煤体注浆材料优选及加固煤体单轴压缩试验

Optimization of Coal Grouting Materials and Uniaxial Compression Test of Reinforced Coal

为了在瓦斯抽采钻孔施工过程中对帷幕注浆加固材料进行优选,通过黏度和抗压强度,确定高延性水泥基复合材料的基本水灰比。采用粉煤灰、微硅粉以及聚乙烯醇作为掺合剂,研究了不同掺合剂配比对注浆加固材料性能的影响,包括浆液黏度、凝结时间及固结煤体渗透率和抗压强度。试验结果表明:高延性水泥基复合材料的基本水灰比为0.75∶1;水灰比对注浆材料的黏度和抗压强度影响显著,注浆材料黏度与固结煤体渗透率、抗压强度、弹性模量受掺合剂配比影响明显;与其它体系相比,体系1(粉煤灰、微硅粉以及聚乙烯配比分别为(5%、15%、3%)注浆材料黏度适中,固结煤体渗透率较低,抗压强度最高,其注浆效果最优。

This paper focuses on the reinforcement material optimization using curtain grouting method during drilling construction for gas extraction. First, the basic water cement ratio of cement based composite material with high ductility is determined based on the viscosity and the compressive strength. Then, the fly ash, silica fume, and polyvinyl alcohol are added to the composite material to investigate the effect of composition ratio on such performances as the viscosity, the setting time, the permeability and the compressive strength. The results show that： the basic water cement ratio is 0.75：1; the water-cement ratio obviously influences the viscosity and compressive strength. The admixture compositions have notable effect on the viscosity of grouting materials, consolidated coal permeability, compressive strength and elasticity modulus;system 1（ fly ash, silica fume and polyvinyl alcohol, 5：15：3 mass fraction） has the optimum grouting effect due to the highest compressive strength, low viscosity and medium viscosity,compared with other systems.