Durability of Reinforced Concrete in Aggressive Sabkha Environments

Abstract

This technical paper reports the results of a study conducted to assess durability of 15 plain and blended cement concretes exposed to a typical salty sabkha environment. The concrete mixtures were designed to evaluate the influence of C3A content, water-cementitious materials ratio, and type of supplementary cementing material, such as fly ash, silica fume, and blast furnace slag, on sulfate attack and reinforcement corrosion in an aggressive sabkha environment. The sulfate attack was evaluated by visual inspection weight change. Reinforcement corrosion was monitored by measuring corrosion potentials and polarization resistance at periodic intervals. Despite the high sulfate concentration in the test solution, classified as aggressive, results of this investigation revealed that sulfate attack was totally hindered in a sabkha environment. Data on time to initiation of reinforcement corrosion and polarization resistance indicated that the main contributing factors for mitigating chloride-induced corrosion in sabkha environments, in increasing order of importance, are: C3A content of cement, water-cement ratio of plain cements, and incorporation of mineral admixtures. The most significant improvement was achieved when the water-to-cementitious materials ratio was synchronously reduced with addition of silica fume.