Hardened properties of self-compacting concrete with different crumb rubber size and content

This paper aims at investigating the effect of crumb rubber size and content on hardened characteristics of self-compacting concrete. To this end, different self-compacting concrete mixtures were designed at constant water-to-binder ratio of 0.35 and 520 kg/m³ of binder content. The class F fly ash was replaced with cement as 30% by weight. Six designated crumb rubber contents of 5%, 10%, 15%, 20%, and 25% and three different sized crumb rubbers (No. 18, No. 5, and mixed crumb rubber) were considered as experimental parameters. According to the obtained results, the use of crumb rubber had a negative effect on the hardened properties of self-compacting concretes and the significant improvement was achieved with addition of all tire wastes types, for ductility.