Download or read book Characterizing the Temperature Effects on Rutting and Fatigue Properties of Asphalt Binders Based on Time Temperature Superposition Principle written by Chao Wang and published by . This book was released on 2019 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this article is to investigate the effects of temperature on rutting and fatigue cracking resistance of asphalt binders based on the time-temperature superposition principle (TTSP) In this study, the TTSP approach was employed to interpret the results of multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests for both neat and styrene-butadiene-styrene (SBS)modified asphalt binders. The higher stress level of 3.2kPa in the standard MSCR test procedure was extended to 10 and 15kPa to verify the stress sensitivity of the nonrecoverable compliance (Jnr) A loading duration of 5 minutes in the standard LAS test was extended to 10 and 15 minutes to develop the fatigue failure criterion at different conditions. The results demonstrate that the time-strain curves of the neat binder during the MSCR tests under different temperatures can be unified into a single strain master curve using the TTSP shift factors, based on which the predictiveJnrshowed good agreement with the measured values. This TTSP-based analysis approach does not work well for the MSCR results of the SBS-modified binder at high temperatures. However, the fatigue failure criterion determined from the LAS tests under different temperatures was verified to be successfully constructed into a single failure criterion according to the TTSP approach for both the neat and SBS-modified binders. Therefore, only an additional caution is raised for the TTS-based analysis on rutting resistance of the modified binder in a high temperature range.

Download or read book Modeling the Effects of Temperature and Loading Rate on Fatigue Property of Asphalt Binder written by Haifang Wen and published by . This book was released on 2010 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue cracking is one of three major distresses for asphalt pavement. Asphalt binder is a very important component of asphaltic mixture. The fatigue performance of asphalt binder also greatly affects that of asphaltic mixture. Asphalt binder's fatigue characteristics are affected by external conditions, such as temperature and loading rate. It is warranted to study the effects of these external conditions on fatigue of asphalt binder and take them into account. New fatigue tests and properties have been proposed to characterize the fatigue behavior of asphalt binders, such as monotonic constant shear-rate tests. This study investigated the effects of temperature and shear rate on fatigue properties of asphalt binder. Two asphalt binders were tested with a range of temperature and shear rates. It was found that time-temperature superposition principle also applies to critical strain energy density and shear strength of asphalt binders. The values of shift factors for building the master curves of critical strain energy and shear strength are comparable.

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 Characterization of Strain Rate and Temperature Dependent Shear Properties of Asphalt Mixtures written by Qiang Li and published by . This book was released on 2014 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shear properties (cohesion and angle of internal friction) are the main material parameters for the rutting evaluation of asphalt mixtures. The strain rate and temperature dependency of shear properties was characterized for three mixtures based on the time-temperature superposition principle (TTSP). The unconfined compression and indirect tension dynamic modulus tests were performed to measure the linear viscoelastic properties of asphalt mixtures by a modified procedure. The uniaxial compression strength test and indirect tension strength test were conducted at three temperatures and four strain rates to calculate shear properties of asphalt mixtures based on the Mohr-Coulomb failure theory. The strength and shear property master curves were developed using the shift factor obtained from the dynamic modulus tests. The analysis results show that TTSP is still valid for asphalt concrete in the damage state regardless of failure modes. The effect of confining pressure on shift factors can be evaluated by the Fillers-Moonan-Tschoegl (FMT) model. The mixture strength and shear properties exhibit a significant temperature and time dependency. The modified cross model can be used to describe the strength and cohesion master curves after slight improvement. Shear property master curves show preliminary promise for use in optimizing material design and improving the accuracy of rutting prediction.

Download or read book Understanding Mechanisms Leading to Asphalt Binder Fatigue written by and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue cracking is one of the primary modes of failure in asphalt pavements. Cracking typically occurs within the asphalt binder phase of asphalt mixtures. Thus, asphalt binder fatigue resistance is critical in determining overall pavement fatigue performance. One procedure commonly used to characterize asphalt binder fatigue resistance is the time sweep test, which consists of repeated torsional loading of a cylindrical specimen in the Dynamic Shear Rheometer (DSR). Generally, apparent changes in material properties with respect to number of cycles of loading are used to define fatigue failure of the asphalt binder. Results of this test have been shown to correlate well with asphalt mixture fatigue performance. However, the mechanisms responsible for changes in material properties during fatigue testing in the DSR were previously not well understood. Results in this study demonstrate that fracture can account for changes in loading resistance of asphalt binders during time sweep testing. Under cyclic torsional loading of cylindrical specimens, macro fracture is shown to manifest in the form of edge fracture. Edge fracture is a circumferential crack starting at the periphery of a cylindrical sample that propagates inward as loading is applied, reducing the effective sample size. Digital visualization of the fractured specimens allowed for determination of the fractured and intact sample area. Predictions of fracture propagation based on measurements of loading resistance and fracture mechanics concepts agreed favorably with actual measurements based on visualization. Furthermore, the fracture morphology and progression of crack growth of asphalt binders matched those observed for other materials under similar loading conditions. Based on these results, fatigue damage characterization of asphalt binders can be improved by incorporating fracture mechanics into an analysis framework for DSR fatigue test results. An analysis framework based on fracture principles is presented. The proposed model allows predicting fatigue life at any loading amplitude using the results of a single fatigue test. Additionally, it is demonstrated that time-temperature superposition is applicable to fatigue crack propagation of asphalt binders, allowing for efficient prediction of fatigue performance at multiple temperatures. The model is validated using a comparison between asphalt mixture and binder fatigue test results.

Download or read book Analysis of the Multiple Stress Creep Recovery Asphalt Binder Test and Specifications for Use in Indiana written by Ali Behnood and published by . This book was released on 2016-10-31 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Superpave specifications and equipment, introduced in 1993, represented a major advancement with respect to offering a better understanding of the behavior and characteristics of asphalt binders based on their rheological properties. However, the Superpave high-temperature test protocol has been shown to be inadequate for characterizing the high-temperature behavior (rutting resistance) of asphalt binders, particularly polymer modified ones. Recently, a specification based on the Multiple Stress Creep Recovery (MSCR) test has been proposed to address the shortcomings of the Superpave high-temperature binder specifications. This study aims to investigate the merits of implementing the MSCR test and specification as a replacement for the conventional high-temperature testing in the Performance Graded (PG) system. A statistical analysis was conducted on a dataset from Indiana Department of Transportation (INDOT) to see how MSCR and PG procedures differ in grading different binders used in the state. In addition, an experimental study was conducted using seventeen different modified and unmodified binders. In addition to binder tests, seven of the binders were selected to conduct asphalt mixture tests such as dynamic modulus and flow number. The results confirm that the MSCR test is a suitable replacement for the current PG high temperature test since it provides a better tool to rank modified asphalt binders as well as unmodified ones. That is, creep compliance from the MSCR test more fundamentally represents binder behavior at high temperatures compared to the PG rutting parameter. In addition, the very simplified approach, known as grade-bumping, used in the current PG system to account for high traffic levels and low speed limits can be eliminated when using the MSCR test. The MSCR test also provides a better coefficient of correlation (at both stress levels) with flow number test results than the PG rutting parameter, again indicating that it more accurately reflects binder performance at high temperatures.

Download or read book Rheological Properties of Asphalt Binders written by Ali Behnood and published by . This book was released on 2016 with total page 197 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Superpave specifications and equipment, introduced in 1993, represented a major advancement with respect to offering a better understanding of the behavior and characteristics of asphalt binders based on their rheological properties. However, the Superpave high-temperature test protocol has been shown to be inadequate for characterizing the high-temperature behavior (rutting resistance) of asphalt binders, particularly polymer modified ones. Recently, a specification based on the Multiple Stress Creep Recovery (MSCR) test has been proposed to address the shortcomings of the Superpave high-temperature binder specifications. This study aims to investigate the merits of implementing the MSCR test and specification as a replacement for the conventional high-temperature testing in the Performance Graded (PG) system.

Download or read book Understanding the Performance of Modified Asphalt Binders in Mixtures written by Kevin D. Stuart and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The overall objective of this study was to determine if the Superpave high-temperature rheological properties of polymer-modified asphalt binders correlate to asphalt mixture rutting resistance. An emphasis was placed on evaluating polymer-modified asphalt binders with identical (or close) high-temperature performance grades (PG's), but varied polymer chemistries. Eleven asphalt binders were obtained for this study: two unmodified asphalt binders, an air-blown asphalt binder, and eight polymer-modified asphalt binders. High-temperature asphalt binder properties were measured by a dynamic shear rheometer (DSR). Mixture rutting resistance was measured by repeated shear at constant height (RSCH), and the French Pavement Rutting Tester (French PRT). The first objective was to verify the findings of a previous study using a different aggregate. In the previous study, it was found that the Superpave high-temperature asphalt binder properties correlated to mixture rutting resistance with few outliers, and a change in high-temperature PG from 70 to 76 increased rutting resistance. However, the correlation between RSCH and asphalt binder G*/sind (delta) depended on DSR frequency. The data suggested that a low DSR frequency, such as 0.1 rad/s, might provide a better grading system than the standard DSR frequency of 10.0 rad/s. This would require a change in the current asphalt binder specification. A diabase aggregate was used in a previous study. The data using a second aggregate, a limestone aggregate, in combination with four of the asphalt binders, agreed with the findings from the diabase mixtures. The second objective was to retest the diabase mixtures at 70 degrees Celsius using RSCH. The test temperatures used in the previous study were 50 degrees Celsius for RSCH and 70 degrees Celsius for the French PRT. The polymer-modified asphalt binders had continuous high-temperature PG's ranging from 71 to 77. Therefore, it was recommended that the test temperature for RSCH be increased to 70 degrees Celsius. Again, the correlation between RSCH and G*/sind was dependent on DSR frequency. The data suggested that a low DSR frequency, such as 0.1 rad/s, might provide a better grading system. However, it is not known whether this finding applies to pavements, or is related to the accelerated nature of the RSCH test. Furthermore, G*/sind (delta) at 0.1 rad/s did not clearly provide a better correlation to RSCH than the high-temperature PG's of the asphalt binders. The degree of correlation between the French PRT and G*/sind at 70 degrees Celsius did not depend on DSR frequency, and there was only one outlier. A correlation between the French PRT and high-temperature PG provided no obvious outliers. No changes to the specification are recommended based on the French PRT results.

Download or read book Characterization of the Bonding Fracture Properties of the Asphalt Aggregate System Using a Thin Film Interface Test written by Junyan Yi and published by . This book was released on 2015 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Adhesion between asphalt-aggregate and cohesion within asphalt mastic has a significant effect on the performance of asphalt mixtures. Conventional testing methods and studies normally only focus on one of the damage modes (adhesion or cohesion), although in real asphalt mixtures (asphalt-aggregate system), these two failure modes can happen together depending on the material and loading conditions. The objective of this paper was to characterize the interface bonding characteristics of the asphalt-aggregate system using the thin-film interface test and the fracture property parameter, critical state energy density (CSED), and identify the key factors that could affect the interface bonding characteristics. The thin-film interface test simulated a more realistic bonding condition and monitored the damage between thin-film asphalt and aggregate. Experimental results showed that the effects of temperature and loading rate on the interface bonding characteristics were significant. The time-temperature superposition principle is found to work in both the linear viscoelastic range (dynamic modulus test) and the damage domain (interface bonding fracture test). Binder type, degree of aging, and types of aggregates all played an important role in the bonding performance for an asphalt-aggregate system.

Download or read book Using Mastic Characterization to Predict Asphalt Mixture Low temperature Cracking Behavior written by and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Low temperature performance grading currently relies solely on Bending Beam Rheometer (BBR) for determining low temperature creep stiffness (S) and rate of modulus relaxation (m-value) at 60s, both determined at low stress-strain levels, in the pre-failure zones. This aspect raises questions with regard to applicability of properties derived from the linear viscoelastic range for prediction of asphalt binder thermal cracking behavior. Furthermore, many researchers have reported a discrepancy between field cracking severity and predictions based on asphalt binder properties since the asphalt binder-aggregate interaction is non-existent in asphalt binder testing. Therefore evaluation of asphalt mastics properties which could save a considerable amount of time and equipment in comparison to mixture testing should be prioritized. These challenges indicate that considering fracture properties of asphalt mastics could be a better approach for prediction of thermal cracking in asphalt pavements. It is believed that development of failure master curves for the damage characterization of asphalt mastics at different temperatures and loading rates would be beneficial for better characterization of resistance to thermal cracking. Therefore, in this dissertation a mechanistic approach on the development of such asphalt mastic failure master curves was derived using the new BBR-SENB test for damage resistance characterization. The complexity of the viscoelastic behavior of asphalt mastics in terms of time and temperature dependency is also recognized by the sensitivity of the failure properties to changes in loading time and temperature. This dissertation documents the development, calibration, and validation of a fundamental analysis framework of asphalt mixtures thermal cracking behavior using asphalt mastics as the continuous phase of these mixtures. Key conceptual components of this study include applying time temperature superposition principles to large strain failure properties, development of asphalt mastic failure master curves, and investigating relationship between mastic viscosity and aggregate structure of asphalt mixtures in the context of thermo-volumetric properties of mixtures. An analysis framework for predicting thermal cracking of asphalt mixtures was developed which include considering asphalt mastics, aggregate internal structure and temperature dependent thermo-volumetric properties. Results where compared to experimental data measured using the ATCA device, which allowed measuring strain and stress build up during cooling.

Download or read book Effects of Climate Aging and Traffic in Characterization of Asphalt Binder Fatigue Using the Las Test written by Hui Chen (Ph.D.) and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The linear amplitude sweep (LAS) test is considered a useful tool for evaluating fatigue of asphalt binders. The effects of oxidative aging, temperature, and loading frequency remain difficult to measure or model in a simple format. In this study, the combined effects of strain, aging and temperature are investigated using the LAS procedure, and a method for estimating binder fatigue behavior at different combinations of these effects from limited measurements is introduced. Recently, the Glover-Rowe (G-R) parameter has also been introduced as a measure of binder cracking resistance and its change with oxidative aging. This approach differs than the LAS in the time required for testing, the range in strain used, and temperature of the tests required to derive the binder fatigue parameters. In addition, there is confusion about what could be the specification acceptance limits to be used and how to consider the temperature of pavement, and traffic volume and speed in the specification criteria for the G-R. In this study, the effect of strain using in testing on the G-R parameter are investigated and a modified criterion for using it in specifications with accounting for traffic conditions and temperature, are introduced. The results of this study show that LAS parameters, A and B, after different aging durations or at different temperatures, have a good relationship with the binder complex modulus (G*) measured at the corresponding conditions. Therefore, a new fatigue life (Nf) model accounting for strain level, temperature and aging is proposed using a power function of the binder G*. The model offers a simple reliable method to predicted values of fatigue life at a wider range of aging, temperature and strain level conditions. Following the concept of Jnr limits for different traffic grades used for the Multiple Stress Creep and Recovery (MSCR) test, the threshold values of the allowable strain in LAS results, and maximum allowable G-R limits, under different traffic volume and speed conditions are defined. Similar to the MSCR approach, four fatigue traffic grades including S, H, V, and E are used in the proposed criteria. To verify that the LAS and G-R parameters are related to asphalt mixtures cracking resistance, and that the binder specification limits are logical, the results of binder testing are compared with mixture testing results and the comparison show clear evidence of the role of binders in mixture behavior in the IDEAL-CT mixture tests.

Download or read book Effects of Climate Aging and Traffic in Characterization of Asphalt Binder Fatigue Using the Las Test written by Hui Chen (Ph.D.) and published by . This book was released on 2021 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The linear amplitude sweep (LAS) test is considered a useful tool for evaluating fatigue of asphalt binders. The effects of oxidative aging, temperature, and loading frequency remain difficult to measure or model in a simple format. In this study, the combined effects of strain, aging and temperature are investigated using the LAS procedure, and a method for estimating binder fatigue behavior at different combinations of these effects from limited measurements is introduced. Recently, the Glover-Rowe (G-R) parameter has also been introduced as a measure of binder cracking resistance and its change with oxidative aging. This approach differs than the LAS in the time required for testing, the range in strain used, and temperature of the tests required to derive the binder fatigue parameters. In addition, there is confusion about what could be the specification acceptance limits to be used and how to consider the temperature of pavement, and traffic volume and speed in the specification criteria for the G-R. In this study, the effect of strain using in testing on the G-R parameter are investigated and a modified criterion for using it in specifications with accounting for traffic conditions and temperature, are introduced. The results of this study show that LAS parameters, A and B, after different aging durations or at different temperatures, have a good relationship with the binder complex modulus (G*) measured at the corresponding conditions. Therefore, a new fatigue life (Nf) model accounting for strain level, temperature and aging is proposed using a power function of the binder G*. The model offers a simple reliable method to predicted values of fatigue life at a wider range of aging, temperature and strain level conditions. Following the concept of Jnr limits for different traffic grades used for the Multiple Stress Creep and Recovery (MSCR) test, the threshold values of the allowable strain in LAS results, and maximum allowable G-R limits, under different traffic volume and speed conditions are defined. Similar to the MSCR approach, four fatigue traffic grades including S, H, V, and E are used in the proposed criteria. To verify that the LAS and G-R parameters are related to asphalt mixtures cracking resistance, and that the binder specification limits are logical, the results of binder testing are compared with mixture testing results and the comparison show clear evidence of the role of binders in mixture behavior in the IDEAL-CT mixture tests.

Download or read book Evaluation of the Effects of Asphalt Binder on the Properties of Hot Mix Asphalt at Intermediate Temperatures written by Haifang Wen and published by . This book was released on 2011 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The asphalt binder is an essential component of asphaltic mixtures. The performance of an asphaltic mixture is directly related to mechanical characteristics of the binder. With the development of new material characterization methods for both asphalt binder and asphaltic mixture, there is a need to re-evaluate the relationship between the properties of binders and asphaltic mixtures such that a proper understanding and selection of an asphalt binder can be made to improve the performance of an asphaltic mixture. In this study, the effects of asphalt binder properties on asphaltic mixtures at intermediate temperatures were evaluated based on recent developments on material characterization methods for both binder and asphaltic mixture. Five asphalt binders and five asphalt mixtures containing these binders with one aggregate were tested. Four of the binders were based on a modification of a base binder with different techniques. Complex shear modulus and monotonic constant shear-rate tests were conducted on asphalt binders, whereas dynamic modulus and indirect tensile strength tests were conducted on the mixtures. The effects of modification techniques on the properties of asphalt binders and the relationships between the properties of binders and asphaltic mixtures were evaluated in this study.

Download or read book Rheological and Rutting Characterization of Asphalt Mixes with Modified Binders written by S. Anjan kumar and published by . This book was released on 2012 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the results of investigations on the rheological properties of modified asphalt binders and their influence on the performance of asphalt mixes. Asphalt mixes with modified binders such as styrene butadiene styrene polymer, crumb rubber, natural rubber, and waste plastics were evaluated for their rheological properties and compared to the properties of asphalt mixes with unmodified VG30 (viscosity grade) asphalt binder. The dynamic modulus values and rutting characteristics of the asphalt mixes were studied with due consideration to different levels of aging and temperature variations. Studies on the rheological properties showed that the energy dissipated by unmodified asphalt (VG30) binder is higher than that of modified asphalt binders. Long-term aged natural rubber and waste plastic modified asphalt binders showed significant increase in the properties compared to unmodified asphalt binder (VG30). Reduced temperature susceptibility of polymer modified asphalt binder showed that only polymer modification can enhance both high temperature rutting resistance and low temperature thermal cracking resistance of asphalt mixes. The transient nature of polymer modified asphalt mix from viscoelastic solid-like to viscoelastic fluid-like condition is significantly shifted to higher temperature compared to that of the mix with unmodified asphalt binder. Aging and rutting indices showed that rubber modified asphalt mixes are highly susceptible to aging. Statistical analysis of test results showed that the process of modification of asphalt binder, aging, and temperature during the test influence the rheological and rutting characteristics of asphalt mixes significantly. Correlation between the asphalt binder properties and its influence on the rutting resistance are found to be statistically significant. The analysis using least significant difference showed that polymer modified asphalt binder significantly improves the aging and rutting resistance of asphalt mixes compared to unmodified asphalt binder.

Download or read book Characterization of Failure Properties of Asphalt Binder written by DA. Anderson and published by . This book was released on 1995 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the characterization of the uniaxial failure properties of the eight core asphalt cements from the Strategic Highway Research Program (SHRP). Uniaxial tensile failure properties of asphalts are highly dependent on temperature and loading (elongation) rate. The tensile failure properties of the eight core asphalts were obtained for various temperatures ranging from -30 to 0°C (22 to 30°F) and elongation rates ranging from 2.5 to 50 mm/min (0.1 to 2 in/min). Mastercurves were obtained for failure stress, failure strain, and failure energy versus loading time using time-temperature superposition. The time-temperature shift factors were obtained from rheological studies of asphalts using dynamic mechanical testing conducted separately but as a part of the same project. A function describing the failure mastercurves was developed.

Download or read book Physical Properties of Asphalt Cement Binders written by John C. Hardin and published by ASTM International. This book was released on 1995 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: A dozen papers from a December 1993 symposium in Dallas/Fort Worth, Texas. Among the topics are why the new proposed rheological properties of asphalt binders are required and how they compare to conventional properties, the development and use of the SHRP direct tension specification test, oxidatio

Download or read book Deformation Characteristics of Geomaterials written by V.A. Rinaldi and published by IOS Press. This book was released on 2015-12-11 with total page 1236 pages. Available in PDF, EPUB and Kindle. Book excerpt: In November 2015, Buenos Aires, Argentina became the location of several important events for geo-professionals, with the simultaneous holding of the 6th International Symposium on Deformation Characteristics of Geomaterials, the 15th Pan-American Conference on Soil Mechanics and Geotechnical Engineering (XV PCSMGE), the 8th South American Congress on Rock Mechanics (SCRM), as well as the 22nd Argentinean Congress of Geotechnical Engineering (CAMSIGXXII). This synergy provided a unique opportunity to exchange ideas and discuss current and future practices in the areas of soil mechanics and rock mechanics, and their applications in civil, energy, environmental, and mining engineering. This book presents the proceedings of the 6th International Symposium on Deformation Characteristics of Geomaterials. As well as 118 articles selected for publication after peer review, it includes 7 lectures delivered by invited keynote speakers and the Third Bishop Lecture, delivered by Professor Herve Di Benedetto of the University of Lyon, France, who presented a reference work on the advanced testing and modeling of bituminous bounded and unbounded granular materials. The conference brought together practitioners, researchers and educators from around the world engaged in the understanding of the deformation properties of geo-materials before failure, and the small strain parameters as fundamental characteristics of geo-materials. The main topics covered by the symposium include experimental investigations from very small strains to beyond failure, including multi-physical approach; HTC M coupling behavior, characterization and modeling of various geo-materials and interfaces; and practical prediction and interpretation of ground responses: field observation and case histories.