A series of experiments and numerical analyses have been carried out to derive a model of the moisture diffusion coefficient in concrete structures. The moisture diffusion coefficient generally depends on the relative humidity and temperature as well as the age of concrete, because microstructures of concrete develop with aging, especially in the early stage of aging. Therefore, the modified model of the moisture diffusion coefficient proposed here takes these three parameters into consideration. Experiments on moisture diffusion were performed to investigate the variation of the moisture diffusion coefficient with age and temperature under three temperature conditions (20, 50, and 80°C). Based on the experimental results, a new model of the moisture diffusion coefficient considering the aging and temperature was developed by a numerical inverse analysis. As it considers porosity, humidity, and temperature, beyond the existing model for hardened concrete, the suggested diffusion coefficient model is applicable to early age concrete.

This paper examined and discussed a Meshless Wavelet Galerkin Method (MWGM) formulation for a first‐order shear deformable beam, the properties of the MWGM, the differences between the MWGM and EFG, and programming methods for the MWGM. The first‐order shear deformable beam (FSDB) consists of a pair of second‐order elliptic differential equations. The weak forms of two differential equations are deduced using Hat wavelet series. The exact integration and reduced integration were used to analyze the problems. Some indeterminate beam problems are considered. Condition numbers of the stiffness matrix were analyzed with exact integration and reduced integration for two cases of these problems. Consequently, the results were converged on the analytic solutions. The shear‐locking phenomenon also occurred in the MWGM as it occurs in the conventional FEM. The stiffness matrix calculated from the reduced integration causes a similar numerical error to the stiffness matrix calculated from the exact integration in the MWGM. The MWGM showed desirable results in the examples.