EFFECT OF CORROSION INHIBITOR ON PROPERTIES OF CONCRETE AND MORTAR MADE WITH DIFFERENT ADMIXTURES

Abstract

The effect of corrosion inhibiting admixture on concrete and mortar properties is investigated experimentally. Two reference concretes and mortars are considered, based on ordinary Portland cement (OPC) and slag cement. The effect of corrosion inhibiting admixture (a sodium nitrite-based inhibitor) is evaluated. The properties of the fresh concrete (setting time, density and workability) and of the hardened concrete (compressive strength, bending tensile strength and splitting tensile strength) are evaluated. From experimental results, it has been observed that addition of sodium nitrite as corrosion inhibitor (CI) decreases the compressive strength of OPC mortar at all ages i.e. 7 and 28 days, while an increasing trend is observed for addition of CI in slag cement mortars. There is no remarkable change in density observed for addition of CI for both types of mortars made with OPC and slag cement. 7 days compressive strength decreases with addition of CI to concrete cube made with OPC, while an increasing trend is observed for concrete made with slag cement. 28 days compressive strength of concrete cubes made with both type of cements decreases with addition of CI. Further addition of silica fume (10%) with combination of CI improves the compressive strength.