Debonding of external CFRP plates from RC structures caused by cyclic loading effects

Author(s): A.J. Badenhorst, G.P.A.G. van Zijl
Paper category: Conference
Book title: Concrete Repair, Rehabilitation and Retrofitting III (ICCRRR)
Editor(s): M.G. Alexander, H.-D. Beushausen, F. Dehn, P. Moyo
Print ISBN: 978-0-415-89952-9
Publisher: Taylor & Francis Group
Pages: 453- 454
Total Pages: 2
Language: English

Abstract: 
The delamination of Carbon Fibre Reinforced Polymer (CFRP) from Reinforced Concrete (RC) subjected to cyclic loading under various loading amplitudes is reported here. A RC model in the shape of an inverse T-section was designed for this purpose. It was pre-cracked and subsequently reinforced with a 50mm wide CFRP strip. Upon curing, the T-section was tested by bolting its lower end to the loading plate of a materials testing machine, and gripping the CFRP strip at the upper end. The eccentricity of the CFRP caused a combined tensile axial force and a bending moment in the RC specimen, simulating debonding of the CFRP strip from a RC member under bending and tension. The debonding of the CFRP strip in the vicinity of the crack was observed. Monotonic pull-off tests were done to determine the failure envelope. Cyclic experiments followed at 85% and 65% of the peak pull-off load. The experimental results were compared to two dimensional plane stress Finite Element Analyses (FEA) of the same section, with careful simulation of boundary conditions, geometry and at the bonded interface with a suitable constitutive model, calibrated by triplet shear test data. The FEA results proved to represent the experimental results reasonably, justifying the use of the model to analyse responses to cyclic loading at 75%, 55% and 45% of the peak pull-off load. From the data conclusions can be drawn on initiation of delamination, delamination rate, and final unstable, near-instantaneous pull-off, both as function of the load level and number of cycles.

Online publication: 2014
Publication Type: abstract_only
Public price (Euros): 0.00