The effect of wax structures and chemical activated scrap rubber on performance of warm rubberized bitumen: insights from model wax compounds

Zhang, Haopeng, Khan, Saad, Zhang, Li, Li, Hui, Khair, Abul, Wang, Haopeng ORCID: 0000-0002-5008-7322, Pan, Jie, Du, Qunle and Ncube, Mthokozisi Hillary (2025) The effect of wax structures and chemical activated scrap rubber on performance of warm rubberized bitumen: insights from model wax compounds FUEL, 402. 136034-. ISSN 0016-2361, 1873-7153

Microsoft Word Revised manuscript with changes marked-wax on warm CRMB.doc - Author Accepted Manuscript Download (29MB)

Abstract

Warm rubberized bitumen (WRB) has potential applications in sustainable asphalt pavements. This paper investigates the influence of chemical structures of wax-based additives on the rheological performance of crumb rubber modified bitumen (CRMB), with the goal of enhancing the understanding of how chemical activation of crumb rubber (CR) affects the performance of WRB at wide temperatures. The results show that CR improves the high-temperature rutting resistance and intermediate-temperature fatigue resistance of bitumen, while chemical activation has the opposite effect on rutting resistance and nearly has no effect on fatigue life. Wax-based additives with long carbon chains improve the high-temperature rutting resistance but deteriorate the fatigue life of inactivated and activated CRMB. The addition of inactivated and activated CR reduces the physical hardening degree of bitumen, and CR after chemical activation has a more significant influence. Nevertheless, waxes are the main contributors to the physical hardening of CRMB. Moreover, the strain sweep test at 5 °C shows potential to characterize low-temperature cracking resistance, and the increased internal stresses in CRMB and WRB caused by isothermal hardening can elevate the cracking risks of asphalt pavement at low temperatures. Overall, this investigation provides valuable insights into the mechanism of the effect of wax structures and grafting-activated recycled rubber on the performance of WRB, which offer guidance for the development of environmentally friendly WRB materials.

Item Type:	Article
Uncontrolled Keywords:	Warm rubberized bitumen, Wax structures, Recycled rubber, Chemical activation, Rheological performance at wide temperatures, Physical hardening
Divisions:	Faculty of Science & Engineering Faculty of Science & Engineering > School of Engineering Faculty of Science & Engineering > School of Engineering > Civil and Environmental Engineering
Depositing User:	Symplectic Admin
Date Deposited:	13 Nov 2025 11:45
Last Modified:	16 Jun 2026 09:35
DOI:	10.1016/j.fuel.2025.136034
Related Websites:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3195372
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