Abstract: Externally bonded fibre reinforced polymer (FRP) retrofits for reinforced concrete elements provide an efficient, economical and accepted method of improving structural performance.
A large volume of research has been conducted on FRP retrofitted structures under static and quasi-static loads. Previous research has resulted in the publication of numerous retrofit design methodologies, including those outlined in ACI 440 (2008) and CSA S806-02 (2007) documents. However, only a limited number of publications address the issue of designing FRP retrofit systems to resist blast induced impulsive loads.
A comprehensive research program has been underway at the University of Ottawa to develop FRP retrofit methodologies for structural and non-structural elements. Simulated blast testing of as-built and FRP retrofitted reinforced concrete wall panels were performed using the University of Ottawa’s Shock Tube. The test program resulted in a large volume of research data for the development of blast-resistant design guidelines. This paper is aimed at highlighting some of the challenges associated with the use of FRPs as a blast retrofit material.
Test results indicate that FRP retrofitted reinforced concrete wall panels may survive initial inbound displacements, only to fail by moment reversals during the negative displacement phase, unless retrofitted on both sides. They also indicate that the increase in flexural stiffness due to the application of FRP, relative to that associated with shear distress, may result in shear failures. A discussion on the increased likelihood of blast-induced shear failures in FRP retrofitted elements will be highlighted. The paper will provide guidance for improved design of FRPs in protecting reinforced concrete walls against blast-induced shock waves.