超细水泥浆液最优配比及注浆效果研究

Study on the optimum proportion and grouting effect of superfine cement slurry

以九龙煤矿-850 m水平运输(胶带)大巷破碎围岩为研究对象,从注浆效果入手,基于超细水泥浆液水灰比、水泥细度的变化,制作了多批次的标准水泥试块,进行流动性、析水率、密度、单轴抗压强度及注浆等实验,研究了不同水灰比和不同细度下超细水泥浆液的各项力学特性和注浆性能。研究结果表明,在搅拌时间、养护时间和温度等其他因素都相同的条件下,超细水泥浆液的水灰比增大时,析水率随之增大,单轴抗压强度随之减小,流动度总体减小,密度变化很小。当水灰比为1.4∶1、细度为1 250目时,超细水泥浆液的各项力学性能最平衡,注浆效果最好。在进行劈裂注浆实验时,用该配比的超细水泥浆液注浆后的试样在破坏前能够吸收更多能量,表现出明显的塑性特征和抗变形能力。

Took broken surrounding rock of belt conveyor roadway with mining level - 850 m in Jiulong Coal Mine as the background, based on the changes of the water cement ratio and the superfine cement fineness, the authors produced a batch of standard cement specimens from the perspective of the grouting effect. The liquidi- ty, drainage rate, density, uniaxial compressive strength, and grouting experiment were carried out. It is the me- chanical properties and grouting performance of superfine cement grouting under different water cement ratio and different fineness that were studied. Research results showed that,in same conditions of the mixing and cu- ring time, temperature and other factors, while water cement ratio of superfine cement slurry increased, the drainage rate increased,the uniaxial compressive strength was less, the overall fluidity decreased, and density changesd very small. When the water cement ratio was 1.4：1 and the fineness was 1 250 mesh,the mechanical properties of superfine cement were mostly balanced, grouting effect was better. In the fracturing grouting exper- iments,it is the specimen with the ratio of the superfine cement injection and pre-broken that can absorb moreenergies, which showed the specimens had obvious characteristics of the plastic and resistance to deformation a- bility.