Modification Study on High Pressure Surface Pre- Grouting Reinforced Cement Base Material for Deep Mine Shaft

In order to meet requirements of the reinforced material performances by the high pressure surface pre- grouting technology of mine roadway in a deep mine shaft, an easy settling, poor diffusivity, short initial setting time and other problems of the conventional single cement grout were solved. In combination with the e ngineering application conditions, a study was conducted on the new cement base grouting and reinforced material to improve the stability and to extend the initial setti ng time. With a water and cement ratio of 1 : 1 grout as study object, screening and preparation tests of the retarder and stabilizer were conducted. Two compound ad mixtures were selected, thus the viscidity of the modified grout could be over 25 s, the max initial setting time could be over 32 h and microstructure of the stone bindin g body would be more compact than before the modification. The 28 day compressive strength and the single cement grout would be the same basically and could be a pplied to the surface pre- grouting reinforcement for mine roadway in deep mine shaft with good effect.