Study On Mechanical Properties And Proportion Analysis Of Gangue Based Shotcrete

There are various ways of comprehensive utilization of coal gangue,but in the process of utilization,most of coal gangue is directly used without distinction.Although certain utilization effect has been achieved,there are certain limitations for specific and efficient utilization.In the process of roadway tunneling,due to the existence of faults,roadway tunneling Angle and other problems,different rock types of coal gangue will be produced in a certain time or in a certain tunneling section.These rock coal gangue can be used as shotcrete coarse and fine aggregate according to local conditions,which plays an important role in environmental protection and mine cost saving.Coal mine in this thesis,based on engineering background,the fundamental mechanical properties of the aggregate are studied,through the different types of rock of coal gangue instead of sprayed concrete aggregate degree of a large amount of material physics experiments,are discussed from the point of view of macro mesoscopic gangue base mechanical properties and the feasibility of sprayed concrete,verify the mudstone of waste rock weak aggregate for the effect of concrete specimen,The optimal ratio of gangue shotcrete and gangue shotcrete with the best rock type is obtained.Specific research results are as follows:(1)Detailed introduction and analysis of the general situation of Wanfu Mine and the layout of the roadways studied.Influences of the existence of faults in the roadways in different time and excavation sections produced different types of coal gangue.Uniaxial strength and tensile strength of coal and gangue were obtained based on rock mechanics testing,and their mineral components and compounds were analyzed and their contents were determined by XRD(X-ray Diffraction,XRF)and Xray fluorescence(XRF,XRF).The change rule of mechanical properties of coal and gangue after water encounter is also studied.(2)Crushed coal,mudstone gangue and sandstone gangue are used to replace the coarse and fine aggregate of shotcrete specimens.The variation rule of mechanical properties of various gangue based shotcrete specimens with different ages is studied,and limestone foundation is used for comparative analysis.The fitting curves and prediction formulas of uniaxial strength and elastic modulus of concrete based on mudstone,sandstone gangue and limestone with different ages are obtained,and the fracture morphology of gangue based shotcrete is further analyzed.(3)The interface transition zone of aggregate to cement microstructure and the distribution and enrichment of chemical elements in the specific analysis,and studies the mudstones coal gangue mixed with waste rock base sprayed concrete for its mechanical properties,the influence of the different types of rocks the classification of waste rock base sprayed concrete analysis process in detail.(4)The variation law of slump and uniaxial compressive strength of sandstonebased shotcrete with different water-cement ratio and gradation was studied.Based on the response surface method,the binary regression equation of uniaxial strength,water-cement ratio and gradation was established,and the interaction relationship between water-cement ratio and gradation was analyzed.The best combination form of the mix ratio was predicted by using Design-Expert software.There are 42 figures,9 tables and 67 references in this thesis.