State Key Laboratory of Coal Resources and Safe Mining,China University of Mining and Technology;School of Mines,China University of Mining and Technology;Open Laboratory，Jiangsu Normal University;School of Mechanical Engineering,Jiangsu University of Technology;Nanjing Institute of China Coal Technology and Engineering Group
Funds:
Key Funding Project of National Natural Science Foundation of China (52034007)
Spray-on membrane was proposed and introduced based on the analysis of problems of conventional mesh and shotcrete in bolting. The development and current research situation of spray-on membrane was summarized. The tensile stress-strain relationship of the membrane was analyzed through the tensile performance in different curing periods,indicting that the mechanical characteristics of the membrane was fast load-bearing response and large deformation capacity.Furthermore a non-reactive polymer cement-based spray-on membrane suitable for coal mine roadways was determined. The normal adhesion performance of the membrane to red sandstone substrate was tested through the direct pulling test,in which the failure occurred inside the substrate indicating the good adhesion between the membrane and the rock substrate. The different stages of load bearing was analyzed and the linear loading capacity of the membrane was calculated through the block supporting test. It is believed that the tested membrane has a good loading capacity based on the evaluation of its block supporting. Potential roles in sealing the rock surface and metal supporting parts,as well as the use of blocking the rock surface while grouting was discussed based on the engineering characteristics of coal mine roadways. A detailed comparison of sprayed-on membrane and mesh as well as shotcrete was carried out in terms of bearing timeliness,bearing capacity,deformation capacity,adhesion to the rock surface,construction performance,structural effect,and airtight performance. According to the analysis,it is believed that spray-on membranes perform well in most indicators,especially in terms of construction,which has obvious advantages. The principle of spray-on membranes’ application in bolting of coal mine roadways was discussed. The function positioning as well as the three typical engineering situations which was not suitable for spray-on membranes in bolting support was analyzed. The research could provide a reference for the application of spray-on membranes in the bolting support of coal mine roadways.
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