Study On Seismic Behavior Of Reinforced Concrete Square Columns Reinforced With Basalt Fiber Cloth

Good seismic performance is helpful for structure resisting strong earthquakes without serious damage,and can greatly reduce the loss of life and property,and gain more valuable time for disaster relief after the earthquake.Among all the members of the bridge,the reinforced concrete pier is the most vulnerable and difficult to repair,and the damage of the pier may directly cause devastating damage such as the collapsing.Therefore,it is necessary to reinforce the original and newly built piers to improve the seismic performance of the structure.In recent years,in the field of seismic strengthening of reinforced concrete structures,fiber reinforced composites(FRP)is a research hotspot.It has the advantages of light weight,high strength and durability.Compared with other FRP materials,the BFRP materials studied in this paper.It is an inorganic non-metallic material,which has the advantages of high temperature resistance and corrosion resistance,abundant reserves,high cost performance and mature technology.With the improvement of seismic performance requirements of structures,the application of BFRP materials in engineering will become more extensive.In order to study the influence of BFRP materials on the seismic behavior of concrete columns,the seismic performance tests of reinforced concrete square columns reinforced with basalt fiber fabrics were carried out.A total of 7 concrete specimens,2 control columns and 5 reinforcement columns were produced.Under the monotonous horizontal force load,four specimens were subjected to the nappe test to study the change of ductility.Under the cyclic reciprocating load,the remaining three specimens were subjected to pseudo-static test.The influence of BFRP on the energy consumption and ductility of the other column.Based on the test results,the mechanism of BFRP on the seismic behavior of rcsquare columns is systematically analyzed to study the bearing capacity,ductility performance and hysteretic energy consumption.The numerical analysis model of square column is performed with ABAQUS to verify the test.The variation law of the seismic performance of the reinforced columns under different variables is obtained according to the parametric analysisThrough the experimental study and numerical simulation analysis of the seismic performance of reinforced concrete square columns,the following important conclusions are obtained:1)For the test piece in the monotonic loading test,the more the BFRP wrap layer,the better the ductility,but the ductility improvement efficiency decreases with the increase of the number of layers,and the most economical wrap layer is 3 layers;2)Under cyclic reciprocating load,concrete specimens mainly consume energy through hysteresis loops.The larger the area of hysteresis loops,the stronger the energy consumption of the specimens.The square column of 2 and 3 layers of BFRP is increased by 24% and 35% respectively.The displacement ductility ratio is increased by 7.25% and 11.41% respectively.The ultimate displacement angle is increased by 9.48% and 17.09% respectively.The improvement of seismic performance is better.3)The plastic damage model in ABAQUS is used to simulate the behavior of concrete.The model can simulate the tensile and compressive damage of concrete.The results of numerical simulation and experimental results can be found.The agreement between the two is very high.It shows that the results and conclusions obtained from the experimental research are accurate and reliable.4)Based on the square column model of column Z2-3,the finite element parametric analysis of the specimens was carried out to study the changes of seismic behavior of BFRP strengthened columns under different influences of different reinforcement ratio,stirrup spacing and concrete grade.The analysis results show that The reinforcement ratio has the most significant influence on the seismic performance of the test piece,the greater the reinforcement ratio,the better the seismic performance of the test piece,and the influence of the stirrup spacing and concrete strength is small.