Time-dependent and steady-state stresses in concrete structures with steel reinforcement, at normal and raised temperatures

Abstract

Synopsis Stresses and displacements in concrete structures are influenced by the creep of concrete. When loads and temperatures are sustained, stresses tend to limiting or steady-state values which are influenced by the presence of steel reinforcement and concrete shrinkage. The paper describes the influence of these two factors in symmetrically reinforced concrete columns. It is shown that two steady-state solutions are possible: an elastic steady state in which all the column load is carried by the reinforcement and the steel remains in the elastic range, and a yield steady state for which there is a shared load between the steel and concrete, but the reinforcement is in a yield condition. The inclusion of shrinkage leads to more rapid stress changes towards the steady state and to an earlier state of yield in some cases.