Hybrid modified wasted rubber powder and its hydration reaction in the cement-based material

As a cross-linked elastomer wasted rubber powder (RP) was hybrid modified by sol-gel method under swelling condition with reactive precursor sodium silicate, and also inducting organic siloxane with hydrophilic groups. The heat of hydration and Ca2+ concentration in the cement hydration process were examined. The chemical reaction in the surface of SRP was characterized by X-ray photoelectron spectroscopy (XPS). The results showed that the hybrid modified rubber powder could take part in the hydration reaction, the Si-O -Si structure on the rubber's surface reacted with hydration products Ca (OH) 2 and generated Si-O-Ca products in the early hydration process, making the rubber powder and the cement paste combine closely together by chemical bonds.