Characterization of emissions from rubber modified asphalt and their impact on environmental burden: Insights into composition variability and hazard assessment

Abstract

Rubber modified asphalt (RMA) is a promising avenue for recycling waste tires but faces concerns over hazardous fumes emission during production and construction. This study employs a specialized apparatus to analyze RMA's emission behavior, focusing on crumb rubber size variations under thermal conditions. Ozone Formation Potential (OFP) and Secondary Organic Aerosol Formation Potential (SOAFP) were quantified to evaluate the environmental burden. Results indicate distinct periods of emission behavior for different pollutants, with H2S emissions primarily occurring within the initial 150 min while volatile organic compounds (VOCs) dominate within the first 270 min. The size of rubber particles and thermal exposure duration influence the VOCs microscopic emission characteristics and environmental burdens. Polycyclic aromatic hydrocarbons (PAHs) emerge as the primary contributors to OFP and SOAFP, accounting for nearly 65 % and 25 %−60 %, respectively. High molecular weight aliphatic hydrocarbons (ALHs) also significantly contribute to SOAFP, with PAHs dominating throughout, while ALHs peak during the middle stage. H2S emissions likely stem from rubber, while early VOC emissions originate from rubber, transitioning to petroleum asphalt during the middle and late stages. Asphalt fractions influence emission behavior and property evolution. These findings inform emission suppression strategies and highlight the need for tailored approaches to mitigate emissions effectively.