The mechanical and physical properties of unfired earth bricks stabilized with gypsum and Elazığ Ferrochrome slag

During the last few years, an increasing interest has been appeared for earth as a building material. Earth-based materials have been studied because of energy efficiency and ecologically sustainability. The chromite deposits, 10% of the world reserves, are processed in Elazığ Ferrochrome Factory in Eastern of Turkey. Elazığ Ferrochrome slag (EFS) as a by-product of the factory is produced roughly 50,000 tons in a year. The disposal, removal and storage of this by-product is a serious problem. Therefore, the utilization of this waste material in building applications is very important. The aim of this work is to investigate effects of gypsum and EFS additives on mechanical and physical properties of unfired earth brick (UEB) materials in order to assess their potential advantages in building applications. The earth material was characterized by laboratory tests. Four different UEB samples were produced by using different compositions of earth, gypsum, EFS and straw fibers. Compressive strength, water absorption coefficient, drying shrinkage, ultrasonic pulse velocity (UPV) and density of the prepared UEB samples were determined. The experimental findings have showed that the usage of gypsum and EFS in stabilizing process of UEBs was advantageous.