Effect of kaolin and sepiolite on fume emissions of rubber modified asphalt

During the process of high temperature mixing, crumb rubber modified asphalt will release fumes, causing potential threat to human health and the environment. To reduce the harmful fumes released during the production of rubber modified asphalt (RA), a high-performance and environmentally friendly rubber modified asphalt (K/S-RA) was prepared by adding kaolin and sepiolite as composite modifier. The improvement of the composite modifier on road performance and its inhibitory effect on the fume emissions of rubber modified asphalt were studied, and the fume suppression mechanism and synergistic effect of the two modifiers were discussed. The results showed that the kaolin and sepiolite composite increased the rutting factor and fatigue factor of rubber modified asphalt, thus improving anti-deformation ability and decreasing it fatigue resistance. The results of Gas chromatography-mass spectrometry (GC-MS) showed that compared with conventional rubber modified asphalt, the concentration of VOCs in K/S-RA was reduced by 42.26%, and the H2S was reduced by 65.28%. Thermogravimetric Analysis and Differential Scanning Calorimetry (TG-DSC) and Brunner-Emmet-Teller (BET) results showed that kaolin and sepiolite had a synergistic effect of heat insulation and adsorption on the fume suppression of rubber modified asphalt.