Expermental Study And Numerical Analysis Of B-PP Hybrid Fiber Reinforced Self-compating Concrete Beam

The hybrid fiber self-compacting concrete is a kind of high-performance concrete with high strength,high durability and high work-ability which is prepared by mixing the hybrid fiber on the basis of self-compacting concrete and adjusting the mixture ratio of the materials.Basalt-polypropylene(B-PP)hybrid fiber self-compacting concrete combines the advantages of both fiber reinforced concrete and self-compacting concrete.It is one of the new high-quality high-performance building materials that scholars at home and abroad are studying.Addition of B-PP hybrid fibers in self-compacting concrete can adjust the dosage of high efficiency water-reducing agent.The fresh concrete can improve the mechanical properties of concrete materials while satisfying the self-confinement.Therefore,the research on the bending and shear properties of B-PP hybrid fiber reinforced concrete beams has certain theoretical and engineering application value.In this paper,five B-PP hybrid fiber self-compacting concrete beams were firstly tested for their flexural properties.The effects of reinforcement ratio of reinforcement,the content of B-PP hybrid fibers and the hybrid ratio on the bending behaviors of the B-PP hybrid fibers self-compacting concrete beams.For the shear resistance of beam,the relations between the reinforcement ratio of stirrup,the content of hybrid fiber and hybrid ratio and the shear resistance of beam are gotten on the basis of load-displacement curve and the failure mode of ten B-PP hybrid fiber self-compacting concrete beams.According to the existing domestic and foreign codes and the bending shear theory model of concrete beam,the initial cracking load,ultimate load,mid-span deflection and crack width of hybrid fiber reinforced self-compacting concrete beams are analyzed and compared.Comparing the experimental results with the theoretical ones,the most reasonable theoretical model for calculating the shear properties of hybrid self-compacting concrete beams is obtained.Finally,by ABAQUS software,the finite element model of B-PP hybrid fiber self-compacting concrete beam which meets the experimental conditions was established,and its bend and shear performance was numerically simulated.By comparing the numerical analysis results with the experimental data,it is concluded that the three-dimensional finite element analysis model can effectively analyze the flexural and shear properties of hybrid fiber reinforced concrete beams.Based on the above models,the influences of reinforcement ratio,fiber content and hybrid ratio on the flexural and shear properties of B-PP hybrid fiber reinforced self compacting concrete beams are deeply discussed.