Experimental investigation of thin-walled concrete-filled steel tube columns with reinforced lattice angle

Experimental behaviour of circular concrete filled steel tube columns and design specifications

“…High rise buildings [1,2], deep underground tunnels [3], bridges [4,5] and towers [6] are some examples of structures in which CFST columns are deployed as main load carrying members. High energy absorption capacity, stiffness and ductility of CFST columns motivate engineers to adopt such members in earthquake prone zones [6,7]. The steel tubing serves as a formwork for concrete core, thus construction time and costs can be reduced [7][8][9].…”

Eccentric compression behavior of circular concrete‐filled steel tubes reinforced with internal latticed steel angles

“…into CFSTs, thus the steel-reinforced concrete-filled steel tubes (SRCFSTs) are formed. [5][6][7][8][9][10][11][12][13] Existing research results have confirmed that some types of steel reinforcing elements (such as reinforcement cages, latticed steel angles, steel tubes, etc.) can provide an additional confining effect on the enclosed concrete, 5,6,12,13 hence the bearing capacity and ductility of SRCFSTs can be improved.…”

“…Besides, in order to get the strain distributions of the inner steel angles, four longitudinal strain gauges were arranged on the steel angles at the mid-span, and the strain gauges were numbered from I-1 to I-4, as shown in Figure 2. The displacement-control scheme with a loading speed of 1 mm/min 12 was used in the compression test. At the beginning of the test, approximately 10% of the design ultimate load of the reference CFSTs was applied to eliminate any possible gapes between the specimens and loading equipment.…”

“…In recent years, to improve the compression and shear properties of the core concrete in CFSTs, some scholars have added different types of steel reinforcing elements (such as the reinforcement cages, profiled steels, steel tubes and lattice steel angles, etc.) into CFSTs, thus the steel‐reinforced concrete‐filled steel tubes (SRCFSTs) are formed 5–13 . Existing research results have confirmed that some types of steel reinforcing elements (such as reinforcement cages, latticed steel angles, steel tubes, etc.)…”

“…Wang et al 8 and Zhu et al 9 experimentally studied the mechanical properties of circular and square CFSTs reinforced with crossed I-section steel, and research results showed the mechanical properties such as the bearing capacity, compression stiffness, and ductility were superior than the counterpart CFSTs. Xu et al 12,13 investigated the axial compression behavior of circular CFSTs reinforced with latticed steel angles by experimental and numerical methods, and research results indicated that the latticed steel angles have an additional confining effect on the enclosed concrete. Hamidian et al 5 and Xiamuxi et al 6 studied the axial compression properties of circular CFSTs reinforced with reinforcement cages, research results also proved the reinforcement cages have a certain confining effect on the enclosed concrete, and the stirrups also have a significant influence on the plastic behavior of the tested specimens after ultimate load.…”