Abstract
This paper aims to study the effect of different particle sizes of granulated blast-furnace slag (GBFS) as a partial or full natural fine aggregate substitution in concretes with different water/cement (w/c) ratios. Natural sand fine aggregate was substituted with GBFS at ratios ranging from 25% to 100%, by weight. Two different particle sizes of GBFS (0.16 and 0.5 mm) and w/c ratios (0.5 and 0.6) were used. Workability, mechanical strength and abrasion resistance at ages ranging from 7 to 180 days were measured. The morphology of selected concrete samples were examined by scanning electron microscopy (SEM). The results showed a negative effect of GBFS fine aggregate on the workability of concrete mixtures. The incorporation of GBFS as a fine aggregate in concretes may increase or decrease mechanical strength and abrasion resistance. This depending on its particle size as well as w/c ratio.