Exploitation of rice agriculture wastes in clay masonry units preparation

This paper deals with the exploitation of both rice husk and straw as partial constituents in the fabrication of clay masonry units. This allows for using harmful wastes that were otherwise burnt besides lowering the amount of clay used in brickmaking. Clay was mixed with different percentages of each waste and water was added in a suitable amount to produce mixes that were molded and dried. Drying shrinkage and green compressive strength were determined for these dry samples. The firing of the dried samples was then carried out at temperatures ranging from 700 to 800ºC with a one-hour soaking time. The following properties were investigated as a function of both firing temperature and percent waste added: loss of ignition, firing shrinkage, cold and boiling water absorption, saturation coefficient, apparent porosity, bulk density, and compressive strength. The properties of masonry units produced by firing at 700ºC and containing 3% of either waste were in good agreement with ASTM C 62 specifications for clay made bricks.