Studying Blended Cement Paste with Nuclear Magnetic Resonance Relaxation Time

The pore structure of cement paste has a relationship with its strength and durability. An appropriate method of measurement is a prerequisite to study the pore structure of cement paste. Among many test methods, Nuclear Magnetic Resonance (NMR) relaxation time is a novel testing methods to study pore structure of cement paste. Different from previous research object is limited to white cement, the test sample in this paper is the blended cement paste containing mineral admixture and has been widely used in practical engineering applications. The factors of pore structure are water to cementitious material ratio, kind of mineral admixture, and mineral admixture content. Measure the same sample at four different ages to obtain the relaxation time distribution to reflect the pore structure. The test results show that, in most cases, the distribution curves of the same kind of paste are in good agreement, and the change of relaxation time distribution of the blended cement paste with different ages can be interpreted as the characteristic of the mineral admixtures in cement paste. So the NMR relaxation time is suitable for study on the blended cement paste. However due to side effects caused by iron content and unsaturated water in gel pore, this method needs further improvement.

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TEMPERATURE CORRECTION MODELS FOR NMR RELAXATION TIME DISTRIBUTION IN CARBONATE ROCKS

10.30632/t60als-2019_hh ◽

2019 ◽

Author(s):

Gabor Husan ◽

Shouxiang Ma ◽

Wei Shao ◽

Songhua Chen

Keyword(s):

Relaxation Time ◽

Carbonate Rocks ◽

Time Distribution ◽

Nmr Relaxation ◽

Temperature Correction ◽

Relaxation Time Distribution ◽

Nmr Relaxation Time

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A laboratory study of NMR relaxation times in unconsolidated heterogeneous sediments

Geophysics ◽

10.1190/1.3581094 ◽

2011 ◽

Vol 76 (4) ◽

pp. G73-G83 ◽

Cited By ~ 29

Author(s):

Elliot Grunewald ◽

Rosemary Knight

Keyword(s):

Grain Size ◽

Relaxation Time ◽

Time Distribution ◽

Relaxation Times ◽

Nmr Relaxation ◽

Unconsolidated Sediments ◽

Relaxation Response ◽

Relaxation Time Distribution ◽

Near Surface ◽

Heterogeneous Sediments

Nuclear magnetic resonance (NMR) relaxation-time measurements can provide critical information about the physiochemical properties of water-saturated media and are used often to characterize geologic materials. In unconsolidated sediments, the link between measured relaxation times and pore-scale properties can be complicated when diffusing water molecules couple the relaxation response of heterogeneous regions within a well-connected pore space. Controlled laboratory experiments have allowed us to investigate what factors control the extent of diffusional coupling in unconsolidated sediments and what information is conveyed by the relaxation-time distribution under varied conditions. A range of sediment samples exhibiting heterogeneity in the form of a bimodal mineralogy of quartz and hematite were mixed with varied mineral concentration and grain size. NMR relaxation measurements and geometric analysis of these mixtures demonstrate the importance of two critical length scales controlling the relaxation response: the diffusion length ℓD, describing the distance a water molecule diffuses during the NMR measurement, and the separation length ℓS, describing the scale at which heterogeneity occurs. For the condition of ℓS > ℓD, which prevails for samples with low hematite concentrations and coarser grain size, coupling is weak and the bimodal relaxation-time distribution independently reflects the relaxation properties of the two mineral constituents in the heterogeneous mixtures. For the condition of ℓS < ℓD, which prevails at higher hematite concentrations and finer grain size, the relaxation-time distribution no longer reflects the presence of a bimodal mineralogy but instead conveys a more complex averaging of the heterogeneous relaxation environments. This study has shown the potential extent and influence of diffusional coupling in unconsolidated heterogeneous sediments, and can serve to inform the interpretation of NMR measurements in near-surface environments where unconsolidated sediments are commonly encountered.

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EVALUATION OF PHYSICAL PROPERTIES OF BLENDED CEMENT PASTE BASED ON PORE STRUCTURE DETERMINED BY THERMOPOROMETRY

Cement Science and Concrete Technology ◽

10.14250/cement.71.177 ◽

2017 ◽

Vol 71 (1) ◽

pp. 177-184

Author(s):

Takuya SUGIYAMA ◽

Masanori MIYAMOTO ◽

Kiyofumi KURUMISAWA ◽

Akira HATANAKA

Keyword(s):

Physical Properties ◽

Pore Structure ◽

Cement Paste ◽

Blended Cement ◽

Blended Cement Paste

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Parameterization of NMR relaxation curves in terms of logarithmic moments of the relaxation time distribution

Journal of Magnetic Resonance ◽

10.1016/j.jmr.2017.04.009 ◽

2017 ◽

Vol 279 ◽

pp. 29-38 ◽

Cited By ~ 6

Author(s):

Oleg V. Petrov ◽

Siegfried Stapf

Keyword(s):

Relaxation Time ◽

Time Distribution ◽

Nmr Relaxation ◽

Relaxation Time Distribution ◽

Relaxation Curves ◽

Logarithmic Moments

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Using non-destructive testing tools to assess the pore structure of slag-blended cement paste under steam curing

Magazine of Concrete Research ◽

10.1680/jmacr.19.00023 ◽

2021 ◽

Vol 73 (2) ◽

pp. 98-107

Author(s):

Xiancui Yan ◽

Linhua Jiang ◽

Zijian Song ◽

Yunjie Chen

Keyword(s):

Pore Structure ◽

Cement Paste ◽

Blended Cement ◽

Non Destructive Testing ◽

Destructive Testing ◽

Steam Curing ◽

Testing Tools ◽

Non Destructive ◽

Blended Cement Paste

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A laboratory study of NMR relaxation times and pore coupling in heterogeneous media

Geophysics ◽

10.1190/1.3223712 ◽

2009 ◽

Vol 74 (6) ◽

pp. E215-E221 ◽

Cited By ~ 45

Author(s):

Elliot Grunewald ◽

Rosemary Knight

Keyword(s):

Relaxation Time ◽

Time Distribution ◽

Heterogeneous Media ◽

Relaxation Times ◽

Nmr Relaxation ◽

Micropore Volume ◽

Heterogeneous Porous Media ◽

Relaxation Time Distribution ◽

Basic Parameters ◽

Nmr Relaxation Times

Nuclear magnetic resonance (NMR) relaxation times of geologic materials are closely related to pore geometry. In heterogeneous media, however, the details of this relationship are poorly understood because of a phenomenon known as pore coupling, which arises when diffusing protons sample multiple pores before relaxing. Laboratory experiments allow us to explore whether surface geochemistry can influence pore coupling and how this process affects the observed relaxation-time distribution. Measurements of the NMR response for microporous silica gel packs, treated with varying amounts of surface-coating iron, demonstrate that samples with less iron exhibit stronger pore coupling than those with abundant iron. When pore coupling is strong, the relaxation-time distribution grossly misrepresents the underlying bimodal pore-size distribution of micropores and macropores. Specifically, the bimodal relaxation-time distribution becomes merged and the relative amplitude of the peaks fails to reflect the true macropore and micropore volume. A reduction in pore coupling, observed with increasing iron content, is attributed to a decrease in the distance protons are able to diffuse before relaxing. Basic parameters describing the shape of the relaxation-time distributions for this range of samples are well-predicted by a 1D analytical model. Experimental results conclusively demonstrate that surface geochemistry is an important factor determining the degree to which pore coupling occurs and illustrate how this phenomenon can affect the interpretation of NMR relaxation measurements in heterogeneous porous media.

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