Research on the influence factors of asphalt rubber mixture fatigue performance

Author(s):  
Ge Xuanrui
Author(s):  
Veena Venudharan ◽  
Krishna Prapoorna Biligiri

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.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1200 ◽  
Author(s):  
Cheng ◽  
Liu ◽  
Ren ◽  
Huang

Crumb rubber, as a recycled material used in asphalt mixture, has gained more attention in recent years due to environmental benefits and the advantages of its pavement, such as excellent resistance to cracking, improved durability, less road maintenance, lower road noise, etc. However, the high-temperature performance of mixture with crumb rubber does not perform well. In order to improve the performance, this paper examined the effect of additives on the laboratory performance of asphalt rubber Stone Matrix Asphalt (AR-SMA) with additives. Three groups of AR-SMA: no additives, Styrene–Butadiene–Styrene (SBS) and Granular Polymer Durable additive (GPDa) were included, with no additives as a control group. Each group was investigated at three asphalt rubber content (ARC): 6.4%, 6.9%, 7.4% with regard to high-temperature and fatigue properties. The results show that with increasing ARC, the high-temperature performance of mixture without additive decreases, and the high-temperature performance increases first and then decreases for SBS and GPDa. Moreover, the rutting resistance of AR-SMA with GPDa at 6.9% ARC performs best. Under the condition of mixtures with appropriate ARC, AR-SMA with GPDa has higher fatigue life and sensitivity to fatigue cracking than the control group. Simultaneously, the fatigue performance of AR-SMA with GPDa is not as significant as that without additive with increasing ARC. In a word, GPDa is a good choice to improve the performance of AR-SMA. However, it should be noted that optimal asphalt content of AR-SMA mixtures with GPDa is higher than that of traditional mixtures.


2018 ◽  
Vol 8 (9) ◽  
pp. 1495 ◽  
Author(s):  
Jiangmiao Yu ◽  
Xianshu Yu ◽  
Zheming Gao ◽  
Feng Guo ◽  
Duanyi Wang ◽  
...  

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.


2012 ◽  
Vol 598 ◽  
pp. 603-607 ◽  
Author(s):  
Lan Wang ◽  
Xiao Hui Meng ◽  
Li Qing Pan ◽  
Ji Quan Zhang

In order to evaluate the shear performance of the rubber powder modified asphalt mixture, we do the triaxial test of Asphalt-Rubber mixture at specified temperature, which use the United States GCTS STX-100 two-way vibration triaxial test system. Through the result of the test, we analysis the factors affecting the shear resistance of asphalt mixture such as modification agent,confining pressure, gradation type and also get the mechanical properties of the asphalt mixture in the triaxial stress state.


2012 ◽  
Vol 535-537 ◽  
pp. 1819-1824 ◽  
Author(s):  
Ai Hong Kang ◽  
Qin Zhang ◽  
Ping Li

It’s a chemical method that adding TOR into asphalt rubber to be TOR asphalt rubber mixture. In this study, 70# basic asphalt from Nanjing Jinling Company and 60 mesh waste rubber powder from Jiangyan Honglei Company were chosen for the SMA13 grading and SUP13 grading by the best preparation technology. The high temperature stability, anti-cracking performance and water stability of TOR asphalt rubber mixture were studied and the influence of dry and wet molding process on road performance of TOR asphalt rubber mixture was compared. The results show that both the dynamic stability and the low-temperature cracking performance of wet forming specimens are better than the dry process. The water stability of wet molding process is also slightly better than the dry process. And expansion rate tests were carried out on asphalt mixtures prepared by dry and wet forming processes on continuous gradation and discontinuous gradation to validate the applicability of discontinuous gradation to asphalt rubber.


2013 ◽  
Vol 96 ◽  
pp. 31-38 ◽  
Author(s):  
Yi Wang ◽  
Jingwen Zhu ◽  
Liping Liu ◽  
Lijun Sun

1998 ◽  
Vol 26 (4) ◽  
pp. 306
Author(s):  
DR Petersen ◽  
RE Link ◽  
DG Goulias ◽  
AH Ali

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