The study on micro-fine cement grouting matial applying in colrl reinforcement

The grouting materials used for mining face coal wall reinforcement are mostly expensive organic materials.The cheap ordinary portland cement can not be used because of its poor dispersion or its low adhesion force.In this paper,micro-fine cement materials are used as new type grouting materials for reinforcement of mining face coal wall.The property of viscosity and setting time of serous fluid and the compressing strength of setting stone are studied.The setting time is short,the compressing strength is 9.6 MPa,the dispersion radius is 3 m,the adhesion force is 3.6 MPa.Good dispersion and reinforcement effect are achieved from the experiment in the gateway for hydraulic powered supports removed from 3305 coal mining face.