 This research proposes an optimization method for increasing the amount of manufactured fine aggregates in concrete mixes. It was found that the void volume of the aggregates correlated strongly with the fresh properties of mortar mixtures, such as workability and compressive strength. By using this information, it was possible to maximize the amount of manufactured aggregates while maintaining acceptable levels of strength. This article was authored by Maria Eva Sosa, Andres Churilano, Yuri Andres Villagranzacardi, and others.