Preparation of modified sulfur-rubber complex pellets and its function of environmental protection

Adding some sulfur and crumb rubber into asphalt can improve the pavement performance of high-temperature rut resistance. However, the H₂S evolution accompanies the mixing of sulfur, crumb rubber and asphalt at a higher temperature. H₂S is harmful to the workers and environment. In this paper, modified sulfur-rubber complex pellets (MSRP) were prepared by adding H₂S-inhibitors in a sufficient amount to reduce or inhibit the H₂S evolution determined by methylene blue spectrophotometry and H₂S gas meter. The effects of different kinds and amounts of sulfur, crumb rubber, filler, H₂S-inhibitors on the H₂S evolution were also discussed in detail. The results indicated that the kind of sulfur had a slight influence on the H₂S evolution. The H₂S evolution increased with the increase of the amount of crumb rubber, and it was significantly reduced by adding a small quantity of filler, H₂S-inhibitor and coordinate reducing additives. The H₂S content in atmosphere was less than 1.0ppm during the production of bituminous mixture added MSRP. The results of the study suggest that MSRP is a new type of economical asphalt additive with a fine environmental protection, which can significantly reduce the H₂S evolution.