Strength of reinforced concrete columns under special complex influences

Abstract

A method for evaluating the strength, stiffness and stability of medium-flexible columns with a square cross-sectional shape and symmetrical reinforcement is proposed. Combined impacts from constant longitudinal force, horizontal impact with trapezoidal pulse shape and deterioration in mechanical properties of concrete from natural influences such as corrosion are taken into account. Various combinations of such influences are also considered. The computational model is represented by volumetric concrete elements rigidly connected to rebars. The dynamic transient process is based on an implicit integration scheme using a stepwise procedure. At each step, the nonlinear problem is solved by the Newton-Raphson method. The data characterizing the degree of danger of occurrence of local strength deterioration for column variants have been compared. The dependence of the value of longitudinal force on the value of transverse impact is found, provided that the load-carrying capacity of the column is ensured.