Effect of copper slag fine aggregate on corrosion processes and behavior in reinforced concrete prism specimen

Abstract

This paper reports the result of experimental on the resistance to chloride diffusion and steel corrosion of concrete mixtures. A series of tests were performed to investigate the effect of copper slag as partial replacement of fine aggregate on corrosion processes and behavior in prism specimens. Chloride migration tests in steady-state were executed at the age of 28 and 91 days in accordance with Japan Society of Civil Engineers (JSCE) G571-2003 to determine the diffusion coefficient of chloride ions permeated through concrete specimens. In addition, some electrochemical tests were carried out through the repeated wet and dry (NaCl 10%) cycles up to 1 year to examines the probability of corrosion of steel bars in concrete, corrosion current density, and the rate of oxygen permeability. Based on the chloride migration test, which was obtained from the cumulative increase of chloride ion concentration, the results indicate that concrete with a longer curing period achieved lower chloride-ion concentration, thus suggesting that there is an increase in the resistance of concrete against chloride attack. The chloride penetration depth and distribution of chloride content in CUS prism specimens after exposure to wet and dry cycles for one year are almost similar to those of the OPC specimens. Thus, the durability performance of CUS concretes with respect to the resistance against chloride ingress was comparable to that of OPC concrete. Besides that, it is generally recognized that the incorporation of fly ash in blended cement by its the pozzolanic reaction of fly ash improves concrete protection against chloride-induced corrosion of steel bars by reducing its diffusivity and the rate of oxygen permeability.