Avaliação do comportamento do concreto convencional e do concreto de ultra-alto desempenho frente à contaminação por cloretos

Abstract

The durability of reinforced concrete structures has been a constant concern of civil engineering. Among the most common causes of degradation is the corrosion of the reinforcement, which can be caused by the attack of chloride ions. Several factors influence the penetration of these ions, including materials, the water/cement ratio and the exposure environment in which these structural elements meet. The objective of this research was to analyze and compare the behavior of conventional concrete and ultra-high performance concrete against chloride contamination. The tests used for the evaluation were the colorimetric method of silver nitrate spray and the Volhard method, applied to specimens immersed in sodium chloride solution for 24 months. The research revealed that, although it presents a higher surface concentration of chlorides, around 0,88% in relation to the cement mass, the ultra-high performance concrete is more resistant to the penetration of these ions when compared to conventional concrete, since the average depth of penetration obtained was 1,41 millimeters, which can be explained by the characteristics of this material, which makes it superior to the conventional concrete and hinder the entry of this aggressive agent.