Mechanistic Assessment of Fatigue Performance and Cost Analysis of Pavement Overlays: Comparison between Conventional Hot Mixed Asphalt, Asphalt Rubber, and Polymer-Modified Mixtures

2019 ◽  
Vol 8 (1) ◽  
pp. 20190118
Author(s):  
Hemant Gc ◽  
Mena I. Souliman ◽  
Waleed Zeiada ◽  
Mayzan Isied
Keyword(s):  
Cost Analysis ◽  
Fatigue Performance ◽  
Asphalt Rubber ◽  
Hot Mixed Asphalt

Conceptualization of Three-Stage Fatigue Failure in Asphalt-Rubber Gap-Graded Mixtures using Dynamic Semi-Circular Bending Test

2020 ◽  
Vol 2674 (7) ◽  
pp. 44-55
Author(s):  
Veena Venudharan ◽  
Krishna Prapoorna Biligiri
Keyword(s):  
Failure Process ◽  
Mouth Opening ◽  
Fatigue Performance ◽  
Bending Test ◽  
Crack Mouth Opening Displacement ◽  
Fatigue Process ◽  
Structural Deterioration ◽  
Asphalt Rubber ◽  
Scb Test ◽  
Cracking Mechanism

The objective of this study was to qualitatively measure the cracking mechanism of asphalt-rubber gap-graded (AR-Gap) mixtures and compare the methodical approach proposed in this research with the conventional fatigue process. As part of experimentation plan, dynamic a semi-circular bending (SCB) test was conducted on 27 AR-Gap mixtures with varying mix parameters, including, binder type, binder content, and aggregate gradation. Fatigue life ( Nf) obtained from the dynamic SCB test was analyzed from a statistical viewpoint, and key relationships that potentially contribute to fatigue performance were identified. Later, crack mouth opening displacement (CMOD) was used to study the cracking mechanism of AR-Gap mixtures. CMOD data were analyzed using the Francken model that theorizes the accumulated damage as a three-stage failure. Further, fatigue tertiary life ( Nft) was determined on the premise of structural deterioration obtained from the three-stage failure process. The fatigue disparity factor (ξ), the ratio of Nf to Nft for each asphalt mix was estimated to compare fatigue performance indices. The score of ξ for all the mixtures exceeded 50%, which was indicative of longer crack initiation and crack propagation phase over the third stage of the fatigue cracking mechanism. Overall, the fatigue mechanism was explained through the conceptualization of the three-stage fatigue process through various intrinsic properties of AR-Gap mixtures.

scholarly journals Fatigue Resistance Characterization of Warm Asphalt Rubber by Multiple Approaches

2018 ◽  
Vol 8 (9) ◽  
pp. 1495 ◽  
Author(s):  
Jiangmiao Yu ◽  
Xianshu Yu ◽  
Zheming Gao ◽  
Feng Guo ◽  
Duanyi Wang ◽  
...  
Keyword(s):  
Fatigue Test ◽  
Fatigue Resistance ◽  
Crumb Rubber ◽  
Waste Recycling ◽  
Fatigue Performance ◽  
Four Point Bending ◽  
Asphalt Rubber ◽  
Shear Fatigue ◽  
Tensile Fatigue ◽  
Indirect Tensile

Warm asphalt rubber (WAR) mixture is a sustainable paving material with advantages including waste recycling and noise reducing. A comprehensive understanding of the fatigue performance of WAR specimens is helpful to its wide application. However, research on evaluating the fatigue performance of WAR binder and mixtures is very limited. This paper applies five fatigue analysis approaches to evaluate the fatigue life of WAR samples with three different warm mix asphalt (WMA) additives. The conventional G*sinδ, linear amplitude sweep (LAS), indirect tensile fatigue test (ITFT), and four-point bending beam (4PB) test were conducted based on available standards. In addition, a novel shear fatigue test was performed on WAR mortars. Test results indicated that the incorporation of crumb rubber has a significantly positive effect on fatigue resistance. WAR with chemical and foaming additives exhibited a poorer performance than asphalt rubber (AR), but their fatigue performance was still greatly superior to the non-rubberized samples. Finally, LAS as well as mortar shear fatigue and 4PB tests provided the same prediction of fatigue resistance, while the results of G*sinδ and the ITFT were inconsistent. It is recommended to use LAS, the mortar shear fatigue test, and the 4PB test for the fatigue resistance evaluation of rubberized specimens. The validation of the findings with more materials and field performances is recommended.

Mechanistic-Empirical Simulations and Life-Cycle Cost Analysis to Determine the Cost and Performance Effectiveness of Asphalt Mixtures Containing Recycled Materials

2018 ◽  
Vol 2672 (40) ◽  
pp. 143-154 ◽  
Author(s):  
Erdem Coleri ◽  
Yuqi Zhang ◽  
Blaine M. Wruck
Keyword(s):  
Life Cycle ◽  
Cost Analysis ◽  
Life Cycle Cost ◽  
Binder Content ◽  
Asphalt Mixtures ◽  
Fatigue Performance ◽  
Asphalt Pavements ◽  
Life Cycle Cost Analysis ◽  
Cost Benefits ◽  
The Cost

Use of reclaimed asphalt pavements (RAP) and recycled asphalt shingles (RAS) in asphalt paving, although considered as sustainable, is a practice that agencies are reluctant to employ because of the unpredictability of asphalt mixes containing recycled materials. The asphalt binder in RAP/RAS is aged and stiffened, which reduces ductility of the pavement. Consequentially, a pavement can exhibit unsatisfactory fatigue performance and have the potential for early cracking failure. Although methods exist to counteract the brittle behavior of pavements containing RAP/RAS (namely binder-grade bumping, binder-grade dumping and high binder content), they are not accounted for in mechanistic-empirical (ME) pavement design. Additionally, the cost benefits of using RAP/RAS in pavements are not easily calculated. For these reasons, characterization of fatigue performance for asphalt pavements containing RAP/RAS in ME design software needs to be accomplished and a life-cycle cost analysis (LCCA) framework for pavements containing RAP/RAS needs to be developed so that agencies can make informed decisions about RAP/RAS use in asphalt mixtures. In this study, laboratory test results for asphalt mixtures with different combinations of RAP/RAS contents, binder contents, and binder types were used to calculate ME pavement model coefficients to perform forward calculations to determine pavement performance. Using predicted performance from ME models, LCCAs were conducted to determine the cost benefits of using binder-grade bumping/dumping and high binder content in Oregon asphalt mixtures. These strategies are expected to increase RAP/RAS use in asphalt mixtures, reduce life-cycle costs, improve the cracking performance and encourage widespread use of RAP/RAS asphalt mixtures.

Evaluation and Validation of Fatigue Testing Methods for Rubberized Bituminous Specimens

2019 ◽  
Vol 2673 (8) ◽  
pp. 603-610 ◽  
Author(s):  
Huayang Yu ◽  
Zihan Zhu ◽  
Duanyi Wang
Keyword(s):  
Fatigue Test ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
Crumb Rubber ◽  
Fatigue Performance ◽  
Organic Chemical ◽  
Poor Correlation ◽  
Test Results ◽  
Asphalt Rubber ◽  
Shear Fatigue

Several fatigue evaluation methods are available to evaluate the durability of bituminous materials. In some cases, the test results may provide poor correlation with the true fatigue performance, especially when additives with complicated components are incorporated. This study aims to characterize the fatigue behavior of different warm asphalt rubber (WAR) specimens modified by both crumb rubber and warm mix asphalt (WMA) additives, and to validate the feasibility of binder and mortar fatigue tests on WAR. Three WARs with organic, chemical, and foaming additives were prepared. G*sin δ and liner amplitude sweep (LAS) tests (on both binders and liquid phases), and the shear fatigue test (on mortars) were performed. The four-point bending beam (4PB) test was used as reference to validate results of binder, liquid phase, and mortar tests. Test results indicated that the fatigue performance of virgin bitumen is obviously improved by crumb rubber. The selected organic additive contributes to superior fatigue resistance, whereas WARs with foaming and chemical WMA modifiers performed more poorly than asphalt rubber in relation to fatigue, but still much better that the non-rubberized samples. Finally, it is noted that for the rubberized bituminous specimens, LAS evaluation for asphalt binder and the shear fatigue test for asphalt mortar provide same prediction as the 4PB test, whereas other tests give inconsistent results. Therefore, it is suggested to use the 4PB test on mixture, the LAS test on binder, and the shear fatigue test on mortar for fatigue performance characterization of bituminous specimens containing crumb rubber particles. Further validation of the above findings on field specimens is suggested.

Cost Analysis: A Methodological Statement

1989 ◽  
Vol 7 (1) ◽  
pp. 27-41 ◽  
Author(s):  
Norman Keith Womer
Keyword(s):  
Cost Analysis
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