Plastic deformation mechanism of calcium-silicate hydrates determined by deviatoric-stress Raman spectroscopy

Gardner, David P.; Li, Jiaqi; Kunz, Martin; Zhu, Chenhui; Monteiro, Paulo J.M.; Maboudian, Roya; Carraro, Carlo

doi:10.1016/j.cemconres.2021.106476

Cited by 20 publications

(6 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Dense C-S-H monoliths (pellets) were then demolded from the die and used for subsequent mechanical investigations. The sampling method follows previous work. , From − previous research, it is found that the loading condition and water content will have an influence on the preferred orientation of C-S-H pellets. In this study, the C-S-H powders were stored in 8 and 100% RH conditions.…”

Section: Methodsmentioning

confidence: 99%

Interfacial Degradation of Calcium Silicate Hydrate and Epoxy under a Hygrothermal Environment: An Experimental and Molecular Model Study

Luo

Zhang

et al. 2023

J. Phys. Chem. C

View full text Add to dashboard Cite

The adhesion at the concrete/epoxy interface is crucial to the reinforcement of carbon fiber-reinforced polymer (CFRP) sheets. The multiscale mechanism of adhesion, particularly under a hygrothermal environment, yet remains largely unclear. This paper combines molecular dynamics (MD) and synthesis experiments of a novel single-phase calcium silicate hydrate (C-S-H) and epoxy composite to investigate the combined effects of aggressive chemicals and temperature on the bonding properties. MD models were constructed under various conditions on C-S-H/epoxy composites, whose equilibrium configuration, dynamic property, bond connection, interfacial interaction energy, and mechanical properties were quantified. In addition, the experiments were carried out under different temperatures and humidity conditions to explore the macroscopic splitting tensile property of the composites and further validate the MD results. The MD results suggest that the Ca ions on the C-S-H surface are crucial to the adhesion by forming Ca−O and Ca−N bonds with epoxy. However, these bonds were reduced in the presence of water molecules, with a reduction also of the interfacial energy. The degradation effects are exacerbated by the presence of NaCl solution, as Na ions gather around the interfacial region of C-S-H/ epoxy, further accumulating water molecules by forming hydrated ion clusters. This process is accelerated by elevated temperature. The experiment results suggest that without the influence of NaCl solution, a moist C-S-H surface turns to gain a stronger bonding with epoxy when the curing temperature is higher (40, 60 °C). Meanwhile, the bonding properties of a dry C-S-H surface and epoxy are less sensitive to temperature. This work provides new insight into understanding the bonding mechanism on the C-S-H/epoxy interface and may benefit the engineering application of CFRP-concrete reinforcement.

show abstract

Section: Methodsmentioning

confidence: 99%

Interfacial Degradation of Calcium Silicate Hydrate and Epoxy under a Hygrothermal Environment: An Experimental and Molecular Model Study

Luo

Zhang

et al. 2023

J. Phys. Chem. C

View full text Add to dashboard Cite

show abstract

“…As previously discussed, [36][37][38][39][40][41][42][43][44] the fluidity of cement slurry can be directly related to the nano-boundary friction between C-S-H particles, as depicted in Figure 3A. First, we analyzed the effect of the water content without PCEs.…”

Section: Lubrication Of Polycarboxylatementioning

confidence: 99%

“…The lower friction on the nanoscale is, the better fluidity on the macroscale will be 36 . There is some research focused on the shear between CSH nanoparticles 37–44 . Manzano et al 40 .…”

Section: Introductionmentioning

confidence: 99%

“…36 There is some research focused on the shear between CSH nanoparticles. [37][38][39][40][41][42][43][44] Manzano et al 40 investigated the relaxation process of C-S-H nanoparticles subjected to shear stress, and they found that the evolution of the shear strength is a function of water mobility for a given interfacial distance and water content. Qomi et al 37 studies also indicate that the water contents affect the viscoelastic of the cement system significantly.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Unlocking cementitious performance: nano‐lubrication via polycarboxylate superplasticizers

Wang,

Ji,

Manzano

et al. 2024

J Am Ceram Soc.

View full text Add to dashboard Cite

Polycarboxylate (PCE) superplasticizers are the most important additive in concrete, which can effectively improve the workability of cement slurry. Different from the traditional regarding of PCEs as dispersants, here, we understand the PCEs as nano‐lubricants. By employing the molecular dynamics simulation, a sophisticated model was used to evaluate the interfacial friction between the C–S–H particles. The results reveal that the PCEs can reduce the interfacial friction between the C–S–H particles, and thus increase the fluidity of cement slurry. Further analyses infer the role of PCE segments in lubrication. The carboxylates on PCEs ensure the anchoring and hinder the separation of Ca ions. The side chains are used to lubricate the C–S–H surface, due to the weak adsorption between the side chains and the C–S–H surface. Predictably, this study not only provides a method to directly evaluate the performance of PCEs but also suggests new insights into the colloid dispersion of the low‐water content system.

show abstract

“…The PS technique was initially used to analyze stress in single-crystal alumina, [17][18][19] bulk polycrystalline alumina, [20][21][22] and alumina-based thin films [23][24][25] but did not involve the detection of stress distributions. Later, several researchers dispersed ruby powders into various matrix materials, including metal Al, 26 polymer, 27 cement, 28 and inorganic glass. 29,30 As a result, the stress distributions inside the matrices could be determined by the PS technique.…”

Section: Introductionmentioning

confidence: 99%

Calibration for determination of compressive stress in glass‐to‐metal seals via photoluminescence spectroscopy

Liu,

Cai,

Gong

et al. 2023

J Am Ceram Soc.

View full text Add to dashboard Cite

Compressive stress in glass‐to‐metal seals is crucial to ensure sealing quality and service reliability. Photoluminescence spectroscopy (PS), which relies on the piezospectroscopic effect of Cr‐doped α‐Al2O3, shows promise for stress detection owing to its rapid detection, non‐destruction, and high resolution. The premise of the PS technique is to fill a glass matrix with alumina particles and detect signals from the alumina. In this study, the interaction between alumina particles and the glass matrix was analyzed to calibrate the measured stresses and investigate the stress state in the glass. Test results for glass‐to‐metal seals are believed to consist of simultaneous internal residual stress and external applied stress. The internal residual stress is formed due to the coefficient of thermal expansion mismatch between glass and alumina and is assumed to transfer by radial compression. In the experiment, it was detected by the PS technique and verified by X‐ray diffraction using an unstressed sample without metal housing. The external applied stress is formed due to metal housing compaction and possibly transferred by the shear effect. The stress distribution within the pre‐stressed sample containing metal housing was also measured by the PS technique. Then, calibrations were conducted on the measured stresses based on the deduced stress transfer relationships. Finally, finite element models were established to simulate the internal residual stress and external applied stress respectively to prove the validity of the calibration method, and mutually anastomotic results were obtained within the target margin of error.

show abstract

Plastic deformation mechanism of calcium-silicate hydrates determined by deviatoric-stress Raman spectroscopy

Cited by 20 publications

References 48 publications

Interfacial Degradation of Calcium Silicate Hydrate and Epoxy under a Hygrothermal Environment: An Experimental and Molecular Model Study

Interfacial Degradation of Calcium Silicate Hydrate and Epoxy under a Hygrothermal Environment: An Experimental and Molecular Model Study

Unlocking cementitious performance: nano‐lubrication via polycarboxylate superplasticizers

Calibration for determination of compressive stress in glass‐to‐metal seals via photoluminescence spectroscopy

Contact Info

Product

Resources

About