EFFECT OF MICROSILICA IN SELF COMPACTING CONCRETE ON SHRINKAGE, STRENGTH, AND RHEOLOGICAL PROPERTIES

Abstract

This study investigates the influence of microsilica on the shrinkage behavior, mechanical strength, and rheological properties of self-compacting concrete (SCC). Microsilica was incorporated at replacement levels of 5%, 10%, and 15% by mass of cement. A comprehensive experimental program, conducted in compliance with national and European standards, evaluated the effects of microsilica on both early and later hardening stages. The results indicate that MS enhances the formation of a denser cementitious matrix through intensified pozzolanic reactions, accelerating hydration and reducing capillary porosity. Compared to the control mixture, the microsilica-modified SCC exhibited a compressive strength increase of up to 19% and a total shrinkage reduction of up to 27%. Additionally, the study analyzed the impact of microsilica on the fresh-state rheology of SCC, improving workability prediction and early-age performance assessment. These findings provide practical insights for optimizing the design of durable reinforced concrete structures, particularly under the climatic conditions of Almaty.