Degree of hydration based prediction of early age basic creep and creep recovery of blended concrete

An accurate estimation of the early-age creep behavior is not only required to successfully control the early age cracking of concrete, but also to analyse the vertical and differential deformations of super high-rise buildings during construction. The fictitious degree of hydration model was developed to study basic creep behavior of hardening concrete, however, nowadays more complex binder systems are applied, consisting of several different types of powders, requiring further validation of the applicability of this creep model. The compressive basic creep and creep recovery of concrete based on ternary blends including Portland cement, blast furnace slag, and fly ash is experimentally studied. The tests are conducted at different ages of loading at early age under varying stress level. It is shown that the fictitious degree of hydration method can be successfully applied to ternary blends, even simplifying the hydration process to one overall reaction, considering only one degree of hydration.