Recently translucent insulation material (bubble sheet) has been used for concrete curing process of mat foundations. The large flatten area of the mat foundations is directly exposed to solar radiation hence the thermal boundary conditions on the surface can be changed compared to those with traditional insulation materials such as sand, styrofoam, etc. In spite of the fact that the different thermal boundary conditions can make different temperature and stress distribution in the mat foundation, many cases in the literature do not consider these conditions for the prediction of the thermal and mechanical behavior of mat foundation in hydration heat and stress analysis.

This research investigated the effects of solar radiation on the behavior of concrete mat foundation when using translucent insulation material in curing process. For the investigation, numerical analysis was conducted to assess the effects of solar radiation on the temperature distribution, thermal stress and thermal crack resistance. A one-dimensional finite element formula was derived with the fundamental laws of heat transfer and Galerkin method. Based on the formula, a one dimensional finite element analysis code was developed using MATLAB. Hydration heat analysis of mat foundation was conducted using the developed code. In addition, three-dimensional heat and stress analysis was conducted using a commercial finite element analysis software ? ABAQUS.

The analysis results showed that the solar radiation on the concrete surface transmitted through the translucent insulation material can significantly affect the temperature distribution, thermal stresses and thermal crack resistance in mat foundations. Based on the results, the research recommended that, if translucent insulation material was used for curing mat foundation, the solar radiation should be considered in hydration heat analysis of concrete mat foundation so as not to overestimate thermal crack resistance in mat foundation.