The encasement of recycled aggregate concrete (RAC) in the steel tube supplies a convenient way to utilize RAC in vertical-load carrying elements, namely, recycled aggregate concrete filled steel tubular (RACFST) columns. This research intends to study the effect of geometrical and material properties of RACFST columns and also provide an empirical model for the evaluation of axial compressive strength of the columns having various recycled coarse aggregate replacement ratios up to 100%. To this, the experimental results of the columns tested in concentric compression were employed for training and testing the developed model as well as for assessing the accuracy and applicability of the available formulations of EC4 and GJB. Besides, the parameters of the experimental data were determined based on the local slenderness and strength limits. For the generation of axial compression strength prediction model, a soft-computing based technique was utilized. The independent variables accounted for the model development were the columns’ outer depth and width, steel tubes’ thickness and yield strength, column length, recycled coarse aggregate replacement ratio and infilled RAC compressive strength. The effectiveness of these parameters was assessed by the principal component analysis. Besides, a sensitive statistical analysis was conducted to validate the efficiency of the proposed model. The results clearly revealed that the proposed model had better prediction performance, yielding about 7% mean absolute percent error, as compared to those of the existing formulations.
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