Evolution of the particle size distribution of tricalcium silicate during hydration by synchrotron X-ray nano-tomography

Neubauer, J.; Sowoidnich, T.; Valentini, Luca; Schulbert, Christian; Naber, C.; Rößler, Christiane; DaSilva, J.; Bellmann, F.

doi:10.1016/j.cemconres.2022.106769

Cited by 8 publications

(5 citation statements)

References 59 publications

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“…PC-52.5, with finer particles D v,50 ∼12 μm, was used for the PXCT study in order to have more hydrating particles in the analysed volume. It is noted that, in a very recent nanotomographic study 7 , researchers milled alite very extensively, all particles<10 μm, in order to fit them within a small field of view (FOV) of ∼50 μm. PC-52.5 was used for the PXCT and laboratory μCT imaging studies and the additional laboratory characterization.…”

Section: Resultsmentioning

confidence: 99%

“…Conversely, there is no agreement in the mechanism(s) to explain the transition from acceleration to deceleration, when there is a degree of hydration of just 10-20% and plenty of space for the hydrates to grow. The most advanced theories, recently discussed 6 , are based on heterogeneous nucleation and growth within confined regions taking into account the initial particle size distributions 7 , for instance, see the reaction zone hypothesis 8 . There are alternatives 9 like the needle model 6 where alite, the most abundant component of PC, hydrates 10 , 11 to yield nonstoichiometric calcium-silicate-hydrate (C-S-H) gel 12 , which nucleates and grows as needles.…”

Section: Introductionmentioning

confidence: 99%

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4D nanoimaging of early age cement hydration

et al. 2023

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Despite a century of research, our understanding of cement dissolution and precipitation processes at early ages is very limited. This is due to the lack of methods that can image these processes with enough spatial resolution, contrast and field of view. Here, we adapt near-field ptychographic nanotomography to in situ visualise the hydration of commercial Portland cement in a record-thick capillary. At 19 h, porous C-S-H gel shell, thickness of 500 nm, covers every alite grain enclosing a water gap. The spatial dissolution rate of small alite grains in the acceleration period, ∼100 nm/h, is approximately four times faster than that of large alite grains in the deceleration stage, ∼25 nm/h. Etch-pit development has also been mapped out. This work is complemented by laboratory and synchrotron microtomographies, allowing to measure the particle size distributions with time. 4D nanoimaging will allow mechanistically study dissolution-precipitation processes including the roles of accelerators and superplasticizers.

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Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

4D nanoimaging of early age cement hydration

et al. 2023

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“…[ 13 ] employed focused ion beam (FIB) nanotomography for morphology analysis and interface topology of ceramics, while Neubauer et al. [ 14 ] analyzed the evolution of tricalcium silicate particle size during hydration using X‐ray nano‐tomography. However, these studies did not analyze 3D particle morphology characteristics rigorously.…”

Section: Introductionmentioning

confidence: 99%

“…However, their study was limited to 2D characterization, which has been demonstrated to underrepresent the shape indices of irregular particles, as a single image of a particle is dependent on the current, random particle orientation, and thus provides limited morphological information of the real, 3D morphology.3D nano-scale shape characterization is challenging because of the limitation in measurement techniques and until recently the lack of openly available processing algorithms for the characterization of three-dimensional particles. Holzer et al [13] employed focused ion beam (FIB) nanotomography for morphology analysis and interface topology of ceramics, while Neubauer et al [14] analyzed the evolution of tricalcium silicate particle size during hydration using X-ray nano-tomography. However, these studies did not analyze 3D particle morphology characteristics rigorously.To the best of the authors' knowledge, there is no previously reported 3D nano-computed tomography analysis of pyrite particles.…”

mentioning

confidence: 99%

“…3D nano-scale shape characterization is challenging because of the limitation in measurement techniques and until recently the lack of openly available processing algorithms for the characterization of three-dimensional particles. Holzer et al [13] employed focused ion beam (FIB) nanotomography for morphology analysis and interface topology of ceramics, while Neubauer et al [14] analyzed the evolution of tricalcium silicate particle size during hydration using X-ray nano-tomography. However, these studies did not analyze 3D particle morphology characteristics rigorously.…”

mentioning

confidence: 99%

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Nano‐Scale Characterization of Particulate Iron Pyrite Morphology in Shale

Angelidakis

Nadimi

Garum

et al. 2022

Part & Part Syst Charact

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This study analyses the morphology of iron pyrite particles within a shale sample, captured using nano-computed tomography (Nano-CT). The complex, framboidal morphology of the iron pyrite particles is characterised using various metrics, and comparisons are drawn on their effectiveness to quantify their observed morphological characteristics. Then, simplified representations of selected iron pyrite particles are generated to facilitate a sensitivity analysis of the effect of imaging resolution on morphological parameters of particle form. A discussion is developed on the required number of pixels per particle diameter for particle shape characterisation. It is shown that shape indices that rely on the simplified main particle dimensions can be accurately calculated even for low fidelity levels of 10 pixels per particle diameter. More complex shape indices, that use vertices, volume and surface area, are more sensitive to image resolution even for 40 pixels per particle diameter.

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