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研究了钻孔密封材料聚氨酯和膨胀水泥冻复合材料(PD复合材料)的微观特性,并考察了其对钻孔密封性能的影响作用.实验模拟了煤矿井下钻孔封孔过程,利用FEI Quanta~(TM)250环境扫描电子显微镜对聚氨酯、PD复合材料本身,以及两者与煤壁的结合、渗透和发展进行微观对比和分析.PD复合材料的渗透系数约为聚氨酯瓦斯渗透性系数的1/48.聚氨酯为蜂窝网状结构,内部孔隙较大,与孔壁结合处存在空白区域;PD复合材料结构严实,内部孔隙极小,在孔壁处与煤体结合密实.PD复合材料比聚氨酯更容易克服钻孔周围裂隙区内瓦斯压力、水锁效应等各种阻力的作用,在钻孔周围裂隙内逐渐渗透,且其自身可以继续在钻孔周围残余裂隙和孔洞内发展.
The microscopic characteristics of the drilling and sealing materials polyurethane and expanded cementitious composites (PD composites) were investigated and their effects on the sealing performance of the borehole were investigated. The drilling and sealing process of the coal mine borehole was simulated experimentally. The FEI Quanta ~ (TM) 250 environmental scanning electron microscope (SEM), microstructure and mechanical properties of polyurethane, PD composites themselves, as well as the combination, penetration and development of the two with the coal wall were compared and analyzed.The permeability coefficient of PD composites was about 1 / 48. Polyurethane is a cellular network structure with large internal porosity and a blank area at the junction with the pore wall. The PD composite has a solid structure with very small internal pores and is densely packed with coal at the pore wall. The PD composite is more It is easy to overcome various resistance functions such as gas pressure and water lock effect in the fracture zone around the borehole and gradually penetrate into the fracture around the borehole and can continue to develop itself in residual cracks and holes around the borehole.