Effect of Warm Mix Agent on Physical and Aging Properties of Crumb Rubber Modified Bitumen

The effects of modified natural zeolite warm mix agent (MNZWMA) and organic viscosity reducing warm mix agent (OVRWMA) on the physical properties, short term thermal oxidation aging, long term thermal oxidation aging and UV aging properties of the crumb rubber modified bitumen (CRMB) were investigated. The results showed that MNZWMA and OVRWMA could improve the high temperature stability and the low temperature crack resistance of CRMB, respectively. During the short term thermal oxidation aging, long term thermal oxidation aging and UV aging, OVRWMA increased softening point increment (SPI) and viscosity aging index (VAI) of CRMB, however, MNZWMA decreased its SPI and VAI. The analysis of FTIR spectra indicated that MNZWMA reduced the formation of carbonyl groups and sulfoxide groups, but OVRWMA accelerated the formation of carbonyl groups and sulfoxide groups to some extent during ultraviolet aging. Therefore, MNZWMA could improve the anti-aging properties, and OVRWMA was not conducive to the anti-aging properties of CRMB.