Experimental Research On Capability Of Circular Steel Tube Reinforced Concrete Short Columns Under Eccentric Compression

In civil engineering, due to design errors, improper construction, the use of functional changes, aging buildings, natural disasters and contingencies and many other reasons, the building need to be strengthen and reinforced. In recent years,because of the safe, reliable and economic advantages in our country gradually the steel casing filled with grout as a new concrete structure reinforcement method.However, there is no uniform method of calculating the circular reinforcing steel casing biased normal section bearing capacity of reinforced concrete short column, to the engineering application of the method of structural reinforcement inconvenience.Therefore, it is necessary to round steel tube reinforced concrete short columns experimental research to find a more simple and practical method to calculate the small reinforcement eccentric compressed columns.In this paper, nine of eccentric compression destructive tests is based on the circular steel casing reinforced concrete short columns bias load capacity were researched. The impact of different changes in the eccentricity of the load capacity of reinforced columns, the research reinforced specimens from loaded to destroy the whole process, examine the damage form of specimens, and short columns and internal forces analysis after reinforcement work mechanism analysis, followed by suggestions for improvement of small eccentric compression capacity formula. Finally,analysis ANSYS nonlinear finite element. The main research results are as follows:(1)Based on test data and phenomena indicate, the ultimate load capacity of circular steel tube reinforcement in specimen with increasing eccentricity, rate of change of the increase carrying capacity reduced;(2)In the pre-loaded specimen, steel casing longitudinal strain and hoop strain curve was horn shape development, gradually increase the ratio of ring and longitudinal strain, strain loading the late change in pressure bent steel casing side of the obvious, the main by the longitudinal compression into a circumferential tension of the steel casing of the internal reinforcement column constraints highlighted therole, grout and concrete core columns in the three-state pressure, the specimen bearing capacity has improved greatly;(3)ANSYS finite element program for load capacity of steel reinforced columns of the whole process nonlinear analysis to simulate the experimental and theoretical and more similar conclusions, a more detailed understanding of the circular steel reinforced concrete short columns in the casing the forces and destruction in case of eccentric compression.