The utilisation of carbon fibre–reinforced polymers (CFRPs) has emerged as a promising method for enhancing the flexural performance of reinforced-concrete (RC) bridges. While extensive research has been conducted on CFRP systems implemented on flat soffit RC beams, further work is required to assess their effectiveness when applied to concavely curved soffit RC members. This paper uses finite element simulations to extend an experimental database on RC beams with curved soffits ranging from 5, 10, 15 and 20 mm/m strengthened using externally bonded FRP. Parametric studies into four different concrete strengths ranging from 25, 35, 48, 57 MPa and additional degrees of soffit curvature up to 50 mm/m were used to generate a total of 88 data points. Further, gene expression programming (GEP) was used to develop an empirical model correlating a capacity reduction factor applied to the maximum FRP strain required to produce intermediate-span crack-induced (IC) debonding for concavely curved soffit RC beams externally strengthened with CFRP. The results of the GEP model demonstrated that the model can be employed as an efficient tool for the prediction of the reduction in the flexural capacity of concavely curved soffit RC beams strengthened externally with NSM CFRP.
