REAÇÃO ÁLCALI-AGREGADO PELO MÉTODO ACELERADO EM PRISMAS DE CONCRETO: Avaliação de agregados gnáissicos provenientes do município de Varginha

Abstract

This study aims to verify the alkali-silica reaction in concrete prisms produced with gneiss rock from the municipality of Varginha-MG, used as coarse aggregate, and potentially harmless sand as fine aggregate, using the accelerated method according to ABNT NBR 15577- 7: 2018, in order to attest only the reactivity of the gneiss as coarse aggregate when using the types of cement CPIII and CPV. To analyze the materials used in the concrete composition, tests were performed to characterize the physical indexes of coarse and fine aggregates, cements, as well as a physical analysis and a chemical analysis of the gneiss and a chemical analysis of cements. The test lasted 5 months and measurements were taken at 5, 10, 15 and 20 weeks, which allowed measuring the expansions caused by the alkali-silica reaction and classifying the degree of reactivity of the aggregate as R1, according to ABNT NBR 15577-1: 2018.