Using Foundry Waste Materials in Concrete for a More Sustainable Future

It is the perspective of the author that the current trend in concrete materials is in the sustainability of the material. One major way of producing sustainable concretes is through the use of waste materials or other recycled materials. This is accomplished by reducing the demand for raw materials such as sand and rock and even cement in some instances. One movement is toward using waste from the steel casting (foundry) and manufacturing industries. According to recent studies, approximately 6-10 million tons of waste is produced annually by the foundry industry and estimates have shown that only 15% of the waste produced is being recycled each year [1]. The increasing scarcity of landfill space and disposal cost has fashioned a need for an alternative disposal method of this large industrial waste, and researchers have discovered that it can be used in concrete. Foundry waste can consist of many products such as spent foundry sand, slag, ash, refractory, coagulant, baghouse dust, pattern shop waste, and debris [1-4]. Of this waste a large percentage consists of spent foundry sand (SFS) from casting molds and slag from smelting of iron ore. A picture of a typical foundry waste can be seen in Figure 1 (Figure 1).