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

Abstract

Waste foundry sand (WFS) is one of the waste residues from the process of elaboration of components in foundries. Presently, its annual production is estimated at three million tons. This residue is derived from a composition of very fine natural sand, which consists predominantly of silica. The material retains properties that render it a compelling candidate for deployment as an alternative constituent to natural fine aggregate in concrete applications. This substitution holds the assurance of fostering enhanced sustainability in both construction and metallurgical industries. Considering these facts, the present study proposed the testing of three different proportions of replacement– 25%, 50%, and 100% by mass - of natural sand by WFS in concrete. To evaluate the feasibility of these replacements, several tests were conducted encompassing mechanical properties as well as aspects related to the durability of the concrete. The results indicated a significant improvement in mechanical performance, wherein there was an increase in compressive strength as the substitution content increased, with no significant variation in elastic modulus. Regarding the aspects associated with durability, both the absorption test and the alkali-aggregate reaction test did not present a statistically significant disparity relative to the core concrete, thereby demonstrating the technical feasibility of WFS utilization in concrete.