Download or read book An Evaluation of Permanent Deformation and Low Temperature Characteristics of Some Recycled Asphalt Concrete Mixtures written by and published by . This book was released on 1988 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book CRREL Report written by and published by . This book was released on 1993 with total page 486 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Permanent Deformation Properties of Asphalt Concrete Mixtures written by Rabbira Garba and published by . This book was released on 2002 with total page 183 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rutting is recognized to be the major distress mechanism in flexible pavements as a result of increase in tire pressures and axle loads. Rutting is caused by the accumulation of permanent deformation in all or some of the layers in the pavement structure. The accumulation of permanent deformation in the asphalt surfacing layer is now recognized to be the major component of rutting in flexible pavements. This is a consequence of increased tire pressures and axle loads, which subjects the asphalt surfacing layer nearest to the tire-pavement contact area to increased stresses. Thus the study of permanent deformation properties of asphalt mixtures has become the focus of research, which aim to mitigate or reduce rutting in flexible pavements. The research work reported in this thesis aims to contribute towards understanding of the material properties and factors affecting permanent deformation in asphalt mixtures, mechanisms of the permanent deformation, and methods of its prediction. The specific objectives of this research work include; review and evaluation of available models for permanent deformation of asphalt concrete mixtures, investigation of the effect of volumetric composition, loading and temperature conditions on the permanent deformation of asphalt concrete, and the identification and definition of simple measures of resistance to permanent deformation. To meet the objectives of the study a laboratory investigation is conducted on several asphalt concrete specimens with varying volumetric composition. Two testing procedures are adopted; the repeated load triaxial and triaxial creep and recovery tests. The tests were conducted at two temperature levels of 25 and 50oC under varying stress conditions. A review of literature on factors affecting permanent deformation and available models for prediction of the permanent deformation is also conducted. The literature review indicated that most of the research work done so far concentrated on evaluation of the effect on permanent deformation response of component material properties such as aggregate gradation, aggregate angularity and binder type (or grade). Most of the studies conducted on permanent deformation properties of asphalt mixtures were also found to be based on different testing procedures and methods of evaluation, which makes it difficult to compare them and draw firm conclusions. The literature also indicated that, as yet, there is no comprehensive model for deformation of asphalt concrete. Results of tests conducted in this study are analysed to investigate the effect of volumetric composition, particularly binder content and void content, and loading conditions on the permanent deformation response of the mixture. Both the binder content and void content are found to significantly influence the permanent deformation characteristics. The effect of loading conditions, i.e., the confining stress and the deviatoric stress, is also found to be significant. Throughout this study emphasis is placed on methods and parameters that are used to evaluate mixtures for their resistance to permanent deformation. The traditionally used parameters such as the slope and intercept of the power model are evaluated for their sensitivities to changes in volumetric composition. This evaluation is based on the premises that any measure of resistance to permanent deformation should be sensitive to changes in volumetric composition to be good enough. It is found that most of these parameters are not sensitive to changes in volumetric composition and therefore are not suitable for comparison of mixtures made from the same materials but with varying proportion of the components. Permanent deformation in asphalt concrete is caused by both densification and shear deformation. The mode of deformation in asphalt concrete pavements, for greater part of their service life, is considered to be the shear deformation. Therefore it is necessary to evaluate mixtures for their susceptibility to shear deformation. The shear deformation manifests itself in the form of large lateral deformation relative to axial deformation. It is found that one dimensional analysis, which does not take the lateral deformation into account may lead to misleading results regarding the resistance to permanent deformation of mixtures. Therefore parameters which include volumetric and lateral strain are proposed for use in evaluation of mixtures. Substantial effort is put into modelling the accumulation of permanent deformation under repeated loading. For this purpose two approaches were selected: the cyclic hardening model based on bounding surface plasticity concept and an elasto-viscoplastic model based on strain decomposition approach. The bounding surface plasticity approach is found to be a convenient method to model the accumulation of permanent deformation. It is demonstrated that deformations calculated using cyclic hardening model based on bounding surface plasticity fits the measured deformation quite well. The elasto-viscoplastic model, which is based on strain decomposition approach, provides a suitable method for analysis of creep and recovery test results. Deformations calculated using this model also fit the measured deformation quite well. Finally a new composite measure of resistance to permanent deformation is developed. The resistance index is based on strain decomposition approach and is simple to calculate. The index incorporates a parameter related to shear susceptibility of mixtures and is sensitive to changes in volumetric composition. It is believed that this index can be used to compare and select mixtures at mixture design stage. If its applicability to other materials is proved by further research, it can also be linked to performance related specifications, as a simple measure of performance with regard to rutting.
Download or read book Evaluation of Low Temperature and Permanent Deformation Characteristics of Some Polymer Modified Asphalts written by Sajjad Rizwan Hussain and published by . This book was released on 1990 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Permanent Deformation Characteristics of Recycled Asphalt Concrete Mixes written by and published by . This book was released on 1987 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Various blends of recovered and virgin asphalt cement were tested for properties including penetration, absolute and kinematic viscosity and water susceptibility. conventional marshall tests were also performed, and permanent strain characteristics were measured by repeated load triaxial tests. the test results show that inclusion of reclaimed material in amounts as low as 30 percent can reduce the permanent strain values significantly. a regression model has been developed to relate permanent strain to the number of load repetitions, to predict permanent deformation under various mix and environmental conditions. for the covering abstract of the conference see irrd 807058.
Download or read book Evaluation of Properties of Recycled Asphalt Concrete Hot Mix written by Elton R. Brown and published by . This book was released on 1983 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recycling of aged asphalt concrete pavements has been demonstrated to be cost-effective and to reduce the demand for natural resources such as aggregate and asphalt. Because of the advantages derived when using recycled materials, the capability to predict long-term performance is needed so that optimum benefits can be obtained. This study was undertaken to evaluate the laboratory performance to recycled asphalt concrete mixtures and to compare these results to those measured for conventional asphalt concrete mixtures. Results of this study indicated a satisfactory comparison between laboratory performance of recycled mixtures and conventional mixtures. Fatigue analysis indicated that conventional mixtures would provide the greatest fatigue resistance in thick asphalt concrete layers at lower temperatures, while the recycled mixtures would provide the greatest fatigue resistance in thin asphalt layers at higher temperatures. Water susceptability was shown to be related more to aggregate type than to mixture type. The data show that recycled mixtures prepared with the recycling agent produced mixtures with the lowest durability and poorest low temperature performance when compared with the recycled mixtures prepared with AC-5 or compared with the conventional mixtures.
Download or read book Evaluation of Permanent Deformation and Fatigue Cracking Resistance Characteristics of Recycled Asphalt Pavement Binder written by K. Wayne Lee and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings Association of Asphalt Paving Technologists Technical Sessions written by Association of Asphalt Paving Technologists and published by . This book was released on 1988 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superpave Mix Design written by Asphalt Institute and published by . This book was released on 2001-01-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Mechanical Tests for Bituminous Mixes Characterization Design and Quality Control written by E. Eustacchio and published by CRC Press. This book was released on 2004-06-02 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book forms the Proceedings of an International RILEM Symposium, the fourth in the series, on Testing of Bituminous Mixes in Budapest, Hungary, October 1990. The aim of the Symposium is to promote tests for the characterization, design and quality control of bituminous mixes which combine the best features of traditional and modern approaches. Among the topics covered are specimen preparation, tests with unique loading (Marshall test, uniaxial tension and creep tests etc), which are used for mix design or control of mechanical properties, and tests with repeated loading, which give information on fatigue, permanent deformation and moduli, especially for mix design.
Download or read book Proceedings written by Association of Asphalt Paving Technologists and published by . This book was released on 1993 with total page 808 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Permanent Deformation Characteristics of Dense graded Mixes Using Asphalt Pavement Analyzer written by Jesús A. Sandoval-Gil and published by . This book was released on 2004 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Asphalt Pavement Analyzer (APA) device was used to characterize the impact of various mix factors on the development of permanent deformation in dense-graded mixes given a standard compactive effort. Factors included two aggregate sizes, three VMA levels, two fines contents, three binder contents and four binder types. All specimens received the same compactive effort (100 gyrations) using the Superpave Gyratory Compactor (SGC). For some tests, testing temperatures followed the standard APA test protocol (64C) and for some others, the test temperature was set at the high temperature of standard performance asphalt binder grade (e.g. 70C for a PG 70-22 asphalt binder). Statistical results showed that increased binder content increased permanent deformation in the 19.0 mm dense graded mixes prepared with the PG 64-22 binder irrespective of the other mix parameters. These effects were not noted in the mixes prepared with PG 70-22 and PG 76-22 binders, when tested at 64C. However, the same effect was noted when mixes prepared with PG 70-22, PG 70-22 Modified and PG 76-22 binders were tested at the high temperature of standard performance asphalt binder grade. All mixes prepared with the stiffer binders showed very low permanent deformation when tested at the standard 64C regardless of the value of the other mix parameters. The statistical analysis of permanent deformation provides evidence that the mixes prepared with the PG 76-22 and PG 70-22 Modified binders perform better than mixes prepared with the PG 70-22 and the PG 64-22 binders. The effect of VMA on permanent deformation depends on the maximum aggregate size used, test temperature, binder type and the fines content. It was not possible to separate these interaction effects. The results of this study suggest that the APA is relatively insensitive to changes in mix properties within the range of variables studied, when using the standard APA test temperature (64C). However, the APA device is sensitive when the test temperature matches the high temperature of the standard performance binder grade (e.g. 70C for a PG 70-22 binder). Based on the results of this study, it appears that the APA can be used to indicate the rut resistance of a mixture. Although some of the mix factors have an interactive effect in the mixes, the APA has a potential to predict the relative rutting of the hot mix asphalt mixes even when polymer modified mixes are used, provided that testing is conducted at the appropriate test temperature.
Download or read book Low temperature Cracking written by D. H. Jung and published by National Research Council. This book was released on 1994 with total page 124 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the thermal stress restrained specimen test (TSRST), which was selected to evaluate the low-temperature cracking resistance of asphalt concrete mixtures. The TSRST system includes a load frame, step-motor-driven load ram, data acquisition hardware and software, temperature controller, and specimen alignment stand. An experiment design that considered a range of mixture and test condition variables was developed to evaluate the suitability of TSRST for characterizing low-temperature cracking resistance of asphalt concrete mixtures. Four asphalts and two aggregates were selected for the experiment. The mixture variables included asphalt type, aggregate type, and air voids content; the test condition variables included specimen size, stress relaxation, aging, and cooling rate.
Download or read book Evaluation of Properties of Recycled Asphalt Concrete Hot Mix written by Elton R. Brown and published by . This book was released on 1984 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Behaviour of Recycled Asphalt Pavement at Low Temperatures written by and published by . This book was released on 1991 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper summarizes the results of a study conducted to evaluate the behaviour of recycled asphalt pavements with respect to low-temperature cracking. For this purpose, a recycled mix consisting of 45.2% reclaimed materials and 54.8% virgn materials as well as a virgin control mix were used in the research program. In the design of both mixes, their initial properties were kept as close as possible to each other to allow for a proper comparison between recycled and virgin asphalt pavements. Using mix properties that were determined experimentally in the laboratory, thermal stresses resulted from drop in temperature and the expected cracking temperatures were determined for both mixes. An experimental analysis based on laboratory tests that consider the pavement properties only as well as a more complete theoretical anaysis based on a finite element computer program known as FETAB were included in this study. The program incorporates subgrade parameters, as well as pavement properties and thickness. Using these variables as inputs to the program, the expected performance of recycled and virgin asphalt pavements of various thicknesses and resting on different types of subgrade, with respect to low-temperature cracking, was studied. The results of the study indicated that recycled asphalt pavements would perform better than virgin asphalt pavments of similar initial properties.
Download or read book A Laboratory Evaluation of Recycled Tire Rubber in Hot Mix Asphalt Paving Systems written by KR. Hansen and published by . This book was released on 1993 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report digests individual studies by separate researchers which compared and evaluated: (1) the physical properties and aging characteristics of the asphalt-rubber and asphalt cement binders; (2) Hveem and Marshall mix design methods, and permanent deformation, low temperature cracking and fatigue characteristics for dense graded asphalt-rubber concrete (ARC) and asphalt concrete mixes; and (3) open-graded asphalt-rubber concrete friction courses.
