Behaviour of foam concrete under sulphate environments

This paper reports the effects of variation in density, concentration and type of cation associated with sulphate on the expansion, mass and strength loss of foam concrete produced with two synthetic surfactants. Comparisons are made between behaviour of foam concrete of different densities and that of corresponding base mixes of mortar without foam. The investigations indicated that the expansion in sodium sulphate environment was up to 28% higher than that of magnesium sulphate environment which can be attributed to greater quantum of ettringite formation in sodium sulphate environment. The major deterioration mechanism in magnesium sulphate environment is disintegration of cementing material and this contributed to loss in mass of 1% and higher sulphate deterioration factor of 0.4 for specimens under very severe magnesium sulphate environment. Irrespective of the type of sulphate environment, the deterioration of foam concrete was lower than that of base mix.