Long-term properties of bond between concrete and FRP

Results of an experimental campaign concerning long-term behavior of bond of FRP plates bonded to concrete are presented. CFRP plates with three different bonded lengths (from 100 mm to 400 mm) have been subject to long term loads by using a mechanical system able to apply a constant traction force. Tests have been carried out in a climatic room with a constant temperature Τ = 20°C and humidity RH = 60%. Strain profile evolution with time along the bonded length have been recorded by using a number of strain gages placed along the plates. An appreciable stress redistribution with time along the plate has been observed. A simplified visco-elastic analytical model has been finally used to reproduce experimental findings. Good matching between experimental and numerical data has been found.