Effect of Reinforcing Bar Chemical Composition on Corrosion Resistance

Abstract

This research report looks at the chemical composition of reinforcing bars, and the sulfur content in particular, and their influences on the corrosion resistance of rebar. The research supports the original hypothesis--which suggests that the reduction in sulfur inclusions would benefit corrosion resistance. The reduction could result in significant savings that would more than offset the higher initial costs for these bars. To test the hypothesis, the study examined the corrosion resistance of four kinds of steel reinforcing bars; ordinary, low sulfur, copper and tungsten, and nickel. As in other series in the past, this research indicates conflicting results for different measurement techniques used to quantify corrosion rates. In addition, the mechanism that results in low sulfur bars showing a three-fold increase in corrosion life are not clear and need more study. The report recommends a long-term follow-up study on the use of both small cube and slab specimens in the laboratory, as well as full-scale specimens in the field.