The scarcity of natural resources worldwide has encouraged the reuse of industrial waste in cementitious materials. In this context, waste foundry sand (WFS) is a promising material for replacing common sand (CS) in non-structural mortars. This study reviews the literature on mortars containing WFS through a structured search and selection process. The review evaluates the mechanical properties of mortars considering WFS characteristics, mix proportions, specimen geometry, and workability conditions, while also discussing sustainability, circular economy benefits, and potential environmental risks. The reviewed literature revealed inconsistencies in the mechanical performance of mortars containing the same WFS replacement level. The reduction in compressive strength (CS) showed a low linear correlation with replacement level (R2 = 0.63). WFS replacement levels between 10 and 25% resulted in CS reductions ranging from approximately 2 to 26%, while higher replacement levels (30%, 50%, and 100%) led to reductions of up to 75%. Furthermore, many studies employed unusual mortar mix designs and failed to evaluate important properties for rendering mortars, such as modulus of elasticity and adhesion strength. Incomplete reporting of experimental parameters also hinders comparisons among studies and contributes to the inconsistencies observed in the literature. Although WFS pretreatment and calcination may enable higher replacement levels, further research is required to assess their compatibility with circular economy principles and their overall environmental benefits. Graphical Abstract
Moura et al. (Sat,) studied this question.