Abstract：
The potential and space structure characteristics of the calcium silicate hydrate (C-S-H) coarse-grained model are the
key to building a reasonable mesoscopic scale model. Based on the atomic scale C-S-H interlayer interaction, the mesoscopic
scale potential function is determined. Then the C-S-H coarse-grained model is constructed with random spatial distribution of
particles. The structural characteristics of the model with different porosities are studied. And the effects of particle positions
on the interaction and stress are analyzed. The results show that when the particles are densely distributed, for example a 0.4
porosity, the pores are tiny and evenly spread. The diameter of pores conforms to a narrow band Gaussian distribution and ranges
from 0.5 nm to 3.5 nm. The stress between particles is mostly pressure with smaller porosity (0.3 or 0.4) and tension with larger
porosity (0.5 or 0.6). The density decreases with high porosity when the tension between particles increases. The configurations
of different C-S-H structures with the same porosity have similar characteristics in terms of particle stress, potential energy and
pore distribution, which further proves that the selected configurations and the results are reasonable. The C-S-H coarse-grained
model can be used as a small-scale basic unit model, which is elementary for the establishment of a large-scale mesoscale model,
thus bridging atomic scale and macro scale models, revealing the fundamental internal development of cement-based materials.
