Jul 2026· Proceedings of the Institution of Civil Engineers : Structures and buildings· Vol 179, pp. 911-922· 0 citations· 21 references
Abstract
To investigate the seismic performance of prefabricated concrete-filled circular steel tubular T-shaped column–composite beam frame joints, six full-scale prefabricated T-shaped joint frame specimens were designed and fabricated. The experimental variables included loading direction and axial compression ratio. Their failure modes, hysteretic behaviour, energy dissipation capacity and stiffness degradation were analysed through low-cycle reversed loading tests. The results showed that the specimens failed at the beam ends by way of a plastic hinge mechanism, and the failure mode satisfied the design requirements of ‘strong column–weak beam’ and ‘strong joint–weak component’. Within a specific range, increasing the axial compression ratio enhanced the specimens’ load-bearing capacity, energy dissipation capacity and ductility, while increasing the shear force in the joint core area. Under the same axial compression ratio, specimens loaded along the flange direction exhibited energy dissipation that was 92.0, 71.0 and 58.9% higher than those loaded along the web, with displacement ductility coefficients increasing by 6.0, 13.0 and 29.6%, respectively. Under seismic loading, the energy dissipation capacity and ductility performance of the T-shaped joints in the special-shaped concrete-filled steel tubular column frames were superior when loaded along the flange direction.
To study the axial compression performance of steel tube-confined concrete, nine short column specimens were designed for axial compression testing. The parameters are the diameter-to-thickness ratio of steel tubes and the contact treatment method at the steel-concrete interface. The failure mode, load-displacement curve, load-strain curve, and load-lateral deformation of the specimens were comparatively analyzed. The results show that the failure mode is mainly shear failure. The confinement effect of the steel tube is fully activated in the elastoplastic stage. The load-displacement curves of these specimens do not have obvious descending branches. A smaller diameter-to-thickness ratio leads to more significant improvements in both load-bearing capacity and ductility during the later loading stage. The use of film-type materials at the steel-concrete interface enhances the confinement effect of steel tubes on concrete, and this improvement becomes increasingly obvious in the later stage of loading.
Tianhao Li, Dongliang Zhang, Kun Fu et al.· Journal of Physics, Conferen...· 0 citations
Steel–concrete composite beams offer significant advantages in long-span, heavy-load, and prefabricated construction; however, the concrete slabs are prone to tensile cracking under negative bending moments. To enhance cracking resistance, uplift-restricted and slip-permitted (URSP) perfobond rib (PBL) connectors were adopted with a cast-in-place high-performance concrete (HPC) topping. Five composite beam-steel column joint specimens were tested under quasi-static cyclic loading. The test variables included connector type, cast-in-place concrete type, and reinforcement grade. In addition, refined numerical simulations were conducted on the test specimens. Both test and numerical results show that: (1) The combined application of URSP-PBL connectors and HPC enhanced the cracking resistance of the composite beam, with the initial cracking load and corresponding cracking displacement increased by approximately 50% compared with the control specimen. (2) The ultimate flexural capacity of the composite beams under negative moments showed limited sensitivity to the type of cast-in-place concrete topping and the reinforcement grade within the tested range. (3) The use of URSP-PBL connectors improved the flexural stiffness of the composite beams. (4) The URSP-PBL specimens showed good energy dissipation capacity under cyclic loading, which was further improved with the addition of HPC in the topping. Within the tested range, the reinforcement grade showed limited influence on this performance. This study provides a scientific basis for the crack control design and engineering application of long-span composite beams.
Juan Chen, Hao Huang, Xiao-Jie Wang et al.· Buildings· 0 citations
The FRP–concrete–steel double-skin tubular column (DSTC) is a novel composite column designed to meet the structural demands for high strength, exceptional durability, and lightweight characteristics. To investigate the axial compression performance of DSTCs, this study conducted axial compression tests on 16 circular DSTCs and three circular fully filled columns (FCSCs). This research focused on analyzing the effects of steel tube wall thickness, void ratio, rubber content, steel fiber content, and GFRP tube wall thickness on stub columns’ failure modes, load–displacement curves, load–strain curves, and stress–strain relationships of concrete. The results demonstrated that GFRP tube wall thickness is the most critical parameter influencing the bearing capacity and deformation capacity of the column. The ultimate bearing capacity of all specimens ranged from 1606.9 to 3447.9 kN; the peak displacement of the specimens ranged from 7.49 to 17.77 mm. Increased void ratios decrease bearing capacity but enhance ductility, whereas steel tube wall thickness and steel fiber content have relatively minor effects. Based on the experimental results, models for the ultimate bearing capacity, ultimate strain, and stress–strain relationship of short columns were proposed, taking into account rubber content. The average predicted-to-experimental capacities ratio is 0.97 and the predicted load–displacement curves match well with the experimental curves, indicating the very high accuracy of the proposed models.
Guanghao Mai, Zhi Shu, Haifeng Li et al.· Buildings· 0 citations
This study investigates the seismic performance of postcast prefabricated concrete columns reinforced with ultrahigh-performance concrete (UHPC) and incorporating internal steel sections at their joints. Through low-cycle reversed loading tests conducted on two prefabricated concrete (PC) columns with UHPC-reinforced steel joints and one RC column cast-in-place, the seismic performance differences between PC and RC are compared. The study examines the influence of varying locations of prefabricated joints on hysteretic behavior, energy dissipation capacity, and deformation capability. The results indicate that the prefabricated columns reinforced with internal steel sections and UHPC connections exhibit higher load-bearing capacity and stiffness, significantly enhancing their seismic performance. Specifically, the PC-2 specimen, with its joint located at the column base, displays excellent initial ductility and energy dissipation but experiences a reduction in load-bearing capacity due to UHPC cracking at the joint in later stages. Conversely, the PC-1 specimen, featuring a joint positioned 450 mm above the bearing platform, exhibits comparable deformation and energy dissipation capabilities to the RC column due to unhindered plastic hinge formation, demonstrating superior seismic performance. The formula for calculating the flexural capacity of I-shaped steel-reinforced concrete sections, based on the internal force equilibrium condition and the lower-bound theorem of plasticity theory, yields a calculation error of less than 10%, confirming its accuracy and providing a scientific basis for relevant design optimizations.
Zhanghua Xia, Junjie Chen, Xianzhong Hu et al.· Journal of Structural Engine...· 0 citations
Load-bearing prefabricated concrete sandwich wall panels (LBPCSW) offer potential for rapid construction and energy efficiency, yet their seismic performance requires systematic evaluation. In this study, quasi-static tests and finite element analysis were conducted on LBPCSW specimens with varying height-to-width ratios and embedded column configurations. The results indicate that the LBPCSW specimens exhibit satisfactory structural integrity, with all specimens achieving ductility coefficients greater than 3.0. Specifically, specimen W1 with a height-to-width ratio of 1:1 failed in shear, whereas specimens with a height-to-width ratio of 2:1 exhibited flexural failure. Compared with W1, specimen W2 with embedded columns at the wall ends demonstrated significantly enhanced load-bearing capacity and ductility. Parametric analysis revealed that concrete layer thickness is the dominant factor influencing load-bearing capacity: taking W1 as an example, as the single-side concrete layer thickness increased from 30 mm to 50 mm, the ultimate load-bearing capacity increased from 182 kN to 246 kN, representing a 35% improvement. In contrast, the effect of concrete strength was relatively minor: increasing the strength grade from C25 to C35 raised the ultimate load-bearing capacity from only 223 kN to 255 kN, an increase of merely 14%. It is concluded that the proposed LBPCSW combine favorable seismic performance with energy efficiency, representing a promising solution for shear wall systems in low-rise rural housing in earthquake-prone regions.
To investigate the seismic behaviour of precast seawater sea-sand concrete beam–column joints with basalt-fibre-reinforced polymer (BFRP) bars, four specimens were tested, including cast-in-situ (CiS) and precast interior/exterior joints. All specimens failed in flexure at beam ends near the column, satisfying the ‘strong joint–weak member’ principle. The CiS interior joints showed higher capacity and stiffness than precast ones, while precast joints exhibited better strength stability and cumulative energy. For exterior joints, the capacity differences were minor; the CiS specimens had 10.3–38.4% higher stiffness, but the precast exterior joints showed better strength stability and energy dissipation, with a 19.1% improvement in energy dissipation, meeting the ‘equivalent to CiS’ requirement. An OpenSees finite-element model effectively simulated the load-bearing behaviour. Parameter analysis indicated that increasing the axial compression ratio, concrete strength, number of U-shaped BFRP bars and beam tensile reinforcement area enhanced the capacity. Notably, the number of beam tensile reinforcements and U-shaped BFRP bars had a greater influence on capacity than the axial compression ratio and concrete strength.
Bo Wei, Peng Mi, Wenjie Li et al.· Proceedings of the Instituti...· 0 citations
