Protection of RC elements strengthened with CFRP against high temperatures

Abstract

The strengthening of RC elements with CFRP is a technique that has been acquiring more and more potential. The bond between the CFRP laminates and the concrete support is usually made with epoxy adhesives. However, it is in this part that the integrity of the system can be affected, namely by exposure to high temperatures. In order to evaluate the thermal behaviour, reference RC and CFRP strengthened RC specimens were tested. After cyclical thermal expositions, with temperatures rising between 20ºC and 80ºC, specimens were subjected to flexural tests. The results demonstrated that the thermal resistance of this strengthened system can not be considered very high. There is a need to find solutions to avoid temperatures near the thermal resistance of the epoxy adhesive. The use of insulation materials can be a good solution to protect the strengthened RC elements. Among tested materials the foamed polyurethane showed the best behaviour.