1. Analysis of the Rheological Performance of Composite Asphalt Rubber and the Influence of Gradation Types on its Mixture Prepared Under the Optimal Specifications.
- Author
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Haibin Li, Chengxue Zhang, Xiaolong Zou, Wenbo Li, Guijuan Zhao, Qingwei Ma, Ping Guo, and Yanping Sheng
- Subjects
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ASPHALT , *ASPHALT modifiers , *RUBBER , *CRUMB rubber , *HIGHWAY engineering , *RHEOLOGY , *CHEMICAL reactions - Abstract
The novel crumb rubber (CR)/styrene-butadiene-styrene (SBS) composite modified asphalt has shown through various researches to have a better engineering performance than many commonly used modified asphalts. On the basis of the optimal preparation scheme of composite asphalt rubber, dynamic shear rheology (DSR) test was conducted to evaluate the rheological property of the modified asphalt, and performance tests were conducted on the composite asphalt rubber mixture. The influence of gradation type and anti-rutting agent on its mixture's performance improvement was then summarized. Three different micro analysis test methods were used to observe the distribution and morphological changes of the modifier in the asphalt. Furthermore, the subsequent physical and chemical reactions that occurred between asphalt and modifier during the modification process were also studied. The results showed that the viscosity of composite asphalt rubber decreased as shear time increased. The rutting factor and the creep rate of the composite asphalt rubber were about 77.9% and 4.4%, respectively, both higher than that of the asphalt rubber. Meanwhile, when compared with the anti-rutting agent used in practical engineering, the high-temperature performance of HXR-I (anti-rutting agent) was improved by 45.3%, the low-temperature performance was improved by 6.3%, and the water stability was improved by 17.8%. The microscopic test results showed that the rubber particles in the composite asphalt rubber swelled and were wrapped by asphalt and distributed around the aggregate. At the same time, it also illustrated that adding anti-rutting agent can improve the performance of the composite asphalt rubber in an effective way, which could adequately meet the required low-temperature performance, thus expanding its application in road engineering. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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