Seismic Performance And Numerical Simulation Analysis Of High-strength Concrete Columns Confined By High-strength Stirrups

The advantages of high-strength concrete mainly include the good workability,the high strength,the excellent durability and the convenient construction,but its brittleness is significant compared with the ordinary concrete.The use of high-strength stirrups is an effective measure to improve the seismic performance of high-strength concrete(HSC)columns.And this mean take the greatest preponderance of the two material.In the meanwhile,it can further enhance loading capacity of the concrete column,reduce the section size of the member,etc.For this article,the earthquake-resistance performance and the skeleton curve of this type of column are studied by binding test study,theoretical analysis and simulation.The main tasks are as follows:1.Based on the low-cycle reversed loading test of ten high-strength concrete columns confined by high-strength stirrups,the stirrup eigenvalue,the stirrup form,the axial compression ratio on the confined effect of HSC columns is studied,and the destruction process were watched in the loading process.In the meanwhile,the load-displacement hysteresis curve was collected.The test results show that the ten specimens are flexural failures.In the failure process,the first crack is horizontal crack in concrete,and then the longitudinal reinforcement yields,and the concrete is finally compressed and peeled off.With the increase of the stirrup characteristic value,the confined effects of high-strength stirrups on high-strength concrete columns is increasing.The ductility is significantly improved,and the stiffness degradation is slowed down.The deformation performance is ultimately enhanced.2.According to the mechanical characteristics of this type columns,the four-liner skeleton curve model for flexure failure is established.Based on the experimental data of this test and other experts test,the relationship between the ductility,the stirrup characteristic value and the axial compression ratio is put forward.Simultaneously,considered the cracking,yielding,maxing and failure loads,as well as corresponding displacements,the skeleton curve model of HSC columns failed in flexure mode is developed.According the comparison shows that the calculation results on the basis of the method in this paper agree with the trend of the test results.3.In ABAQUS,ten structural models of high-strength concrete columns confined by highstrength stirrups are established,and the seismic performance of this type of column under lowcycle reciprocating loads is simulated and analyzed.The DAMAGEC,the PEMAG,hysteresis loop,spine loop,strength attenuation and rigidity degradation is extracted from ABAQUS.The finite element analysis are compared with the experiment result and the theoretical calculation values to prove the reasonableness of the established flexure failure skeleton curve and the established finite element model.Afterwards,in order to analyze the affecting factors such as stirrup diameter,axial compression ratio,concrete strength and stirrup spacing on the seismic performance of this type of column,thirty-one kinds of reciprocating loading conditions are established in ABAQUS.The influence of parameters on the seismic performance of highstrength concrete columns is analyzed.