A proposed model for creep in mass concrete under variable ambient conditions

The creep characteristic of the concrete used in real structures is different from that of those test specimens in the laboratory because of the remarkable hydration heat resulting in the big bulk and the service condition with varying temperature and relative humidity. A creep model had been proposed to describe the creep characteristic of the massive concrete under the natural climatic variations. The equivalent age of loading and the equivalent duration of loading are introduced to include the effects of the variable temperature and relative humidity on creep. The experiment has been conducted to prove the proposed creep model and the effects of the hydration heat and the change of the service condition on creep have been discussed. It has been found that the hydration heat causes the decrease of the creep and the variations in temperature and relative humidity have obvious influence on the creep characteristic of concrete.