Nonlinear analysis of temperature and moisture distributions in early-age concrete structures based on degree of hydration

Time is not generally an exact parameter to control the chemical and physical processes, but the degree of hydration is. Therefore, it is necessary that all material parameters and the development Of microstructure should be formulated in terms of degree of hydration. The Purpose of the present study is first to refine the mathematical models for the degree of hydration, and moisture and temperature distributions in early-age concrete, and then to incorporate those models into a three-dimensional finite element procedure. Mathematical formulation of the degree of hydration is based on the combination of three rate functions of reaction that represent the effect of moisture condition as well as temperature. In moisture transfer moisture transport coefficient, capacity, and sink are strongly, dependent on the degree of hydration as well as the water-cement ratio (w/c). The realistic models and finite element program developed in this study provide fairly good results on the temperature and moisture distribution for early-age concrete and correlate very well with actual test data.