The effect of preloading on the strength of jacketed R/C columns

The influence of core preloading on the strength of jacketed reinforced concrete (R/C) columns is analytically investigated. A recently proposed method for arbitrary composite section analysis in biaxial bending and axial load is extended to include preloading actions. A parametric evaluation of the preloading effect using quantitative indices is performed, considering the variability of several parameters such as section geometry, amount of reinforcement, and various axial and moment preloading levels. Results are presented in the form of 3D failure surfaces and moment–curvature curves. Specific cases where the preloading effect is more pronounced are finally highlighted.