Performance of RC beams rehabilitated with NSM CFRP strips using innovative high-strength self-compacting cementitious adhesive (IHSSC-CA) made with graphene oxide

This paper presents the results of an experimental study of near-surface mounted (NSM) carbon fibre reinforced polymer (CFRP)-repaired and strengthened reinforced concrete (RC) beams with innovative high-strength self-compacting cementitious adhesive (IHSSC-CA), with the particular objective of improving the ductility. Graphene oxide and cementitious materials were used to synthesise the IHSSC-CA. An analytical model is developed to predict the maximum tensile strain in NSM CFRP strips based on the experimental results. ACI 440.2R-08 guide was used to calculate the ultimate flexural capacity of the tested specimens based on the predicted tensile strain in NSM CFRP strips. The test results confirm the effectiveness of using IHSSC-CA to improve the flexural strength, CFRP strip utilisation, stiffness, residual strength and ductility of RC beams repaired and strengthened with NSM CFRP strips. Moreover, the statistical model proposed to predict the maximum tensile strain in CFRP strips has good agreement with the experimental results and can be used in the design of NSM CFRP-repaired and strengthened RC members with cement-based (IHSSC-CA) and epoxy adhesives. Furthermore, the ultimate flexural capacity of the repaired and strengthened RC beams using NSM CFRP strips with cement-based (IHSSC-CA) and epoxy adhesives can be predicted adequately using the ACI 440.2R-08.