| It is necessary to study and analyze the bond-slip properties between steel shape and concrete deeply, For establishing reasonably a set of calculating theory and analysis method about strengths stiffness and deflection of SRC(Steel Reinforced Concrete) eccentric loading columns. On the other hand, due to the difference of the loading form on eccentric loading column with Push-out test and Short-column test, the bond-slip performance can't be displayed in it. So, the bond stress and slip of SRC eccentric loading columns must be accurately measured and studied further.In this paper, a reasonable and feasible method of test measurement and analysis about the bond-slip properties of SRC eccentric loading columns was firstly presented. Based on the former test of our research group, "The Embedded Electronic Steel-Concrete Slip Transfer" (Patent Authorization No.ZL-02-2-61881.3) was manufactured and exploited phasely, by which the interior slip between the steel shape and concrete along the embedment length could be directly measured, and the most difficult problem of experimental research was consequently solved. All these provided a basis for the further study on the bond-slip properties of SRC eccentric loading columns.20 SRC eccentric loading specimens were designed taking the relative eccentricity e0/h the slendemess ratio 10/h as the factors. According to the mechanical behavior of eccentric loading columns, Unidirectional Embedded Electronic Steel-Concrete Slip Transfers and Double-directional Embedded Electronic Steel-Concrete Slip Transfers were respectively placed inside these 20 specimens and electronic strain gauges were also installed on the steel shape flanges webs and concrete. The change of the mechanical behavior and interior slip of the 20 specimens in the whole process of loading was fully observed.By the summarizes and the whole analysis with the experimental results of the 20 specimens, the slip-distributions on tensile and compressive side of steel shape flange were obtained and the influence of the factors such as relative eccentricity e0/h the slendemess ratio 10/h on the bond-slip properties was further studied.According to the force balance equations, the values and distributions of bond stress betweensteel shape flange and concrete in eccentric loading columns were established by statistically regression with experiment data. And the influence of the factors such as relative eccentricity e0/h, the slenderness ratio l0/h on the bond-slip properties was analyzed.With the distributions of bond stress and local slip, all specimens' bond-slip curves were simulated. And the calculating formula of characteristic slip and bond strength was conducted by mathematically disposal and statistically regression of bond-slip curves; By revising the shape of bond-slip curves through "merge to one", the model of bond-slip relation was confirmed and then a detailed definition on the model was conducted using position functions.Based on the reasonable model of bond-slip, theoretical calculating about slip and slip strain was done. And then the influence of it between steel shape flange and concrete on stiffness deflection of eccentric loading columns was conducted and a simple calculating formula about stiffness of eccentric loading columns was built.By conducting the degree of influence of slip strain on average strain of a member section, some parameters of corrected even section were accurately calculated, which made the corrected even section more reasonable. And then a calculating model of bearing capacity for eccentric loading columns was proposed by using limit balance equations.Based on the reasonable relationship of bond-slip, by using nonlinear spring element simulating bond-slip model in columns, three-dimensional finite analysis for eccentric loading column was done with the two cases including considering and not considering the bond-slip performance between steel shape and concrete. And then the simulation results were compared with experimental results, which concluded...
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