Nano-granular texture of cement hydrates

¹ Multiscale Material Science for Energy and Environment, MIT - CNRS Joint Laboratory at Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
² Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
³ PHENIX Laboratory, CNRS and University Pierre et Marie Curie, 75252 PARIS cedex 5, France
⁴ Department of Physics and Institute for Soft Matter Synthesis and Metrology, Georgetown University, Washington, DC 20057, USA
⁵ CINaM, CNRS and Aix-Marseille University, Campus de Luminy, 13288 Marseille Cedex 09, France

^* e-mail: hekate@mit.edu
^** e-mail: pellenq@mit.edu

Published online: 30 June 2017

Abstract

Mechanical behavior of concrete crucially depends on cement hydrates, the “glue” of cement. The design of high performance and more environmentally friendly cements demands a deeper understanding of the formation of the multiscale structure of cement hydrates, when they precipitate and densify. We investigate the precipitation and setting of nano-grains of cement hydrates using a combination of Monte Carlo and Molecular Dynamics numerical simulations and study their texture from nano up to the micron scale. We characterize the texture of cement hydrates using the local volume fraction distribution, the pore size distribution, the scattering intensity and the chord length distribution and we compare them with experiments. Our nano-granular model provides cement structure with realistic texture and mechanics and can be further used to investigate degradation mechanisms.