The role of admixed graphene oxide in a cement hydration system

Xu, Gang; Du, Sen; He, Jialuo; Shi, Xianming

doi:10.1016/j.carbon.2019.03.072

Cited by 120 publications

(39 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Finally, the hydration process falls in the deceleration and steady-state stages due to the infilling and accretion of the hydration products formed [31]. the dissolution of the slag [34]. Consequently, the addition of rGO nanosheets can shorten the induction period, thus promoting the hydration of the slag.…”

Section: Hydration Processmentioning

confidence: 99%

“…Second, rGO nanosheets can provide many nucleation sites for the formation of C-S-H and C-A-S-H. As a result, the effect of the delayed nucleation stage is diminished. Finally, the reactions of Ca 2+ ions and oxygen-containing groups on the rGO surface can decrease the Ca concentration and promote the dissolution of the slag [34]. Consequently, the addition of rGO nanosheets can shorten the induction period, thus promoting the hydration of the slag.…”

Section: Hydration Processmentioning

confidence: 99%

“…The poorly crystalline C-S-H(I) is more ordered than the C-S-H phase [40]. According to Xu et al [34], the C-S-H(I) phase features a high content of Si and therefore can present as a Si-rich hydrate. Finally, katoite (C 3 AH 6 , PDF #01-011-1713) and strätlingite (PDF #00-014-0631) are not found in the studied samples, although they were detected in other studies.…”

Section: Xrd Analysismentioning

confidence: 99%

“…In zone 2, the rGO-geopolymer pastes exhibit some complicated features due to the addition of rGO nanosheets. Since Al element in high alkaline solutions generally exists in the form of electronegative tetrahedron such as Al(OH) − 4 , rGO nanosheets with negative charges would repulse Al-containing phases [34]. This indicates that the Al element around the rGO nanosheets has a relatively low concentration.…”

Section: Nmr Analysismentioning

confidence: 99%

See 3 more Smart Citations

Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition

Long

Luo

et al. 2019

Nanomaterials

View full text Add to dashboard Cite

With the development of nanotechnology, reduced graphene oxide (rGO) has been used to improve the flexural strength of geopolymers. However, the reinforcing mechanism of rGO nanosheets on the flexural strength of geopolymers remains unclear. Here, this reinforcing mechanism was investigated from the perspectives of hydration and chemical composition. The effect of the reduction degree on rGO-reinforced geopolymers was also studied using isothermal calorimetry (IC), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) tests. Results show that the hydration degree and flexural strength of geopolymers effectively increase due to rGO addition. After alkali reduction at a temperature of 60 °C, rGO nanosheets have maximum reinforcement on the flexural strength of geopolymers with an increment of 51.2%. It is attributed to the promotion of slag hydration, as well as the simultaneous formation of calcium silicate hydrate with low Ca/Si ratio (C-S-H(I)) and calcium aluminosilicate hydrate (C-A-S-H) phases due to the inhibiting effect of rGO nanosheets on Al substitution on the end-of-chain silicates of C-S-H and C-A-S-H gels. In addition, different reduction degrees have almost no effect on the chemical composition of rGO-reinforced geopolymers, while excessive reduction impairs the improving effect of rGO nanosheets on the hydration process and flexural strength of geopolymers due to significant structural defects.

show abstract

Section: Hydration Processmentioning

confidence: 99%

Section: Hydration Processmentioning

confidence: 99%

Section: Xrd Analysismentioning

confidence: 99%

Section: Nmr Analysismentioning

confidence: 99%

See 2 more Smart Citations

Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition

Long

Luo

et al. 2019

Nanomaterials

View full text Add to dashboard Cite

show abstract

“…Existing studies have confirmed that GO can regulate the hydration products of cement and significantly improve the mechanical properties of cement composites [8][9][10][11][12]. Xu [13] and Hou [14] examined the role of GO in cement composites by using experiments and a molecular dynamics (MD) simulation. The reinforcing mechanisms of GO on cement composites can be attributed to the promoted cement hydration, the refined pore structure, the compacted microstructure [15], which opened a new prospect to modify cement composites at the micro-molecular level [7].…”

Section: Introductionmentioning

confidence: 99%

The Role of Graphene Oxide on the Hydration Process and Chemical Shrinkage of Cement Composites

Xu¹

2020

Ceramics - Silikaty

View full text Add to dashboard Cite

Graphene oxide (GO) has attracted increasing attention for its application in cementitious materials as it can be used to regulate the hydration products of cement and improve the properties of cement composites. This paper investigated the role of GO on the hydration process and chemical shrinkage of a cement paste through an experimental study and molecular dynamics simulation. The hydration heat flow of a cement composite with GO (CCG) was characterised by using an isothermal calorimeter. The chemical shrinkage of the CCG was also measured by applying a modified method based on ASTM C1608. The test results have shown that incorporating GO can mainly accelerate the hydration rate of cement composites at the early stage, but would not change the four-stage process of the cement hydration. The addition of GO by 0.3 wt% of cement is able to reduce the chemical shrinkage of the cement composites. This regulation effect is mainly attributed to the hydrogen bonding, which has been verified by the molecular dynamics simulation.

show abstract

Influence of physico‐mechanical and electrical resistivity performance of high volume fly‐ash cementitious mortar with low carbon

Maurya

Kothiyal

2023

Structural Concrete

View full text Add to dashboard Cite

A graphene oxide (GO) has the potential to improve the strength and hardness of cementitious matrix. The agglomeration of GO in an alkaline medium of cement matrix reduced the reinforcing efficiency. In this study, two types of control samples were fabricated named OPC‐C (OPC control) and HVFA‐C (OPC + 50% FA control) without the addition of GO and four HVFA cementitious mortar samples HVFA‐G1, HVFA‐G2, HVFA‐G3, and HVFA‐G4 were prepared with incorporation of GO 0.005%, 0.010%, 0.020% and 0.040%, respectively. The results revealed that the superplasticizer stabilized GO in cement mortar, significantly improves the compressive (27.12%) and split tensile strength (38.16%) in the HVFA‐G3 mix as compared to HVFA‐C at a curing age of 90 days. The maximum electrical resistivity attained in HVFA‐G4 (83%) mix as compared to OPC‐C at a curing age of 90 days. In addition, microstructural analysis of HVFA cementitious mortar was conducted using a Field Emission‐Scanning Electron Microscope (FE‐SEM), while the crystallization behavior of hydration products ware examined through Powdered X‐Ray Diffraction (PXRD). Furthermore, the chemical bonding between the hydration products was studied using Fourier Transform Infrared Spectroscopy (FT‐IR). Overall, it is concluded that the superplasticizer stabilized GO in HVFA cementitious mortar, helps to achieve better mechanical strength, electrical resistivity performance, and microstructural behavior.

show abstract

The role of admixed graphene oxide in a cement hydration system

Cited by 120 publications

References 42 publications

Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition

Reinforcing Mechanism of Reduced Graphene Oxide on Flexural Strength of Geopolymers: A Synergetic Analysis of Hydration and Chemical Composition

The Role of Graphene Oxide on the Hydration Process and Chemical Shrinkage of Cement Composites

Influence of physico‐mechanical and electrical resistivity performance of high volume fly‐ash cementitious mortar with low carbon

Contact Info

Product

Resources

About