LAUSR

Abstract In this computational study, the nanoscale mechanical properties of C-S-H composite materials under different temperatures are evaluated with molecular dynamics (MD). The effects of different proportions of crystals, levels of porosity, and degrees of temperature on the nanoscale mechanical properties of the C-S-H composites are investigated. The initial computational models are built up based on tobermorite and jennite crystals, and the geometries of the models are then optimized before performing MD simulations at 25 °C, 80 °C, and 200–1500 °C with the interval of 100 °C, respectively. The resulting mechanical properties of the composites are evaluated under different conditions. The self-consistent (SC), Mori-Tanaka (MT), and Voigt methods are used to understand the effects of crystal proportions and porosities on the mechanical properties of the C-S-H composites at three representative temperatures. It is found that both the bulk and shear moduli of the C-S-H composites are decreased with the increasing temperature. Regarding the influence of porosity, a specific proportional relationship is obtained based on the results with the SC, MT, and Voigt methods. The reported findings provide a better insight into the thermomechanical response of the C-S-H composites.