Bonding carbon-fibre plates to highway structures in winter: a case study

The operational life of a 1960s reinforced concrete interchange on Britain's M5 motorway was successfully extended with carbon-fibre plates 2 years ago. The structure had previously been strengthened in the 1970s by an externally bonded steel plate system, but this had reached the end of its serviceable life. This paper describes the many challenges faced during the design of a replacement carbon-fibre plate system, given the needs for minimum disruption and maximum adhesion. Innovative solutions led to achievements such as maintaining live load conditions throughout works and ensuring the plates were securely bonded in winter conditions with low temperatures. The paper then demonstrates how early contractor involvement helped to deliver the most efficient, effective, sustainable and safest solution on time and to budget.