Molecular dynamics simulations for evaluation of surfactant compatibility and mechanical characteristics of carbon nanotubes incorporated cementitious composite

Identification of the suitable surfactant that effectively disperses carbon nanotubes (CNTs) and also ensuring the compatibility of surfactant with constituents/hydrates of cementitious composite is very important to develop efficient CNT incorporated cementitious composite. In view of this, molecular dynamics (MD) simulations are carried out to investigate the dispersibility of CNTs by surfactants and their compatibility with the major hydrate, i.e., calcium-silicate-hydrate (CSH). The results obtained from the MD simulations are validated with experimental investigations. Further, detailed investigations are carried out to determine the stress-strain behaviour, bulk and shear modulus, bond properties, etc. of CNT incorporated composite. The incorporation of CNT into CSH has significantly improved its strength, and elastic- and shear- modulus. This study also demonstrates that incorporation of CNT into CSH system changes the composite from brittle to a ductile one, and the degree of ductility imparted can be quantitatively evaluated. The findings of this study will help in designing the cementitious composite with desired properties. (C) 2020 Elsevier Ltd. All rights reserved.