On the use of recycled tire rubber to develop low E-modulus ECC for durable concrete repairs

The durability of concrete repairs is often limited due to restrained drying shrinkage. In this study, recycled tire rubber is used to develop deliberately low elastic modulus and highly ductile ECC repair material so as to alleviate repair failure induced by restrained drying shrinkage. Emphasis of this study is placed on the influence of tire rubber on the mechanical properties and cracking tendency of ECC repair material. It is revealed that the addition of tire rubber in ECC mixtures dramatically improves the tensile ductility but lowers the compressive strength, tensile strength, and elastic modulus. In spite of the increase in free drying shrinkage deformation, the reduction in elastic modulus of ECC containing tire rubber is demonstrated to be effective in reducing the cracking tendency of ECC repairs, which suggests that an improved durability of concrete repairs can be achieved by ECC material containing recycled tire rubber.