Effect of Sawdust and Coconut Shell on the Mechanical Properties of Concrete

The increased demand for infrastructure due to global population growth has resulted in the depletion of natural aggregate sources and the escalation in the cost of building materials. There is also the problem of environmental pollution as a result of wastes generated from agricultural activities. This has led to various studies aimed at investigating the use of waste materials as substitutes for natural aggregates in concrete. In this research, sawdust (SD) And coconut shell (CS) were used as partial replacements for fine and coarse aggregates respectively in concrete. Concrete cubes, cylinders and prisms were cast and tested for compressive, split-tensile and flexural strengths at 0% (control), 10%, 20%, 30% and 40% replacement of sand and granite by weight with SD and CS respectively, after curing in water for 7, 14 and 28 days. The results showed that as SD and CS increased in the matrix, the concrete's compressive, split-tensile and flexural strengths decreased. The modified mixes can however be used as economic alternatives for lightweight concrete production as the production cost reduces with an increase in the SD and CS in the matrix. An optimum of 10% substitution by weight of fine and coarse aggregates with SD and CS respectively is recommended for concrete production.