Effect of moulding pressure on the properties of fired and water cured lime-rich clay building bricks

The effect of moulding pressure on the physico-mechanical properties of lime-rich clay building bricks made by firing and subsequently cured in water was investigated from 75 up to 600 kg/cm2. The bricks were pre-fired at 850°C for one hour with a heating rate of 5°C/min, then cured in tap water for 90 days. The results show the good improvement of water curing on the compressive strength of the product up to a moulding pression of 450 kg/cm2. Increasing the moulding pressure from 450 up to 600 kg/cm2 leads to a lesser effect of water curing on the strength. The optimum compressive strength is attained at 300 kg/cm2 moulding pressure and a water curing of 90 days, and amounts almost 370 kg/cm2.