Conventional properties, rheological properties, and storage stability of crumb rubber modified asphalt with WCO and ABS

Abstract

To enhance the performance of asphalt and conserve resources, there is growing interest in the use of diverse waste polymer materials to modify asphalt. In this study, waste cooking oil (WCO) was used to activate crumb rubber (CR) and acrylonitrile–butadienestyrene (ABS) to obtain crumb rubber modified asphalt (CRMA) with low temperature sensitivity, excellent storage stability, and improved working performance. The physical properties of the modified asphalt were evaluated by conventional tests and rheological tests. The cohesive properties and compatibility of modified asphalt were investigated by the 60℃ dynamic viscosity, cigar tube test, and fluorescence microscope. The test results showed that WCO activated ABS/CR reduced the penetration of CRMA but increased its softening point and low temperature fracture work. In addition, the WCO activated ABS/CR could reduce the rotational viscosity of CRMA, and the viscosity-temperature curves prove that WCO activation of ABS/CR reduced the mixing and compaction temperature. Besides, the dynamic viscosity value of CRMA at 60℃ was also improved. The addition of ABS has a higher complex modulus and a lower phase angle, thus reducing the temperature sensitivity of asphalt. The zero shear viscosity (ZSV) value of the compound CRMA was six times higher than that of single CRMA. Additionally, proper proportions of ABS and WCO reduced the separation index (SI) of CRMA and enhanced its storage stability. Notably, group “AWCRMA1” exhibits a much higher ZSV than other asphalts while exhibiting lesser temperature sensitivity.