Comparative analysis and temporal behavior of discarded foundry sand incorporated into cementitious matrices

Abstract

The reuse of industrial waste is crucial for sustainable practices in the foundry industry. This study characterizes discarded foundry sand (WFS), comparing it with common sand (CS) and evaluating its temporal behavior and dimensional variation in cementitious matrices. Granulometry tests, fine material content, specific and bulk density, void ratio, water absorption, MEV, solid waste classification, phenol analysis in leachate extract, loss on ignition, TGA, FTIR, GC-MS, EDS, and acute toxicity tests were conducted. Temporal analysis showed a reduction in carbon values over storage time, attributed to the chemical alteration of organic compounds. Loss on ignition and TGA tests corroborated the detected phenol concentrations, while FTIR analysis indicated partial decomposition of the phenolic resin during the industrial process. The dimensional variation of fresh mortar was assessed, highlighting the importance of using 20 cm molds with indicator discs for precise measurement. The results suggest that WFS can be used as a raw material in the construction industry, in accordance with current legislation.