Deviations from the Principle of Superposition and their Consequences on Structural Behavior

Abstract

The focus of this study is on deviations from the linear viscoelastic behavior of concrete occurring at high stress levels, at early age loading and in case of unloading implying strain reversal. Paper describes the series of creep tests that was performed on high strength concrete specimens undergoing creep under constant stress, followed by a period of recording of the creep recovery after complete unloading.The experiment data show that the creep recovery deviates strongly from the numerical predictions obtained by the application of the principle of superposition but seems to conform rather well to the recovery model proposed.