Investigação do comportamento mecânico de concretos com resíduos da construção civil: análise experimental e modelagem de homogeneização computacional via MEC

Abstract

This study investigates the mechanical behavior of concrete in which natural aggregates are partially or fully replaced by recycled aggregates derived from construction and demolition waste (CDW). The research combines experimental testing and numerical modeling with a multiscale approach, using the Boundary Element Method (BEM) to represent the concrete microstructure through the Representative Volume Element (RVE). The formulation adopted considers a matrix with elastoplastic behavior modeled by the Mohr-Coulomb criterion, aggregates with elastic behavior, and cohesive contact and fracture elements to model cracking in the Interfacial Transition Zone (ITZ). Replacements of 0%, 13.96%, 27.02%, 49.68%, and 100% of conventional coarse aggregate with recycled coarse aggregate were analyzed. Experimental results showed a reduction in strength as the replacement level increased, in agreement with existing literature. The numerical modeling closely matched the physical test results, validating the adopted approach. Once calibrated, the models were used to simulate other replacement ratios, allowing the prediction of recycled concrete behavior without the need for additional physical tests. The study highlights the technical and environmental potential of using CDW in structural concrete, combining sustainability with reliable mechanical performance.