Abstract
Steel reinforced ultra-high-performance concrete (SRUHPC) columns have promising applications in
high-performance composite structures owing to their high strength, stiffness, and durability. To accurately describe
the compressive behavior of UHPC in SRUHPC columns, this study classifies UHPC into unconfined, single
confined, and double confined regions according to the confinement provided by stirrups and section steel.
Unconfined UHPC is treated as steel fiber-reinforced high-strength concrete, and calculation methods for the peak
compressive stress of UHPC under different confinement conditions are proposed. Based on the stress–strain
relationship of confined high-strength concrete, equations for the peak compressive strain and ultimate compressive
strain are further developed, and a full compressive stress–strain constitutive model is established. The proposed
model is used to predict the axial load–strain response of SRUHPC short columns and is validated against test results.
The average calculated-to-experimental ratios for peak load and peak strain are 0.9635 and 1.0506, with coefficients
of variation of 0.0457 and 0.1892, respectively, indicating good prediction accuracy. The proposed model can
provide a useful reference for predicting the axial compressive behavior and nonlinear analysis of SRUHPC short
columns within the investigated parameter range.
Key Words
axial compression; compression constitutive relationship; confinement effect; SRUHPC short
columns; ultra high performance concret
Address
Zuqiang Liu:1)School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China
Yamin Zhao:School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Chin
Xiaonan Wang:School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Chin
Jianyang Xue:School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Chin
Zhiming Zhou:School of Civil Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, Chin
Abstract
A finite element model based on the direct stiffness method was proposed for steel-concrete composite
beams, in consideration of the distinct geometric configurations and mechanical characteristics of their upper
concrete layer and lower steel layer. Specifically, the Euler-Bernoulli beam theory was adopted to simulate the
concrete layer, while the Timoshenko beam theory was applied to the steel layer. In the model, discrete flexible shear
connectors were equivalently modeled using the interfacial bond-slip model, and different rotational angles were
assumed for the two layers to better reflect the actual deformation characteristics of composite beams. Meanwhile,
the interfacial compressive force induced by the rotational angle difference was incorporated into the equilibrium
equations. On this basis, a finite element analysis model for steel-concrete composite beams was established and the
corresponding calculation program was developed, which was subsequently used to analyze and compare two
numerical examples. The results demonstrate that the proposed element model outperforms the existing composite
beam elements based on the double-layer Euler-Bernoulli and double-layer Timoshenko beam theories in terms of
calculation accuracy and efficiency. Moreover, such advantages are further highlighted and enhanced when the
model is applied to the analysis of time-dependent and ultimate bearing performance of steel-concrete composite
beams.
Key Words
direct stiffness method; exact element stiffness matrix; interfacial slip; novel finite element
model; steel-concrete composite beams
Address
Jihua Deng:1)School of Civil and Environmental Engineering, Changsha University of Science & Technology,
Changsha 410114, Hunan, China
2)Ministry of Education Key Laboratory of Safety Control of Bridge Engineering, Changsha University of
Science & Technology, Changsha 410114, Hunan, China
Jihua Luo:1)School of Civil and Environmental Engineering, Changsha University of Science & Technology,
Changsha 410114, Hunan, China
Jianping Tan:1)School of Civil and Environmental Engineering, Changsha University of Science & Technology,
Changsha 410114, Hunan, China
Luyi Liang: 1)School of Civil and Environmental Engineering, Changsha University of Science & Technology,
Changsha 410114, Hunan, China
Abstract
To investigate the influence of corrosion on the seismic performance of steel reinforced concrete (SRC)
columns, a total of 12 pre-corroded SRC columns and 3 uncorroded SRC columns were designed and fabricated,
considering key parameters including section steel type, steel corrosion degree, axial compression ratio, shear-span
ratio, and batten plate spacing. Through the quasi-static low-cycle reciprocating loading test, the failure characteristics
and hysteresis curves of each specimen and other seismic performance data were obtained. The test results indicate
that flexural failure occurs when the shear-span ratio is large, whereas flexural-shear or flexural-shear-bond
composite failure is observed when the shear-span ratio is small. Within the parameter range of this test, the corroded
steel contributes to the improvement of horizontal bearing capacity and energy dissipation capacity of the pre
corroded columns, with the maximum increase in horizontal bearing capacity reaching 19.1 %. Compared with
hollow angle steel-reinforced concrete (HASRC) columns, both solid-core H-shaped steel reinforced concrete
(SHSRC) columns and hollow channel steel reinforced concrete (HCSRC) columns exhibit higher horizontal
bearing capacity and a slower strength degradation rate. Within the parameter range of this test, increasing the axial
compression ratio, reducing the batten plate spacing, or decreasing the shear-span ratio can enhance the horizontal
bearing capacity of corroded SRC columns. In contrast, an increase in the shear-span ratio can improve the energy
dissipation capacity of the structure and slow down the strength degradation rate. Finally, a calculation method for the
horizontal bearing capacity of the three types of pre-corroded SRC columns is proposed.
Key Words
calculation of bearing capacity; natural corrosion; pre-corroded steel reinforced concrete
columns; seismic performance; shear span ratio
Address
Chuanyuan Xiao:1)School of Civil Engineering and Architectural Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China
2)3Engineering Research Center for Assembly Structure Safety Prevention and Control, Guangxi Zhuang Autonomous Region, Liuzhou 545006, China
Qiang Hu:1)School of Civil Engineering and Architectural Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China
2)3Engineering Research Center for Assembly Structure Safety Prevention and Control, Guangxi Zhuang Autonomous Region, Liuzhou 545006, China
Lili Jin:School of Municipal Construction and Transportation, Guangxi Polytechnic of Construction 530007, China
Yuliang Chen:1)School of Civil Engineering and Architectural Engineering, Guangxi University of Science and Technology, Liuzhou 545006, China
2)3Engineering Research Center for Assembly Structure Safety Prevention and Control, Guangxi Zhuang Autonomous Region, Liuzhou 545006, China
Abstract
High strength steel (HSS)-ultra high performance concrete (UHPC) composite beams offer a feasible
solution for structural lightweighting and long‑span applications. Based on previous experimental studies, this paper
conducts numerical investigations into the static shear behavior of HSS-UHPC stud shear connectors and the static
flexural performance of HSS-UHPC composite beams under sagging moment. Refined numerical models of HSS
UHPC stud shear connectors and composite beams were developed, and a tensile constitutive model incorporating
strain-hardening effects for UHPC was proposed. An approach for accurately predicting the static failure processes of
HSS-UHPC stud shear connectors and composite beams was established. Numerical predictions of shear capacities
of pushout specimens and flexural capacities of composite beams agreed with test results within 5.5% and 2.5%,
respectively. Then the effects of key parameters were investigated through parametric analyses. The results indicate
that the increases in compressive strength of UHPC, as well as the diameter and tensile strength of studs markedly
enhance the shear capacity of HSS-UHPC stud shear connectors. The flexural capacity of HSS-UHPC composite
beams under sagging moment increased significantly with compressive strength of UHPC, UHPC slab thickness,
steel strength and degree of shear connection. Once the degree of shear connection attains full shear connection,
further increases in degree of shear connection had negligible influence on the flexural capacity of HSS-UHPC
composite beams. Regression of parametric results rendered design formulas for shear connection capacity and
flexural capacity of HSS-UHPC composite beams, validated against experimental and numerical results. Finally,
recommendations for practical engineering design were proposed. This study fills the gap in the understanding of
load‑carrying behavior of HSS-UHPC composite beams and provide reference for their practical engineering
application.
Key Words
composite beam; high strength steel; numerical study; static bearing behavior; stud shear
connector; UHPC
Address
Shun Xiao:1)College of Civil Engineering, Tongji University, Shanghai 200092, China
2)Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences
Co. Ltd., Shanghai 200032, China
Lewei Tong:1)College of Civil Engineering, Tongji University, Shanghai 200092, China
2)Department of Civil Engineering, Tongji University Zhejiang College, Jiaxing 314051, China
Luhua Chen:College of Civil Engineering, Tongji University, Shanghai 200092, China
Xiaoqing Wang:Department of Civil Engineering, Tongji University Zhejiang College, Jiaxing 314051, China
Jia Zhu:epartment of Civil Engineering, Tongji University Zhejiang College, Jiaxing 314051, China
Abstract
This study investigated a novel Composite Trough Beam with Corrugated steel web wrapped with outer
Steel plate (CTBCS), in which the concrete webs of a traditional trough beam are replaced by corrugated steel webs
and an outer steel plate is added to the bottom concrete plate. Compared with the traditional trough beam, the
proposed structure exhibits improved crack resistance, higher bearing capacity, and lower self-weight. The failure
mechanism and mode discrimination method of composite trough beams are still unclear. To this end, this paper
investigated these properties by combining theoretical, experimental, and numerical approaches. First, boundary
judgment methods were established using theoretical derivations for three failure modes of CTBCS: brittle failure,
punching shear failure of bottom plate and shear failure of corrugated steel web. Second, experiments were
conducted on two CTBCS specimens with different structural parameters to compare and analyze their failure modes
and bearing capacities under concentrated loads. Third, quarter-symmetric ABAQUS models were developed and
validated against theoretical and experimental results. The validated model was then employed to investigate the
effects of three key parameters: the thicknesses of bottom concrete plate, outer steel plate, and corrugated steel web.
Results show that brittle failure occurs when the thickness of outer steel plate exceeds 2 mm, making strict control of
this parameter is essential for safe design; when the bottom concrete plate is thinner than 11 cm, its punching shear
capacity is lower than the bending bearing capacity of CTBCS, leading to punching shear failure in bottom plate;
when the shear capacity of corrugated steel web falls below 80% of the total shear capacity of CTBCS, shear failure
occurs in corrugated steel web. The study results in this paper can provide reference value for structural design and
engineering application of CTBCS.
Abstract
8 specimens were designed in order to study the effect of ceramic recycled coarse aggregate (CRCA)
replacement ratio and hollow section ratio on ceramic recycled self-compacting concrete-filled double-skin square
steel tubular (CCDSST) column under axial load. The test results indicated that the specimens occurred bulging
failure in the middle with good ductility, and the axial bearing capacity decreased non-obviously with the increase of
the replacement ratio, and first increased and then decreased with the increase of the hollow section ratio. The finite
element (FE) models were used to simulate the specimens and study the effects of parameters (e.g., hollow section
ratio, steel strength, CRCA replacement ratio, and nominal steel content) on the axial compressive behavior of
CCDSST members. The results indicated that the FE calculation results were in good agreement with the
experimental results, and the axial bearing capacity of CCDSST columns decreases with the increase of the steel
strength of the inner and outer tubes, concrete strength and nominal steel content, but increases with the increase of
the hollow section ratio, and decreases initially and then increases with the increase of the replacement ratio. Based
on the results of FE analysis, simplified formulas for calculating the ultimate bearing capacity of CCDSST column
under axial compression were proposed, and the calculation results were in good agreement with the experimental
results.
Key Words
axial test; ceramic recycled concrete; concrete-filled double-skin square steel tubular; finite
element analysis
Address
Jingtuan You:School of building engineering, Fujian Polytechnic of Information Technology, Fuzhou, 25001, China
Huizhi Wang:China Academy of Building Research, Beijing 100013, China
Abstract
Steel rapidly loses strength at elevated temperatures, making passive fire protection essential for
structural fire safety. This study presents a data-driven thermal-boundary reconstruction procedure based on
surface-temperature fitting for incorporating experimentally measured steel-temperature histories into finite
element method (FEM) thermal-stress analysis. Temperature records obtained from standard fire-resistance tests
were converted into continuous time-dependent functions and spatially reconstructed across the upper flange, web,
and lower flange to define a transient steel-surface temperature field. Applied to a simply supported protected H
shaped steel beam, the model exhibited lower steel temperatures and a smaller maximum absolute mid-span
deflection than an idealized convection-only unprotected reference model. These differences are scenario-specific
because the two cases employed different thermal-boundary formulations. A case-based assessment against an
independent beam experiment yielded a mid-span deflection error of 8.35% and an average error of 3.27%. The
procedure provides a practical means of translating representative fire-test data into FEM thermal boundary
conditions, although its applicability depends on the representativeness of the input data and the scope of the case
based assessment.
Key Words
finite element method; fire-resistant coating; fire; intumescent coating; steel; surface
temperature fitting
Address
Heui-Yung Chang:Department of Civil Engineering, National Chung Hsing University, Taiwan
Chu-Tsen Liao:Department of Architecture, National Taiwan University of Science and Technology, Taiwan
Pin-Chen Lai:Department of Civil Engineering, National Cheng Kung University, Taiwan
Chi-Ming Lai:Department of Civil Engineering, National Cheng Kung University, Taiwan
Abstract
This paper presents an experimental study on the axial compressive performance of PVC-CFRP Pipe
Constrained Profiled Steel Reinforced Concrete (PC-CPSRC) short columns. A total of 10 PC-CPSRC short
columns is tested, along with 7 PVC-CFRP pipe-constrained concrete short columns without built-in profiles for
comparison. All PC-CPSRC short columns fail by the fracture of CFRP strips in the ring direction, cracking of the
PVC pipe, crushing of concrete, and buckling of the H-shape profile steel. The load-displacement curves of the PC
CPSRC short columns exhibit three stages: a linear phase, a nonlinear phase, and a descending phase after reaching
the peak load. Based on the validated finite element (FE) model, a parametric analysis is conducted to evaluate the
effects of key parameters. The results indicate that the axial compressive capacity can be improved by increasing the
section size, concrete strength, steel content, and steel strength, as well as by reducing the CFRP strip hoop spacing.
Among these parameters, the section size shows the most significant influence, whereas the steel strength has the
least effect. A theoretical model for predicting the axial compressive capacity of PC-CPSRC short columns is
developed based on the double-shear unified strength theory and the elastic-plastic limit analysis theory of thick
walled cylinders. The predicted results agree well with various experimental data, demonstrating the accuracy and
applicability of the proposed model.
Key Words
axial compressive capacity; confinement pipe; experimental study; finite element simulation;
profiled steel concrete; short column
Address
Qinglin Tao:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243032, China
Haoran Yu:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243032, China
Yingzi Liu:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243032, China
Jiayou Han:Shanghai Meishan Iron & Steel Co., Ltd., Nanjing 210039, Jiangsu, China
Ben Niu:Dept. of Civil Engineering and Architecture, Anhui University of Technology, Ma'anshan 243032, China
Zhengyi Kong:Institute for Sustainable Built Environment, Heriot-Watt University, Edinburgh, United Kingdom
Quang-Viet Vu:Faculty of Advanced Technology and Engineering, VNU Vietnam Japan University, Hanoi, Vietnam
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