In situ  1 H-TD-NMR: Quantification and microstructure development during the early hydration of alite and OPC

Ectors, Dominique; Goetz-Neunhoeffer, F.; Hergeth, Wolf‐Dieter; Dietrich, Ulf; Neubauer, J.

doi:10.1016/j.cemconres.2015.10.011

Cited by 45 publications

(14 citation statements)

References 22 publications

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“…As a result, the scattering contribution of free water does not change further and quantification remains at a constant level. This observation is also consistent with the results of a 1 H-TD-NMR study (Ectors et al, 2016). The authors found a strong decrease of the relaxation time of the free water until the heat flow maximum of the main reaction, and subsequently only a slight change of the relaxation time occurs in the further progress of the reaction.…”

Section: Figuresupporting

confidence: 90%

Quantitative X-ray diffraction of free, not chemically bound water with the PONKCS method

et al. 2018

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The free water in calcined phyllosilicate–water mixtures exhibits a distinctly different behaviour in its X‐ray amorphous scattering contribution as opposed to fly ash– or limestone powder–water mixtures. While fly ash and limestone powder yield a continuous increase in the scattering contribution when water is added, the scattering contribution stagnates for calcined phyllosilicates over a wide range of water addition. There is a direct correlation between the consistency of the sample and the X‐ray amorphous scattering contribution caused by the water. The same correlation can also be found in in situ X‐ray diffraction measurements of hydrating systems. As long as the sample has a pasty consistency, the scattering contribution of the water decreases with progressive reaction. After the transition from fresh paste to final set, there is no further reduction of the X‐ray amorphous scattering contribution caused by the free water, which means that the free water cannot be quantified correctly from this point in time.

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Section: Figuresupporting

confidence: 90%

Quantitative X-ray diffraction of free, not chemically bound water with the PONKCS method

et al. 2018

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“…In NMR T 2 measurements rigidly bound protons, for example protons bound in a crystal structure, exhibited shorter T 2 times while protons loosely bound, for example protons of the pore water, exhibited longer T 2 times. The amplitude of the Gaussian fit thus corresponded to the protons bound in the crystal structure of the formed portlandite (CH) and the amplitude of the exponential fits corresponded to the protons in the C-S-H structure and the free water [3,5]. Figure 2 shows that this proton fraction can be further split into three major reservoirs, in accordance with the existing literature [3], by measuring the CPMG decay of the sample in combination with multiexponential fitting as described above.…”

Section: Combination Of Td-nmr and Semsupporting

confidence: 64%

“…With this technique the water in the pores is the probe and thus does not need to be removed. As 1 H-TD-NMR is sensitive to all protons present in the sample, it is also suited to measure nanoscale water-filled pores in the C-S-H structure [3,4] and to quantify the amount of hydrate phases developed and mixing water consumed during cement hydration [3,5,6].…”

Section: Introductionmentioning

confidence: 99%

C-S-H Pore Size Characterization Via a Combined Nuclear Magnetic Resonance (NMR)–Scanning Electron Microscopy (SEM) Surface Relaxivity Calibration

et al. 2020

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A new method for the nuclear magnetic resonance (NMR) surface relaxivity calibration in hydrated cement samples is proposed. This method relies on a combined analysis of 28-d hydrated tricalcium silicate samples by scanning electron microscopy (SEM) image analysis and 1H-time-domain (TD)-NMR relaxometry. Pore surface and volume data for interhydrate pores are obtained from high resolution SEM images on surfaces obtained by argon broad ion beam sectioning. These data are combined with T2 relaxation times from 1H-TD-NMR to calculate the systems surface relaxivity according to the fast exchange model of relaxation. This new method is compared to an alternative method that employs sequential drying to calibrate the systems surface relaxivity.

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“…45 In combination with calorimetric test, in situ X-ray diffraction (XRD), etc, not only microstructural feature but also the hydration dynamics can be well characterized in situ and in real time. [42][43][44] Given that the role of CSH in the elasticity evolution is not fully experimentally characterized, the pure alite paste, instead of cement paste, was employed in this work. The Gʹ of pure alite pastes with different mass ratios of water to powder was measured by SAOS method.…”

Section: Introductionmentioning

confidence: 99%

“…However, all the above methods cannot provide a clear information of the hydration details of cement at early age. Low field 1 H nuclear magnetic resonance (NMR) relaxometry is a promising candidate, which has been proved to be a powerful nondestructive method for the determination of the microstructural feature of cement‐based material 37‐45 . 1 H NMR relaxometry probes the proton populations associated with different physical and chemical environments in cement‐based material.…”

Section: Introductionmentioning

confidence: 99%

Evolution of elastic behavior of alite paste at early hydration stages

et al. 2020

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Elastic behavior is an important aspect of fresh cement‐based materials. In this paper, the elasticity development of fresh pure alite paste within 5 hours was monitored in situ by small amplitude oscillation shear. Isothermal microcalorimetry, X‐ray diffraction, scanning electronic microscopy, 1H nuclear magnetic resonance, zeta potential measurements were used to investigate the underlying mechanisms. It was found that the evolution of storage modulus can be characterized by three different stages. The first stage stems from the compression of electrical double layer and the slight increase of solid volume fraction; the second stage is only controlled by the colloidal interaction; and the third stage is associated to the significant growth of solid volume fraction, the enhancement of short‐range attraction and the rigidification of calcium silicate hydrate (CSH) network. Moreover, the relationship between the formation of CSH and the growth of elasticity was also quantified.

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In situ 1 H-TD-NMR: Quantification and microstructure development during the early hydration of alite and OPC

Cited by 45 publications

References 22 publications

Quantitative X-ray diffraction of free, not chemically bound water with the PONKCS method

Quantitative X-ray diffraction of free, not chemically bound water with the PONKCS method

C-S-H Pore Size Characterization Via a Combined Nuclear Magnetic Resonance (NMR)–Scanning Electron Microscopy (SEM) Surface Relaxivity Calibration

Evolution of elastic behavior of alite paste at early hydration stages

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