Behaviour of FRP-confined compound concrete–filled circular thin steel tubes under axial compression

Abstract

This article presents test results of a recent study on the axial compressive behaviour of fibre-reinforced polymer–confined compound concrete–filled thin steel tubes. The usage of compound concrete, which is a mixture of fresh concrete and large pieces of recycled concrete lumps, can recycle waste concrete in a simple but effective way. Totally, three series of tests were conducted, with the parameters including the relative strength between fresh concrete and recycled concrete lumps, the volumetric percentage (i.e. mix ratio) of recycled concrete lumps, the diameter-to-thickness ratio of the steel tubes, and the thickness of the fibre-reinforced polymer jackets being investigated. The stress–strain curves of the steel tube and compound concrete core were derived and the effects of different parameters were then examined and discussed. An existing stress–strain curve model of fibre-reinforced polymer–confined normal concrete-filled steel tubes was also found performing well in predicting the behaviour of fibre-reinforced polymer–confined compound concrete-filled steel tubes.

Circular hybrid double-skin tubular columns with a stiffener-reinforced steel inner tube and a large-rupture-strain FRP outer tube: Compressive behavior

“…Fiber reinforced polymer (FRP) composites have been widely adopted as a type of confining material for concrete in structural engineering in the past two decades because of its structural advantages such as high strength, low density, excellent corrosion resistance and ease in construction [e.g., [1][2][3][4][5][6][7][8][9]. In addition to its most popular application of being used as externally bonded reinforcement in structural retrofitting industry, the use of FRP in new buildings and constructions has become increasingly popular in last decade [e.g., 6,[10][11][12][13][14][15][16][17][18][19].…”

Axial monotonic and cyclic compressive behavior of square GFRP tube–confined steel-reinforced concrete composite columns

“…The results testified that the ultimate compressive strength and failure strain could be greatly improved. There is abundant literature on this subject that (He and Chen, 2019; Wei et al, 2014; Xie et al, 2017; Xue and Gong, 2016; Yu et al, 2016; Zeng et al, 2020; Zhao et al, 2020) focuses on the circular cross sections with different shapes of inner encased steel and different kinds of FRP. These studies confirm the excellent mechanical properties of FSRCs.…”