Corrosion Rate and Weight Loss of Geopolymer Mortar Coated Concrete Specimens with Different Thicknesses

Abstract

This study is about the use of geopolymer mortar as an alternative repair material to reduce the corrosion rate of building structures. The experiment was conducted by comparing the corrosion rate and weight loss of concrete specimens with different thicknesses of geopolymer mortar coating with concrete specimens coated with Sikagrout 215M. Observations showed that the specimens with 2.5 cm thick geopolymer mortar coating cracked faster and had higher current values than the others. Corrosion rate measurements showed that the specimen with 4 cm thickness geopolymer mortar coating had the lowest corrosion rate, while the specimen with Sikagrout 215M coating had a higher corrosion rate. Visualization of the cracked specimens shows that the geopolymer mortar layer’s thickness affects the reinforcement’s rust formation. Geopolymer concrete with proper coating thickness can reduce the corrosion rate and weight loss of concrete structures. This research further explains the effect of coating thickness and coating type in protecting steel in concrete from corrosion.