Temperature In The Adhesive Layer of Externally Bonded Composite Reinforcement Heated By The Sun

The paper describes the measurements of temperature growth in different types of the epoxy adhesive bonding external strengthening. A total of six types of models were tested: CFRP sheet and strip, two SRP tapes adhered to the concrete sample, CFRP strip and SRP tape on a timber sample. Changes in temperature were investigated during the summer in the southern Poland. The maximum measured temperatures for all models exceeded regarded as safe temperature limit of 45°C. The highest recorded adhesive temperature refers to a sample of CFRP strengthened timber and exceeded 70°C. For the structure such a high temperature may result in almost complete loss of adhesion and thus the efficiency of strengthening. Test results may be a warning against the use of FRP external strengthening exposed to direct sunlight without any protection.