Evaluation of the ultimate strength of R.C. rectangular columns subjected to axial force, bending moment and shear force

This paper describes a mathematical tool for the calculation of the ultimate strength of reinforced concrete rectangular columns subjected to combined internal forces including shear. The proposed method is based on the application of the static theorem of limit analysis and considers simplified stress fields to simulate stresses in steel bars and (unconfined and confined) concrete. Both truss and arch effects are taken into account. To assess the effectiveness of the method, the relations developed are applied with reference to a large number of columns tested in the past by many researchers and a comparison between the theoretical and experimental results is drawn. Finally, the results of the proposed method are compared to others deriving from the application of more simplified methods present in the literature.