Nanotechnology in Cement-Based Materials: A Review of Durability, Modeling, and Advanced Characterization

In the context of increasing applications of various nanomaterials in construction, this work reviews the renewed knowledge of nanotechnology in cement-based materials, focusing on the relevant papers published over the last decade. The addition of nanomaterials in cement-based materials, associated with their dispersion in cement composites, is explored to evaluate their effects on the resistance of cement-based materials to physical deteriorations, chemical deteriorations, and rebar corrosion. This review also examines the proposed nanoscale modeling of interactions between admixed nanomaterials and cement hydration products. At last, the recent progress of advanced characterization that employs techniques to characterize the properties of cement-based materials at the nanoscale is summarized.

Nanoscale Modeling and Elastic Properties of Portlandite and Graphene Based on Atomic Finite Element Method

The development of multi-scale modeling methods reveals to be of undeniable practical importance, especially to describe and predict the mechanical properties of structural materials. The present work aims to relate the atomic scale with the macro-scale performances. To this purpose a model of a crystalline structure based on the Atomic Finite Element Method (AFEM) is developed. The interatomic bonding forces of Van der Waals, the Coulomb electrostatic force and the covalent chemical bond are taken into account. It is then applied to Portlandite (CH) as well as to graphene (triple-layer graphene sheet, TLGSs). Elastic modulus of these structures based on AFEM is determined. Then, modeling of a single crystal can be traced back to the homogenized elastic properties of polycrystals. Elastic constants and elastic modulus by AFEM algorithm are in quite good agreement with literature experiment. These modeling method and algorithm provide some basic reference to other hexagonal structures.