Effect of formic acid as an accelerator on foam-stability, compressive strength, and pore size distribution of foam concrete

Abstract

In this study, the formic acid as an accelerator was used to increase the properties of the foamed concrete. The impact of formic acid on the performance of foam concrete was investigated experimentally. The experimental results reveal that using formic acid as an accelerator can significantly increase the rate of yield stress evolution in the matrix. The matrix with the higher yield stress evolution rate tends to increase the stability of the fresh foam concrete. In addition, the –COOH in formic acid can absorb the moisture in the foam, thus increasing foam drainage. The excess formic acid in the base mix can reduce the stability of the fresh foam concrete. The compressive strength of foam concrete can be significantly increased with the addition of 1.0% formic acid. A more homogeneous and finer pore structure of foam concrete can be obtained with the incorporation of 1.0% formic acid, which may result in lower water absorption and higher compressive strength.