Unveiling the Influence of Activators on Stability and Pore Features of Foamed Concrete

In this study, sodium hydroxide and calcium hydroxide are employed as activators to enhance the properties of foam concrete with hybrid alkali-activated cementitious material as the base mix. The effect of the activators on the properties of foam concrete is studied. The experimental results reveal that the presence of sodium hydroxide can also enhance the hydration rate of the base mix and increase the density of the pore wall in foamed concrete, thus enhancing the compressive strength of foamed concrete. Meanwhile, the addition of excessive sodium hydroxide may introduce too much water and increase the settlement of foamed concrete, thus resulting in a coarse and uneven pore structure. The settlement of the foam concrete with calcium hydroxide as an activator can be significantly increased, which is more related to the settlement of the matrix. The presence of calcium hydroxide could enhance dense pore walls, thus increasing the compressive strength and lowering water absorption.