CRITERIA FOR PERCOLATION THRESHOLD IN DISCRETE MICROSTRUCTURAL MODELS OF CEMENT PASTE

Currently discrete models of the cement paste microstructure consist of a set of elementary cubic cells called voxels are widely used to evaluate thermodynamic and mechanical characteristics of cement-based composites. One of the important states of the hydrated cement system is percolation of the solid phase at which a transition from a plastic state to a solid state occurs. In percolation theory, this point is called the percolation threshold. The percolation threshold plays an important role in predicting thermodynamic and mechanical characteristics of cement-based composites. The classical approach for evaluating the percolation threshold in discrete models of cement paste is based on the burning algorithm. However, this approach leads to high variability of the percolation threshold in hydrated cement systems causing significant data distortion in the predicted characteristics of cement-based composites. This article presents refined criteria for the percolation threshold of the solid phase in discrete models of cement paste, which facilitates to reduce the degree of scatter in percolation threshold values.