Nano-scale investigation of elastic properties of hydrated cement paste constituents using molecular dynamics simulations

Hydrated cement paste (HCP), which is present in various cement-based materials, includes a number of constituents with distinct nano-structures. To understand the elastic properties of the HCP at the nano-scale, a comprehensive set of crystalline structures that represent the main HCP constituents is developed for Molecular Dynamics (MD) simulations. The accuracy of estimated values is verified by comparing them with the results from experimental tests and other atomistic simulation methods. The outcome of MD simulations is extended to predict the elastic properties of the C-S-H gel by rescaling the values calculated for the individual crystalline structures. To take into account the contribution of porosity, a detailed microporomechanics study is conducted on low- and high-density phases of C-S-H. The obtained results indicate that MD simulations are capable of capturing the elastic properties of the C-S-H gel. This is further verified by comparing the rescaled values with the predictions from nano-indentation tests. (C) 2014 Elsevier B.V. All rights reserved.