Effect of paste aggregate ratio and curing methods on the performance of one-part alkali-activated concrete

This paper is aimed to investigate the engineering properties of high calcium fly ash-based one-part geopolymer concrete using different paste aggregate ratio (0.57, 0.45 and 0.35) and curing conditions (ambient curing, solar curing, and water curing). High calcium fly ash was activated with anhydrous sodium metasilicate powder at 12 of the total precursor materials and cured at three different curing conditions. Workability, compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, Poisson's ratio, water absorption, and porosity have been investigated. The experimental results showed that the mechanical strength of one-part alkali-activated concrete (OPAAC) increases with the decrease in paste aggregate ratio across all the curing methods considered. The strength growth for ambient and water cured specimens is gradual and almost comparable to the solar cured specimens. Compressive strength of almost 70 MPa was obtained for ambient and water cured OPAAC and 90 MPa for solar-cured OPAAC. The paste aggregate ratio has little effect on the porosity of the OPAAC. Regardless of the curing methods, the developed one-part alkali-activated concrete exhibits excellent deformation and durability properties. © 2020 Elsevier Ltd