Effect of graphene oxide as a nanomaterial on the bond behaviour of engineered cementitious composites by applying RSM modelling and optimization

A crucial aspect of the design approach for bar-reinforced concrete buildings is the proper transfer of loads between the concrete and steel reinforcement via bonding. Bar pull-out tests were done to see how graphene oxide (GO) affected the bond strength, bond energy, and bond stresseslip response of deformed reinforcing bars implanted in engineered cementitious composites (ECC). This was done to improve the bond strength of steel/concrete composites. This article examines the bonding behaviour of steel reinforcing bars in a mixture of GO-modified ECC. The findings of pull-out assessments conducted on two distinct diameters (12 and 16 mm) of reinforcement steel bar inserted in ECC are initially provided. The investigation's findings are then utilised to determine the bond-slip interactions that describes the relations between the ECC mixtures and steel reinforcement bars. According to the experiment results, the introduction of GO as a nano-reinforcement in the ECC mixture had a considerable positive effect on the bar-matrix interactions owing to its bridging function. After 28 days, the bond strength of steel bars with widths of 12 and 16 mm was increased by 54.80% and 26.70%, respectively, when 0.05 wt% of GO was added to 1% of PVA fibre. The response surface methodology (RSM) is employed for developing predictive algorithms, which are then utilised in performing multi-variate optimization on bond-slip parameters, including bond strength, bond slip and bond energy. The acquired actual and predicted findings suggest that the created models are adequate for interpreting the bond performance of reinforcement steel bars in the GO-ECC. (c) 2023 The Author(s). Published by Elsevier B.V.