Effect of ozone aging on the rheological and chemical properties of crumb rubber-modified bitumen

Abstract

Crumb rubber can not only solve the environmental pressure but also improve the properties of bituminous pavement. To study the characteristics and mechanism of ozone aging on CRMB, the effects of ozone aging on the rheological properties and chemical composition of crumb rubber-modified bitumen (CRMB) were explored. It was also compared with thermal oxygen. The results show that the macromolecules such as aromatic rings and polar functional group were formed after ozone aging, and the average molecular weight of CRMB increased. Ozone reacted rapidly with the CRMB surface at the beginning of the reaction and leaded to an increase in surface roughness. The risk of fatigue cracking increased. The effect of ozone aging (3 days, 60°C, 1000 ppb) on CRMB was similar to that of long-term aging. The effect of ozone on CRMB was mainly due to the ozone sensitivity of the crumb rubber modifier.