Model Experimental Study And Application Of Shotcrete Structure With Carbon Fiber And Steel Wire Mesh

The lack of crack resistance and tensile properties of concrete materials leads to cracks in concrete,resulting in reduction of impermeability,loss of sealing and supporting effect on surrounding rock,and then lead to roadway damage.To study the compressive,tensile and flexural properties of concrete with different grid density carbon fiber mesh and different content of carbon fiber short cut wire,the method of combining mechanical properties test and structural model test were adopted,and the optimal carbon fiber mesh density and the optimal carbon fiber short cut wire content of synergistic reinforced concrete were determined.The model test of carbon fiber steel wire mesh reinforced concrete arch structure is carried out,and the new technology of carbon fiber wire mesh reinforced concrete support is developed.Through a variety of test methods and microscopic analysis,the method of alkali excitation materials to improve the impermeability of concrete is proposed.The main research contents and conclusions are as follows:(1)Mechanical properties test and analysis of carbon fiber reinforced concreteBy testing the compressive strength,splitting tensile strength and flexural strength of concrete with different grid density carbon fiber mesh and different content of carbon fiber short cut wire,the synergistic strengthening mechanism of carbon fiber mesh and carbon fiber short cut wire is analyzed.The results show that the carbon fiber short cut wire effectively increase the tensile strength of concrete specimens,the carbon fiber mesh effectively improves the flexural strength of concrete beams,and the incorporation of carbon fiber mesh and carbon fiber short cut wire plays a synergistic strengthening effect of carbon fiber.Through experimental research,the appropriate dosage of carbon fiber mesh and carbon fiber wire for synergistic reinforcement of tensile and flexural properties of concrete was proposed.(2)Model experimental and theoretical analysis on bearing capacity of carbon fiber reinforced concrete shotcrete arch structureThe bearing capacity and deformation model tests of different grid sizes and different fiber bundle carbon fiber reinforced concrete shotcrete layers were carried out.Compared with the specimens without carbon fiber mesh,the ultimate bearing capacity of 80 mm and 120 mm grid spacing carbon fiber reinforced concrete shotcrete arch increased by 43.9%and 39.0%,respectively.The most unfavorable position of concrete arch under load is on both sides of the highest point of concrete arch.Carbon fiber steel wire mesh improves the deformation performance of concrete arch structure and improves the ductility of the spray layer structure.Through theoretical analysis,the mechanical model of shotcrete support structure in underground coal mine is established.According to the axially force diagram and bending moment diagram,the dangerous section position of concrete arch is found,which provides a theoretical basis for roadway support and reinforcement.(3)Experiment and analysis on impermeability of alkali-activated carbon fiber reinforced concreteThe impermeability test and microscopic analysis of concrete with alkali activated material improvement were carried out.The results showed that the incorporation of carbon fiber mesh not only led to a significant increase in the porosity of concrete,but also significantly reduced the proportion of harmless holes and low-harm holes,and significantly increased the proportion of harmful holes and serious harmful holes.Condensation characteristics,mechanical properties and cohesion of alkali activated materials are analyzed.Through impermeability test and mercury intrusion test,the method of improving impermeability of concrete by alkali activated materials is proposed.(4)Engineering application of carbon fiber reinforced concrete support technologyThe engineering application of carbon fiber shotcrete shows that the carbon fiber mesh can effectively improve the mechanical performance and deformation performance of concrete spray layer structure.The field monitoring results show that the carbon fiber network has played a role in strengthening crack prevention,reducing the deformation of roadway,improving the quality of mine roadway support engineering,reducing the amount of roadway maintenance,prolonging the service life of support engineering,and achieving better social and economic benefits.Figure[67]Table[38]Reference[158]...