Study On The Influence Of Environmental Humidity On Creep Of Concrete

Creep as one of the most important long-term properties of concrete has important influences on concrete structures especially large-scale concrete structure. Within the researches of concrete creep, environmental factors have always been the concern of many scholars. It is generally accepted that environment humidity as one of the environmental affects concrete creep considerably. The environmental humidity cycling, drying and high level humidity on concrete structures have significant effects on concrete creep. In present domestic researches, studies on humidity diffusion within concrete are relative inadequate; and few models can take comprehensive consideration on humidity factors. So study on effect of environmental humidity is quite helpful to both on theoretical research and engineering practice.According to humidity diffusion theory of concrete, this paper studied the distribution of humidity field within concrete at both constant humidity condition and variable humidity condition using finite element method. The calculated results are compared with that using empirical method. It can be shown from the comparison that the finite element method it has satisfied accuracy on simulation of interior humidity field of concrete. Coupled with the changing of humidity field within concrete and improved microprestress solidification theory, creep of concrete at constant environment humidity and different humidity levels was studied. The results were compared with that calculated by B3 creep model. It can be concluded that the improved microprestress solidification theory can show the creep at different humidity condition well. Moreover, the coupling finite element method and the improved microprestress solidification theory can have a more comprehensive study on creep of concrete under environment humidity.