Synergistic Reduction in Asphalt VOC Emissions by Hydrochloric Acid-Modified Zeolite and LDHs

Asphalt releases a large number of irritating fumes during construction and use, which is a serious emission pollution that not only damages the atmospheric environment but also produces highly toxic and carcinogenic volatile organic compounds (VOCs), posing a health risk to human beings. In this study, a compound-doped modified bitumen for reducing VOC emission was prepared by using zeolite as the main adsorbent material, modified by hydrochloric acid, and LDHs as a synergistic adsorbent material. By determining its basic and rheological properties, the results show that the compounding of LDHs and HCL-modified zeolite added to asphalt can improve the high-temperature performance of asphalt binder, but at the same time, the anti-fatigue property will be decreased. By GC-MS experimental analysis, a total of 72.2% fewer volatile organic compounds (VOCs) were released by the compound modified asphalt compound than by virgin asphalt, which resulted in a significant reduction in asphalt fume emissions. It shows that the asphalt VOC molecules are well adsorbed by the porous adsorption of LDHs and zeolite materials, and it is also found experimentally that they inhibit the emission of VOCs through the blocking and adsorption effects. This study provides a scientific basis for inhibiting the emission of VOCs during asphalt pavement construction.