Fracture Criterion for Carbon Fiber Reinforced Polymer Sheet to Concrete Interface Subjected to Coupled Pull-Out and Push-Off Actions

• Published in: Advances in Structural Engineering Vol. 12; no. 5; pp. 663 - 682
• Main Authors: Dai, Jian-Guo, Wan, Bao-Lin, Yokota, Hiroshi, Ueda, Tamon
• Format: Journal Article
• Language: English; Japanese
• Published: London, England SAGE Publications 01.10.2009
• Subjects: concrete; critical strain energy release rate; Fiber reinforced polymer; mode I; fracture criterion; interface; mode II; mixed-mode
• ISSN: 1369-4332; 2048-4011
• DOI: 10.1260/136943309789867917

Flexural strengthening of reinforced concrete (RC) beams using externally bonded fiber reinforced polymer (FRP) sheet is a popular application nowadays. In this application, the FRP to concrete bond interface is typically exposed to a mixed-mode loading condition at the vicinity of a critical flexural/shear crack, which includes a pull-out action parallel to the interface and introduced by the opening displacement of the flexural/shear crack together with a push-off action perpendicular to the interface and introduced by the shear sliding displacement of the flexural/shear crack. This paper presents an experimental program to evaluate the fracture properties of the FRP to concrete interface under the coupled pull-out (mode II) and push-off (mode I) loading condition. An analytical model was developed to evaluate the mode I and mode II strain energy release rates and the corresponding fracture mechanisms of the FRP to concrete interface under a pure bending action, a pure dowel action, and the coupled action of both, respectively. The reliability of the proposed analytical model was verified in comparison with the experimental results.