Uso de materiales reciclados como reemplazo parcial del agregado fino en el concreto

Abstract

CONDITION FOR PUBLICATION OF PROJECT. The development of the construction industry involves high consumption of natural resources and considerable waste generation. In search of more sustainable alternatives, this research evaluates the performance of concrete when partially replacing fine aggregate with rice husk ash (RHA), polyethylene terephthalate (PET), and shredded waste tire rubber at substitution levels of 2.5%, 5%, and 10%. Mixtures were prepared following ASTM standards, evaluating mechanical and physical properties (compressive strength, tensile strength, modulus of elasticity, air content, density, and workability), complemented by microstructural (SEM) and thermogravimetric (TGA) analyses. The results showed that the incorporation of these materials affected the mechanical properties; however, rice husk ash presented the least impact on compressive and tensile strength due to its pozzolanic nature; PET showed less impact on early-age strengths, while rubber exhibited a lower loss in modulus of elasticity compared to the other materials. TGA analysis revealed non-linear thermal behavior with increasing substitution percentages. It is concluded that substitutions of up to 5% provide a balance between sustainability and structural performance. Keywords: fine aggregate, shredded rubber, rice husk ash, PET, mechanical properties.