Abstract
Geopolymers have been shown to exhibit a significantly higher degree of resistance to corrosive environments when compared with cement concrete. The present paper expounds on the impact of sulphuric, hydrochloric and acetic acid solutions on the durability of mortars with geopolymer binders composed of metahalloysite and alkali activators. An activator with sodium water glass to NaOH solution ratios of 1, 2 and 3 and NaOH solution concentrations of 4, 8 and 12 mol/dm3 was used. It was found that when increasing sodium water glass content from 1 to 3 in relation to the 8M or 12M NaOH solution in the activator, a significant reduction in the compressive strength of the mortar with this geopolymer binder was obtained after 28 days of exposure to the acid solutions. A smaller decrease in strength occurred with the acetic acid solution than with the sulphuric or hydrochloric acid solutions.