Deformation in Concrete with External CFRP Sheet Reinforcement

This is the authors' abstract. We don't add key points for this paper.

A detailed experimental investigation of local and global deformations of tensile-loaded, cracked, rectangular, concrete prisms reinforced with externally bonded carbon fiber reinforced polymer (CFRP) sheets was carried out. High and low modulus sheets were applied using three different thicknesses of epoxy interlayer between the sheet and concrete. It was found that the stiffness of the CFRP sheet had a dominant effect on global tension stiffening, whereas interlayer thickness had a dominant effect on local load transfer and damage formation. Thicker interlayers transferred load into through-cracked concrete over longer transfer zones, thereby increasing the spacing of subsequent cracks in the concrete. The combined effect on global stiffness of changes in transfer zones and crack spacing due to interlayer thickness was negligible. Increasing the stiffness of the CFRP sheet resulted in considerably increased global tension stiffening. Full field strain measurements by moiré interferometry revealed detailed information about local load transfer in the CFRP sheet, epoxy interlayer, and concrete in the vicinity of cracks.