Using foundry slag of ferrous metals as fine aggregate for concrete

Foundry slag, obtained by induction, is waste from the ferrous industry whose destination is landfills. Due to its huge production and the main materials used, concrete can be a very interesting solution to incorporate this residue, turning it into a by-product. However, there is a need for more durability research studies regarding alkali-silica reactions, resistance to sulphates and susceptibility to corrosion, which sometimes, in practice, can make some slags in concrete impracticable. This study aims to evaluate the possibilities of the effective incorporation of this slag in concrete mixtures as a substitute for fine aggregates. Within this context, an experimental programme was carried out in order to evaluate the performance of concrete mixtures incorporating grey cast iron furnace slag. Properties of fresh and hardened concrete were experimentally investigated. All the results of the performed tests indicate a better performance of mixtures containing this furnace slag compared with plain cement reference concrete in terms of mechanical properties and durability indicators, excluding the results of alkali-silica reaction. Regarding the accelerated test for alkali-silica reaction and the standards for this effect, the selected slag is classified as potentiality reactive, making this application in cementitious based materials unfeasible.