MANIFESTAÇÕES PATOLÓGICAS EXPANSIVAS EM ESTRUTURAS DE CONCRETO: ensaio laboratorial em barras de argamassa atacadas por sulfatos e investigação em estrutura da Estação de Tratamento de Esgoto do município de Coqueiral - MG

Abstract

The study of pathologies in reinforced concrete structure is of great importance for professionals in the civil construction industry. The understanding of the behavior of structures in adverse environments, subjected to the interference of local agents that may affect the quality of concrete, makes the studies developed increasingly widespread. The degradation of reinforced concrete can occur by mechanical, physical, chemical or biological processes. This work especially addresses the sulfate attack in concrete structures because it is a very common and important pathology to be studied and analyzed. Mortar bars were made to verify the expansibility caused by this type of attack. The bars were produced with the most abundant aggregate sold in the region, the gneiss from the Santo Antônio quarry in Varginha - MG. Subsequently, a case study of the Sewage Treatment Plant in the city of Coqueiral - MG was carried out. No sulfates were detected in the mineralogical analysis. The mortar bars showed expansions of 0.10%, not significant, but attributed to cement and not to aggregate. The concentration of sulfates found in TEE was 29.75 mg/L, classified as weak aggressiveness, is not potentially harmful. However, the structure presents a pathological manifestation, less severe, leaching. A mitigating method was proposed for this, waterproofing. It is essential to know the composition of the aggregates of a given region for the professionals who work there. The more widespread the knowledge about reinforced concrete pathologies among the professionals in the environment, the earlier the diagnoses in the structure will occur