Modification of Asphalt Concrete With Sulfur‐Containing Waste

Abstract

The expediency of involving large‐tonnage sulfur production waste from Rozdil Mining and Chemical Enterprise Sirka (Ukraine) in road surface production has been substantiated theoretically and practically. In particular, the possibility of using waste from sulfur ores flotation enrichment and sulfur filtration purification from ash and organic impurities and their mixtures in the production of modified hot mix asphalt were investigated. It was found that sulfur content changes in bitumen can influence its operational properties: at sulfur concentrations of 5 wt. %, it acts as a plasticizer and at sulfur content ≥ 20 wt. %, it behaves as a filler. There are reasons to state that it is most effective to introduce sulfur into asphalt concrete (AC) as filler aggregate directly in the preparation process of sulfur asphalt mixes in an asphalt mixer. It is shown that the strength of sulfur AC grows over time and reaches maximum values within 15 days. It has been established experimentally that the use of highly sulfur‐concentrated filler aggregates instead of traditional limestone minerals significantly improves the main operational characteristics of AC, in particular: strength at a temperature of 20°C and at a temperature of 50°C; heat resistance; bitumen content to achieve regulated residual porosity is reduced. It was demonstrated that increasing the sulfur content in filler aggregate makes it possible to reduce the bitumen content in AC. Pilot construction of road pavements was conducted, which confirmed that sulfur AC has better operational characteristics compared with regular AC.