Physical analysis
The fired specimens were subjected to various physical analyses. Bulk density, water absorption and apparent porosity were determined by Archimedes's immersion technique on keeping the sample in boiling water followed by ASTM C20-00. Plasticity of clay sample was determined by Atterberg's method. Linear shrinkage was determined by the test sample length after drying at 110 °C and the sample length after firing at different temperatures.
The mechanical strength and Young's modulus were studied by Universal Testing Machine (UTM Testometric Model FS-300KN). Particle size of clay was determined with laser scattering particle size analyzer (Model-Microtrac S3500). The microstructure of tiles body was examined by Scanning Electron Microscope (SEM Hitachi-3400N).