Behavior of steel fibers reinforced self-stressing and self-compacting concrete-filled steel tube subjected to bending

This paper described an experimental work for steel fibers reinforced self-stressing and self-compacting concrete-filled steel tube (FSSCFST) specimens subjected to bending. The study aimed to evaluate the effect of self-stress and steel fibers on the behavior of self-compacting concrete filled steel tube (SCCFST) specimens. Twenty-seven SCCFST specimens reinforced with steel fibers, self-stress or their couple were tested under bending. The variables considered in the test were self-stress, thickness of steel tube, concrete strength and steel fiber volume percentage. Experimental results showed that the FSSCFST specimens behaved in a relatively ductile manner, but steel fibers and self-stress failed to change the failure mode of CFST specimens. Self-stress can slightly increase the flexural capacity and lead to a higher flexural rigidity. Steel fibers can lengthen the elastic stage and improve the flexural capacity of FSSCFST specimens. This beneficial effect of steel fibers decreased with the increasing of steel tube thickness. A formula was proposed to predict the flexural capacity of FSSCFST specimens, and the comparison between predictions and experiment results proved the accuracy of the formula. (C) 2017 Published by Elsevier Ltd.