Integration of Computational Model and SEM Imaging Technology to Investigate Internal Frost Damage in Cementitious Materials

摘要

This study investigates the internal-frost damage due to ice crystallization pressure in capillary pores of concrete. The pore structures have significant impact on freeze-thaw durability of cement/concrete samples. The scanning electron microscope (SEM) techniques were applied to characterize freeze-thaw damage within pore structure. The digital sample was generated from SEM imaging processing. In the microscale pore system, the crystallization pressures at subcooling temperatures were calculated using interface energy balance with thermodynamic analysis. The largest crystallization pressure on the pore wall was used for the fracture simulation with the developed Extended Finite Element Model (XFEM). The largest crystallization pressure on the pore wall was used for the fracture simulation with the developed Extended Finite Element Model (XFEM). One comparison study between model simulation and test results indicates that internal-frost damage model can reasonably predict the crack nucleation and propagation within multiphase cement microstructure.