• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.80-83
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• 2004

The FRP plate or sheet bonding technology was widely used for strengthening deficient RC structures. The strengthened structure using FRP bonding scheme, however, experience the complex interfacial behaviour which is difficult to predict. Therefore, the unbonded scheme using some anchorage device can be is an alternative for more reliable design. In this study, wedge-type anchor for FRP plate is developed for the unbonded flexural strengthening scheme. Some parameter study using 2D finite element method is performed. The analysis parameters are taken as wedge-guide friction coefficients, wedge- FRP ,.friction coefficient and wedge inclination angle. Based on the parameter study, more efficient anchors are designed and tested. The test result show that the developed anchor assure about $80\%$ FRP strength, which is higher performance than typical bonding scheme. Last, 3D finite element analysis is performed.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.5 s.57
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• pp.169-179
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• 2009

The purpose of this paper is to find an efficient heat source to amplify the surface temperature of damaged concrete structures for infrared thermography. we compare two different heat sources of far-infrared lamp and halogen lamp each other for their efficiency. The two heat sources were applied to the concrete specimens. Two different concrete specimens were used: one was the concrete containing internal void and the other was wrapped with partially unbonded fiber reinforced polymer sheet. it was found that the far-infrared lamp was more efficient than the halogen lamp. In addition, we propose a new algorithm to make the damage zone displayed clear in the image obtained from the thermographic operation. The algorithm is a combination of Gauss filtering process and the Prewitt mask operation.