THE STRUCTURE OF WATER IN CALCIUM-SILICATE-HYDRATES STUDIED BY NEUTRON DIFFRACTION WITH ISOTOPIC SUBSTITUTION.

20 Jan 2021, 17:15
25m

Speaker

Mrs Zhanar Zhakiyeva (ILL)

Description

Water is an essential component in hydraulic binders, exerting control on the hydration reactions and on the long-term behavior of cementitious structures acting as a vector of ionic transportation. Here, a protocol based on water sorption isotherms, X-ray diffraction and thermogravimetric analysis was designed to obtain C-S-H with controlled distribution of interlayer, adsorbed and bulk pore water. Neutron diffraction with isotopic substitution was then used to obtain information about the local ordering of water of these samples. The hydrogen isotope first-order difference method provided a composite radial distribution function centered on the water hydrogens. We also applied molecular dynamics simulations of C-S-H models with varying water contents, which showed a deviation of the H-bond characteristics of the adsorbed water as compared with bulk water. These experimental and computational results provide for the first time a detailed structural description of water and the local environment of hydrogen in C-S-H.

Scientist Profile I am a PhD student

Primary authors

Dr Alejandro Fernandez-Martinez (CNRS & UGA) Dr Alexander Van-Driessche (CNRS & UGA) Dr Francis Claret (BRGM) Dr Gabriel Cuello (ILL) Dr Henry Fischer (ILL) Dr Ian Bourg (Princeton University) Mrs Zhanar Zhakiyeva (ILL)

Presentation materials