Investigation into bond behaviour of a new CFRP anchorage system for concrete utilising a mechanically strengthened substrate

Failure of CFRP strengthening systems when applied to concrete structures is usually typified by de-lamination of the CFRP from the concrete substrate. To prevent this type of failure, current standards and design guidelines impose strict limitations on the maximum strain level of the composite material which may be utilised in design. Emerging research has shown that anchoring the ends of the CFRP plates or sheets can result in a significantly higher load/stress being reached before de-bonding occurs. This paper investigates a method of anchoring CFRP laminates by utilisation of a mechanical chase cut into the concrete over the anchorage length. Experiments have shown this to be an effective way to improve the strength of the concrete substrate, resulting in higher CFRP bond strength and improvements in maximum elongations, bond stress, slip and load carrying capacity of the CFRP to concrete joint.