Activation energy and conduction in carbon fibre reinforced cement matrices

McCarter, William John; Starrs, G.; Chrisp, T. M.; Banfill, Phillip Frank Gower

doi:10.1007/s10853-007-1517-x

Cited by 34 publications

(21 citation statements)

References 13 publications

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“…Few researchers have evaluated the effect of temperature on the sensing behavior and the electrical resistivity of SSC. McCarter et al [ 57 ] investigated the impact of the temperature from 10 °C to 60 °C on the plain cement mortar and the cement mortar containing carbon fibers. The results presented in Figure 11 a,b show that the resistivity of both mixtures declined with the rise in temperature.…”

Section: Sensing Properties Of Self-sensing Concretementioning

confidence: 99%

Self-Sensing Cementitious Composites: Review and Perspective

2021

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Self-sensing concrete (SSC) has been vastly studied for its possibility to provide a cost-effective solution for structural health monitoring of concrete structures, rendering it very attractive in real-life applications. In this review paper, comprehensive information about the components of self-sensing concrete, dispersion methods and mix design, as well as the recent progress in the field of self-sensing concrete, has been provided. The information and recent research findings about self-sensing materials for smart composites, their properties, measurement of self-sensing signal and the behavior of self-sensing concrete under different loading conditions are included. Factors influencing the electrical resistance of self-sensitive concrete such as dry-wet cycle, ice formation and freeze thaw cycle and current frequency, etc., which were not covered by previous review papers on self-sensing concrete, are discussed in detail. Finally, major emphasis is placed on the application of self-sensing technology in existing and new structures.

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Section: Sensing Properties Of Self-sensing Concretementioning

confidence: 99%

Self-Sensing Cementitious Composites: Review and Perspective

2021

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“…The glossy surfaces and weak bond of graphite particles could be a reason of strength drop [6]. However, the carbon fiber improves compressive strength as its benefit on mechanical properties is generally known [7]. Moreover, the above mentioned influences of water, graphite powder, and carbon fiber on the compressive strength were directly proportionate to the amount added.…”

Section: Compressive Strengthmentioning

confidence: 99%

Effect of Carbon Fiber and Graphite Powder on Resistivity of Cement-based Sensor under Compression

2014

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Structural health monitoring currently becomes an important part in the maintenance of concrete structures. Thus, using of sensors to monitor the structural behavior is necessary. Cement-based sensors have been developed recently to be embeddable in structures and to be implemented by measuring the change in their resistivity. In this research, the electrical resistivity and compressive strength of the cement-based sensors with the addition of carbon fiber (2% and 4% by volume fraction) and graphite powder (2%, 4%, and 10% by weight of cement) were studied. Three water to binder ratios (w/b) that are 0.3, 0.4 and 0.5 were varied. For 28 days after demolding, the resistivity of the non-load-bearing sensors was monitored to determine the influence of their maturity. At the age of 28 days, their compressive strength was evaluated. Subsequently, the fractional change in resistivity (FCR) of the sensors was measured under a set of compressive loading, which comprised of three cycles of loading; first loading to the strain of 0.0025, then to 0.005 and 0.01. From the test results, it is showed that the carbon fiber was more favorable than the graphite powder. Although the addition of graphite powder could reduce the resistivity, it dropped the compressive strength and highly fluctuated the resistivity results of the cement-based sensors. In term of the piezoresistivity, all of the sensors when loaded provided good responses only when the compressive strain was less than 0.005.

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“…The resistivity of graphite fibers decreases with elevated temperature as is typical for semiconductors. [28][29][30][31] Thus, the composite is expected to have a negative coefficient of resistivity in the fiber direction because the thermal expansion is negligible, due to the small thermal expansion coefficient of graphite fibers. However, the properties in the transverse direction have to include the thermal expansion of polymer, which might decrease the contacts between neighboring graphite fibers and increase the resistivity.…”

Section: Dependency Of Electrical Resistance On Temperature Changementioning

confidence: 99%

Investigation of temperature dependency of electrical resistance changes for structural management of graphite/polymer composite

Takahashi

Hahn

2011

Journal of Composite Materials

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This article investigates the dependency of electrical resistance on temperature for graphite/polymer composites. The electrical resistance change of a unidirectional laminate is measured with elevated temperature in the fiber, transverse and through-thickness directions. Because of the properties of graphite fibers, the electrical resistance decreases as temperature increases in any direction. The activation energy is calculated from an Arrhenius plot to evaluate the difference among the different directions. The activation energy is the lowest in the fiber direction due to the high electrical conductivity of graphite fibers. Since electric current flows thorough the contacts between neighboring graphite fibers, similar activation energies are required in the transverse and through-thickness directions, indicating transversely isotropic properties. These characteristics will be used to establish the relationship between electrical resistance outputs and structural conditions, and will be eventually applied to an in-service structural management system using addressable conducting network, which is a grid arrangement of conducting lines on a composite panel.

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Activation energy and conduction in carbon fibre reinforced cement matrices

Cited by 34 publications

References 13 publications

Self-Sensing Cementitious Composites: Review and Perspective

Self-Sensing Cementitious Composites: Review and Perspective

Effect of Carbon Fiber and Graphite Powder on Resistivity of Cement-based Sensor under Compression

Investigation of temperature dependency of electrical resistance changes for structural management of graphite/polymer composite

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