Mesoscale insights on the structure, mechanical performances and the damage process of calcium-silicate-hydrate

The colloidal calcium-silicate-hydrate (C-S-H) gel largely controls the mechanical properties of concrete. However, little remains known about how the structural features of the C-S-H gel control its mechanical properties. The aim of the current study is therefore to investigate the structure, mechanical properties and the crack propagation of the colloidal C-S-H gel at the mesoscale. To achieve this, Grand Canonical Monte Carlo methods were utilized to construct the colloidal C-S-H gel. The structure features were demonstrated by the pore size distribution. Subsequently, computational uniaxial tension tests were performed on the C-S-H gel specimens using a non-local peridynamics (PD) model. On the basis of the simulated stress-strain response, the Young's modulus and tensile strength can be obtained. The modelling results show that both the strength and Young's modulus grow exponentially with the packing fraction increasing which shows reasonable agreement with the literature, revealing the feasibility of the PD method for the investigation of mechanical performance of C-S-H gel at mesoscale. (C) 2021 Elsevier Ltd. All rights reserved.