Sustainable concrete production through the integration of waste foundry sand, fly ash, silica fume and metakaolin.

This exploratory study investigates the use of waste foundry sand (WFS), combined with supplement cementitious materials (SCMs), in concrete production. The Preliminary Investigation is based on three groups, where the first group studies different percentages of natural sand replacement with WFS (i.e. 5%, 10%, 15% and 20%), the second group analyses the addition of 5% silica fume with WFS, and the third group observes 10% metakaolin inclusion with WFS. The studied parameters include density, nondestructive test (UPV), compressive and tensile strength, acid resistance, and environmental benefit analysis. According to the results, the compressive strength of the concrete mix is enhanced by 17% by adding 20% WFS and 5% silica fume, and this value increases by 23% when adding an additional 10% metakaolin. Furthermore, the use of 20% WFS leads to a 3.27% decrease in the cost of concrete as compared to the control mix, with a decrease of 2.1% and 5.1% for silica and metakaolin-containing mixes, respectively.