Theoretical Modeling of Concrete Moisture Diffusion Surface Factor

Moisture field is an important factor in determining the durability, surface drying shrinkage stress and cracking of concrete. In the curing process, moisture diffusion surface factor is the basic parameter to obtain the moisture field of concrete. In this research, the third boundary condition of concrete moisture field was derived in considering the pore areas on concrete surface and pore moisture diffusion coefficient. The concrete surface moisture convection and diffusion processes were simplified as the convective mass transfer of incompressible fluid in one-dimensional flat wall. This research established a theoretical model on the moisture diffusion surface factor of concrete during the curing period based on the mass conservation and flat wall convective mass transfer principle. And an approximate solution of the model was provided.