This study explores the durability of green cementitious material of geopolymer concrete. Geopolymer concrete is produced from the polycondensation reaction of aluminosilicate materials (fly ash, Ground Granulated Blast furnace Slag (GGBS)) with alkaline activator solutions. Geopolymer concrete has excellent mechanical properties and its production requires low energy and results in low levels of CO₂ emission. Due to the high demand for river sand, manufactured sand is used as a replacement material in geopolymer concrete under ambient curing conditions. In this study, the durability of G30 grade geopolymer concrete has been investigated using tests acid resistance, water absorption, sulphate resistance, Rapid Chloride Penetration Test (RCPT), and rate of absorption (Sorptivity) test. The sulphuric acid, sodium sulphate, and water absorption tests were carried out at 28 days, 56 days, and 90 days for both the geopolymer and the conventional concrete. The reduction percentage in water absorption and compressive strength loss was found to be better in geopolymer concrete than in conventional concrete. Geopolymer concrete’s chloride penetrability and rate of absorption were analogous to conventional concrete. Regression analysis for geopolymer and conventional concretes in the rate of absorption test showed a good relationship between absorption and the square root of time.

Geopolymer concrete is a booming technology in the construction industry. Much research is occurring in geopolymer concrete, as it emits low carbon dioxide into the atmosphere, is eco-friendly material and is an alternative for cement. This research mainly focuses on the use of fly ash based geopolymer concrete in ambient curing conditions and the use of manufactured sand due to the scarcity of natural sand. Mainly studies have evolved on the workability, setting time and compressive strength by the effect of ground granulated blast furnace slag (GGBFS), manufactured sand (M-sand), alkaline activator solutions to binder ratio and the proportions of sodium silicate to sodium hydroxide (SS/SH) in geopolymer concrete and mortar. The experimental studies were carried out using nine geopolymer concrete mixes and the comparisons were made. The workability of concrete decreases by increasing the percentage of GGBFS, M-sand and the proportions of SS/SH whereas workability of concrete increases when increasing the alkaline liquid to binder ratio. The compressive strength of geopolymer mortar and concrete increases when the percentage of GGBFS and M-sand is increased, and it decreases by increasing the alkaline liquid content. There is no change in strength by decreasing the proportions of SS/SH.