Heat evolution due to cement hydration in foamed concrete

Abstract

Foamed concrete is nowadays considered an attractive building material as a result of flexible production technology and excellent target properties, along with economic benefits. Heat generated in foamed concrete during cement hydration is found to differ significantly from normal-weight concrete. Foamed concrete that is placed in a regular-shaped well-insulated mould experiences significant core temperature rises and, although several documents discussing the thermal effect in foamed concrete have been published, there is still a lack of information revealing the interrelations of foamed concrete parameters and their effect on temperature rise. Laboratory tests were carried out with foamed concrete of variable densities and volumes under semi-adiabatic curing conditions. The observed trends were used as the initial input for a mathematical model of temperature prediction in foamed concrete. The heat evolution process under real production conditions can be controlled by optimising the mix composition. If the thermal energy in foamed concrete is properly employed it can result in considerable improvement of the final product characteristics while production costs decrease.