Experimental study on the utilization of waste foundry sand as embankment and structural fill

Metal casting industries, either ferrous or non-ferrous, produce a large quantity of the waste foundry sand (WFS). Currently, it is either discarded to landfill or collected by waste organizations to extract iron remnants after washing. This research evaluates the reuse of WFS as a replacement of sand in structural fill and embankments. Sand was used to replace WFS at a replacement level of 0, 4, 6, 8 and 10% by weight. Geotechnical and environmental tests were performed to assess the durability and physical properties of WFS samples. Features like the gradation and friction angle were similar for the samples having varying sand percentages. Moreover, the California bearing ratio indicated that WFS having 10% sand replacement will make the hardest fill material. However, it is recommended to use WFS with 6% sand replacement, since it best meets the criteria of specific gravity, optimum moisture content, maximum dry density, permeability and the California bearing ratio for structural fill, embankment and road sub-base material. The chemical composition of WFS indicated the absence of any hazardous material, which may hinder its use as fill material.