Effect of mineral admixtures on sulfate resistance of mortars under electrical field

Abstract

This paper presents a study on sulfate resistance of mortars blended with and without silica fume or fly ash under electrical field. Performance of the mortars was determined by various means such as visual examination, sulfate concentration, flexural and compressive strength, as well as mineralogical analysis. The results showed that electrical field accelerated the deterioration induced by sulfate attack, as it sped up the ingress of sulfate ions into the mortar. The use of mineral admixtures improved the sulfate resistance of mortars. However, a relatively great amount of migrated sulfate as well as expansive sulfate products (gypsum and ettringite) were still found in the blended cement mortars under the electrical field, for which their deterioration was also notable. Therefore, the electrical field also accelerated sulfate attack on the mortars blended with mineral admixtures.