Performance of Alkali-Activated Aerated Concrete using Class C Fly Ash

This paper focuses on the factors influencing the properties of alkali-activated aerated paste and mortar with high calcium fly ash as the source material, by comparing oven and ambient curing conditions. Design of experiments with response surface methodology is used to study the influence of each of the parameters on the properties of alkali-activated paste and mortar. To achieve a stable pore formation with aeration cooled liquid alkaline solution with a temperature below 15 C is used. The influence of each of the factor and their interaction effects on properties such as density, compressive strength and absorption of water were studied. For a constant dry density, the compressive strength achieved by ambient curing is higher compared to oven curing i.e. for a density of 900 kg/m3 the compressive strength with ambient curing is 4.5MPa while for oven curing it is 2.75MPa. But less water absorption is observed for oven curing compared to ambient curing. While the water absorption achieved was lower for oven curing it was higher for ambient curing resulting in not less than 10%.