jismart2023043: Silica Fume and Slag as Cement Replacement in UHPC With Steel Fiber

Abstract

Ultra-High Performance Concrete (UHPC) is one of the most advanced cement-based construction materials. However, it may not be sustainable due to the high dosage of energy-intensive constituents such as cement and silica sand in its formulation. Therefore, the proposed work aimed to produce UHPC by using a low carbon emission and embodied energy alternative constituent material such as inorganic industrial by-product, namely silica fume (SF) and ground granulated blast-furnace slag (GGBS) as cement replacement material. The binary blended UHPC mix was prepared at the beginning stage by substituting the OPC with 0%, 5%, 10% and 15% of SF. The optimum binary blended UHPC mix, which was the mix proportion with 5% SF content, was being further optimised by substituting more OPC content with GGBS at 10%, 20%, 30% and 40%. Fiber reinforcement optimisation was conducted subsequently based on the optimal ternary blended UHPC mix, which was the mix proportion with 20% GGBS content by incorporating steel fiber from 1% to 3% of the binder volume. Steel fibre reinforcement was found to be optimum at 2% of the binder volume. The mechanical strength of the optimum ternary blended mix UHPC marked an improvement of 27.13% on the strength gained compared to the fully OPC mix without reinforcement.