• Computers and Concrete
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• v.28 no.5
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• pp.497-506
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• 2021

Steel-concrete composite structures and precast concrete elements have a common prefabrication process and allow fast construction. The use of hollow-core slabs associated with composite floors can be advantageous. However, there are few studies on the subject, impeding the application of such systems. In this paper, a numerical model representing the considered system using the FE (finite element)-based software DIANA is developed. The results of an experimental test were also presented in Souza (2016) and were used to validate the model. Comparisons between the numerical and test results were performed in terms of the load versus displacement, load versus slip, and load versus strain curves, showing satisfactory agreement. In addition, a wide parametric study was performed, evaluating the influence of several parameters on the behaviour of the composite system: The strength of the steel beam, thickness of the web, thickness and width of the bottom flange of the steel beam and concrete cover thickness on top of the beam. The results indicated a great influence of the steel strength and the thickness of the bottom flange of the steel beam on the capacity of the composite floor. The remaining parameters had limited influences on the results.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.661-669
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• 2009

Various kinds of shear connectors such as headed stud, channel, perforated steel plate and others are commonly used to transfer stress and conduct composite performance in steel concrete composite structures, and many researches have been conducted to improve the characteristics of different types of shear connectors. It is focused in this study on the pull-out and pushout performance of steel pipe pile cap with the open type perfobond for the composite connection to the spread footing. A parameter analysis was conducted, using ABAQUS, a nonlinear finite element analysis program, to obtain data for determining the characteristics of the structure and to allow various parametric analyses of steel pipe cap with the open perfobond.

• Steel and Composite Structures
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• v.36 no.5
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• pp.553-568
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• 2020

Steel-concrete composite structures have been extensively used in building, bridges, and other civil engineering infrastructure. Shear stud connectors between steel and concrete are essential in composite members to guarantee the effectiveness of their behavior in terms of strength and deformability. This study focuses on investigating the shear stiffness of headed studs embedded in several types of concrete with wide range of compressive strength, and their effects on the elastic behavior of steel-concrete composite girders were evaluated. Firstly, totally 206 monotonic push-out tests from the literature were reviewed to investigate the shear stiffness of headed studs embedded in various types of concrete (NC, HPC, UHPC etc.). Shear stiffness of studs is defined as the secant stiffness of the load-slip curve at 0.5V_u, and a formulation for predicting defined shear stiffness in elastic state was proposed, indicating that the stud diameter and the elastic modulus of steel and concrete are the main factors. And the shear stiffness predicted by the new formula agree well with test results for studs with a diameter ranging from 10 to 30 mm in the concrete with compressive strength ranging from 22.0 to 200.0MPa. Then, the effects of shear stiffness on the elastic behaviors of composite girders with different sizes and under different loading conditions were analyzed, the equations for calculating the stress and deformation of simply supported composite girders considering the influence of connection's shear stiffness were derived under different loading conditions using classical linear partial-interaction theory. As the increasing of shear stiffness, the stress and deflection at the most unfavorable section under partial connected condition tend to be those under full connected condition, but the approaching speed decreases gradually. Finally, the connector's shear stiffness was recommended for fully connection in composite girders with different dimensions under different loading conditions. The findings from present study may provide a reference for the prediction of shear stiffness for headed studs and the elastic design of steel-concrete composite girder.

• Steel and Composite Structures
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• v.19 no.4
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• pp.843-860
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• 2015

Recycled tire rubber-filled concrete (RRFC) is employed into the steel-concrete composite structures due to its good ductility and crack resistance. Push-out tests were conducted to investigate the static behavior of steel and rubber-filled concrete composite beam with different rubber mixed concrete and studs. The results of the experimental investigations show that large studs lead a higher ultimate strength but worse ductility in normal concrete. Rubber particles in RRFC were shown to have little effect on shear strength when the compressive strength was equal to that of normal concrete, but can have a better ductility for studs in rubber-filled concrete. This improvement is more obvious for the composite beam with large stud to make good use of the high strength. Besides that the uplift of concrete slabs can be increased and the quantity and width of cracks can be reduced by RRFC efficiently. Based on the test result, a modified empirical equation of ultimate slip was proposed to take not only the compressive strength, but also the ductility of the concrete into consideration.

• Journal of the Korea institute for structural maintenance and inspection
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• v.8 no.3
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• pp.243-250
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• 2004

In SPS system, steel beams are used as not only temporary struts supporting the wale but main flexural members of building. Previous experimental works show that RC wale-steel beam joints have some flexural rigidity. In this paper, nonlinear analysis is performed using DRAIN-2DX program to investigate the behaviors of the underground composite frames constructed with SPS system when the rigidity of RC wale-steel beam joints change. Analysis variables are the procedure of construction, magnitude of lateral forces, and flexural rigidity of the RC wale-steel beam joint with stud connector. Analysis results show the effects of joint rigidity for the yielding process of frame and the moment and deflection at the mid-span of beam.

• Land and Housing Review
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• v.8 no.3
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• pp.211-221
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• 2017

This study proposed hybrid coupled shear wall in the steel plate insertion method, which is capable of reinforcing the shear strength of the entire wall without increasing wall thickness in the wall-slab apartment buildings. The proposed hybrid coupled shear wall was tested for its effectiveness, shear strength and seismic behavior in experiment. As a test result, the shear strength improvement by the proposed hybrid coupled shear was found effective. Integral-type of steel plate insertion was found more effective than separate-type steel plate insertion. In this case, if the stud enforcement method proposed in this study was used, the shear strength of hybrid coupled shear wall was recommended to calculate using the KBC2016 0709.4.1(3) method. The steel plate inserted in the proposed method was found to have no significant impact on the final fracture behavior and bending strength of hybrid coupled shear wall. The shear strength at the final destruction of the wall was merely about 1/50 of the entire design shear strength. Thus, it is deemed that the wall was over excessively designed regarding the shear force in the existing design method. This finding indicates further study on wall designing to ensure effective and economic designing based on appropriate strength estimation under the destruction mechanism.

• Structural Engineering and Mechanics
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• v.59 no.5
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• pp.933-950
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• 2016

Decks, interior beams, edge beams and girders are the parts of a steel floor system. If the deck is optimized without considering beam optimization, finding best result is simple. However, a deck with higher cost may increase the composite action of the beams and decrease the beam cost reducing the total cost. Also different number of floor divisions can improve the total floor cost. Increasing beam capacity by using castellated beams is other efficient method to save the costs. In this study, floor optimization is performed and these three issues are discussed. Floor division number and deck sections are some of the variables. Also for each beam, profile section of the beam, beam cutting depth, cutting angle, spacing between holes and number of filled holes at the ends of castellated beams are other variables. Constraints include the application of stress, stability, deflection and vibration limitations according to the load and resistance factor (LRFD) design. Objective function is the total cost of the floor consisting of the steel profile cost, cutting and welding cost, concrete cost, steel deck cost, shear stud cost and construction costs. Optimization is performed by enhanced colliding body optimization (ECBO), Results show that using castellated beams, selecting a deck with higher price and considering different number of floor divisions can decrease the total cost of the floor.

• Steel and Composite Structures
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• v.46 no.2
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• pp.175-193
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• 2023

Stainless steel-concrete composite beam has become an attractive structural form for offshore bridges and iconic high-rise buildings, owing to the superior corrosion resistance and excellent ductility of stainless steel material. In a composite beam, stainless steel shear connectors play an important role by establishing the interconnection between stainless steel beam and concrete slab. To enable the best use of high strength stainless steel shear connectors in composite beams, high strength concrete is recommended. To date, the application of stainless steel shear connectors in composite beams is still very limited due to the lack of research and proper design recommendations. In this paper, a total of seven pushout specimens were tested to investigate the load-slip behaviour of stainless steel shear connectors. A thorough discussion has been made on the differences between stainless steel bolted connectors and welded studs, in terms of the failure modes, load-slip behaviour and ultimate shear resistance. In parallel with the experimental programme, a finite element model was developed in ABAQUS to simulate the behaviour of stainless steel shear connectors, with which the effects of shear connector strength, concrete strength and embedded connector height to diameter ratio (h/d) were evaluated. The obtained experimental and numerical results were analysed and compared with existing codes of practice, including AS/NZS 2327, EN 1994-1-1 and ANSI/AISC 360-16. The comparison results indicated that the current codes need to be improved for the design of high strength stainless steel shear connectors. On this basis, modified design approaches were proposed to predict the shear capacity of stainless steel bolted connectors and welded studs in the composite beams.

• Journal of the Society of Disaster Information
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• v.9 no.4
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• pp.400-412
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• 2013

For the composite behavior of steel tube and inner concrete, the shear connectors should be applied to the CFT structures. However, the present design codes don't provide the design criteria that can be applied on shear connectors in the CFT structures typically filled with plain concrete. This study has been carried out to propose design criteria (shear strength and resistance factor) for the stud shear connectors in CFT structures. Experimental tests using the push-out specimens with the plain concrete blocks and finite element analysis were conducted for the purpose of verifying the main failure mode to propose the shear strength of studs in CFT structures. From the results of this study, the main failure mode of studs in CFT structures is splitting crack of concrete and this failure mode reduces shear strength of studs in CFT structures relatively to those embedded in RC blocks.

• Steel and Composite Structures
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• v.38 no.1
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• pp.87-102
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• 2021

To investigate the failure form, bending stiffness, and residual bearing capacity of monolithic composite beams with laminated slab throughout the fire process, fire tests of four monolithic composite beams with laminated slab were performed under constant load and temperature increase. Different factors such as post-pouring layer thickness, lap length of the prefabricated bottom slab, and stud spacing were considered in the fire test. The test results demonstrate that, under the same fire time and external load, the post-pouring layer thickness and stud spacing are important parameters that affect the fire resistance of monolithic composite beams with laminated slab. Similarly, the post-pouring layer thickness and stud spacing are the predominant factors affecting the bending stiffness of monolithic composite beams with laminated slab after fire exposure. The failure forms of monolithic composite beams with laminated slab after the fire are approximately the same as those at room temperature. In both cases, the beams underwent bending failure. However, after exposure to the high-temperature fire, cracks appeared earlier in the monolithic composite beams with laminated slab, and both the residual bearing capacity and bending stiffness were reduced by varying degrees. In this test, the bending bearing capacity and ductility of monolithic composite beams with laminated slab after fire exposure were reduced by 23.3% and 55.4%, respectively, compared with those tested at room temperature. Calculation methods for the residual bearing capacity and bending stiffness of monolithic composite beams with laminated slab in and after the fire are proposed, which demonstrated good accuracy.