Properties and Swelling Mechanism of Hole Sealing Material

摘要

Grouting to reinforce the surrounding rock is new technology in coal mine supporting. The hole sealing material is a key to grouting. In this paper, properties such as setting time, swelling rate and strength of a new hole sealing material which was fabricated using high alumina cement, lime gypsum and additives were studied. The swelling mechanism of this material was probed experimentally. The results shows that the newly developed sealing material has desired setting time, high strength and large swelling rate, which can meet the demand of mine reinforcing. Furthermore, the swelling mechanism is due to the main hydration product - ettringite which has a small crystal size and has a radial distribution in the hydrated structure.