Analysis of the Technical Feasibility of Sustainable Concrete Production Using Waste Foundry Sand as a Fine Aggregate

Waste foundation sand (WFS) is one of the most abundant residues in the foundation industry. Currently, its annual production is estimated to be three million tons. This material has properties that make it an attractive candidate for implantation as an alternative constituent to a natural fine aggregate in concrete applications. This application can promote greater sustainability, as it would establish a noble destination for the waste generated in large quantities by the metallurgical industry in addition to reducing the exploitation of a natural resource widely used by the civil construction industry. Given this, the present study observed the test of three different proportions of replacement, 25, 50, and 100% by mass, of natural sand by WFS in concrete. To assess the feasibility of these replacements, several tests were carried out covering mechanical properties and aspects related to the durability of concrete. The results indicated a significant improvement in the mechanical performance, with a resistance gain of 25% in relation to the reference concrete. As for the modulus of elasticity, there was no significant variation. As for aspects related to durability, both the absorption test and the alkali aggregate reaction test did not show statistically significant disparity, which attests to the technical feasibility of using nonconcrete WFS.