Physical and mechanical performance test and application of modified cement base grouting material

Wang Qiang; Li Wenzhou

doi:10.13199/j.cnki.cst.2016.12.010

Abstract：According to the high cost and high cousumption of the chemical grout in the deep borehole high pressure grouting process of the broken coal and rock mass in the coal mining face,there was a poor binding problems between the rock binding mass and coal mass with the ordinary Portland cement grout,a modified liquid applied to the ordinary Portland cement grout was developed.A lab analysis was conducted on the viscosity,calculi rate,8 type model tensile strength,bonding performances of grout binding rock under the bolt pulling condition as well as other physical and mechanical performances of modified cement base grouting material.The results showed that when the dosage of the cement modified liquid was not over 20％,the dosage would have less influences to the fluidity of the grout and could meet the requirements of the grout for the high pressure deep borehole grouting.Under the condition of the different water and cement ratio,the calculi rate of the grout would be over 98％,the modified liquid would not be obvious to improve the calculi rate of the grout and would not make the calculi rate decreased.Under the condition of the bolt pulling,the bond performanccs test showed that when the water and cement ratio was 0.7:1.0 and the modified liquid dosage was 15％,the bonding performances of the rock binding mass would be best.The high pressure deep borehole grouting would be better to have a single cement grout,the sodium silicate volume would be 3％～4％ of the cement quantity and the dosage of the cement modified liquid would be 15％～ 20％ of the cement grout quantity.The modified cement base grouting material was applied to the underground mine test of the high pressure deep borehole grouting during the terminal period of N1-3 island coal mining face in Lu'an Changcun Mine.The site test showed that the grout consumption volume and grouting cost were highly reduced and the terminal period was shortened.