• Composites Research
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• v.25 no.6
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• pp.205-210
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• 2012

The single carbon fiber tensile test was performed with electrical resistance measurement. Tensile property of single carbon fiber which accompanied by the relationship between the electric resistance and the strain was investigated. Since the collected data showed a linear relationship between them, the coefficient of fiber slip ratio (FSR) was obtained by computation. The fragmentation specimen (FS) was tested under tensile loading, and the single carbon fiber broke first due to the stress transferring form matrix to reinforcing fiber. The stress distribution of carbon fiber could be observed via the electrical resistance change. Slipping between carbon fiber and matrix was predicted based on the fragmentation test results, and the FSR was used to evaluate interfacial adhesion comparatively. The large FSR indicated poor interfacial bonding. Work of adhesion between carbon fiber and matrix was measured to verify the FSR method, and two results exhibited a consistent conclusion.

• Journal of the Korea Concrete Institute
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• v.20 no.3
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• pp.383-391
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• 2008

The effects of concrete strength on bond-slip behavior and the failure mechanisms of glass fiber reinforced polymer (GFRP) bar embedded in concrete under direct pullout were investigated in this study. Total of twenty seven specimens were prepared by placing two different types of GFRP bars and conventional steel rebar in 25 MPa, 55 MPa, and 75 MPa concrete and tested according to CSA S806-02. The test results showed that the bond strength of the GFRP rebars as well as the steel increased with the concrete strength. However, the increase in the bond strength with respect to the concrete strength was not as significant in the GFRP series as the steel, and it was attributed to the interlaminar failure mechanism observed in the GFRP test specimens.