The use of different forms of waste in the manufacture of ceramic bricks

In this study, various industrial wastes such as urban sewage sludge, bagasse, and sludge from the brewing industry, olive mill wastewater, and coffee ground residue were blended with clay to produce bricks. The clay and waste were characterized by X-ray diffraction, X-ray fluorescence, and thermogravimetric, differential thermal, and chemical elemental analysis. The bricks were manufactured from clay and the optimal proportion of waste. The influence of the waste addition on the linear shrinkage, bulk density, water absorption, and mechanical and thermal properties was investigated. Water absorption increased to above 35% when urban sewage sludge, brewing industry sludge and bagasse were incorporated into the body, but the compressive strength decreased by a maximum of 19% and the thermal insulation increased by at least 8%. The incorporation of coffee grounds and olive mill wastewater of clay was more beneficial, with compressive strength values similar to bricks without waste and a 19% improvement in thermal conductivity. Water absorption and the SEM micrographs indicated that the changes in the results were due to the type of porosity formed by the quantity and the type of waste. (C) 2011 Elsevier B.V. All rights reserved.