Upscaling coarse-grained simulation study for hydrated cement paste from mesoscale to microscale

Abstract

In this paper, upscaled mesoscale and microscale models are introduced for hydrated cementitious materials by employing the discrete element method and coarse-grained (CG) simulation. At the mesoscale, the hydration process is simulated using the grand canonical Monte Carlo (GCMC) process. Subsequently, an exploration of dynamic, structural, and mechanical properties ensues through mean square displacement (MSD), radial distribution function (RDF), pore systems analysis, and uniaxial tension tests are conducted based on the constructed CG C–S–H gel model. The structural and mechanical performance of this model affirms its consistency with previous experimental investigations. On the other hand, the microscale model is established based on an existing microstructure model of cement paste. Mechanical properties and failure mechanism analyses, influenced significantly by the inner microstructure and components (specifically the degree of hydration with a fixed water-to-cement ratio), are investigated using the uniaxial tension test. Additionally, the microscale simulation serves to validate the feasibility of modeling micro-scale cementitious materials with the discrete CG-MD method.

Keywords

• Cementitious materials
• Coarse-grained molecular dynamics
• Mesoscale
• Microscale
• Discrete element method