Analysis of damage development in cement paste due to ice nucleation at different temperatures

From the thermodynamic considerations and from a virtual microstructure of cement paste, a quantitative assessment of the internal damage of cement paste due to hydraulic pressure is investigated by 3D lattice fracture model. Two issues are solved in this study: (1) the capillary pores related to the penetration of ice crystals are characterized by a multi-step digitalization algorithm. (2) The hydraulic pressure PL is achieved through an iterative fracture process simulation where the creation of micro-cracks is taken into account. The iterative fracture process simulation then is verified by a benchmark test. Simulations indicate that randomly distributed micro-cracks are formed at a low ice crystal saturation degree SC (defined as the molar percentage of water transformed into ice crystals), while local propagation of micro-cracks occurs and transverse cracks can be formed at high SC. Comparison of SC and cracks pattern by simulation and by experiments are finally discussed.