Laboratory investigation on fumes generated by different modified asphalt binders

Asphalt fumes are generated during pavement construction, endangering health of surrounding people and polluting atmosphere. Fumes from 5 types of modified asphalt and base asphalt binders were studied through thermal weight loss characteristics, asphalt molecular weight distributions, and chemical compositions. The results indicated that thermal weight loss and volatile organic compounds (VOC) integrations were quadratically related. Molecular weights of 75.30% fumes were from 150 to 400, including alkanes, benzenes and polycyclic aromatic hydrocarbons (PAHs). Extra toxic emissions like PAHs, were released by crumb rubber asphalt. Budun rock asphalt, styrene-butadienestyrene modified asphalt and high-viscosity modified asphalt suppressed some components but produced additional emissions, while warm mix asphalt barely increased emissions. This study attributed that emissions of various modified asphalt binders were different, and extra toxic emissions were released with the addition of crumb rubber and other additives, supporting the subsequent research on the mechanism of asphalt fume generation and mitigation.