Zerstörungsfreie Bestimmung der Auslaugung von Beton mittels einseitiger Wasserstoff‐Kernspinresonanz

Holthausen, Robert Schulte; Raupach, Michael; Merkel, Melanie; Breit, Wolfgang

doi:10.1002/bate.202010081

Cited by 2 publications

(3 citation statements)

References 9 publications

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“…For evaluation, the individual CPMG decay curves were first corrected and normalized, whereby the signal amplitude obtained called ΦNMR in per cent allows direct inference to the volumetric water content of the sample [7,8]. For signal evaluation, fixed T2 relaxation times of T2-1 = 60 µs, T2-2 = 300 µs and T2-3 = 2600 µs were used and T2-4 was determined by the fit, in correspondence to a past publication [12]. As discussed further in the text, a T2 relaxation time of 60 µs while gaining a first echo at 76 µs provides only strongly reduced accuracy in the results of the crystalline signal A1.…”

Section: Methodsmentioning

confidence: 99%

“…Based on 1 H NMR measurements in a previous publication [12], the hydration process of the SLU panDOMO K 1 was monitored and described in more detail and these results are shortly revisited here. In Figure 1a, the heat flow of panDOMO K1 indicates a twostep hydration process with the first process initiating the setting of the material and a second, longer-running process causing hardening.…”

Section: Introductionmentioning

confidence: 99%

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A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

Holthausen,

Glawe,

Sieksmeier

et al. 2023

ce papers

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Self‐leveling underlayments (SLU) are used for smoothing and levelling sub‐floors before any flexible flooring is applied. Though being comparatively simple in its requirements, commercial SLUs have become one of the most complex cementitious mixtures in dry‐mortar technology. By using ternary binders, most SLUs are designed to be self‐drying, binding most of the mixing water in crystalline cementitious phases, allowing a fast work progress. In this study, the simultaneous hydration and drying of a commercial SLU are monitored with single‐sided 1H nuclear magnetic resonance (NMR). This technique allows the quantification of chemically bound water and water in different pore environments with superior time and depth resolution. The technique is combined with conventional testing techniques enabling a more comprehensive view on the processes at hand. Results allow quantification of hydration and self‐drying, superimposed by physical drying effects over time. Additionally, the drying of a PVC adhesive through water absorption into a well‐dried SLU are visualized with this technique. The results are discussed in the context of moisture transport processes and floor‐laying readiness of the material.

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

Holthausen,

Glawe,

Sieksmeier

et al. 2023

ce papers

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“…3 In this study, 1 H NMR is used as a primary investigation tool and combined with conventional laboratory measurements to acquire new information on the durability and deterioration of concrete samples under leaching attack. The results presented here have partly been published before in German language 24,25 and are part of a comprehensive study on the leaching and realkalization of cementitious materials in drinking water reservoirs. 26,27 2 | EXPERIMENTS…”

Section: H Nuclear Magnetic Resonancementioning

confidence: 99%

Monitoring the microstructural deterioration of concrete exposed to leaching in purified water

Holthausen¹,

Raupach

Merkel³

et al. 2022

Civil Engineering Design

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Concrete is considered to be durable in permanent contact with water, making it a preferred material for the construction of drinking water reservoirs. More severe conditions, however, such as contact with purified water lead to the leaching of calcium and the deterioration of concrete surfaces. Due to the diffusive nature, deterioration begins superficially and ingresses with time. Consequently, concrete surfaces are severely damaged and the rebar‐protective alkalinity can be lost. In this study, results from long‐term laboratory leaching experiments in purified water of differently prepared concrete surfaces relevant for drinking water reservoirs are reported. Samples are monitored by both conventional laboratory techniques and, for the first time, by single‐sided 1H nuclear magnetic resonance to gain knowledge on appearance and performance as well as the microstructural changes with sub‐millimeter depth resolution. Results give a deepened insight into the time‐ and depth‐depending material changes. Concrete with a lower w/c ratio, more durable cement, or a densified surface shows a slowed deterioration. The progressing leaching deterioration is described using a combined diffusion‐erosion model that allows a more direct comparison of results to other exposures.

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Zerstörungsfreie Bestimmung der Auslaugung von Beton mittels einseitiger Wasserstoff‐Kernspinresonanz

Cited by 2 publications

References 9 publications

A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

Monitoring the microstructural deterioration of concrete exposed to leaching in purified water

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Zerstörungsfreie Bestimmung der Auslaugung von Beton mittels einseitiger Wasserstoff‐Kernspinresonanz

Cited by 2 publications

References 9 publications

A single‐sided 1H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

A single‐sided 1H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

Monitoring the microstructural deterioration of concrete exposed to leaching in purified water

Contact Info

Product

Resources

About

A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment

A single‐sided ¹H NMR study of the self‐drying properties of a ternary self‐levelling underlayment