A review of sulfidation gases test methods, generation mechanism, and suppression deodorants of crumb rubber modified asphalt

• Published in: Fuel (Guildford) 2025-04, Vol.385, p.134161, Article 134161
• Main Authors: Zhao, Wenhui, Niu, Yanhui, Geng, Jiuguang, Li, Xu, He, Zewen
• Format: Article
• Language: English
• Subjects: Crumb rubber modified asphalt; Deodorants; Detection methods; Generation mechanism; Storage stability evaluation methods; Sulfidation gases
• ISSN: 0016-2361
• DOI: 10.1016/j.fuel.2024.134161

•Encouraged to quantitatively study the release of sulfidation gases from CR MA.•Suggested to further research the conversion mechanism of sulfide in CR MA.•Conducted emission reduction effect of composite deodorants on sulfidation gases.•Urged electrochemical titration methods for evaluating the storage stability of CR MA. Crumb rubber modified asphalt (CR MA) has been widely used in pavement engineering, however, its production and construction process generate toxic flue gases with odors that pose significant risks to the health of workers and ecological. This article reviews the detection methods, collection devices, and sources of odor (sulfidation gases) of CR MA. The mechanism of sulfidation gases generation is discussed, the results show that the release of sulfidation gases is closely related to the desulfurization and degradation of rubber powder. And low environmental impact materials for pavements are summarized, the existing deodorants have limited emission reduction effect on various sulfidation gases in CR MA flue gas. Finally, the impact of incorporating deodorants on the compatibility between rubber powder and asphalt is discussed. The electrochemical titration method is able to determine the effective rubber powder content, so as to characterize the storage stability of CR MA. The overarching goal of this review is to prompt researchers to quantitatively observe the formation mechanism of sulfidation gases based on the conversion mechanism of sulfide in asphalt during thermal conversion. Therefore, researchers are encouraged to carry out the research and development of composite suppression deodorants based on the associated mechanism of desulfurization and degradation of crumb rubber. Furthermore, in coordination with the existing low environmental impact pavement materials, the emission reduction of sulfidation gases will be further realized. Besides, the applicability of electrochemical titration in evaluating the storage stability and the research on the road performance of deodorants CR MA is prospected.