Research On Uniaxial Compressive Behaviour And Application Of Compact Reinforced Composite

Compact Reinforced Composite(CRC),is a kind of performance steel fiber reinforced concrete.Compared to ordinary concrete,it has better compressive properties,tensile properties,durability,abrasion resistance,cracking resistance and good adhesion between steel and concrete,so it is widely used in the repair and reinforcement of seismic structures,impact resistant structures and concrete structure.CRC,who has good market competitiveness,can make the repair of structural components more solid and reliable,but also can reduce the cost of maintenance in the harsh conditions.At present,there are few studies on the mechanical properties of CRC,which hinders the popularization and application of this material.Therefore,it is of great theoretical and practical value to study the mechanical properties of CRC.The research contents of this paper are as follows:(1)The grading of quartz sand was calculated by G.Hüsken method based on the maximum bulk density theory and verified by experiments.And the influence of water-cement ratio,sand-to-plastic ratio and steel fiber content on CRC slurry slump was analyzed by single factor test.Then found the optimum blending ratio of CRC,and finally established the relationship between the content of steel fiber and the compressive strength of CRC.(2)The compressive process and the failure mechanism of the CRC prism were analyzed by the uniaxial compression test.Based on the experimental results,promote the conversion coefficient of compressive strength of the CRC prism and the compressive strength of the cube compressive strength,the secant modulus of the CRC,the origin elastic modulus and the Poisson's ratio.And based on the test results of the CRC stress-strain curve rise section,the mathematic model of the CRC curve of theuniaxial compression is established by theoretical analysis.(3)From the aspect of micro-mechanics,the paper based on the Monte Carlo method and used Matlab software to write the steel fiber random delivery program.Then created two point coordinates of the fiber and established the random distribution of the three-dimensional model of steel fiber.Through the interaction of AutoCAD and Rhino software,a large amount of steel fiber data was imported into Abaqus.Then generated the complex steel fiber distribution model and carried out the nonlinear finite element analysis.And the influence of the randomness of steel fiber distribution and its characteristic on the properties of the material was discussed.Finally compared the simulation results with the experimental results,and the reliability of the simulation method was proved.(4)Through the quasi-static test,two seismic tests of the fracture of steel reinforced concrete beam-shaped joints with CRC were completed.And analyze the damage to the specimen before and after the repair of the specimen,the adhesive properties of CRC and ordinary concrete,the bearing capacity,the degradation of the strength and stiffness and the energy consumption.Then comprehensively evaluate the seismic performance of the repaired specimens.The results show that the bond strength between CRC and ordinary concrete is quite well.If the repair measures properly,the bearing capacity of the specimen can be recovered after the repair.In addition,the initial stiffness of the specimen after repair is lower than that of the original specimen,but the hysteresis curve is full,and the degradation of strength and stiffness is slower and the energy dissipation is better.