Study On The Ratio And Properties Of New Cement-Polyurethane Composite Grouting Materials

With the increase of coal mining depth,the mechanical properties of underground soft rock mass are particularly complicated.The mechanical properties of soft rock mass can be effectively improved by grouting reinforcement technology.The traditional polyurethane chemical pulp has good reinforcement performance,but the traditional polyurethane grouting material as anchor material has low anchoring force,large heat release during curing,and uncontrollable grouting time,which is not conducive to the safety of coal mine production.In this paper,a new type of cement-polyurethane composite grouting material is studied.The physical and mechanical properties of the cement-based polyurethane grouting material are studied by the ratio test to make it have high-strength anchoring force and low heat release under the optimal ratio.Grouting material with controllable grouting time can be widely used in coal mine anchoring and support technology.?1?Based on the principle of composite technology of polyurethane grouting material and cement material,the optimal ratio composition of cement polyurethane grouting material is determined by orthogonal test and experimental results:water-cement ratio is 0.6:1,mud-mixing ratio It is 2:3,the diluent content is 5%,and the ultimate tensile strength of the material is 77.96kN,the compressive strength is 57.185MPa,the gel time is 435s,and the maximum curing temperature is 80°C.?2?The mechanical parameters of the 5^#coal seam roof in Nanyangpo mining area were determined by similar material simulation.The anchoring properties of cement slurry,cement polyurethane and pure polyurethane in rock were tested.The three materials were analyzed as full in rock.The form of damage when anchoring the material with long anchors.?3?By using FLAC^3D,a numerical model of anchoring performance analysis including anchoring surrounding rock,cement-polyurethane composite grouting material bonding material,cement slurry bonding material and anchor rod was established,and the bolt and the two bonding materials were used.The contact surface unit is set between the bonding material and the surrounding rock mass.The interaction of the anchoring interface is studied.The axial stress of the two materials as the bonding material is compared.The deformation of the surrounding rock under the external load is analyzed.The influence of the axial stress of the anchor.?4?The comparison shows that cement-polyurethane composite grouting material can be used as a bolting material for coal mine anchoring,with high strength anchoring force,low heat release and controllable grouting time.It can replace traditional pure polyurethane pulp to some extent.Wood and cement slurry,the construction process is simple,the curing time is short,and the construction cost is greatly reduced.