Strengthening of Reinforced Concrete (RC) structures with externally bonded Fibre Reinforced Polymer (FRP) reinforcement has become increasingly popular in the construction industry last two decades. Failure of the FRP strengthening is generally initiated by debonding of the FRP reinforcement from the concrete surface. It is expected that temperature will affect this debonding behaviour due to the significant difference in the coefficient of thermal expansion between concrete and FRP and due to the change of the material properties at elevated temperatures, especially of the adhesive. This paper presents the results of an experimental investigation into the effect of temperature on the strengthening of reinforced concrete beams with externally bonded Carbon Fibre Reinforced Polymer (CFRP) reinforcement. Four different beam configurations have been investigated, each at 20°C, 50°C and 70°C. Test results have shown that, compared to room temperature, the type of failure and the failure load of the beams tested at 50°C were not significantly affected. At 70°C, the type of failure changed for one of the beams from failure in the concrete adjacent to the concreteadhesive interface to failure exactly in the concrete-adhesive interface. The failure loads of the beams tested at 70°C were not significantly affected compared to room temperature, except for the beam with a relatively short laminate length. For this beam, the load capacity is

Synopsis: Synopsis: Synopsis: Synopsis: Synopsis: Fiber Reinforced Polymers have proven to be effective strengthening materials in the construction industry, due to their low weight (easy to apply), non- corrosiveness and high strength. Extensive research has been carried out into the strengthening of concrete structures with externally bonded FRP. It turned out that debonding of the FRP is governing the design of most FRP strengthening applications. One of the parameters, which may affect the bond properties of the FRP-concrete joint, is the ambient temperature. Only little research into the influence of temperature on the bond behavior has been carried out so far. This paper presents the results of an exploratory experimental and numerical investigation in which the influence of temperature on the debonding behavior of externally bonded CFRP was investigated. Two different test setups were applied. Results showed that the failure load of CFRP strengthened concrete structures was affected by the temperature, but depended on the used test setup. Two types of failure were observed. For low to moderate temperatures (-10°C to +40°C), failure occurred in the concrete, leaving 1-3 mm of concrete attached to the adhesive. For elevated temperatures (50°C to 75°C), failure of the adhesive-concrete interface occurred, without leaving any concrete attached to the adhesive.