Enhancing ductility and sustainability of calcium oxide-activated slag-based HSC using waste rubber, wire, and PET

In this study, a sustainable high-strength concrete (HSC) was developed for the first time, utilizing calcium oxide-activated slag (CAS) and incorporating waste rubber, waste wire, and polyethylene terephthalate (PET). To assess the performance of waste wire compared to other fibers, polypropylene, barchip, and glass fibers were added as reinforcements. Comprehensive tests were conducted to evaluate the mechanical properties, encompassing compressive, tensile, and flexural strength of the developed concrete. To assess energy absorption, various tests, including impact resistance, dynamic modulus of elasticity, four-point bending deflection, and digital image correlation (DIC), were conducted. Additionally, a life cycle assessment (LCA) was undertaken to ev improvements in environmental performance. The research findings uncovered that using waste wire combined with PET powder yielded the highest compressive strength, flexural strength, and modulus of elasticity, achieving values of 60 MPa, 5.6 MPa, and 36.8 GPa, respectively. Based on bending test results, the composite with waste wire and barchip fibers exhibited ductile behavior, with ultimate deflections of approximately 2.5 mm and 1.3 mm, respectively, whereas the composite with polypropylene fibers failed at an ultimate deflection of approximately 0.8 mm. Furthermore, the LCA analysis demonstrated that HSC-CAS containing waste wire exhibited the best environmental performance, both in the overall score and in each factor evaluated, achieving 38% and 28% improvements relative to those with glass and barchip fibers, respectively. The highest impact resistance was observed in rubberized concrete containing waste wire fibers, with a value of 5224.5 J, approximately four times that of fiber-free concrete.