The morphology of C–S–H: Lessons from 1H nuclear magnetic resonance relaxometry

Valori, Andrea; McDonald, P.J.; Scrivener, Karen

doi:10.1016/j.cemconres.2013.03.011

Cited by 183 publications

(95 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given relaxation times of the order of 100 µs and diffusivities of the order of 10 −9 m 2 /s, the implication therefore is that pore sizes must be of the order of µm. Such a large size is at odds with independent and NMR observations that suggest gel pores are nano-sized [13,14]. The 2L model, by contrast, allows spins to depart the layer to return at a later time.…”

Section: −1contrasting

confidence: 41%

“…For a pore of thickness equivalent to 10 surface layers, for example, mixing of surface and bulk water can only occur over timescales longer than ≈ 10 × 10 µs which is similar to typical spin-spin relaxation times T 2 of 1 H in C-S-H, about 100 µs [14]. This work is motivated by the desire to resolve the above inconsistencies, to identify the nanoscale structure of C-S-H in cement and, in particular, to understand the behaviour of water in the nanoscale pores formed by C-S-H.…”

Section: −1mentioning

confidence: 99%

“…Yet, a bulk water molecule diffuses a distance of about 0.4 µm in 13 µs, a distance which is much larger than typical pore thickness in cementitious materials where, despite uncertainty as to the morphology of mature C-S-H, most pores have sizes ranging from about 2 nm to 50 nm [7,13,14]. Furthermore, the fast-exchange model has limited application if τ s ≈ 10 µs.…”

Section: −1mentioning

confidence: 99%

See 2 more Smart Citations

Model for the interpretation of nuclear magnetic resonance relaxometry of hydrated porous silicate materials

et al. 2015

View full text Add to dashboard Cite

Nuclear magnetic resonance (NMR) relaxation experimentation is an effective technique for probing the dynamics of proton spins in porous media but interpretation requires the application of appropriate spin diffusion models. Molecular dynamics (MD) simulations of porous silicate-based systems containing a quasi-two-dimensional water-filled pore are presented. The MD simulations suggest that the residency time of the water on the pore surface is in the range 0.03-12 ns, typically 2-5 orders of magnitude less than values determined from fits to experimental NMR measurements using the established surface-layer (SL) diffusion models of Korb and co-workers [Phys. Rev. E 56, 1934Rev. E 56, , (1997]. Instead, MD identifies four distinct water layers in a tobermorite-based pore containing surface Ca 2+ ions. Three highly-structured water layers exist within 1 nm of the surface and the central region of the pore contains a homogeneous region of bulk-like water. These regions are referred to as layer 1 and 2 (L1, L2), transition layer (TL) and bulk (B), respectively. Guided by the MD simulations, a two-layer (2L) spin-diffusion NMR relaxation model is proposed comprising two two-dimensional layers of slow-and fast-moving water associated with L2 and layers TL+B respectively. The 2L model provides an improved fit to NMR relaxation times obtained from cementitious material compared to the SL model, yields diffusion correlation times in the range 18-75 ns and 28-40 ps in good agreement with MD, and resolves the surface residency time discrepancy. The 2L model, coupled with NMR relaxation experimentation, provides a simple yet powerful method of characterising the dynamical properties of proton-bearing porous silicate-based systems such as porous glasses, cementitious materials and oil-bearing rocks.

show abstract

Section: −1contrasting

confidence: 41%

Section: −1mentioning

confidence: 99%

Section: −1mentioning

confidence: 99%

See 1 more Smart Citation

Model for the interpretation of nuclear magnetic resonance relaxometry of hydrated porous silicate materials

et al. 2015

View full text Add to dashboard Cite

show abstract

“…1 H NMR relaxometry has been used sporadically to study cement pastes over several decades. A recent paper from Valori et al [11] reviews the progress made in characterising cement-based materials by water relaxation techniques and states the current knowledge of applying 1 H NMR to cement. We have shown in recent publications [12,13] how quantitative non-invasive 1 H NMR relaxometry can be used to fully describe plain white Portland cement pastes including pore sizes, C-S-H chemical composition and the evolution of C-S-H density over time.…”

Section: Introductionmentioning

confidence: 99%

Influence of silica fume on the microstructure of cement pastes: New insights from 1H NMR relaxometry

Müller

Scrivener

Skibsted

et al. 2015

Cement and Concrete Research

Self Cite

168

View full text Add to dashboard Cite

“…Small angle scattering profiles (Chiang et al 2012(Chiang et al , 2013Nicoleau et al 2013;Trapote-Barreira et al 2015) and 1 H-NMR relaxometry (Korb 2009;McDonald et al 2010;Muller et al 2012Muller et al , 2013Muller et al , 2015Valori et al 2013) give insights on this topic. An example of elaboration to explain the relationships between C-S-H microstructure change under the first drying and physical properties is shown in the references (Maruyama et al 2014a(Maruyama et al , 2016a.…”

Section: Cement Paste Properties Under the First Dryingmentioning

confidence: 99%

Multi-scale Review for Possible Mechanisms of Natural Frequency Change of Reinforced Concrete Structures under an Ordinary Drying Condition

Maruyama

2016

ACT

View full text Add to dashboard Cite

Based on a review from a view point of multi-scale perspective, it is concluded that possible mechanisms of natural frequency change of concrete structures under an ordinary drying condition are reduction of Young's modulus of concrete and stiffness reduction of reinforced concrete member due to shrinkage-induced cracking. Both two mechanisms can be provoked by drying, which is natural environmental condition for all the building structures. This natural frequency change is important for the integrity analysis of nuclear power plants because seismic response change and sympathetic vibration between structure and installed implementations are expected. In addition, to understand the mechanism this mechanism should contributed to post-earthquake integrity evaluation which is necessary to efficient and continuous operation of nuclear power plants. The lost parts of scientific knowledge and needs of experimental data for whole picture of this natural frequency change have been pointed out.

show abstract

The morphology of C–S–H: Lessons from 1H nuclear magnetic resonance relaxometry

Cited by 183 publications

References 48 publications

Model for the interpretation of nuclear magnetic resonance relaxometry of hydrated porous silicate materials

Model for the interpretation of nuclear magnetic resonance relaxometry of hydrated porous silicate materials

Influence of silica fume on the microstructure of cement pastes: New insights from 1H NMR relaxometry

Multi-scale Review for Possible Mechanisms of Natural Frequency Change of Reinforced Concrete Structures under an Ordinary Drying Condition

Contact Info

Product

Resources

About