THE EFFECT OF USING SILICA FUME IN HIGH STRENGTH CONCRETE ON WORKABILITY AND COMPRESSIVE STRENGTH: REVIEW
Supplementary Cementitious Materials (SCMs) are widely used to replace Ordinary Portland Cement (OPC) in High Strength Concrete (HSC). The addition of SCMs to HSC mixes generally results in altering the properties of the resulted HSC. This study focuses on reviewing the effect of a common SCM – Silica fume (SF)– as a partial cement replacement at different replacement levels by weight on workability and compressive strength of HSC. First, the researchers reviewed the chemical reactivity and particle characterization of SF. They also reviewed several research papers on the fresh and hardened properties of HSC mixes containing SF.
The review showed a significant enhancement in the compressive strength of HSC when OPC was partially replaced with SF. It also demonstrated the disagreement among researchers about the effect of SF on the workability of HSC.
While reviewing the research papers, the authors identified the optimum weight replacement of SF indicated in the reviewed papers. The researchers concluded that there are differences in the chemical composition, particle shape and size, and surface area of SF as compared to OPC. These differences in the characteristics of SF influence water demand, packing ability, and reactivity of the HSC mix, which could explain the change in the workability and compressive strength of the resulted HSC.