LAUSR

Abstract Deterioration due to chloride penetration has been regarded as the major problem among the factors leading to a decrease in the durability of reinforced concrete (RC). Corrosion of steel bars in concrete propagates in the presence of water and oxygen by electro-chemical reactions. In recent years, the use of industrial by-products as construction materials has been promoted since it reduces pollutant waste and beneficial in construction works toward sustainable development. Copper slag fine aggregate (CUS) is an industrial by-product produced through the process of manufacturing copper. The aim of this study is to investigate the effects of CUS on the ingress of corrosive substances, including chloride ions and water, including dissolved oxygen associated with corrosion behavior and processes of horizontal steel bars in the reinforced concrete prototype specimen. A detailed analysis was carried out on the heterogeneity in cover concrete and integrity of horizontal steel bars due to bleeding water in concrete mixtures with a partial replacement of CUS and fly ash (FA) and ordinary Portland cement (OPC) as a control specimen. In this study, it is assumed that the deterioration of concrete structures results from chloride ion penetration in the sea. Chloride-induced corrosion through the wet and dry cycles are examined with respect to chloride ion concentrations and some parameters related to electro-chemical measurements. The results show that the partial replacement of fine aggregate with CUS (30 vol%) in reinforced concrete column specimens led to a lower rate of oxygen permeability on the cathodic reactions, which could be illustrated by changes of cathodic polarization properties in column specimens. Although macrocell corrosion is partly pronounced in CUS concrete due to cracking caused by segregation, the microcell corrosion current density observed in CUS concrete specimens is generally less severe compared to those observed in OPC concrete specimens. Based on the results obtained by XRD analysis, the addition of CUS in concrete mixtures as a sand replacement does not register new peaks but increases in peak intensity. The result indicates that CUS replacement does not affect the composition of minerals of concrete mixtures tested, and thus, it is evidently compatible with OPC mixtures. This beneficial effect of the addition of copper slag fine aggregate could contribute to good durability performance in concrete as a solution to the environmental problem of disposal industrial waste, and copper slag concrete has a wide application in the structures constructed in a marine environment.