Effect of Shear Key and Edge Length of Near Surface-Mounted FRP Plate in Concrete

Title & Authors
Effect of Shear Key and Edge Length of Near Surface-Mounted FRP Plate in Concrete
Seo, Soo-Yeon;

Abstract
This paper presents a bond test to find the effect of shear key and edge length from the bonded FRP in near surface-mounted(NSM) retrofit using FRP plate. Main parameters in the test are the location and size of shear key and the edge length. For the test, 10 specimens were made by embedding FRP plate of $\small{3.6mm{\times}16mm}$ into $\small{400mm{\times}200(300)mm{\times}400mm}$ concrete block and fixing it by using epoxy. Tensile load was applied to the FRP of the specimens until failure and was recorded at each load increase. In addition, the bond slip and elongation of FRP were measured during the test. From the test, it was found that the further the shear key located from the loading, the higher strength we could get. The bond strength inversely depended on the size of shear key. Especially, when the size of shear key was to be lagger than certain size, the bond strength decreased to very low value; even less than that of the case without shear key. The bond strength somewhat increased corresponding to the increase of edge length from the bonded end of FRP to loading in spite of same bond length. The bond-slip between FRP and concrete governed overall deformation in the bond test of NSM FRP so that the effect of excessive slip is necessary to be considered in the design.
Keywords
Bond test;Shear key;Edge length;Near surface-mounted retrofit;FRP plate;Location and size;Bond slip;
Language
Korean
Cited by
References
1.
Ali, M., Oehlers, D., Friffith,, M.C., and Seracino R. (2008), Interfacial Stress Transfer of Near Surface-Mounted FRP-to-Concrete Joints, Engineering Structures, 30, 1861-1868.

2.
Blaschko, M. (2013), Bond Behavior of CFRP Strips Glued Into Slits", Proceeding, 6th International Symposium on FRPRCS, Singapore, 203-214.

3.
Ceroni, F. et. al. (2010), Modeling of Tension Stiffening Behavior of RC Ties Strengtened with FRP Sheets, Journal of Composite Construction, ASCE, 8(6), 510-518.

4.
Chung, W.T. (2009), Flexural Behavior of Reinforced Concrete Beams Strengthened with NSM CFRP Reinforcements Considering the Equivalent Section, Doctoral Thesis in Civil and Environmental Engineering, Myongji University, 57-221.

5.
Lim, D.H. (2008), An Experimental Study on the Flexural Behavior of RC Beams Strengthened with NSM and EBR CFRP Strips, Journal of the Korea Concrete Institute, 20(5), 601-609.

6.
Seo, S., Feo, L., and Hui, D. (2013(a)), Bond Strength of Near-Surface-Mounted FRP Plate for Retrofit of Concrete Structures, Composite Structures, 95, 719-727,

7.
Seo, S.Y., Choi, K.B., and Kwon, Y.S. (2012), Retrofit Capacity of Near-Surface-Mounted RC Beam by using FRP Plate, Journal of the Korea Institute for Structural Maintenance and Inspection, 16(1), 18-26 .

8.
Seo, S.Y., and Kim, M.S. (2013(b)), Bond Strength of Near-Surface-Mounted FRP Plate in Concrete Corresponding to Space and Bond Length, Journal of the Korea Concrete Institute, 25(1), 37-43.

9.
Seo, S.Y (2014), Analysis on the Interfacial Bond-Slip Relationship between Near Surface-Mounted FRP Plate and Concrete, Journal of the Korea Concrete Institute, 26(1), 79-86.

10.
Seo, S.Y., Yoon, S.J. Kwon, Y.S., and Choi, K.B. (2011), Bond Behavior between Near-Surface- Mounted Fiber Reinforced Polymer Plates and Concrete in Structural Strengthening, Journal of the Korea Concrete Institute, 23(5), 675-682.

11.
Seracino, R., Jones, N., Ali, M., Page, M., and Oehlers, D. (2007), Bond Strength of Near-Surface Mounted FRP Strip-to-Concrete Joints, Journal of Composites for Construction, ASCE, 11(4), 401-409.