Preserving the environment by reducing carbon dioxide emissions from cement production is one of the most significant current sustainability requires. This can be achieved by identifying an alternative that has characteristics similar to those of cement, by suggesting geopolymer concrete as a substitute for normal concrete. This article presents the findings of an experiment conducted to examine the effects of permeability and mechanical properties of geopolymer concrete based on low-calcium fly ash. Also, investigate possible relationship between permeability and strength properties. The experiments were conducted by varying the curing condition (24, 70℃), alkali activator to fly ash ratio (0.45, 0.5. 0.55) and dosage of superplasticizer (1.5%, 2%, 2.5%). It was found curing samples at higher temperatures (70℃) has been shown to increase strength properties. Whereas the improvement was 32%, 15% and 23% for each of the compressive strength test, modulus of elasticity and flexural strength respectively. While the improvement value for absorption was 2.6%, and 19% for the sorptivity. It was discovered that samples with an alkali to fly ash ratio (0.45) had better strength characteristics. Where the compressive strength was improved by 36%, and 27% for the absorption. Also, greater strength loss is observed in samples that contain higher superplasticizer dosages (1.5%) than in samples with lower comparable values. With a 30% improvement for both compressive strength and absorption tests. Correspondingly, more strength was lost by samples with higher water absorption and sorptivity than by samples with lower comparable values. The experimental program’s results show that the sorptivity and water absorption of the samples influence the mechanical characteristics of geopolymer concrete.
