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 Permanent Deformation Characteristics of Oregon Mixes Using the Asphalt Pavement Analyzer written by James Ray Lundy and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Permanent Deformation Characteristics of Oregon Mixes Using the Asphalt Pavement Analyzer written by James Ray Lundy and published by . This book was released on 2004 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Asphalt Concrete written by Carl L. Monismith and published by DIANE Publishing. This book was released on 1998-07 with total page 81 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summarizes research results concerned with the behavior of asphalt-aggregate mixes for pavements. An objective of this project was the development of a series of accelerated performance tests for asphalt-aggregate mixes together with methods for analyzing asphalt-aggregate interactions which significantly affect performance. Methodologies to define the fatigue, permanent deformation, thermal cracking, water sensitivity, and aging characteristics are described and use of these procedures in mix design/analysis stems which permit performance predictions under a variety of environmental and traffic loading conditions is illustrated.

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 Permanent Deformation Characteristics of Hot Mix Asphalt Mixtures Using Superpave Technology written by William Marty McNamara and published by . This book was released on 1999 with total page 614 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Influence of Aggregate Gradation and Particle Shape texture on Permanent Deformation of Hot Mix Asphalt Pavements written by Randolph C. Ahlrich and published by . This book was released on 1995 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Correlating Permanent Deformation Characteristics of Hot Mix Asphalt with Aggregate Geometric Irregularities written by C-Y Kuo and published by . This book was released on 2002 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Regression analyses were performed to study the correlation between the permanent deformation characteristics of hot mix asphalt (HMA) mixtures and their aggregate geometric irregularities. Permanent deformation of HMA mixtures was characterized by permanent strain, creep modulus, and slope of the creep curve from unconfined repeated load deformation tests. The fine aggregate angularity (FAA) test was used to characterize fine aggregates while coarse aggregates were characterized with either the particle index (PI) test, the modified National Aggregate Association flow test (modified NAA), or image analysis. Regression analyses indicate strong correlation between the permanent deformation characteristics of HMA mixtures and the aggregate geometric irregularities. Use of imaging indices for characterizing coarse aggregates gives better coefficients of determination than do other coarse aggregate characteristics such as PI and modified NAA. The imaging indices have major potential in evaluating aggregate geometric irregularities for engineering analysis.

Download or read book Investigation of Binder Aging and Mixture Performance in Service Reclaimed Asphalt Pavement Mixtures written by Stacey D. Diefenderfer and published by . This book was released on 2018 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 2007, the Virginia Department of Transportation piloted a specification allowing up to 30% reclaimed asphalt pavement (RAP) in certain dense-graded asphalt surface mixtures while changing virgin binder grade requirements. The change affected only mixtures requiring an end binder grade of either PG 64-22 or PG 70-22. For mixtures specifying PG 64-22 binder, the virgin binder grade at RAP contents of 30% or less was no longer required to change. For mixtures specifying PG 70-22 binder, the virgin binder grade at RAP contents of 21% to 30% was no longer required to change from PG 64-22 to PG 64-28. Prior to this, both types of surface mixtures were allowed to contain only up to 20% RAP before binder grade adjustments were required. An initial laboratory study of mixtures produced under the pilot specification indicated that there were no significant differences for fatigue, rutting, and susceptibility to moisture between the higher content (21% to 30%) RAP mixtures and comparison mixtures (20% RAP or less). The current study evaluated the in-service performance of these mixtures after approximately 7 years and encompassed field visits and a laboratory investigation of a sample of 23 in-service pavements used in the initial laboratory evaluation. Cores were collected from each site and used to evaluate the binder and mixture properties. These data were compared to data from the original construction, when available, to assess the changes in the mixtures over time. Historical performance and maintenance data were also collected and evaluated to investigate the long-term performance characteristics of the sites. Laboratory testing, including dynamic modulus determination, repeated load permanent deformation analysis, and extracted binder grading and analysis, consistently showed no trends in the results with regard to RAP content. Overlay test results were influenced by more than just RAP (air-void content, etc.), and therefore no trend directly related to RAP content was shown. No trends in field performance could be determined because of the underlying structural conditions. Individual locations were found to show better or worse pavement performance, but this was attributed primarily to structural differences in the pavements and preexisting conditions. Surface deterioration observed in numerous test sections included fatigue cracking, longitudinal cracking, transverse cracking, raveling, and potholes. Binder analysis indicated that depth within a layer (in this case, top half versus bottom half) significantly affects binder properties, with stiffness decreasing with depth. However, increasing RAP contents appeared to mitigate the differences between the top half and bottom half of layers, possibly because of the preexisting aged composition of the RAP and its influence on the virgin binder properties.

Download or read book Aggregate Contribution to Hot Mix Asphalt HMA Performance written by and published by ASTM International. This book was released on with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aggregate Contribution to Hot Mix Asphalt HMA Performance written by Thomas D. White and published by ASTM International. This book was released on 2001 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt: Containing 13 papers from the December 2000 conference in Orlando, Florida, this book covers the use of the PURWheel laboratory tracking device, the Asphalt Pavement Analyzer, the identification of aggregate role, the evaluation of sensitivity, fine aggregate angularity, guidelines for the selection

Download or read book Permanent Deformation Response of Asphalt Aggregate Mixes written by Christine W. Curtis and published by National Research Council. This book was released on 1994 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the research conducted on permanent deformation of asphalt concrete mixes as part of the SHRP Asphalt Research Program. Divided into three sections the report addresses the following: the development of a series of accelerated performance tests to measure the permanent deformation response and a constitutive relationship to define it; validation of the binder properties included in the SHRP binder specification; and the use of the test methodology in an asphalt concrete mix design and analysis system.

Download or read book Asphalt aggregate Mixture Analysis System AAMAS written by National Research Council (U.S.). Transportation Research Board and published by Transportation Research Board. This book was released on 1991 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscoelastic and Permanent Deformation Characteristics of Asphalt Aggregate Mixes Tested as Hollow Cylinders and Subjected to Dynamic Axiel and Shear Loads written by Sirous Heydari Alavi and published by . This book was released on 1992 with total page 560 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 Measurement of Aggregate Texture and Its Influence on Hot Mix Asphalt HMA Permanent Deformation written by T. Fletcher and published by . This book was released on 2002 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aggregate shape has a significant effect on the performance of asphalt mixes. Designing well-performing asphalt pavements requires developing methods to quantify rapidly and accurately the different aggregate shape properties, and most importantly, relate these properties to performance. Aggregate texture has been identified in several studies to be the shape property that has the most significant influence on asphalt mix performance. This study presents a new procedure for measuring aggregate texture using image analysis techniques. The main advantages of this new procedure are the ability to capture the different sizes of texture elements, to separate the true texture from the color variations on the aggregate surface, and to characterize both fine and coarse aggregates. The procedure is used to measure texture for a wide range of fine and coarse aggregates, and the results are compared with the laboratory performance of asphalt mixes. The analysis shows that the procedure yields detailed information on aggregate texture in a short time. The texture measurements have very good correlation with the resistance of asphalt mixes to permanent deformation measured in the laboratory using different wheel tracking devices.

Download or read book Viscoelastic and Permanent Deformation Characteristics of Asphalt aggregate Mixes Tested as Hollow Cylinders and Subjected to Dynamic Axial and Shear Loads written by Sirous Heydari Alavi and published by . This book was released on 1992 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: