Evaluation of Steel Slag Powder as Filler in Hot-Mix Asphalt Mixtures

Abstract

Abstract Steel slag has been used as an aggregate for asphalt mixtures for many years, but its excessive volume expansion has limited its wide applicability. With the development of steel-making technology, a considerable amount of steel slag powder (SSP) was produced in Shanghai. The objective of this article is to evaluate the feasibility of using SSP as a filler in hot-mix asphalt mixtures (HMAs), with the aim to eliminate the volume expansion of steel slag asphalt mixture while retaining good pavement performance. First, a common AC-13 mixture was designed with limestone aggregate and mineral filler. Then, 25, 50, 75, and 100 % of the limestone mineral filler in the AC-13 was replaced by SSP, according to the volume ratio, respectively. The asphalt content was kept constant in this process. Then the volume expansion property, rutting resistance property, low temperature property, moisture property, and failure property of the asphalt mixtures were checked. According to the test results, the AC-13 that used SSP exhibited negligible volume expansion, while other properties were better than those of the common AC-13, especially the rutting resistance and moisture properties. The test results also showed that the higher the replacement ratio of SSP, the greater the effect on the properties of the asphalt mixtures. Finally, it was concluded that SSP could replace mineral filler in asphalt concrete (AC) with better pavement performances and acceptable volume expansion.