Abstract:In order to reduce the cost of mine in comprehensive treatment work, the experimental study of "the proportion of cement grouting material with fly ash content" was carried out. The orthogonal experiment was designed to study the water precipitation rate, seed setting rate and compressive strength of the fly-ash - cement grouting material. The feasibility of each experimental scheme was studied and the optimal scheme was selected and the field industrial experiment was conducted. The results show that the solid ratio is the main influencing factor of uniaxial compressive strength, the water-solid ratio is the main influencing factor of water extraction rate and seed setting rate, and the water glass content has no significant influence on the compressive strength. The strength change model was carried out under the conditions of different solid ratio, water-solid ratio and curing age. Solid ratio, water-solid ratio and curing age were positively correlated with strength, and the value of solid ratio coefficient was the largest, indicating that solid ratio had the most significant influence on strength. Second grade fly ash, solid ratio 4:6, water solid ratio 1:1.4 and water glass content 0% were selected as the optimal scheme, and industrial experiments were conducted to meet the site requirements. At present, this method is gradually applied to other filling roof areas in the mine.