Study On The Shear Performance Of RC Beams Reinforced With Basalt Fiber Grid-Enhances ECC

With the booming development of the construction industry,most structures have reached the stage of reinforcement and maintenance.However,the traditional reinforcement methods and materials can not fully meet the needs of the current mainstream technology.Reinforced concrete structures are often reinforced by steel mesh,but the steel is easy to be corroded in the corrosion environment,leading to the great safety risks of the structure.Therefore,the technical innovation of reinforcement materials and reinforcement methods is becoming more and more important.It is a new reinforcement technology to use the basalt fiber mesh reinforced ECC composite material instead of the traditional steel reinforcement mesh for structural reinforcement,in the shear reinforcement of the reinforced concrete beam,the composite reinforcement material shows the advantages of light weight,high strength,corrosion resistance and high temperature resistance,which can effectively improve its shear bearing capacity.While the carrying capacity of the structure is improved,it can also reduce the deformation of the structure and inhibit the development of cracks in the structure.In addition,when using the fiber grid material to reinforce the reinforced concrete structural members,the fiber grid shows the characteristics of bidirectional force,which can improve the bearing capacity of the reinforced structural components.Therefore,the basalt fiber grid-enhances ECC composite reinforcement technology is better than the traditional reinforcement technology in improving the bearing capacity of the structural members,increasing the ductility,resisting stripping,crack control,and optimizing the construction performance.This paper studies the shear resistance of RC beam reinforced with basalt fiber grid-enhances ECC.The calculation formula of shear bearing capacity of RC beam reinforced with basalt fiber grid-enhances ECC is improved.The development of this project can provide theoretical reference for the subsequent structural reinforcement technology,and is of great significance to guide the practical engineering.The following work was mainly carried out:(1)Experimental study on the basic mechanical properties of materials.The basic mechanical properties of concrete,reinforcement,basalt fiber mesh,Engineered Cementitious Composite(ECC)and other materials used in the test of basalt fiber grid reinforced ECC reinforced RC beam.The results show that the selected materials have good properties and can meet the test needs.(2)Experimental Study on shear resistance of RC beam reinforced with basalt fiber grid-enhances ECC.A total of 7 test beams were designed,including 1unreinforced test beam,3 cast-in-place reinforcement test beams and 3 prefabricated paste reinforced test beams,through the four-point bending static loading test,the influence of the reinforcement method,basalt fiber grid specification(fracture strength),shear span ratio and other parameters on the reinforcement performance of RC beam is deeply analyzed.The test results show that: compared with the unreinforced beam,the reinforced beam improves the cracking load of the pure bend section,the cracking load,the limit displacement of the shear bend section,which can effectively improve the shear capacity of the beam;Under the comparison of the two different reinforcement methods,it is found that the improvement effect of the cast-in-place reinforcement beam is more obvious than that of the precast reinforced beam,but both reinforcement methods have partial slight stripping damage after reaching the ultimate load.(3)Finite element analysis of shear resistance of RC beam reinforced with basalt fiber grid-enhances ECC.The model building and numerical analysis of the test beam are conducted using ABAQUS / CAE 6.14-4 finite element software,comparing the finite element simulation results and the test results.Where the coefficient of variation of the limit load ratio of the test value to the simulated value is 0.033,The coefficient of variation of the ratio of the limit displacement of the simulated value is 0.095,which verifies the accuracy of the finite element simulation results.(4)Based on the truss-arch model,the shear mechanism of the test beam is analyzed,the calculation formula for calculating shear capacity of reinforced RC beam with basalt fiber grid-enhances ECC is improved,and the calculation results agree well with the test results data.And through the collected data for calculation and analysis,it was verified that the improved formula has high prediction accuracy and can effectively predict the shear bearing capacity of reinforced beams,providing practical reference for the design of reinforced structures.