Bending deflection reinforced concrete elements determination

Abstract

Longitudinal reinforced concrete elements stiffness exhaustion, often used in building practice, precedes obtaining bearing capacity, and therefore deflections determination becomes a determining factor in their design. In connection with it precise methods for determining such reinforced concrete elements deflections become especially relevant. The elastic-plastic properties of concrete and cracks in the stretched zone of reinforced concrete elements lead to a significant change in their bending stiffness. That is why the deflections determined by the materials classical resistance formulas differ significantly from the real ones. A large quantity of methods for determining deflections is based on the elastic characteristics correction of reinforced concrete elements consolidated section. Such methods, although providing calculation satisfactory results, are rather approximate and have empirical nature, due to it they have limited application. More precise calculation methods consist of curvature usage to determine deflections. The curvature of reinforced concrete elements cross sections is determined directly from the equilibrium equations, which are written taking into account nonlinear materials deformation diagrams. Calculation examples for bending reinforced concrete elements deflection are given.