Hydration of white cement by spin grouping NMR

MacTavish, J.C.; Miljković, L.; Pintar, M. M.; Blinc, R.; Lahajnar, G.

doi:10.1016/0008-8846(85)90048-1

Cited by 35 publications

(12 citation statements)

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“…[1][2][3][4][5][6][7] The nondestructive NMR monitoring of the hardening process turned out to be surprisingly sensitive as well as quantitative. [4][5][6][7] It has been demonstrated 8 that the dependence of the NMR spin-lattice relaxation rate 1/T 1 on hydration time directly measures the increase of the solid surface in cement gel and therefore the number of adsorptive sites of newly formed hydration products. The method relies on the fact that during hydration some water enters the structure of the newly formed minerals whereas the liquidlike ''exchangeable'' water remains in close contact with the cement gel surface.…”

Section: Introductionmentioning

confidence: 99%

Two-dimensional nuclear magnetic resonance study of a hydrated porous medium: An application to white cement

Dolinšek

Apih

Lahajnar

et al. 1998

Journal of Applied Physics

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Articles you may be interested inTacticity effects on the barriers to rotation of the ester methyl group in poly (methyl methacrylate): A deuteron magnetic resonance study Unconventional Heisenberg spin triangle in magnetic molecule { V 15}: A proton nuclear magnetic resonance study J. Appl. Phys. 93, 7810 (2003); 10.1063/1.1540051 1 H and 23 Na nuclear magnetic resonance study of V6 magnetic molecular clusters A two-dimensional deuterium nuclear magnetic resonance study of molecular reorientation in sugar/water glasses J.Structure and dynamics of a hydrated white cement were investigated by the T 1 -weighted lineshape, two-dimensional ͑2D͒ exchange, and 2D separation of inhomogeneous and homogeneous lineshapes nuclear magnetic resonance ͑NMR͒ techniques. T 1 weighting of the proton spectrum eliminates the strong bulk water signal from the pores so that the weaker spectrum of the solid cement matrix becomes observable. The proton spectrum of the solid cement fraction exhibits a characteristic Pake doublet shape and shows a close similarity to the powder spectra of pure calcium hydroxide and the crystalline water of gypsum. The 2D exchange NMR spectrum of white cement demonstrates the existence of slow chemical exchange processes of protons in the solid matrix on a sub-kHz frequency scale. This exchange is orders of magnitude slower than the exchange between the surface and bulk water. The 2D NMR separation of inhomogeneous and homogeneous lineshapes technique demonstrates that the absorption lines of a set white cement are inhomogeneously broadened due to the existence of a distribution of static local magnetic fields. The major contribution to these fields comes from the dipolar fields of the paramagnetic electrons whereas the magnetic susceptibility differences of the liquid and solid fractions add a small part at the solid-liquid boundary where the direction of the external magnetic field is changed.

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Section: Introductionmentioning

confidence: 99%

Two-dimensional nuclear magnetic resonance study of a hydrated porous medium: An application to white cement

Dolinšek

Apih

Lahajnar

et al. 1998

Journal of Applied Physics

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“…The components (b) and (c) refer to the protons of water in capillaries and gel pores, respectively [3,5].…”

Section: Resultsmentioning

confidence: 99%

“…In aceordance with efficiency of the proton T~ relaxation rlaechanisms the composite NMR signal can be resolved into spin groups [3]. Each component is characterized by its own relaxation parameters T 1 and M O (fraction in total magnetization).…”

Section: Introductionmentioning

confidence: 99%

The1HT 1 study of the influence of clay addition on Portland cement hydration

1997

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Effects of addition of three standard clay minerals, Na-montmorillonite, illite and kaolinite, on Portland cement hydration properties were studied. The IH spin-lattiee relaxation of exchangeable water was monitored during hydration time and the data were processed by spin-grouping analysis. The values and evolution dynamics of both resolved T l eomponents and corresponding magnetization fractions show that each day mineral lowers the fluidity of Portland cement paste and accelerates its hydration in dormant. In advanced stages of hydration, the Na-montmorillonite provŸ the accelerating influence, while the kaolinite exhibits the retarding effect. The final values of gel pores to capillaries pereentage fractions ratio indieate a slightly lower porosity of samples with Namontmorillonite anda higher porosity of pastes with the same percentage of illite or kaolinite, regarding to the pure hardened Portland cement.

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“…Figure 1 shows that the spin-lattice relaxation time TI falls off significantly faster than T,; and M,, in fact, changes little over this period. There is suspicion in the literature (McTavish et al, 1985) that part of the water proton content in a hydrating cement may have relaxation times so short that it is "invisible" to normal liquid state NMR techniques. M, here does not necessarily represent total water content; however, it does represent the maximum signal available in a spin-echo imaging experiment.…”

Section: Methodsmentioning

confidence: 99%

Nuclear magnetic resonance imaging of simulated voids in cement slurries

et al. 1991

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The initial technological development of nuclear magnetic resonance (NMR) imaging was motivated primarily by applications in medicine and biology (for example, Morris, 1986); however, increasing attention is now being given to applications to nonliving systems such as porous media (Osment et al., 1990) and polymer science (Jackson et al., 1991). These applications place higher demands on hardware performance and ingenuity in imaging protocol design, principally because of the broader linewidths and shorter relaxation times found in such heterogeneous systems compared with those of biological tissues. NMR relaxometry in heterogeneous systems has provided insight into pore sizes, surface area, and molecular dynamics in porous media (Banavar and Schwartz, 1989), suspensicns (Fripiat et al., 1982), and hydrating cement (Lasic, 1989). Most of the latter are studies of the 'H (proton) resonance of water in a hydrating slurry. Even for relaxometry, measurements can be difficult in commercial cements (Mc-Tavish et al., 1985) because of the short relaxation times typically found. Standard imaging experiments are almost unviable; the broad linewidth severely limits the spatial resolution which can be achieved, and in spin-echo techniques (Mansfield and Morris, 1982) the short transverse relaxation time T2 usually causes severe attenuation of the NMR signal by the time spatially encoded data can be acquired. This conclusion is in opposition to a naive view that the high water content of cement slurries makes them a natural candidate for NMR studies. Nevertheless, with a suitable compromise in material choice and some ingenuity in experiment design, high contrast images of simulated voids in a wet cement slurry can be obtained, as we demonstrate in this work.By "void" we mean both nonporous solid objects and gasor vapor-filled bubbles or fissures giving negligible liquid-state proton NMR signal. The motivation of this study was to develop a technique by which movement of gas "voids" within a slurry could be examined experimentally. Natural gas migration is an important failure mode of oil-well cementing E. J. Fordham is on leave from Schlumberger Cambridge Research Ltd.operations (Parcevaux et al., 1990). The imaging speeds achieved (down to 5 seconds per slice-selective image) indicate that this technique is feasible for such applications. Other viable applications may be in imaging aggregate distribution or crack detection in model concretes and in ceramic casting, or indeed in void detection in any other proton-containing material with comparable values of its NMR parameters. MaterialsTwo cements were examined. The imaging study used a cosmetic white Portland cement "Snowcrete" supplied by Blue Circle Industries PLC. Comparison relaxation measurements on a sample of an oilfield Class G cement were also made. The white cement differs from typical ordinary portland cements (OPC's) in having a very low iron content (less than 0.5% Fe,O, w/w) and a correspondingly higher aluminum content. The silicate contents are very simil...

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Hydration of white cement by spin grouping NMR

Cited by 35 publications

References 1 publication

Two-dimensional nuclear magnetic resonance study of a hydrated porous medium: An application to white cement

Two-dimensional nuclear magnetic resonance study of a hydrated porous medium: An application to white cement

The1HT 1 study of the influence of clay addition on Portland cement hydration

Nuclear magnetic resonance imaging of simulated voids in cement slurries

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