THE INFLUENCE OF CRUMB RUBBER ON THE FREEZE-THAW RESISTANCE OF CONCRETE

Waste tires are a persistent challenge in waste management. To reduce environmental impact and utilize this material more effectively, its use in concrete mixtures has been studied. This research aims to incorporate waste materials into concrete production while ensuring acceptable performance. The study presents results where fine aggregate was partially replaced with crumb rubber (2.5% and 5% by volume). All mixtures were designed with a w/c= 0.55 and compared with a control and a mixture with a chemical air-entraining admixture. Fresh concrete properties were monitored after 10, 30, and 60 minutes. After 60 minutes, rubber-modified mixtures showed increased air content and decreased density. The hardened concrete with rubber had lower compressive strength but better resistance after 200 freeze-thaw cycles compared to the control.