Application of biological desulfurization technology in crumb rubber modified asphalt: Performance optimization and high-temperature emission suppression
Juan Xie, Yan Zhou, Xucheng Zhao, Zheyu Ding, Shuaihui Li
Abstract
The high viscosity of crumb rubber modified asphalt (CRMA) raises the temperature of construction mixing. This increases the harmful emissions in the paving process of asphalt construction, which limits its application in the road field to a certain extent. Therefore, in this paper, two microorganisms were utilized to conduct desulfurization treatment on crumb rubber (CR) to obtain bio-desulfurized crumb rubber (BCR). Upon this foundation, bio-desulfurized crumb rubber modified asphalts (BCRMA) were prepared. Firstly, the microscopic morphologies and chemical structures of BCR were characterized. After biological treatment, the number, area and porosity of the pores on the surface of BCR increased significantly. The pore size, sulfur element content and the crosslinking density decreased. Subsequently, the performance of BCRMA was studied. The low-temperature property and the compatibility of BCR with base asphalt (BA) were improved. The high-temperature property decreased, but the decrease was not significant. Finally, the concentration and types of volatile organic compounds (VOCs) and hydrogen sulfide (H 2 S) at high temperatures were detected. After bio-desulfurization, the concentration of VOCs and H 2 S in the modified asphalt flue gas were significantly reduced. The types of sulfur-containing organic compounds (SCs) were reduced by 50 %, which effectively inhibited harmful emissions to the environment and human health.