An investigation on the performance of 1200 kg/m3 lightweight foamed concrete incorporated with calcium stearate

Abstract

Lightweight foamed concrete (LFC) is normally used on the exterior of buildings such as walls and roof slabs, which causes it to be often exposed to natural weathering such as rain. Since water is an agent of deterioration towards the durability of LFC in long term, calcium stearate, is introduced into LFC. Calcium stearate (CS) is a type of water repellent agent that reduces the penetration of water into LFC. This research aims to investigate the effect of incorporating CS into the LFC mix in terms of its strength performance. Four types of LFC containing different percentages of CS ranging from 0 % to 0.6 % of cement weight were cast and water cured for 7, 28 and 56 days before being tested for its strength properties. It was found that adding CS into the LFC does not affect the workability of fresh concrete. The finding also showed that CS only retards the strength development rate of LFC during the early ages of LFC instead of reducing its overall strength. Under continuous curing, LFC with CS can achieve strength similar to the strength obtained by the control mix. If the early strength of LFC is not a major concern, incorporating CS into LFC will have an added advantage of lower water absorption which improves the durability of LFC.