Abstract
The utilization of alternative supplementary cementitious materials (ASCM) and additives in concrete becomes a daily practice due to the increased awareness of their socio-ecological impacts. Exploring for renewable resources of ASCM has been the driving force for the research on this topic since decades. Waste materials have been shown to possess intrinsic physico-chemical properties dependent on their chemical source and physical status. However, wastes evolved in the form of fine dust are known to cause chemical, biological and visual pollution when left in open areas without collection and proper recycling or damping. The ornamental stone factories, necessary for the decoration of the contemporary constructions, produce fine limestone dust (FLSD), which was elucidated as an example in this study. A huge amount of FLSD is released from this industry. The incorporation of a high volume of FLSD and hybrid combination of steel fibers and polyvinyl alcohol (PVA) microfibers in the production of high-performance concrete (HPC) was the main objective of the study. The replacement level of 45% FLSD has enabled a high dispersion of 0.35% PVA microfibers in the presence of 1% steel fibers of the total mix volume. Moreover, the presence of FLSD has also mitigated the occurrence of PVA balling effect, which often takes place at much lower dosages. The results of the mechanical and chloride-ion penetration resistance of the final concrete mixture were encouraging. Both high compressive strength of 70 MPa and elevated modulus of rupture of 12 MPa with a cementitious matrix of very low penetration for chloride ions, supported with enhanced microstructure, could be obtained. The production of high-performance hybrid fiber-reinforced concrete containing high volume ornamental stone dust is proved feasible, ecofriendly and sustainable. (C) 2020 Elsevier Ltd. All rights reserved.