Upcycling waste tires into High-Strength Engineered Geopolymer Composites (HS-EGC): Double-stage modeling of over-saturated cracking behavior

Under uniaxial tension, Engineered Geopolymer Composites (EGC) typically exhibit over-saturated cracking behaviors. This study aims to assess and model the double-stage crack evolutions of rubberized EGC, which is of significance to its future applications. A Weibull-based probabilistic model was developed based on crack width data and the modification of Weibull parameters. The modeling results showed good agreement with the experimental and best-fit results, demonstrating its capability in characterizing crack width evolution. In addition, compared with the reported rubberized ECC and EGC, the mixture incorporating 100% crumb rubber developed in this study exhibited a more favorable balance between mechanical performance and sustainability. It yielded the lowest VIKOR index of 0.02 under the equal-weighting multi-criteria decision analysis (MCDA) framework and showed the strongest ranking robustness in the Monte Carlo Simulation (MCS) analysis with randomly assigned weights. These findings demonstrate a viable pathway for upcycling waste tires into sustainable high-performance construction materials.