Data-oriented analysis of axial capacity of externally CFRP-confined concrete columns transversely reinforced with steel hoops or spirals

Limited research is available in the literature for exploring the axial compressive behavior of circular concrete columns confined by both external CFRP wraps and internal transverse steel reinforcement (SCC columns). The main objective of the present work is to develop an empirical model and an analytical model for predicting the axial compressive strength of SCC columns by considering the interaction between the CFRP composite and steel reinforcement confinement action. An extensive experimental database of 76 SCC columns has been developed from the literature work. A general regression analysis method and curve-fitting techniques on the experimental test results of SCC columns are used for developing the new empirical model. The confinement mechanics-based analytical model has also been suggested by considering the influence of CFRP and transverse steel confinement. The comparative study solidly substantiated the superiority of the proposed empirical model over the proposed analytical model and the previous models with R-2 =0.892, RMSE=12.83, and MAE=9.78. A parametric study is also performed using the proposed empirical strength model to examine the effect of different parameters of SCC columns confined by both CFRP and transverse steel.