In-Service Deformations of Reinforced Concrete Columns in Biaxial Bending

A method of analysis to evaluate the long-term response of reinforced concrete cross-sections subjected to sustained axial force and biaxial bending is presented. The method is particularly useful for determining the time-dependent deformations of reinforced concrete columns in building structures under sustained service loads. The effects of creep and shrinkage of the concrete are evaluated using the age-adjusted effective modulus method of analysis. The crosssection is assumed to remain uncracked throughout, but the method may be readily extended to include the loss of stiffness caused by cracking using a simple iterative technique.