Steel-concrete Composite Joints Research Articles

Research on Load Transfer Mechanism of Steel-Concrete Joint Section of Hybrid Beam Cable-Stayed Bridge

The WuSu Bridge of HeiXiaZi Island is a hybrid girder cable-stayed bridge with one pylons and single cable plane. Based on the similarity principle, a 1:3 reduced scale test model of steel-concrete joint section was designed to study the load transfer mechanism and verify the rationality. The test model was loaded according to the serviceability limit state, and the stress distribution of control sections and main members were obtained. The finite element analysis on the test model was carried out and the load transfer mechanism was studied by the way of combining the test results and the FEA results. As shown in the results, the load from steel is smoothly delivered to concrete through steel-concrete joint section, and the load distribution of the components of steel-concrete joint section is rational. It is proved that the steel-concrete composite joint section is reasonably designed.

Mechanical Model of Steel-concrete Composite Joint under Sagging Bending Moment

Abstract In buildings with steel-concrete composite floors, joints are designed to transmit mainly hogging bending moment. In case of the large horizontal loads due to wind, earthquake or accidental events, sagging bending moments in a joint can also occur. Additionally, large deformations of the structure cause tying and prying effects. In the paper, a mechanical model based on “component method” for evaluation of characteristics of the composite joint is presented. The influence of tying and prying actions on distribution of the internal forces in a joint is also analyzed. The procedure for calculation of the characteristics of the composite joint with bolted endplate connection is elaborated too.

Structural details of steel girder–abutment joints in integral bridges: An experimental study

Integral bridges, which have integrated superstructures and substructures, should essentially maintain the rigid behavior and structural safety of the various existing joints. Especially temperature sensitive, girder-abutment joints for integral steel bridges are steel–concrete composite structures and require sufficient rigid behavior. Yet, various design guidelines and standards do not state these specific designs or construction methods. This study proposes structural details of girder-abutment joints in integral steel bridges for enhanced rigid behavior and load-resisting and crack-resisting capacity. Thus, this study additionally suggests various joints that apply stud shear connectors and perfobond rib shear connectors to existing empirically constructed girder-abutment joints. This study verifies the performance and evaluates the behavior of the proposed steel girder-abutment joints through experimental loading tests of empirically constructed joint specimens and specimens of the proposed joints. Also, this study performs FE analysis (non-linear structural analysis), which applies contact interaction of the interface of the steel–concrete composite joints. As a result of the experimental loading test, all the existing empirical joints and the proposed joints demonstrated sufficient rigidity and crack-resisting capacity under required design and yield load and are applicable as girder-abutment joints for integral steel bridges. Moreover, the proposed joints are judged to be structurally superior to the empirically constructed joints by the results of analysis for load-displacement relationships, crack-propagation behaviors, and load-strain relationships. Like the proposed girder-abutment joints in this study, joints with improved rigid behavior and load-resisting and crack-resisting capacity may resolve and properly control durability and serviceability issues of integral bridges.

Study on Pressure-Bending Stress Transfer in the Joint of the Steel-Concrete Composite Arch Bridge

Effective combination and carry-loading together between steel and concrete play important roles for the steel-concrete composite structure. The steel-concrete composite joint decides the constructing safety and life-cycle performance as the key member for the steel-concrete composite arch bridge. The stress distribution in the steel-concrete composite joint was studied by model test under pressure-bending load. And the stress transfer was probed in the steel box, composite joint and reinforced concrete box. The result shows that the steel and reinforced concrete boxes are under elastic compression in the steel-concrete composite joint. The bearing plate can effectively reduce the stress in concrete and steel boxes. This plate and stiffener can smoothly transfer and scatter the stress from steel box to concrete box. The failure mode is concrete cracking near the interface between steel box and concrete box under large eccentric compression.

Vibration characteristics of steel-concrete composite joints damaged with steel corrosion

Vibration characteristics of steel-concrete composite joints damaged with steel corrosion

Finite Element Modelling of the Behaviour of a Certain Class of Composite Steel-Concrete Beam-To-Column Joints / Skonczenie-Elementowe Modelowanie Zachowania Sie Pewnej Klasy Wezłów Zespolonych Stalowo-Betonowych W Połaczeniach Rygli Ze Słupami

Abstract Beam-to-column end-plate joints can be classified as rigid (fully restrained), semi-rigid (partially restrained) or pinned, depending on their type, configuration and the connector arrangement. Fully restrained joints are needed for rigid frames in which there is assumed that the frame joints have sufficient rigidity to maintain - under the service state - the angles between the intersecting members, ensuring the full moment transfer. In contrast in semi-continuous frames, partially restrained joints are characterized by relative rotations occurring between the intersecting members so that the bending moment can only be transferred partially. In recent years, the idea of using partially restrained, unstiffened joints in building structures has gained momentum since this idea appears to be more practical and economical. Semi-continuous frames can resist actions by the bending moment transfer in partially restrained joints, allowing in the same time for a certain degree of rotation that enhances the overall ductile performance of these structures. One of the effective ways that affects ductility of end-plate beam-to-column joints is to use thinner end-plates than those used nowadays in practical applications. In the current study, a certain class of steel-concrete composite joints is examined in which the thickness of end-plates is to be equivalent to approximately 40-60% of the bolt diameter used in all the composite joints investigated in the considered joint class. This paper is an extension of the authors’ earlier investigation on numerical modelling of the behaviour of steel frame joints. The aim of current investigations is to develop as simple as possible and yet reliable three-dimensional (3D) FE model of the composite joint behaviour that is capable of capturing the important factors controlling the performance of steel-concrete end-plate joints in which the end-plate thickness is chosen to be lesser than that used nowadays in conventional joint detailing. A 3D FE model constructed for composite joints of the considered joint class is reported in this paper and numerical simulations using the ABAQUS computer code are validated against experimental investigations conducted at the Warsaw University of Technology. Comparison between the nonlinear FE analysis and full scale experimental results of the considered class of composite joints is presented which conclusively allows for the accuracy assessment of the modelling technique developed. Comparison between the FE results and test data shows a reasonable agreement between the numerical FE model developed and physical model of experimentally examined joint specimens. Finally, practical conclusions for engineering applications are drawn.

Calibration of model parameters for the cyclic response of end-plate beam-to-column steel-concrete composite joints

Composite joints, considering the composite action of steel and concrete, exhibit, in general, high strength and high ductility. As a consequence, the use of this type of joint has been increasing in many countries, especially in those that are located in earthquake-prone regions. In this paper, a hysteretic model with pinching is presented that is able to reproduce the cyclic response of steel and composite joints. Secondly, the computer implementation and adaptation of the model in a spring element within the computer code Seismosoft is described. The model is subsequently calibrated using a series of experimental test results for composite joints subjected to cyclic loading. Finally, typical parameters for the various joint configurations are proposed.

Effects of partial fire protection on temperature developments in steel joints protected by intumescent coating

This paper presents experimental results of temperature distribution in fire in four typical types of steel–concrete composite joint (web cleat, fin plate, flush endplate and flexible endplate) with different fire-protection schemes. The test specimens were unloaded and the steelwork of each joint assembly was exposed to a standard fire condition [ISO 834, 1975: Fire Resistance Tests, Elements of Building Construction, International Organization for Standardization, Geneva] in a furnace. In total, 14 tests were conducted, including 4 tests without any fire protection and 10 tests with different schemes of fire protection. The main objective of these tests was to investigate the effects of three practical fire-protection schemes as alternatives to full fire protection of the entire joint assembly. The three alternative methods of fire protection were: (1) protecting a segment, instead of the entire length, of the beams; (2) unprotected bolts and (3) protecting the columns only. The main results of these tests are: (1) if all the steel work (excluding the bolts) in the joint assembly was protected, whether or not protecting the bolts had very little effect on temperatures in the protected steelwork other than the bolts. The bolt temperatures were higher if they were not protected than if they were protected, but the unprotected bolt temperatures in a joint with fire protection to other steelwork were much lower than bolt temperatures in a totally unprotected joint; (2) as far as joint temperatures are concerned, protecting a segment of 400 mm of the beam was sufficient to achieve full protection and (3) if only the column was protected, only the joint components that were in the immediate vicinity of the column (such as welds) developed noticeably lower temperatures than if the joint assembly was unprotected, but due to heat conduction from the unprotected steel beams, these temperature values were much higher than if the joint assembly was protected. Furthermore, the column temperatures in the joint region were much higher than the protected column temperatures.

Analysis of rigid and semi-rigid steel-concrete composite joints under monotonic loading - Part II: Parametric study and comparison with the Eurocode 4 proposal

Analysis of rigid and semi-rigid steel-concrete composite joints under monotonic loading - Part II: Parametric study and comparison with the Eurocode 4 proposal

Analysis of rigid and semi-rigid steel-concrete composite joints under monotonic loading - Part I: Finite element modelling and validation

The paper concerns the modelling of rigid and semi-rigid steel-concrete composite joints under monotonic loading through use of the Abaqus program, a widespread finite element code. By comparing numerical and experimental results obtained on cruciform tests, it is shown that the proposed modelling allows a good fit of the global joint response in terms of moment-rotation law. Even the local response in terms of stresses and strains is adequately predicted. Hence, this numerical approach may represent a useful tool for attaining a better understanding of experimental results. It may also be used to perform parametric analyses and to calibrate simplified mechanical models for practical applications. rn

Analytical evaluation of the moment-rotation response of beam-to-column composite joints under static loading

The analysis of steel-concrete composite joints presents some particular aspects that increase their complexity when compared to bare steel joints. In particular, the influence of slab reinforcement and column concrete encasement clearly change the moment-rotation response of the joint. Starting from an energy approach developed in the context of steel joints, an extension to composite joints is presented in this paper that is able to provide closed-form analytical solutions. In addition, the possibility of tri-linear or non-linear component behaviour is also incorporated in the model, enabling adequate treatment of the influence of cracked concrete in tension and the softening response of the column web in compression. This methodology is validated through comparison with experimental tests carried out at the University of Coimbra.

Modelling of steel-concrete composite joints

Modelling of steel-concrete composite joints