Tensile strength of corroded steel bars

Abstract

Among the pathological manifestations associated with reinforced concrete, corrosion of the reinforcement is one of the most serious issues since it is related to the durability of the structures and the safety of the users. Although the reinforcement in the structural components is protected by a covering layer, carbonation or the presence of chlorides in the concrete generates necessary conditions for corrosion of the reinforcement. This causes a reduction in the cross section and the generation of products that, due to their volumetric expansion, cause cracks in the interior of the concrete. This work evaluates the effects of corrosion on mechanical properties of corroded reinforcements through accelerated conditions in the laboratory. Steel bars installed inside cylindrical concrete specimens are subjected to accelerated corrosion, immersed in a saline solution with the application of an electric current for periods of 1, 3, 5 and 7 d. After corrosion, the steel bars are removed and their weight loss, degree of corrosion and tensile strength are evaluated. The results demonstrate an increased degree of corrosion with exposure time to the saline solution and the non-uniform reduction of the tensile strength of the bars due to the formation of corrosion pits with varying depth along the bar.

Keywords

• corrosão
• concreto
• armadura
• propriedades mecânicas
• estruturas