Experimental Study on the Properties of Fired Sand–Clay Ceramic Products for Masonry Applications

This study reports the effect of fine sand addition on the properties of fired clay bricks. Fine sand was sieved to $-75\mathrm{\mu m}$ and incorporated at varied weight proportions (5, 10, 15, 20, 25, 30, 35, and 40 wt.%) to clay in the preparation of fired bricks. The samples produced were oven dried at 110°C for 12 h, and fired at a temperature of 1,200°C in an electric furnace. The samples were examined for physical, thermal, and mechanical properties. Result of the tests showed a reduction in porosity, water absorption, weight loss, and firing shrinkage with increasing sand addition, although the bulk density increased as the percentage weight content of sand increased. Thermal properties such as thermal conductivity, thermal diffusivity, and thermal emissivity increased with fine sand addition while reduction in coefficient of thermal expansion and specific heat capacity was observed. Also, the thermal shock resistance improved with increase in fine sand addition up to 25 wt.%, before further decline was observed. The hardness and impact value were enhanced with increasing additives. It is noted that samples immersed in rainwater were found to experience depreciation in hardness, resistance to impact, compressive and flexural strengths as the number of days of immersion increased. It was concluded that bricks produced are good for building in temperate region in which much flooding is not experienced.