Influences of agro-wastes on the physico-mechanical and durability properties of unfired clay blocks

Abstract

The increasing demand for construction materials along with the challenge of waste management has necessitated the development of sustainable materials utilising wastes properly. Therefore, this research examines the utilisation of various agricultural wastes, such as Eggshell Powder (ESP), Sawdust Powder (SDP) and Coconut Husk Powder (CHP), in the production of unfired clay blocks. Samples were made with various percentages of wastes: 10–50% of dry wt. of clay for ESP and 2.5–10% for SDP and CHP. In this study, the physico-mechanical and durability properties of unfired clay blocks were investigated by conducting density, linear shrinkage, capillary water absorption, flexural strength, compressive strength, ultrasonic pulse velocity test, drip test and water spray test. The tests were carried out in two phases, with the first phase including the individual integration of waste in the mixture and the second phase combining ESP (10–30%) with the optimum SDP (2.5%) and CHP (2.5%). The test results show that when the additives were used individually, the 40% ESP samples performed the best whereas for SDP and CHP 2.5% content showed better performance. Contrarily, the samples' overall characteristics deteriorated when ESP, SDP, and CHP were used together. Nevertheless, all the samples met the strength requirement of the standards and passed the durability tests. The results of this study might be useful in assessing the potential of ESP, SDP and CHP for the production of unfired clay blocks as well as finding a feasible solution to the waste management problem.