Utilization of Scoria as Aggregate in Lightweight Concrete

In Nigeria, concrete production with conventional building materials are widely used. These type of materials are costly. Structural lightweight concrete is receiving more attention now since it offers the required concrete density, cost saving and reduction of negative environmental effects. This study investigates the physical and mechanical properties of lightweight concrete using scoria as partial replacement of coarse aggregate. Grade 25 concrete was produced with 0, 10, 20, 30, 50, 80, 90 and 100% scoria replacing coarse aggregate. The concretes were assessed in terms of water absorption, density, flexural and split tensile strengths. The result revealed that water absorption increases with increase in percentage of scoria with the optimum of 10.20% at 100% replacement. The split tensile strength decreases with increase in scoria from 2.32 N/mm2 to 0.74 N/mm2 for 0% and 100% replacement respectively at 28 days curing. Also flexural strength decreases with increase in scoria with the optimum strength of 4.55 N/mm2 at 10% replacement. The density decreased from 2584 Kg/m3 to 1870.9 Kg/m3 for 0% and 100% coarse aggregate replacement respectively. The scoria aggregate satisfied the requirements of lightweight aggregate for structural concrete as per ASTM C 330.