Combined Influence of Copper Slag and Microsilica on the Strength and Density of Structural Concrete

Abstract

This research experimentally evaluates the combined effect of microsilica and copper slag on the compressive strength and density of structural concrete designed for F’c = 280 kg/cm2. The study addresses the need to incorporate industrial by-products as a sustainable technical alternative in the construction industry. A quantitative experimental design was developed using 120 cylindrical specimens (10×20 cm), produced according to the ACI 211.1 mix design method. Microsilica was incorporated at proportions of 4%, 6%, and 8% by weight of cement, while copper slag replaced fine aggregate at levels of 10%, 20%, and 30%. The specimens were tested at 7, 14, and 28 days in accordance with ASTM C39. The results indicated that the optimal combination was 6% microsilica and 10% copper slag, achieving an average compressive strength of 351.43 kg/cm2 at 28 days, representing a 25.56% increase compared to the control mix. Additionally, a 3.95% increase in density was observed, indicating improved matrix compactness. It is concluded that the proper incorporation of these materials significantly enhances the mechanical performance of structural concrete and represents a technically viable alternative within the framework of sustainable construction.