• 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.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.1A
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• pp.15-24
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• 2008

This paper presents the analytical method for the long-term behavior of simply supported composite beams with precast decks prestressed in the longitudinal direction. The objectives of time-dependent analysis are to estimate losses of prestress on the concrete slab and long-term deflection due to creep and shrinkage of concrete, relaxation of prestressing steel. Also, the time-dependent analysis was carried out using the presented analytical method to evaluate the effects of several parameters on the long-term behavior of composite bridge with precast deck, including geometrical shapes of composite beams, compressive strength of concrete and magnitude of initial prestress. The results of the analysis indicated that, in the effects of geometrical shapes of composite beams, the main parameters affecting the losses of prestress and the long-term deflection were the cross sectional area and the moment of inertia of steel beam, respectively. Finally, the determination method for the required initial prestress was proposed by evaluation of the loss characteristics due to shrinkage and creep of concrete.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.106-114
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• 2009

The steel design based on the width of transverse crack which is the major factor to affect a long-term performance of continuously reinforced concrete pavement was developed. For this study, twenty-one cities of Texas were selected and the temperature data was collected at those locations during the past ten years. From the data, zero-stress temperatures were calculated by the PavePro program and the widths of transverse crack were analyzed by the CRCP program. The variables used to this numerical analysis were slab thickness, coefficient of thermal expansion of concrete, steel ratio, and design temperature. The total of 448 factorial runs were made and the regression analysis was performed using the results. Steel ratios from the regression equations were backcalculated and a steel design table was proposed.

• Journal of Korean Society of Steel Construction
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• v.16 no.2 s.69
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• pp.225-233
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• 2004

Composite action is generally achieved by providing shear connections between steel top flange and concrete topping. Composite sections have greater stiffness than the summation of the individual stiffness of slab and beam. Therefore, they can carry larger loads or similar loads with appreciably smaller deflection and are less prone to transient vibration. T-type Steel Composite beam (TSC-beam) was developed to increase these advantages. Ten specimens were tested for this study. During the experiment, crack pattern and deflection of beam were investigated. The examined results of TSC beam system were compared with results from the typical composite beam and RC beam.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.733-739
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• 2011

B2S(Ballasted track To Slab track) that is track system has been first developed in 2004 with foundation of rich experience and know-how of subway track upkeep and mending of facilities in 36 years to improve an existence pebble track at a concrete track. 'B2S' is admitted technology through patent registration in the domestic and Europe and it's made by a factory and put together at field, so it's able to construct precisely and to reduce a construction period. In addition, safety, the ecological balance and durability are excellent, and walking, cleaning, etc. has the advantage of easy maintenance. 'B2S' is currently laying 27.7km at Seoulmetro as of end of 2010 standard, but it'll be expected to be applied to a domestic Metro more from now on. It is possible to classify the total cost resolution structure of B2S system by R&D cost, test production and experiment cost, the initial facility cost, maintenance cost, disposal cost. In this research, it seems useful for selection evaluation which considered the life cycle cost or economics of the concrete track structure by analyzing an initial cost of facilities.

• Smart Structures and Systems
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• v.9 no.3
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• pp.253-271
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• 2012

Finite element (FE) model updating is a useful tool for global damage detection technique, which identifies the damage of the structure using measured vibration data. This paper presents the application of a finite element model updating method to detect the damage of a small-scale reinforced concrete building structure using measured acceleration data from shaking table tests. An iterative FE model updating strategy using the least-squares solution based on sensitivity of frequency response functions and natural frequencies was provided. In addition, a side constraint to mitigate numerical difficulties associated with ill-conditioning was described. The test structure was subjected to six El Centro 1942 ground motion histories with different Peak Ground Accelerations (PGA) ranging from 0.06 g to 0.5 g, and analytical models corresponding to each stage of the shaking were obtained using the model updating method. Flexural stiffness values of the structural members were chosen as the updating parameters. In model updating at each stage of shaking, the initial values of the parameter were set to those obtained from the previous stage. Severity of damage at each stage of shaking was determined from the change of the updated stiffness values. Results indicated that larger reductions in stiffness values occurred at the slab members than at the wall members, and this was consistent with the observed damage pattern of the test structure.

• Journal of the Korea Concrete Institute
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• v.14 no.5
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• pp.668-676
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• 2002

Especially, when orthotropic material such as uni-dierectionally woven Carbon Fiber Sheet, resisting only the unidirectional tension, is used to strengthening bridge deck, the direction and width of the strengthening material should be considered very carefully. Thus, analysis of the failure characteristics and the premature failure mechanism of the strengthened decks based on the test results are required. In this study, the premature failure due to the interface debonding of strengthening material of the strengthened deck slab are inquired into failure mechanism through both experiments results and analyses with prototype strengthened deck specimens using carbon fiber sheet. From the test results, interface debonding of strengthening material is occured at the crack face

• Structural Engineering and Mechanics
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• v.19 no.1
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• pp.1-20
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• 2005

The expertise required in the judicious use of nonlinear finite element (FE) packages for design-assistance purposes is not widely available to the average engineer, whose sole aim may be to obtain an estimate for a single design parameter, such as the limit load capacity of a structure. Such a parameter may be required for the design of a proposed reinforced concrete (RC) floor slab or bridge deck with a given set of geometrical and material details. This paper outlines a procedure for developing design-assistance equations for carrying out such predictions for partially restrained RC slabs under uniformly distributed loading condition, based on a database of FE results previously generated from a large number of 'numerical model' slabs. The developed equations have been used for predicting the peak loads of a number of experimental RC slabs having varying degrees of edge restraints; with results showing a reasonable degree of accuracy and low level of scatter. The simplicity of the equations makes them attractive and their successful use in the field of application reported in this paper suggest that the outlined procedure may also be extended to other classes of concrete structures.

• Steel and Composite Structures
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• v.12 no.5
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• pp.395-412
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• 2012

The present work addresses the rotational capacity of steel-concrete composite beams, which is a key issue for the seismic design of composite frames. Several experimental tests from the literature are summarised, and the effects of various parameters on the available plastic rotation are discussed. Furthermore, a number of remarks are made regarding the need for supplementary experimental results. The authors carried out experimental tests on four composite beams in which the type, width and connection degree of the slab were varied. During the tests, the deflection and strains in the steel profiles and bars were measured and recorded, wherein the observed trends in the measured parameters indicated that the failure mode of the beam was influenced by global and local buckling. A comparison of the experimental results to the theoretical ultimate strengths and moment-curvature relationships confirms that buckling phenomena occurred after section yielding, even if a consistent plastic rotation developed. This rotational capacity is well evaluated by a formulation that is available in the literature.

• Journal of the Korean Society for Railway
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• v.12 no.6
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• pp.835-843
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• 2009

Recently the more stable roadbed is required due to the high speed and design load. Therefore the reinforced roadbed was introduced as the solution. But the thickness and stiffness of reinforced roadbed in design code is being conservatively assessed by the foreign code without considering the domestic construction condition. In this paper, adequate Young's modulus, drain capacity, freezing depth, economical efficiency, bearing capacity, construction condition and 3-D finite element method were employed to determine the proper thickness of reinforced roadbed at the embankment section.