Sustainable Asphalt Mixtures Comprising Steel Slag Filler and SBS-Modified Binder: An Experimental Investigation
Ahmed Farhan Al-Tameemi, Zahraa Talib Al-Fayyadh, Hasan Al-Mosawe, Yu Wang, Aous Abdulhussain Moyet
Abstract
Utilizing steel slag powder as a mineral filler in asphalt concrete mixtures has garnered increasing attention due to its attractive benefits in both sustainability and material properties. The paper aims to critically evaluate the replacement of mineral filler with steel slag to produce a sustainable mixture. The replacement was made at 3 varied contents, i.e., 0%, 50%, and 100%, and meanwhile working together with a modified asphalt binder using 4% styrene-butadiene-styrene polymer. All designed mixtures were tested for volumetric properties and Marshall stability; an indirect tensile test was performed to determine the moisture susceptibility of all the mixtures of optimized binder content. At last, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) analyses were performed to examine the crystal structure, microscopic attributes, and chemical composition of the steel slag particles and the limestone dust and compare their differences. The study showed that steel slag used for mineral filler can significantly enhance Marshall properties and moisture susceptibility of asphalt mixtures. Working together with the SBS-modified binder, the positive effect was further pronounced. SEM analysis revealed that steel slag has a rough, angular surface texture with a high porosity and specific surface area. EDX analysis confirmed the pozzolanic composition of steel slag. Doi: 10.28991/CEJ-2025-011-04-04 Full Text: PDF