Simplified approach to evaluate creep and shrinkage effects in steel-concrete composite beams

A simplified approach to evaluate creep and shrinkage effects in a steel-concrete composite beam with rigid or deformable connections, based on the age-adjusted effective modulus method, is presented. An aging coefficient, χ, evaluated in the absence of connection is adopted and exactly characterized by a theoretical point of view. Simplified expressions to evaluate χ and an easy to use, closed-form solution in the hypothesis of rigid connections and uncracked concrete are proposed. Numerical comparisons show how the proposed approach provides accurate results independently of the connection stiffness and load condition, and how it can substitute appropriately the more popular effective modulus method.