Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 31106
Experimental Investigation on the Effect of Bond Thickness on the Interface Behaviour of Fibre Reinforced Polymer Sheet Bonded to Timber

Authors: Abbas Vahedian, Rijun Shrestha, Keith Crews


The bond mechanism between timber and fibre reinforced polymer (FRP) is relatively complex and is influenced by a number of variables including bond thickness, bond width, bond length, material properties, and geometries. This study investigates the influence of bond thickness on the behaviour of interface, failure mode, and bond strength of externally bonded FRP-to-timber interface. In the present study, 106 single shear joint specimens have been investigated. Experiment results showed that higher layers of FRP increase the ultimate load carrying capacity of interface; conversely, such increase led to decrease the slip of interface. Moreover, samples with more layers of FRPs may fail in a brittle manner without noticeable warning that collapse is imminent.

Keywords: FRP, single shear test, bond thickness, bond strength

Digital Object Identifier (DOI):

Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 395


[1] Rescalvo, F. J., et al., Experimental and analytical analysis for bending load capacity of old timber beams with defects when reinforced with carbon fiber strips. Composite Structures, 2018. 186: p. 29-38.
[2] Hollaway, L. C., A review of the present and future utilisation of FRP composites in the civil infrastructure with reference to their important in-service properties. Construction and Building Materials, 2010. 24(12): p. 2419-2445.
[3] Bedon, C. and C. Louter, Numerical analysis of glass-FRP posttensioned beams–review and assessment. Composite Structures, 2017. 177: p. 129-140.
[4] Bedon, C. and C. Louter, Numerical investigation on structural glass beams with GFRP-embedded rods, including effects of pre-stress. Composite Structures, 2018. 184: p. 650-661.
[5] Cao, S., et al., ESPI measurement of bond-slip relationships of FRPconcrete interface. Journal of Composites for Construction, 2007. 11(2): p. 149-160.
[6] Mazzotti, C., et al., An experimental study on delamination of FRP plates bonded to concrete. Construction and Building Materials, 2008. 22(7): p. 1409-1421.
[7] Nakaba, K., et al., Bond behavior between fiber-reinforced polymer laminates and concrete. ACI Structural Journal, 2001. 98(3).
[8] Aram, M. R., et al., Debonding failure modes of flexural FRPstrengthened RC beams. Composites part B: engineering, 2008. 39(5): p. 826-841.
[9] Dai, J., et al., Unified analytical approaches for determining shear bond characteristics of FRP-concrete interfaces through pullout tests. Journal of Advanced Concrete Technology, 2006. 4(1): p. 133-145.
[10] Ferracuti, B., et al., Interface law for FRP–concrete delamination. Composite structures, 2007. 80(4): p. 523-531.
[11] Vahedian, A., et al., Effective bond length and bond behaviour of FRP externally bonded to timber. Construction and Building Materials, 2017. 151: p. 742-754.
[12] Vahedian, A., et al. Timber Type Effect on Bond Strength of FRP Externally Bonded Timber. in World Conference on Timber Engineering. 2018.
[13] Vahedian, A., et al. Width effect of FRP externally bonded to timber. in 9th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE 2018). 2018.
[14] BS_EN_408, Timber structures - structural timber and glued laminated timber - determination of some physical and mechanical properties, in BS EN 408:2010. 2010, British Standards Institution: London, UK.
[15] ASTM-D3039/D3039M, Standard test method for tensile properties of polymer matrix composite materials, in American Society for Testing and Materials. 2014, West Conshohocken, PA: USA.
[16] Vahedian, A., et al., Analysis of externally bonded Carbon Fibre Reinforced Polymers sheet to timber interface. Composite Structures, 2018. 191.
[17] Bizindavyi, L. and K. Neale, Transfer lengths and bond strengths for composites bonded to concrete. Journal of composites for construction, 1999. 3(4): p. 153-160.