Development of Composites from Iron-Rich Galvanized Sludge with Slag Based Cementitious Material and Waste Foundry Sand

Galvanized sludge (GS) generated from the cable wires manufacturing industry, waste foundry sand (WFS) from steel manufacturing and granulated blast furnace slag (GBFS), are the wastes that pollute the environment. This study investigated the use of these three materials to develop a value-added composite that can be utilized in the building and construction industry. The GS was stabilized with alkaline activated WFS and alkaline activated GBFS. The chemical composition of the materials was studied by analyzing the elemental composition, mineralogy, and micrography. To determine the optimum mix design, the unconfined compressive strength and water absorption tests were carried out on the developed composites. The GS was predominated with ferric oxide, while the WFS was laden with mainly, silicon dioxide and aluminum oxides. The results obtained showed that alkaline activated WFS yielded the highest UCS of 3.3 MPa, as compared to 1 MPa from the GBFS binder. The microstructure of stabilized GS changed from heterogeneous particles to finer homogeneous particles. The WFS stabilized GS can be used for different applications, for semi-load bearing applications.