English：

In order to explore the application of 630MPa high⁃strength steel bar in concrete eccentriccompression members, three concrete column specimens were designed and fabricated, and themechanical properties of different eccentricities under vertical load were studied. By analyzing the failuremode of the component, the strain, bearing capacity, lateral deflection and crack distribution of the steelbar and concrete, the mechanical properties of the 630MPa high⁃strength steel bar under eccentriccompression were evaluated. The results show that: similar to the typical failure mode of ordinaryreinforced concrete under large eccentric compression, the 630MPa high⁃strength reinforced concretecolumns are characterized by tensile failure. When the failure occurs, the tensile and compressive steelbars can reach yield, and the concrete in the compression zone can also reach the ultimate compressivestrain of 0. 003 3. The section deformation of the specimen conforms to the plane section assumption, andthe bearing capacity can be calculated by the current standard formula. The test value of crack widthcorresponding to the limit state of normal use is greater than the calculated value of the standard formula,and slightly higher than the limit value of the standard. It is suggested that small diameter steel barsshould be selected on the tensile side of large eccentric compression and bending members or thereinforcement ratio should be appropriately increased to reduce the crack width.