Development and application of new waterproof grouting materials of polyurethane

In order to achieve effective chemical reinforcement for broken coal and rock mass with rich water, new waterproof grouting materials of polyurethane are developed. Under large-area leakage of broken coal and rock mass, normal chemical reaction can proceed. The cementing time is 1~10 min (adjustable), and the water amout above 95% is proved for time ponding. The new materials are of good reforcing performance. The cohesive strength exceeds 1 MPa for the crack face of coal and the compressive strength exceeds 8 MPa for the rockmass. It fills the gap of waterproof and reinforcement of the broken coal and rock mass in mines with large-area leakage. The engineering application has proved the validation of the new materials.