Reduction in environmental problems using rice-husk ash in concrete

The production of cement (key binding component of concrete) is costly, consumes high energy, depletes natural resources and emits huge amounts of greenhouse gases (1 ton of cement production emits 1 ton of CO2). Consequently, environmental degradation, serious pollution and health hazards associated with cement and concrete industries, have come under intense scrutiny from environmentalists and the governments. Developed and some developing nations, are already using industrial and agricultural wastes in concrete. These wastes also pose several environmental problems. Partial inclusion of waste instead of 100% cement has been found to be environmentally safe, stable, durable as well as economical. The present study used rice-husk ash (RHA) as a partial replacement of cement in concrete. X-ray diffraction analysis, scanning electron microscopic examination, compressive strength (without and with superplasticizers), flexural strength, resistance to aggressive chemicals and cost analysis were carried out. Concrete and mortars containing 25% RHA as a replacement of cement, exhibited same or better results compared to conventional concrete. Moreover, it leads to substantial cost savings not to mention benefits to the environment. (C) 2011 Elsevier Ltd. All rights reserved.