Experimental and numerical evaluation of the mechanical behavior of alkali-activated slag concrete with recycled waste glass and dealuminated metakaolin powders

This study aims to evaluate the mechanical performance of ambient-cured Alkali-Activated Slag Concrete (AASC) incorporating different coarse aggregates (dolomite and basalt), recycled waste glass powder (WGP), dealuminated metakaolin (DK), and steel fibers (SF). An experimental program was conducted to assess the mechanical properties of the investigated mixes. Microstructural characteristics were also examined using SEM-EDX analysis to support the interpretation of mechanical trends. Furthermore, finite element (FE) simulation models were developed in ABAQUS and validated against experimental results. The findings indicate that AASC incorporating 10% DK and 1% SF exhibits the highest overall mechanical performance. Based on the experimental results, a nonlinear Concrete Damaged Plasticity (CDP) model was developed and rigorously calibrated, enabling reliable FE simulation of AASC behavior. The validated model was subsequently employed in an extensive parametric study to investigate the flexural response of reinforced AASC beams, which demonstrated that the inclusion of 1% SF increased load-carrying capacity by approximately 46% while reducing mid-span deflection by about 19.7%. The results show that the optimized mixes, particularly those incorporating WGP + SF or DK + SF, achieved higher ultimate loads, reduced deflections, delayed crack initiation, and improved ductility. The proposed FE model accurately predicts load capacity and failure modes, providing a robust tool for future structural design and optimization of sustainable AASC elements utilizing industrial by-products and waste materials. The novelty of this study lies in the comprehensive investigation of recycled WGP and DK, each combined with SF in AASC, supported by integrated experimental and numerical analyses to elucidate their synergistic effects on mechanical behavior.