Abstract
This paper conducted push-out tests with 12 short-column specimens to investigate the interfacial shear transfer
performance of shaped steel with stud connectors embedded in Engineered Cementitious Composite (ECC). The influences of
diverse design parameters, such as ECC compressive strength, fiber volume content, stud diameter, stud set position, and cover
thickness, were evaluated on the crack de-velopment process, failure modes, and load-slip curves. The results indicated that the
failure modes included splitting failure, shaped steel yield failure, matrix crushed failure, stud shear failure and mixed failure.
The ordinary concrete specimen exhibited a brittle splitting failure, while the ECC specimen presented an obvious ductility in its
failure mode owing to the fiber bridging effect effectively that limited the development and extension of cracks. Besides, the
ultimate load improved as ECC com-pressive strength, fiber volume content, and cover thickness increased. A calculation
method for the interfacial shear capacity of shaped steel with stud connectors in ECC was proposed by considering the
combined action of the natural bond force and stud connectors, and the calculated results fitted well with the test results.
Key Words
failure modes; push-out tests; shaped steel-ECC; shear transfer performance; stud connectors
Address
Jiaojiao Pan:1)School of Civil Engineering, Xijing University, No. 1 Xijing Road, Xi'an, Shaanxi Province, China 2)Shaanxi Key Laboratory of Safety and Durability of Concrete Structures, No. 1 Xijing Road, Xi'an, Shaanxi Province, China
Zhenbin Huang:School of Civil Engineering, Xijing University, No. 1 Xijing Road, Xi'an, Shaanxi Province, China
Wei Zhang:Power China Northwest Engineering Corporation Limited, No. 18 Chengnan Avenue, Xi'an, Shaanxi Province, China
Mingke Deng:School of Civil Engineering, Xi'an University of Architecture and Technology, No. 13 Yanta Road, Xi'an, Shaanxi Province, China
Abstract
The effect of lateral load due to wind and earthquakes is significant in the case of modular tall buildings. A lateral
load-resisting system such as a stability core is provided to resist the lateral load. The connection between a core system and a
module plays a vital role in the structural performance of modular tall buildings. This paper proposes an innovative connection
between the steel-concrete composite module and composite shear wall (module-to-core connection) with the help of a novel
connector and hollo-bolt, which is very simple in geometry, easy to install, and has fewer components. Moreover, the
mechanical behavior of connection under different loading conditions is studied. To determine the shear and tensile capacity of
the module-to-core connection based on the finite element simulation, an investigation is carried out considering a vertical
sliding load on top of the connector and a horizontal pulling load on the beam perpendicular to the shear wall respectively. A
parametric study is carried out considering the diameter and grade of the bolt, spacing of shear studs in a steel-concrete
composite shear wall, and thickness of the steel plate of a shear wall and vertical steel plate of the novel connector. Results show
that the shear and tensile capacity of the connection is equal to the hollo-bolt's shear and tensile capacity, providing suitable
thickness for a steel plate of the composite core wall and novel connector, and enough shear studs around the connection. This
study can be the reference for the design of module-to-core connections.
Key Words
modular tall buildings; module-to-core connection; novel connector; steel-concrete composite module;
tensile and shear capacity
Address
Arjun Kandel:Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
Huu-Tai Thai:Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
Mahbub Khan:School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
Brian Uy:School of Civil and Environmental Engineering, UNSW Sydney, NSW 2052, Australia
Tuan Ngo:Department of Infrastructure Engineering, The University of Melbourne, Parkville, VIC 3010, Australia
Abstract
The bond behavior between shaped steel and high strength self-compacting concrete is crucial for ensuring the
collaborative behavior of these two materials. This bond behavior serves as the foundation for the effective interaction and
structural integrity of steel-concrete composite systems. Given the increasing use of shaped steel reinforced high strength self
compacting concrete in modern high-rise building construction, understanding the bond behavior is essential for improving the
design of steel-concrete structures. To investigate the bond behavior at the interface between the shaped steel and high-strength
self-compacting concrete, nine specimens were designed and fabricated, varying the thickness of the concrete cover and the
embedded length of the shaped steel. Push-out tests were conducted to observe the failure process and patterns of the specimens.
The complete load-slip curves at the loading end were obtained, and the effects of different variables on bond strength were
analyzed. The results indicate that the ultimate bond strength increases with the thickness of the concrete cover, with a maximum
increase of 94.9%. Conversely, the ultimate bond strength decreases with the increase of the embedded length of the shaped
steel, with a maximum reduction of 38.1%. The interfacial bond shear stiffness initially increases and then decreases with
increasing concrete cover thickness, with a maximum increase of 85.1%. As the embedded length of the shaped steel increases,
the bond shear stiffness also increases, with a maximum rise of 30.0%. With thicker concrete cover, the development of
interfacial damage is delayed. As the embedded length of the shaped steel increases, the rate of interfacial damage slows down.
The formula for predicting the bond strength between high-strength self-compacting concrete and steel was proposed, which
effectively predicts the bond strength between these materials. Additionally, the bond stress-slip curve equations were
established, showing good agreement with the experimental curves.
Key Words
bond behavior; bond strength; high strength compacting concrete; push-out experiment; shaped steel
Address
Zhixin Ma:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P.R. China
Yan Liang:College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P.R. China
Zongping Chen:1)College of Civil Engineering and Architecture, Guangxi University, Nanning 530004, P.R. China
2)College of Architecture and Civil Engineering, Nanning University, Nanning 530200, P.R. China
3)Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education, Guangxi University, Nanning 530004, P.R. China
Abstract
The combination of precast concrete slabs and steel beams connected by deconstructable high-strength friction-grip
bolts has emerged as a promising solution for sustainable construction. However, the lack of design guidelines and r egulations
has restricted its widespread use. This study aims to conduct a reliability analysis to evaluate the flexural resistance factor (Φ) for
composite beams with HSFGB shear connectors, as the AISC Specifications incorporate the shear connector resistance factor as
part of the overall resistance factor of the composite beam. To analyze the behavior of the composite beam, a three-dimensional
finite element model was developed and validated. Additionally, a sensitivity analysis was performed to investigate the impact of
various parameters on the flexural strength of the composite beam. The flexural resistance factor for this type of composite beam
with varying degrees of connection was evaluated providing an acceptable level of safety. The variability and uncertainty in
connectors were determined based on existing push-out tests using statistical analysis. A reliability study found that the reduction
factor of flexural resistance for this type of composite beam is dependent on the degree of shear connection. Additionally, using
the flexural resistance factor recommended for conventional composite beams with welded shear connectors in the AISC code is
unconservative for deconstructable composite beams.
Key Words
deconstructability; flexural resistance factor; reliability analysis; shear connector; sustainable construction
Address
Masoomeh Erfani Jazi:Department of Civil Engineering, Faculty of Civil Engineering and Transportation, University of Isfahan, Hezar Jerib Ave., University Blvd., Isfahan, Iran
Maryam Daei:Department of Civil Engineering, Faculty of Civil Engineering and Transportation, University of Isfahan,
Hezar Jerib Ave., University Blvd., Isfahan, Iran
Abdolreza Ataei:Department of Civil Engineering, Faculty of Civil Engineering and Transportation, University of Isfahan,
Hezar Jerib Ave., University Blvd., Isfahan, Iran
Abstract
Bolted connections with obvious semi-rigid characteristics will experience additional moments caused by the
second-order effects in structures, leading to inferior seismic performance of precast shear walls compared to cast-in-place shear
walls. In order to investigate the influence of semi-rigidity, a new box-shaped connection with apparent semi-rigid features has
been proposed. Cyclic loading tests were conducted on a full-scale shear wall specimen (BPSW) with a box-shaped connection
and a cast-in-place shear wall specimen (SW1). Failure characteristics, seismic performance, and deformation composition were
comprehensively analyzed. Test results indicate that that both BPSW and SW1 exhibit the same bending failure mode. The
seismic performance, as indicated by the hysteretic envelope area in BPSW, is slightly smaller than that of SW1. The reduced
ductility, initial stiffness, and energy dissipation in BPSW can be attributed to the semi-rigid behavior, which affects the
deformation behavior of the precast shear wall structure. Additionally, the deformation composition analysis reveals that
rotational deformation of the new box-shaped connection in BPSW cannot be ignored as it accounts for more than 30% of the
horizontal displacement. In accordance with previous models, a theoretical model for rotational deformation that offers insights
into the semi-rigid nature and seismic performance of the box-shaped connection is proposed. The proposed model demonstrates
good agreement with experimental results and provides valuable insights into the semi-rigid behavior and seismic response of
such precast connections.
Abstract
The shear properties of eight steel fiber reinforced concrete (SFRC) beams reinforced with glass fiber reinforced
polymer (GFRP) stirrups, referred to as GFRP-R-SFRC beams, are reported under four-point loading. Two parameters of the
volume fraction of steel fibers (Vf) and the shear span ratio (λ) are considered, and their effects on the failure mode, mid-span
deflection, crack width, strains of SFRC and longitudinal rebars, and shear capacity of GFRP-R-SFRC beams are then
investigated. As the λ increases from 1.5 to 3.0, the GFRP-R-SFRC beams sequentially experience three failure modes:
diagonal compression failure, shear compression failure, and diagonal tension failure. The incorporation of 1.5% steel fibers
results in a reduction of the maximum deflection, maximum crack width, rebar strain and concrete strain by 2.3%, 16.8%,
15.7%, and 5.1%, respectively, indicating an enhancement in the post-cracking stiffness of GFRP-R-SFRC beams. Due to the
crack-bridging effect of steel fibers, the average strain, maximum strain, and utilization ratio of GFRP stirrups increase with the
increase of Vf. The shear capacity of GFRP-R-SFRC beams increases by 25.6% as the Vf increases from 0% to 1.5%, and the
enhancement in shear capacity (25.6%) due to the addition of steel fibers shows a similar effect to that observed in conventional
SFRC beams (12.7%). However, an increase in λ leads to a decrease in shear capacity, as the failure mode of the beam shifts
from a shear-dominated pattern to a flexure-dominated pattern, which is similar with conventional SFRC beams. Considering
the positive contribution of steel fibers, a modified computational model is proposed for evaluating the shear capacity of FRP-R
SFRC beams. A good agreement between the predicted and experimental results is shown.
Address
Wenlong Li:1)Department of Civil Engineering and Anhui University of Technology, Maxiang Road 59, Maanshan, China
2)College of Information Engineering and Fuyang Normal University, Qinghe East Road 59, Fuyang, China
Wei Huang:College of Information Engineering and Fuyang Normal University, Qinghe East Road 59, Fuyang, China
Zhengyi Kong:Institute for Sustainable Built Environment, Heriot-Watt University, Edinburgh, United Kingdom
Weihua Fan:College of Information Engineering and Fuyang Normal University, Qinghe East Road 59, Fuyang, China
Ke Zhang:College of Information Engineering and Fuyang Normal University, Qinghe East Road 59, Fuyang, China
