Characterization of Permanent Deformation of Asphalt Mixtures with Minimum Strain Rate, LVECD Program, and Triaxial Stress Sweep Test

2017 ◽  
Vol 2631 (1) ◽  
pp. 96-104 ◽  
Author(s):  
Dahae Kim ◽  
Y. Richard Kim
Keyword(s):  
Permanent Deformation ◽  
Single Layer ◽  
Asphalt Mixtures ◽  
Triaxial Stress ◽  
Structural Level ◽  
Flow Number ◽  
Specific Test ◽  
Rutting Resistance ◽  
Testing Effort ◽  
Repeated Load

The rutting resistance of asphalt concrete is typically assessed by using flow number tests in the lab in accordance with AASHTO TP 79. However, the flow number represents the rutting resistance of the material with regard to ranking for only a specific test condition. A significant amount of testing effort is needed to evaluate rutting resistance by using the flow number test under various loading conditions and temperatures. Therefore, researchers have developed alternative test methods to reduce the testing effort. For example, the incremental repeated-load permanent deformation test and the triaxial stress sweep (TSS) test are two promising protocols that can predict the permanent deformation of asphalt mixtures efficiently and accurately. This study compares the minimum strain rates (MSRs) obtained from incremental repeated-load permanent deformation and TSS tests to examine the ability of the TSS test to analyze the MSRs of asphalt mixtures. In addition, the viscoplastic shift model calibrated from the TSS test that is implemented in the layered viscoelastic pavement analysis for critical distresses (LVECD) program was used to predict the rut depths of 16 pavement sections from four sources. The MSRs and rut depths predicted from the LVECD program were compared with actual measured rut depths. The results of this study indicated that the MSR results could only be used to rank the rutting susceptibility of single-layer asphalt pavements. For a multilayered pavement system, structural level analysis is necessary to predict the accurate rutting performance and rut depths of the test sections.

Expedited Testing Program for Performance Characterization of Asphalt Mixtures

2019 ◽  
Vol 2673 (12) ◽  
pp. 225-233
Author(s):  
Intikhab Haidar ◽  
Charles W. Schwartz ◽  
Sadaf Khosravifar
Keyword(s):  
Permanent Deformation ◽  
Performance Testing ◽  
Testing Procedure ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Test Specifications ◽  
Research Grade ◽  
Repeated Load ◽  
Lengthy Process

The past two decades have seen significant efforts to standardize a series of simplified test methods to characterize the dynamic modulus (DM) and repeated load permanent deformation (RLPD) performance characteristics of asphalt mixtures using the asphalt mixtures performance tester (AMPT). While the current AASHTO T 79 test specifications for the AMPT are faster and easier to perform than their preceding research grade test protocols, there is still reluctance among highway agencies and industry to conduct performance testing using the AMPT. One significant reason is the lengthy process of sample preparation and testing for the DM and RLPD tests. Two studies to expedite this process are reported here. First, the potential for abbreviating the DM testing procedure was examined. It provides the option to fully exclude testing at 40°C by adding an additional frequency of 0.01 Hz at 20°C. This approach reduces time for testing as well as for sample conditioning at high temperature. Second, the possibility of reducing the total number of required specimens was evaluated. The variation of the DM under repetitive testing and the appropriateness of performing the RLPD test on samples already tested for DM were evaluated. The results showed that specimen damage or densification because of DM testing is insignificant. As a consequence, DM test specimens can be re-used for RLPD testing, reducing the required number of samples from 12 to 9.

Numerical and Graphical Method to Assess Permanent Deformation Potential for Repeated Compressive Loading of Asphalt Mixtures

2000 ◽  
Vol 1723 (1) ◽  
pp. 150-158 ◽  
Author(s):  
Rajesh K. Bhairampally ◽  
Robert L. Lytton ◽  
Dallas N. Little
Keyword(s):  
Strain Energy ◽  
Graphical Method ◽  
Permanent Deformation ◽  
Compressive Loading ◽  
Hydrated Lime ◽  
Numerical Approach ◽  
Empirical Models ◽  
Asphalt Mixtures ◽  
Deformation Potential ◽  
Repeated Load

Repeated-load permanent deformation testing has long been a popular way to characterize the performance of asphalt mixtures and to account for damage that leads to rutting. A number of empirical models have been used to fit repeated-load permanent deformation data. One such model, developed by Tseng and Lytton in 1989, fits permanent deformation data of most asphalt mixtures well. However, some mixtures exhibit a rate of damage that is in excess of that predicted by the 1989 Tseng and Lytton model. A numerical adaptation of the Tseng and Lytton empirical model is presented that readily characterizes such damage-susceptible mixtures. The excessive rate of damage is explained and reconciled in terms of plastic work theory and dissipated strain energy. The numerical approach is used to demonstrate the corrective effects of two types of additives to the mixtures: a recycled coproduct and hydrated lime.

scholarly journals Rutting Resistance Evaluation of Structural Combinations of Asphalt Pavement Subjected to Heavy Duty

2012 ◽  
Vol 5 ◽  
pp. 316-321 ◽  
Author(s):  
Ze Jiao Dong ◽  
Xiang Bing Gong ◽  
Gui Qing Xiao ◽  
Teng Long
Keyword(s):  
Structural Design ◽  
Design Method ◽  
Asphalt Pavement ◽  
Single Layer ◽  
Asphalt Mixtures ◽  
Heavy Duty ◽  
Wheel Load ◽  
Rutting Resistance ◽  
Pavement Structures ◽  
Resistance Performance

Rut，referred to as a common damage of asphalt pavement ，is still a knotty problem to pavement researchers. Many reasons could cause rut, among which heavy duty, improper pavement structural combination design are two principal factors. As a result, three pavement structures and seven types of asphalt mixtures were used to evaluate the rutting resistance performance of different structural combinations. At first, through Marshall design method, the properties of asphalt mixtures were obtained such as gradation, asphalt content and so on. Based on the comparison of gradations and anti-rutting additives, the single layer rut was tested by wheel tracking test. Then, in order to consider influence of pavement structural design on pavement rut, six types of structure combinations under identical heavy duty condition were designed to perform rutting test. It shows that anti-rutting gradation and anti-rutting additives can improve rutting resistance performance of single layer. Also, a proper structural design could provide a better bearing capacity of wheel load even for heavy duty. It is better to integrate the anti-rutting gradation and anti-rutting additives into structural design. In this paper the results provide some new insight into the relationship between rutting resistance and mixture gradation, anti-rutting additives, heavy duty and structural combination. The consideration of these factors will give a better pavement design.

Permanent deformation response parameters of asphalt mixtures for a new mix-confined repeated load test

2013 ◽  
Vol 20 (5) ◽  
pp. 1434-1442 ◽  
Author(s):  
Gong-yun Liao ◽  
Yi-wen Yang ◽  
Xiao-ming Huang ◽  
Jin-yuan Xiang
Keyword(s):  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Load Test ◽  
Deformation Response ◽  
Repeated Load

scholarly journals Evaluation of permanent deformation of asphalt rubber using multiple stress creep recovery tests and flow number tests

TRANSPORTES ◽  
2020 ◽  
Vol 28 (2) ◽  
pp. 76-86
Author(s):  
Luis Miguel Gutierrez Klinsky ◽  
Vivian Silveira dos Santos Bardini ◽  
Valeria Cristina De Faria
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixtures ◽  
Creep Recovery ◽  
Excellent Correlation ◽  
Flow Number ◽  
Multiple Stress ◽  
Asphalt Rubber ◽  
Modified Binders ◽  
Multiple Stress Creep Recovery

This study used the Multiple Stress Creep Recovery Test (MSCR) and the Flow number test to analyze the characteristics of asphalt rubber and its use in hot mix asphalt (HMA) regarding to their ability to withstand permanent deformation. MSCR tests were done in three commercial asphalt rubber and in the traditional asphalt binder 50/70. Flow number tests were performed in twenty four specimens of asphalt rubber mixtures and eight specimens of conventional asphalt mixtures. The results of these tests showed that all the asphalt rubber samples had lower compliance values (Jnr) in the MSCR test, which denotes that these modified binders improved the rutting resistance of HMA. This behavior was confirmed with flow number results, since the HMA produced with asphalt rubber had always higher flow number values, when compared to the conventional asphalt mixtures. The analysis of the data showed excellent correlation between Jnr values and FN values.

scholarly journals Rutting mechanisms and advanced laboratory testing of asphalt mixtures resistance against permanent deformation

2011 ◽  
Vol 9 (3) ◽  
pp. 407-417 ◽  
Author(s):  
Miomir Miljkovic ◽  
Martin Radenberg
Keyword(s):  
Traffic Safety ◽  
Triaxial Compression ◽  
Permanent Deformation ◽  
Asphalt Pavements ◽  
Flow Number ◽  
Potential Link ◽  
Deformation Test ◽  
Test Flow ◽  
Repeated Load

Permanent deformation in asphalt layers which manifestation on pavement surface is named rutting represents one of the most significant distresses of asphalt pavements. Depending on the level, it can be a huge inconvenience for traffic safety, driving comfort, and overall pavement life-cycle. Rutting may be classified into three basic types: one-dimensional or vertical compaction, lateral flow or plastic movement, and mechanical deformation. As an addition to Superpave? mixture volumetric design three, so called, simple performance tests (SPT) were recommended. Each of these tests in conduced in uniaxial or triaxial compression of cylindrical specimens. They cover the determination of dynamic modulus, repeated load permanent deformation test (flow number), and static load permanent deformation test (flow time). These tests provide relatively good insight in on-site mixture performance. An application of these tests provides a potential link between mixture design and structural analysis that was an underlying goal of substantial amount of earlier flexible pavement researches.

scholarly journals Characterization of neat and modified asphalt binders and mixtures in relation to permanent deformation

2019 ◽  
Vol 26 (1) ◽  
pp. 379-387
Author(s):  
Iuri S. Bessa ◽  
Márcia M. Takahashi ◽  
Kamilla L. Vasconcelos ◽  
Liedi L. B. Bernucci
Keyword(s):  
Permanent Deformation ◽  
Asphalt Binder ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Asphalt Binders ◽  
Rutting Resistance ◽  
Modified Asphalt ◽  
Recoverable Compliance ◽  
Modified Binder ◽  
Deformation Tests

AbstractThe addition of polymers on asphalt binders aims to enhance their performance, especially at high temperatures, which correspond to rutting resistance. The Superpave rutting parameter (|G*|/sinδ) has been considered to be inadequate to characterize the performance of modified materials, therefore the Multiple Stress Creep and Recovery (MSCR) test was developed, providing the parameter non-recoverable compliance (Jnr). This research has the main objective of correlating asphalt binders performance-based characterization with rutting resistance of asphalt mixtures, and presents results obtained for one conventional (50/70 penetration grade) and two modified asphalt binders (2.1% RET and 1.9% RET) regarding their rheological characteristics. With the use of the dynamic shear rheometer (DSR), master curves and MSCR results were obtained for the three binders. In addition, permanent deformation tests were performed on the asphalt mixtures by means of laboratory traffic simulation. The rutting characterization indicated higher permanent deformation resistance for the modified binders for the asphalt binder and the asphalt mixture testing. The main conclusions were that the use of modified binder reduced in approximately 50% the Jnr values and the rut depth; also, the asphalt binders’ characteristics were able to predict the asphalt mixtures rutting resistance.

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