Chloride Penetration and Binding in Recycled Concrete

Abstract

Recycled concrete use is necessary in order to decrease the environmental impact of the construction industry. Coarse aggregates from crushed concrete may lead to relatively high porosity in the resultant concrete. For this reason, recycled concrete may seem detrimental to the durability of reinforced concrete structures, particularly when they are exposed to marine environments. The objective of this paper is to analyze the influence of coarse aggregates from concrete on the chloride penetration rate and binding capacity of concrete under marine exposure. Concrete specimens were molded and exposed to a natural marine atmosphere. After exposure periods of 6, 12, and 18 months, ingress profiles of total and water soluble chlorides were measured. Results indicate that recycled aggregate incorporation causes two opposed effects on concrete: It increases its chloride penetration rate and chloride binding capacity. Therefore, water soluble chloride contents in conventional and recycled concrete series have similar values.