Durability Performance of Reinforced Concrete-Based Fly Ash Exposed to Combined Chloride-Sulfate Attack

Abstract

This study investigates the durability performance of local fly ash as a supplementary cementitious material (SCM) in reinforced concrete. In this paper the effect of the fly ash on the durability of reinforced concrete under combined chloride-sulfate penetration has been investigated. Two mixes made by tow formulations: a control mix made of ordinary cement OPC (M1) and a mix substituted with 17% of fly ash (M2) exposed to combined chloride-sulfate attack. The durability performances of these concrete mini pipes were experimentally investigated and evaluated by electrochemical impedance spectroscopy (EIS). The results indicate that the concrete pipe substituted with fly ash shows a high mechanical polarisation resistance compared to the traditional concrete pipe. Moreover, the EDS analysis and visual inspection confirm the results found by the electrochemical measurements. Ultimately, the fly ash as a SCM could improve the service life of reinforced concrete pipe in combined chloride-sulfate attack.