A two-staged surface treatment to improve properties of rubber modified cement composites

► Innovative approach – two-staged surface treatment. ► Chemical bonding between rubber particles and cement hydration products. ► “Hard shell” coating around rubber particle. ► Improved compressive strength of rubber modified cement composites. This laboratory study presents a new approach – two staged surface treatment – to treat rubber particles for improving the performance of rubber-modified cement composites. In the first stage, silane coupling agent is used to modify rubber particle surface and develop chemical bonds between rubber particles and cement paste. In the second stage, cement is used to coat the silane-treated particles. The purpose of the cement coating is to develop a “hard shell” around rubber particles after cement hydration. The proposed surface treatment was validated through a laboratory experiment. The experiment results showed that after the two-staged surface treatment of rubber particles, the compressive strength of rubber-modified cement composites could be increased by up to 110%, which could potentially increase application of rubber-modified cement composites.