Influences of CNT dispersion and pore characteristics on the electrical performance of cementitious composites

Kim, Gwangmok; Yang, Beomjoo; Cho, KJ; Kim, EM; Lee, Haeng‐Ki

doi:10.1016/j.compstruct.2016.12.049

Cited by 111 publications

(30 citation statements)

References 41 publications

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“…However, the increase of electrical resistance with curing time for the specimens reinforced with more than 0.5% concentration is lesser in comparison with other specimens, especially after 7 days of curing. The reason for this can be explained by the fact that the concentrations of CNT + GNP greater than the percolation threshold leads to the well-established continuous CNT + GNP conductive pathways which are not affected significantly by dried pores [46,47]. Table 6 summarizes results of other studies and shows the high efficiency of hybrid CNT + GNP used in this research.…”

Section: Electrical Resistance Resultsmentioning

confidence: 80%

“…Additionally, it can be observed that in all reinforced and plain cementitious composites, the electrical resistance increased by increasing curing age and hydration period. This is because of the formation of finer pores due to cement hydration which leads to a decrease in pore water and cuts off the conductive pathway of water [46]. Moreover, cement hydration process also can make a gap in CNT + GNP conductive paths by changing in cementitious composite microstructure and surrounding the CNMs as visible in Figure 17.…”

Section: Electrical Resistance Resultsmentioning

confidence: 99%

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Ultra-Sensitive Affordable Cementitious Composite with High Mechanical and Microstructural Performances by Hybrid CNT/GNP

2020

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In this paper a hybrid combination of carbon nanotubes (CNTs) and graphene nanoplatelets (GNPs) was used for developing cementitious self-sensing composite with high mechanical, microstructural and durability performances. The mixture of these two nanoparticles with different 1D and 2D geometrical shapes can reduce the percolation threshold to a certain amount which can avoid agglomeration formation and also reinforce the microstructure due to percolation and electron quantum tunneling amplification. In this route, different concentrations of CNT + GNP were dispersed by Pluronic F-127 and tributyl phosphate (TBP) with 3 h sonication at 40 °C and incorporated into the cementitious mortar. Mechanical, microstructural, and durability of the reinforced mortar were investigated by various tests in different hydration periods (7, 28, and 90 days). Additionally, the piezoresistivity behavior of specimens was also evaluated by the four-probe method under flexural and compression cyclic loading. Results demonstrated that hybrid CNT + GNP can significantly improve mechanical and microstructural properties of cementitious composite by filler function, bridging cracks, and increasing hydration rate mechanisms. CNT + GNP intruded specimens also showed higher resistance against climatic cycle tests. Generally, the trend of all results demonstrates an optimal concentration of CNT (0.25%) + GNP (0.25%). Furthermore, increasing CNT + GNP concentration leads to sharp changes in electrical resistivity of reinforced specimens under small variation of strain achieving high gauge factor in both flexural and compression loading modes.

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Section: Electrical Resistance Resultsmentioning

confidence: 80%

Section: Electrical Resistance Resultsmentioning

confidence: 99%

Ultra-Sensitive Affordable Cementitious Composite with High Mechanical and Microstructural Performances by Hybrid CNT/GNP

2020

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“…G.M. Kim [25] et al studied the effect of CNT dispersion and pore structure on their electrical properties. The results show that the addition of water reducer and silica fume greatly improve its electrical properties, but their mechanism of action is different: water reducer can reduce the van der Waals force between carbon nanotubes to achieve dispersion; silica fume refines the pore size.…”

Section: Introductionmentioning

confidence: 99%

Experimental Study on Mechanical and Functional Properties of Reduced Graphene Oxide/Cement Composites

Zhang

She

et al. 2020

Materials

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This study develops a novel self-sensing cement composite by simply mixing reduced graphene oxide (rGO) in cementitious material. The experimental results indicate that, owing to the excellent dispersion method, the nucleation and two-dimensional morphological effect of rGO optimizes the microstructure inside cement-based material. This would increase the electric conductivity, thermal property and self-induction system of cement material, making it much easier for cementitious material to better warn about impending damage. The use of rGO can improve the electric conductivity and electric shielding property of rGO-paste by 23% and 45%. The remarkable enhancement was that the voltage change rate of 1.00 wt.%-rGO paste under six-cycle loads increased from 4% to 12.6%, with strain sensitivity up to 363.10, without compromising the mechanical properties. The maximum compressive strength of the rGO-mortar can be increased from 55 MPa to 71 MPa. In conclusion, the research findings provide an effective strategy to functionalize cement materials by mixing rGO and to achieve the stronger electric shielding property and higher-pressure sensitivity of rGO–cement composites, leading to the development of a novel high strength self-sensing cement material with a flexural strength up to 49%.

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“…Kang et al [6] improved the strength by adding 0.1% CNTs to mixtures of cement and silica fume. Kim et al [7] focused on the thermal conductivity of CNT-embedded cementitious composites. Choi et al [8] reported that 1% of CNT addition enhanced the compressive strength by more than 50% compared to ordinary Portland cement (OPC).…”

Section: Introductionmentioning

confidence: 99%

Effects of CNT Dosages in Cement Composites on the Mechanical Properties and Hydration Reaction with Low Water-to-Binder Ratio

Jung

Kim

et al. 2019

Applied Sciences

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This study aimed to investigate the potential use of carbon nanotubes (CNTs), which are an innovative construction material preferred by many researchers. Long-term microstructure enhancement and on-site application are major reasons to conduct research on CNT-cement composites; thus, a study on mechanical properties as well as the thermal conductivity of CNT-cement composites was carried out. As the CNT content increased, the thermal conductivity of CNT-cement composites was also enhanced. In addition, a couple of microstructure analyses such as isothermal calorimetry, thermal gravimetric analysis and SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) for observing hydration reaction rate and types of hydration products were conducted to establish the advantage of CNT use in cement composites. Strength development of CNT-cement composites at early ages was slow, although eventually CNTs containing water developed equivalent level of strengths at last as internal curing effects.

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Influences of CNT dispersion and pore characteristics on the electrical performance of cementitious composites

Cited by 111 publications

References 41 publications

Ultra-Sensitive Affordable Cementitious Composite with High Mechanical and Microstructural Performances by Hybrid CNT/GNP

Ultra-Sensitive Affordable Cementitious Composite with High Mechanical and Microstructural Performances by Hybrid CNT/GNP

Experimental Study on Mechanical and Functional Properties of Reduced Graphene Oxide/Cement Composites

Effects of CNT Dosages in Cement Composites on the Mechanical Properties and Hydration Reaction with Low Water-to-Binder Ratio

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