Experimental Study On Axial Compression Of Reinforced Concrete Column Reinforced With Pre-stressed Plastic Steel Strip And Angle Steel

The reinforcement and repair of concrete structures has always been one of the research hotspots in the academic field of structural engineering.In view of the complicated construction process of the existing reinforcement technology,the high price of materials or the difficulty of measuring the prestress,this paper proposes a new prestressed plastic steel strip-angle steel composite reinforcement technology.This composite reinforcement method makes full use of the plastic steel strip and angle steel.The advantages of strengthening the concrete column,so that it can coordinate and bear the force together,can better improve the mechanical properties of the original component.The reinforcement technology has the advantages of simple construction,low cost,easy control and measurement of prestressing,and can provide a reference for practical engineering applications.Carried out the axial compression test of three prestressed plastic steel strips-angle steel composite reinforced reinforced concrete square columns and 1 unreinforced reinforced concrete column,studied the prestressed plastic steel strips-angle steel composite reinforcement and the different reinforcement spacing of the plastic steel strips.The influence of failure characteristics,bearing capacity and ductility of reinforced concrete columns.The test results show that the failure characteristics of reinforced concrete columns reinforced with pre-stressed plastic-steel strips are basically the same as those of unreinforced specimens,but the initial cracking load of the reinforced specimens is greater;with the increase of the reinforcement spacing of the plastic-steel strips,the bearing capacity increases The amplitudes are 36.6%,13.6%,and 8.2%respectively;the maximum increase in the limit displacement is 62.0%,37.8%,and 24.3%,respectively.The load-bearing capacity of the components has been improved significantly,indicating that the lateral restraining force provided by the prestressed plastic steel strips can effectively delay the appearance and development of cracks in reinforced concrete columns,and improve the brittle failure of the components to a certain extent.The angle steel can provide a larger vertical direction.The bearing capacity and the ultimate displacement of the specimen have been greatly increased,and the load displacement after the component is broken down is relatively gentle,indicating that the ductility of the specimen has also been significantly improved.The finite element analysis software ABAQUS is used to carry out numerical simulation analysis.The results of the finite element simulation and the test of the reinforced concrete short column reinforced by the prestressed plastic steel strip and angle steel are compared and analyzed.The results show that the results of the finite element calculation are in good agreement with the experimental data,and the accuracy of the finite element model is verified.Based on the simulation analysis,the multi parameter analysis of different prestressing level,spacing of plastic steel strip,number of layers and width is carried out,and the change law of ultimate bearing capacity and ductility of composite reinforced members under different parameter variables is obtained.The results show that the load increase is more obvious when the plastic-steel strip reinforcement spacing in the composite reinforced component is from 200mm to 100mm.As the plastic-steel strip reinforcement spacing continues to decrease,the load improvement effect of the component is not significant.At the same time,this paper also analyzes the four aspects of different prestress levels,plastic steel strip spacing,number of layers,and width.The results show that they have improved the bearing capacity and ductility of composite reinforcement members.According to the relevant literature and test results,the stress mechanism of the reinforced concrete column reinforced by the prestressed plastic steel strip-angle steel composite is analyzed,that is,the prestressed plastic steel strip provides the hoop active restraint force for the component.Under the action of the axial pressure,the specimen the core concrete in the middle is in a three-way stress state,which delays the development of cracks.At the same time,the angle steel and the concrete work together to bear the axial pressure,which improves the load-bearing capacity and ductility of the specimen.Based on previous scholars’ relevant research,calculation assumptions were put forward,and the formula for calculating the axial compressive bearing capacity of reinforced concrete columns reinforced with prestressed plastic steel strips and outer steel composites was deduced.The ultimate bearing capacity of the test basically coincides with the calculated ultimate bearing capacity.Provide a certain reference basis for related reinforcement engineering design.