Effects of fly ash addition on thermomechanical properties of earthenware wall tile compositions

The effect of fly ash addition as a substitution of sand stone on the thermomechanical properties of traditional earthenware wall tile composition was studied. Considerable improvement (8.0 to 18.6%) in mechanical strength was observed on replacement of quartz by fly ash up to the complete replacement in the biscuit firing temperature range of 1050 and 1150°C. The increase in strength may be attributed to the gradual decrease in stresses in the fired bodies due to the decrease in the content of sand stone. There is a significant reduction in percentage thermal expansion of body mixes at 600°C in the samples fired at 1100°C due to gradual replacement of sand stone by fly ash in the compositions. This would make the body mixes more thermal shock resistant in comparison to the reference body. Moreover, this investigation showed promising result and encouraged the utilisation of waste material like fly ash in the production of value added traditional ceramic products like earthenware glazed wall tile with improved thermomechanical properties.