Development and application of new composite grouting material for sealing groundwater inflow and reinforcing wall rock in deep mine

With cement, bentonite, water glass, J85 accelerator, retarder and water as raw materials, a new composite grouting material used to seal groundwater inflow and reinforce wall rock in deep fractured rock mass was developed in this paper. Based on the reaction mechanism of raw material, the pumpable time, stone rate, initial setting time, plastic strength and unconfined compressive strength of multi-group proportion grouts were tested by orthogonal experiment. Then, the optimum proportion of composite grouting material was selected and applied to the grouting engineering for sealing groundwater inflow and reinforcing wall rock in mine shaft lining. The results show the mixing proportion of the maximum pumpable time, maximum stone rate and minimum initial setting time of grout are A(K4)B(K1)C(K4)D(K2), A(K3)B(K1)C(K1)D(K4) and A(K3)B(K3)C(K4)D(K1), respectively. The mixing proportion of the maximum plastic strength and unconfined compressive strength of grouts concretion bodies are A(K1)B(K1)C(K1)D(K3) and A(K1)B(K1)C(K1)D(K1), respectively. Balanced the above 5 indicators overall and determined the optimum proportion of grouts: bentonite-cement ratio of 1.0, water-solid ratio of 3.5, accelerator content of 2.9% and retarder content of 1.45%. This new composite grouting material had good effect on the grouting engineering for sealing groundwater inflow and reinforcing wall rock in deep fractured rock mass.