the same laboratory compaction is used on both specimen sets. Finally, for Smart Road mixtures produced according to the job mix formula, the use of polymer-modified binder or stone matrix asphalt was shown to increase the expected fatigue life. However, results for all mixes indicated that fatigue resistance rankings might change depending on the applied strain level. This study contributes to the understanding of the factors involved in fatigue performance of asphalt mixtures. Considering that approximately 95% of Virginia's interstate and primary roadways incorporate asphalt surface mixtures, and that fatigue is a leading cause of deterioration, gains in the understanding of fatigue processes and prevention have great potential payoff by improving both the mixture and pavement design practices.
Download or read book Special Report written by and published by . This book was released on 1973 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structural Behavior of Asphalt Pavements written by Lijun Sun and published by Butterworth-Heinemann. This book was released on 2016-08-09 with total page 1072 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Behavior of Asphalt Pavements provides engineers and researchers with a detailed guide to the structural behavioral dynamics of asphalt pavement including: pavement temperature distribution, mechanistic response of pavement structure under the application of heavy vehicles, distress mechanism of pavement, and pavement deterioration performance and dynamic equations. An authoritative guide for understanding the key mechanisms for creating longer lasting pavements, Structural Behavior of Asphalt Pavements describes the intrinsic consistency between macroscopic performance and microscopic response, structure and material, as well as global and local performances, and demonstrates the process of pavement analyses and designs, approaching science from empirical analyses. - Analyzes the external and internal factors influencing pavement temperature field, and provide a review of existing pavement temperature prediction models - Introduces a "Bridge Principle through which pavement performance and fatigue properties are consolidated - Defines the intrinsic consistency between macroscopic performance and microscopic response, structure and material, as well as global and local performance - Summaries the mechanistic response of pavement structure under the application of heavy vehicle, distress mechanism of pavement, pavement deterioration performance and dynamic equations, and life cycle analysis of pavement
Download or read book Report 29 Pavement Performance Prediction and Evaluation PPPE Interlaboratory tests Report of RILEM TC 152 PBM and 182 PEB written by Manfred Partl and published by RILEM Publications. This book was released on with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Special Report Highway Research Board written by National Research Council (U.S.). Highway Research Board and published by . This book was released on 1973 with total page 496 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Asphalt Paving Technology 2011 written by Eugene L. Skok and published by DEStech Publications, Inc. This book was released on 2011-06-28 with total page 801 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book written by and published by . This book was released on 1932 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AASHTO Guide for Design of Pavement Structures 1993 written by American Association of State Highway and Transportation Officials and published by AASHTO. This book was released on 1993 with total page 622 pages. Available in PDF, EPUB and Kindle. Book excerpt: Design related project level pavement management - Economic evaluation of alternative pavement design strategies - Reliability / - Pavement design procedures for new construction or reconstruction : Design requirements - Highway pavement structural design - Low-volume road design / - Pavement design procedures for rehabilitation of existing pavements : Rehabilitation concepts - Guides for field data collection - Rehabilitation methods other than overlay - Rehabilitation methods with overlays / - Mechanistic-empirical design procedures.
Download or read book Creep and Fatigue Characteristics of Superpave Mixtures written by Stacey D. Diefenderfer and published by . This book was released on 2005 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory creep and fatigue testing was performed on five Superpave surface hot-mix asphalt mixtures placed at the Virginia Smart Road. Differences in creep and fatigue response attributable to production and compaction methods were investigated. In addition, changes in creep response resulting from differences in specimen size were evaluated. Further, an evaluation of the effects of loading frequency, presence of rest periods, and specimen location within the pavement on fatigue life was conducted. Creep compliance values were determined using viscoelastic-based calculations, and time-temperature superposition was used to generate mastercurves. Reported creep compliance response models from the literature were found inadequate for accurately describing the creep compliance mastercurves generated during this study. Differences in creep response between specimens of different sizes were found to be due to specimen and test variability, rather than size. An evaluation of the effects of laboratory and plant production and laboratory and field compaction was inconclusive as material variability appeared greater than production or compaction variability. Simple regression models were found to be satisfactory for use in the development of prediction models for fatigue, although test data are necessary for calibration to particular mixture types. No relationships were found between fatigue model coefficients and volumetric properties of the mixtures tested because of the limited range of volumetric properties. Variability in volumetric properties between the mixtures produced at the plant and those produced to match the job mix formula did not significantly influence the predicted laboratory fatigue performance. Laboratory fatigue lives were similar between the laboratory-compacted fatigue specimens and specimens cut from the pavement; differences observed in performance were attributable to different air void contents. Predicted fatigue life was found to be statistically independent of the frequency of the applied loads or presence of rest periods for the mixtures, frequencies, and rest periods considered in this study. Minimal differences were observed between fatigue life predictions for plant-produced, field-compacted specimens cut from different locations in the pavement. This study contributes to the understanding of the factors involved in creep and fatigue performance of asphalt mixtures. The mixture responses characterized by this study are related to the rutting and fatigue performance of asphalt pavements. The choice of appropriate asphalt materials to resist rutting and fatigue deterioration will result in reduced maintenance needs and longer service lives for pavements.
Download or read book Engineering Properties of Asphalt Mixtures and the Relationship to Their Performance written by Gerald A. Huber and published by ASTM International. This book was released on 1995 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thirteen papers presented at the conference on [title], held in Phoenix, Arizona, December, 1994, discuss the products of the strategic highway research program, the Superpave method of mix design, and test methods for fatigue cracking and permanent deformation. Lacks an index. Annotation c. by Book
Download or read book Asphalt Institute Quarterly written by and published by . This book was released on 1972 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Semiconductor Laser Theory written by Prasanta Kumar Basu and published by CRC Press. This book was released on 2015-07-16 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a comprehensive background of semiconductor lasers. It covers their structure, materials, operating principles supported by proper theory, and light power output, as well as conversion efficiency and how frequently the devices can be switched on and off. It also discusses the different lasers working at different wavelengths, viz, ultraviolet, visible, infrared and mid and far infrared regions of electromagnetic spectrum along with proper structure, materials and theory.
Download or read book Rock Springs written by Richard Ford and published by A&C Black. This book was released on 2012-06-04 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: In these ten stories, Ford mines literary gold from the wind-scrubbed landscape of the American West - and from the guarded hopes and gnawing loneliness of the people who live there. A refugee from justice driving across Wyoming with his daughter; an unhappy girlfriend and a stolen Mercedes; a boy watching his family dissolve in a night of tragicomic violence; two men and a woman swapping hard-luck stories in a frontier bar as they try to sweeten their luck. Rock Springs is a masterpiece of taut narration, cleanly chiselled prose, and empathy so generous that it feels like a kind of grace.
