Resistance of geopolymer mortar to acid and chloride attacks

This paper presents an experimental study on the chemical erosion resistance of geopolymer mortar (GM) to sulphuric acid and sodium chloride attacks. The variations of mechanical properties and mass of geopolymer mortar after soaked in water, sodium chloride and sulphuric acid solutions for different durations (30, 60, 90, 180, 270 and 360 days) were investigated. The test results showed that geopolymer mortar had good resistance to sodium chloride and sulfuric acid erosion solutions. The maximum degradation in flexural, compressive and tensile strength of geopolymer mortar soaked in sodium chloride and sulphuric acid solutions, during the whole soaking duration (360 days) was 6%, 11% and 15% respectively, compared to that in tap water. The strength fluctuation of geopolymer mortar in sulphuric acid solutions was higher than that in sodium chloride solutions. At the first 60 days of immersion, the compressive and tensile strength of geopolymer mortar in tap water, sodium chloride solutions and sulphuric acid solutions decreased, but its strength restored again after 60 days.