Bond stress versus slip model for CFRP plates bonded to concrete

Document Type

Conference publication

Publication details

Loo, MKY, Foster, SJ & Smith, ST 2007, 'Bond stress versus slip model for CFRP plates bonded to concrete', in ST Smith (ed.), Proceedings of the first Asia-pacific conference on FRP in structures: APFIS 2007, Hong Kong, China, 12-14 December, Department of Civil Engineering, Hong Kong University, Hong Kong, pp. 709-716. ISBN: 9789628014149.


Bond stress versus slip properties of externally bonded carbon fibre reinforced polymer (CFRP) used in repair and strengthening is fundamental input in any numerical or design model. The tests needed to obtain such data, however, are expensive in time of preparation and in the processing of the strain information collected. Previously, Foster and Khomwan (2005) had proposed a model where both the ultimate load and effective bond length are required for calculation of the bond-stress versus slip relationship for externally bonded FRPs. Based on finite element analysis results, a new relationship for the bond strength and effective bond length is presented for CFRP bonded plates. The finite element results show that the effective length is significantly influenced by the concrete compressive strength and, to a much lesser extent, the FRP stiffness and adhesive shear modulus.