Influence of swelling-degradation degree on rheological properties, thermal pyrolysis kinetics, and emission components of waste crumb rubber modified bitumen

This study investigated the effects of swelling-degradation degree on the rheological properties and thermal pyrolysis behaviors of crumb rubber modified bitumen (CRMB). The equilibrium viscosity of CRMB in 160 °C-swelling process is 10.5 Pa·s at 8 h. During the 200℃-degradation procedure, the viscosity increased to a maximum value of 20.58 Pa·s at 7.5 h and gradually reduced to a stable value of 11.09 Pa·s after 35 h. The swelling and degradation processes exhibit the opposite influence on the rheological properties of CRMB. Moreover, the degradation process accelerated the pyrolysis rate of CRMB but hindered the release of toxic gas CO and hydrocarbons.