Non-uniform corrosion influences on mechanical performances of stainless-clad bimetallic steel bars

Abstract

As a type of corrosion-resistant reinforcement, the stainless-clad bimetallic steel bar (SCBSB) has the advantages of low price and good mechanical properties, which causes them to be widely used in engineering structures. In the actual service process of the structure, the steel bar always corrodes first on the side close to the concrete cover. This type of non-uniform corrosion characteristic may lead to the mechanical properties of steel bars being very different from those with ideal uniform corrosion. Therefore, studying the degradation law of the mechanical properties of SCBSBs with non-uniform corrosion has important engineering value and research significance. In this study, the non-uniform corrosion mechanism was described, and non-uniformly corroded SCBSB specimens at different corrosion degrees were obtained by the electrochemical accelerated corrosion method. Through tests and analyses, the mechanical properties and toughness degradation laws of the SCBSB with non-uniform corrosion were obtained. Models were proposed to predict the mechanical properties and toughness of SCBSBs with non-uniform corrosion at any corrosion degree. In addition, through a finite element analysis, the mechanical property degradation laws of SCBSBs with three corrosion forms were analyzed. According to the experimental results, it was suggested that the corrosion degree of SCBSBs should be controlled within 14.39% to meet engineering requirements. The resistances of reinforced concrete beam with different corroded degrees SCBSBs were discussed to clarify the effect of corrosion type on durability of reinforced concrete members.