Study on fired bricks with replacing clay by fly ash in high volume ratio

In present paper fly ash in wet state with low quality was used as raw material to replace clay to make fired bricks. The effect of fly ash with high replacing ratio of clay on firing parameters and properties of bricks were studied. The results indicate that the plasticity index of mixture of fly ash and clay decrease dramatically with increasing of replacing ratio of fly ash. Additive A can be chosen to improve the plasticity index of mixture to meet plastic extrusion used in most brick making factories. The sintering temperature of bricks with high replacing ratio of fly ash was about 1050 °C, which is 50-100 °C higher than that of clay bricks. The properties of fired bricks were improved by using pulverized fly ash. The fired bricks with high volume ratio of fly ash were of high compressive strength, low water absorption, no cracking due to lime, no frost and high resistance to frost-melting.