Effect of Silica Fume Addition and Firing Temperature on Physico-Mechanical Properties of Clay Bricks

Abstract

The aim of this research is to study the additive effect of fumed silica waste on some physical and mechanical properties of clay bricks. Ts perform that, five batches of Egyptian clay and fumed silica were designed with fumed silica ratio 0, 2, 4, 6 and 8 mass-%, shaped into a cylinder mould and fired at 800°C, 900°C and 1000°C. The chemical and mineral composition of the raw materials was carried out using XRF and XRD as well as SEM and EDAX, respectively. Phase composition, physical and mechanical properties of fired batched were investigated to evaluate the changes occurred as a result of fumed silica addition and firing. We concluded that addition of fumed silica leads to; reduce density, shrinkage and compressive strength, while the water absorption and porosity increased. The rising of the firing temperature leads to increase density and compressive strength as well as the linear shrinkage, while reducing the porosity and water absorption. All samples have sufficient strength values greater than 20 MPa. These results confirm that the brick samples produced from fumed silica addition with clay with different ratio could be used as a construction material.