Evaluación de la resistencia a la tracción indirecta de una mezcla MDC-25 elaborada con agregados de concreto reciclado de alta y baja resistencia, provenientes de probetas de ensayo

Abstract

This experimental research focused on evaluating the performance of hot mix asphalt MDC-25 produced with recycled concrete aggregate (RCA), particularly in terms of moisture susceptibility. Two mixtures were designed and tested: Mixture-1, made with -RCA-1 (sourced from unfailed concrete specimens with compressive strengths greater than 55 MPa), and Mixture-2, made with -RCA-2 (sourced from unfailed concrete specimens with a compressive strength of 21 MPa). The coarse aggregate fraction was the only variable, while the fine fraction and the 60/70 asphalt binder were kept constant. The process included the recovery and crushing of concrete specimens, the characterization of both RCA types, the Marshall design of MDC-25 mixtures with 100% replacement of the coarse fraction, and the performance evaluation through the Indirect Tensile Strength test (ITS) under dry and wet conditions, following the INV E-725 standard, in order to calculate the Tensile Strength Ratio (TSR). The results showed that Mixture-1 achieved a TSR of 78.7%, while Mixture-2 reached 57.1%, indicating lower moisture susceptibility when using RCA from f’c ≥ 55 MPa concrete. However, both values fell below the 80% threshold established by INVIAS 2022, highlighting the need for pre-treatment of RCA or adjustments in the replacement percentage to improve the performance of asphalt mixtures incorporating this type of aggregate.