Research On The Axial Compression Properties Of RC Column Strengthened With Coat Steel Tube Steel Fiber Self-Compacting Concrete

At the beginning of the building construction,the service life of the building was taken into account.In recent years,a large number of buildings in China are nearly the service life,which are in urgent need of identification,maintenance and reinforcement.At present,the coat steel pipe reinforcement is mainly used for buildings to be strengthened column,Under this reinforcement method can give full play to the role of steel tube on the column hoop,Can effectively improve the axial pressure bearing capacity and ductility of the reinforced column,The reinforcement performance of buildings has been significantly improved;And steel fiber self-compacting concrete is the self-compacting concrete and steel fiber is well combined together,Using the high fluidity and passability of self-dense concrete,Mixed with steel fiber can be evenly distributed inside the concrete,Thus to give full play to the ductility properties of the fiber,Can improve the axial pressure bearing capacity of concrete to a certain extent,The paper concrete concrete method of outer steel tube steel fiber.This paper analyzes the reinforcement method through experimental study and simulation analysis:In this paper,six specimens were made for axial pressure bearing capacity test,observing the damage pattern and load-displacement curve change of the specimens at any time in the test.Finally,these two aspects were deeply analyzed to study the axial pressure performance of the specimens under different parameter conditions.The test in this paper mainly include 3 steel fiber volume ratio specimens,2 steel pipe wall thickness specimens,2 self-compacting concrete strength and 1unreinforced RC column.The test results show that the wall thickness of steel pipe and the strength of self-compacting concrete have a great influence on the axial pressure performance of the specimen,and the volume rate of steel fiber has a small impact on the axial pressure performance of the reinforced specimen.Validation of the model will be performed after the trial,which is used to link the trial and the simulation.In this paper,S2 specimen is selected as the specimen for simulation verification.The verification method is to compare the load-displacement curve and the difference of the specimen through the ABAQUS model of the specimen,and determine the error of the two is within the acceptable range and meet the requirements of modeling.This paper mainly designs 25 limit element models,including 7 different steel fiber volume rate models,4 different self-compacting concrete strength models,4 different steel pipe wall thickness models,5 different high thickness ratio models,and 5 different section size models.By analyzing the specimens of different parameters,the failure pattern,load-displacement curve,energy consumption coefficient and ductility coefficient are obtained.The results show that the overall failure pattern of each specimen is not different,and the maximum load increases with the increase of steel fiber volume rate,self-compacting concrete strength,high thickness ratio and steel fiber length will increase the energy consumption of the specimen with the wall thickness and the strength of the test section;the steel fiber volume rate and wall thickness have little influence on the ductility coefficient of reinforced test.