Effects of firing temperature, and ratio of steel/iron slag on the mechanical and physical properties of clay bricks, the case of Jimma town

Abstract

A construction brick made from clay soil and iron slag with variable temperature has been synthesized. In the process iron slag was collected from steely RMI Bishoftu Ethiopia and clay soil was taken from Jimma town Frustalle area. The samples was then grinded grounded properly and sieved to have a fine sample. The samples clay was mixed with a proportion containing; no slag, 10% slag, 20% slag and 30% slag and water to attain a plastic property and the brick was synthesized. The synthesized brick is then fired at a temperature of 9000C. 10000C and 11000C and samples were arranged for characterization. The characterization was made in to three parts; the mineralogical and morphological property, the physical property and the compression strength. The mineralogical characterization result shows the clay composed of quartz as a main content while feldspar and other are the main content at the same time the content of quartz in the clay brick decreases with increasing in temperature. The mineralogical characterization result of iron slag also shows the main component of hematite while Ca2SiO4 and CaAl2O4 are the other component. The increase in firing temperature cause in the decomposition of Ca2SiO4 and CaAl2O4 and favor the formation of quartz, crystobollite and kaolinite, this indicated that the samples have good mechanical and physico-sintering properties. Finally the physical and mechanical characterization result indicates, the addition of iron slag improves the property of the brick. But the result outcome indicates that the weight loss on ignition violet the expected result and the percentage of firing shrinkage at 30% slag addition above 10000C did not change.