Monitoring of Hydration of White Cement Paste with Proton NMR Spin–Spin Relaxation

Abstract

By monitoring the free induction decay and spin-echo envelope (acquired with the Meiboom-Gill modified Carr-Purcell pulse sequence), during hydration of white cement paste, information about growth patterns of various cements is obtained. In particular, the secondary hydration water is characterized through direct observation, and a relatively immobile, near solidlike water phase, observed for the first time in hydrating cement, is discussed.

Nanopore Structure Buildup during Endodontic Cement Hydration Studied by Time-Domain Nuclear Magnetic Resonance of Lower and Higher Mobility 1H

“…A component (fitted as a Gaussian, defined as time for decay to one-half), arising at about half a day and settling after 2 days to about 60 µs has been reported. 5 Also, by 2D analysis, a tail with T 2 of the order of 50 µs and T 1 of about 200 µs has been reported. 6,7,11,12 This component would contribute to both solidlike and liquidlike in our two spin groups, computed for solid-liquid separation and producing files for T 1 analysis, although, since its FID decay is exponential rather than approximately Gaussian, it should be classified as liquid.…”

A unilateral NMR magnet for sub-structure analysis in the built environment: The Surface GARField

“…If a distribution of pore sizes is present in the material, then there will be a corresponding distribution in the observed relaxation rates. This basic method has been demonstrated previously in cement based materials [7][8][9][10]. The surface relaxation rates of water molecules is determined by interactions with paramagnetic species S in the solid structure.…”

“…On the one hand, this includes the analysis of fresh cement paste hydration and the subsequent development of porosity [7][8][9][10]. On the other, it extends to studies of the long-term degradation of cement due to, for example, the transport and build-up of sub-surface water [11,12].…”

1H NMR spin-spin relaxation and imaging in porous systems: an application to the morphological study of white portland cement during hydration in the presence of organics

“…For the first time, Greener et al [17] could distinguish, besides the three main water forms, a secondary hydration water, relatively immobile, near solid-like water phase. As well, more recently Plassais et al [18] interpreted the T 1 distribution curves in hydrated cement pastes in terms of one solid-related time and three pore related times.…”