Axial stress strain behavior of FRP-confined rectangular rubber concrete columns with different aspect ratio

Abstract

At present, the mechanical properties of FRP-confined rectangular rubber concrete columns have not been studied. To fill this gap, thirty-six concrete columns were prepared and tested under axial compression in this study. The effects of the aspect ratio (1, 1.25 and 1.5), rubber volume replacement ratios of fine aggregates (0 %, 40 % and 60 %) and FRP layer number (2 and 3) on the failure state and stress–strain relationship were investigated. The test results showed that with increasing section aspect ratio and rubber volume replacement ratio, the damage zone of the specimen increased, and the compressive strength decreased. As the number of FRP layers increasing, the damage zone and compressive strength of the specimens both showed an upward trend. Based on the test results, the stress–strain model, compressive strength model and ultimate strain model of FRP-confined rubber concrete columns were proposed. The proposed models can accurately predict the stress–strain relationship, compressive strength and ultimate strain of FRP-confined rectangular rubber concrete.