DESIGN AND TESTING OF INTERLOCKING CERAMICS BRICKS FOR LOW-COST KILN

The high cost of conventional kiln bricks limits the adoption of ceramic production in small-scale and rural enterprises. This study focuses on the design and testing of ceramic bricks produced from locally available clay and industrial/agricultural waste materials for use in low-cost kilns. The bricks were formulated by blending clay with varying proportions of rice husk ash, sawdust, and crushed fired ceramic waste to improve thermal insulation, reduce weight, and lower production cost. Test specimens were molded, air-dried, and fired at temperatures ranging from 800°C to 1000°C in a prototype low-cost kiln constructed with minimal energy input. The produced bricks were subjected to laboratory tests including compressive strength, thermal conductivity, linear shrinkage, water absorption, and thermal shock resistance in accordance with ASTM standards. Results showed that bricks containing 15% rice husk ash and fired at 900°C exhibited optimal performance with compressive strength of 6.8 MPa, thermal conductivity of 0.32 W/m·K, and water absorption below 18%, meeting requirements for insulating firebricks. Cost analysis revealed a 35–45% reduction compared to commercial refractory bricks. The study demonstrates that ceramic bricks for low-cost kilns can be effectively produced using local materials and simple firing techniques, providing an affordable alternative for small-scale ceramic industries. This approach promotes waste utilization, energy efficiency, and economic viability in rural ceramic production.