This study reports the findings of an experimental investigation into the behaviour of an inclined shear plane in reinforced concrete, such as a diagonal crack in the web of a beam, strengthened with externally bonded Carbon Fibre Reinforced Polymer (CFRP) fabric. A modified push-off test of novel geometry was developed for this study. This test generates a diagonal failure plane subject to combined shear and tension. Both unwrapped and wrapped tests were conducted, allowing the load sharing and load displacement behaviour of the reinforced concrete, and the reinforced concrete with externally bonded CFRP fabric, to be investigated. Fully wrapped and U-wrapped CFRP fabric configurations were tested. Results indicate that for the arrangement tested, concrete, steel and CFRP contributions to resistance are not independent, and that effective anchorage lengths given in the UK and US guidance for U-wrapped CFRP may not be adequate in some cases.