Mussel Inspired Modification of Rubber Crumbs for Improved Interfacial Adhesion in Rubber Cement Mortar

Crumb rubbers exhibit extensive potential applications as infrastructure materials due to the low elastic modulus. Nevertheless, the poor interfacial adhesion between rubber crumb and cement matrix limits the scale applications of crumb rubbers in cement-based composites. In this study, mussel-inspired modification of crumb rubbers is investigated. The hydrophilicity of rubber surface has apparently improved after polydopamine (PDA) modification. Effects of the surface modifications of rubbers on the compressive strength, fluidity, and tribology behaviors of rubberized mortars have been systematically characterized. The superiority of PDA modification for crumb rubbers has been demonstrated by comparing those with the other polyphenol modifications and the routine oxidation modification. The compressive strength of the PDA modified rubber cement mortar increases by 37% comparing with that of the ordinary rubber cement mortar. The mechanical and low-temperature tribology behaviors of PDA-rubberized mortars indicate a promising way to improve the service performance of the rubberized mortars and concretes.