Influência da adição de carepa na resistência à compressão do concreto

Abstract

Scale is a coproduct generated by the oxidation of the steel surface during heating, cooling, surface treatment, and/or exposure to time (oxidation) (Cunha, 2006). This study investigates the influence of adding steel scale—a coproduct of the steel industry classified as hazardous waste (Class I) by ABNT NBR 10004 (2020)—on the properties of Portland cement concrete, with the aim of assessing its potential for reuse in civil construction and reducing the consumption of natural resources.The methodology adopted was experimental, based on the casting and compressive testing of cylindrical concrete specimens with the addition of steel scale at increasing concentrations (0%, 1.5%, 3%, 5%, and 6%) relative to the mass of solid materials. Characterization tests (particle size distribution, void index, and water absorption) and mechanical compressive strength tests at 7 and 28 days were carried out in accordance with the relevant technical standards.The results indicated that increasing the steel scale content in the mix design led to higher void index and water absorption in the hardened concrete, rising from 13.82% to 18.35%. The main conclusion revealed that, at the concentrations tested, the incorporation of steel scale significantly reduced the characteristic compressive strength of the concrete (approximately a 25% to 30% decrease) compared to the reference mix.