Flue gas composition of waste rubber modified asphalt (WRMA) and effect of deodorants on hazardous constituents and WRMA.

Waste rubber modified asphalt (WRMA) produces hazardous flue gas during preparation, which severely pollutes the environment and endangers the health of construction personnel. This paper designed an asphalt flue gas generation with a collection device and proposed the extraction methods of solid, liquid, and gas components separately. Deodorant was incorporated into WRMA to alleviate the negativity of detrimental pollutant emissions. Then, gas chromatography-mass spectrometry, electrochemical sensing technology, Fourier transform infrared spectroscopy, fluorescence microscopy, and waste rubber extraction test were combined to explore the main compositions of asphalt flue gas and illustrate the effect of deodorants on hazardous flue gas and WRMA. Results reveal that the main hazardous constituents are sulfur-containing organics, benzene homologs, and H2S in the WRMA flue gas. Deodorants can improve the stability of waste rubber in WRMA, inhibit the degradation of waste rubber, reduce the release concentration of H2S, enhance the oxidation resistance of sulfur-containing groups, and further promote the aging resistance of WRMA to realize deodorization and environmental protection. Therefore, the addition of deodorants can alleviate the release of hazardous flue gas from WRMA, which is conducive to the popularization and application of WRMA in pavement engineering.