Performance evolution and technique optimization of crumb rubber modified bitumen under thermal effect throughout the production and construction process

Abstract

Crumb rubber modified bitumen (CRMB) offers an eco-friendly solution for recycling end-of-life tires (ELTs). Crumb rubber in hot bitumen will maintain swelling over an extended period under the thermal effect, forming a strengthened gel-like structure which is the critical factor behind the superior service performance of CRMB. Current research mainly focuses on the CRMB performance prepared with various technique parameters in the production stage, overlooking that the binders will be subjected to the thermal effect of short-term aging during the subsequent construction process. This ongoing thermal effect can continuously affect the bitumen-rubber interaction, thereby altering the performance. This study comprehensively investigated the performance evolution and technique optimization of CRMB under the thermal effect throughout the production and construction process. CRMB with varying rubber dosages and blending times, including unswelling binders, were prepared. Viscosity-temperature curves determined appropriate short-term aging temperatures. Molecular weight distribution, high-temperature performance, and anti-cracking properties were evaluated. The liquid phase was separated to quantify the swelling degree via particle effect (PE) analysis. Results show that high-temperature performance improves under prolonged thermal exposure, while anti-cracking performance strongly correlates with the swelling degree. A performance-balanced design optimized technique parameters, enabling controlled swelling for superior service performance of CRMB.