Steel-concrete Composite Beams Research Articles

Seismic performance of full-scale prefabricated semi-rigid bolted connection between RC column and composite beam

This paper presents a novel proposal for an assembled bolted joint between precast reinforced concrete (RC) column and steel-concrete composite beams, focusing on its seismic performance. To evaluate the joint's behavior, a comprehensive experimental investigation was conducted on a full-scale RC column to composite beam joint specimen subjected to pseudo-static loading. The study aimed to analyze the joint's failure mode, bearing capacity, ductility, and energy dissipation characteristics. The joint stiffness was assessed by analyzing the bending moment-rotation (M-θ) curve of the beam in accordance with the European standard BS EN 1993-1-8:2005. The experimental results demonstrate that the proposed assembled bolted joint exhibits semi-rigid behavior under positive moments and approaches rigidity under negative moments. To further enhance our understanding of the joint's performance, a finite element model was developed using ABAQUS. The stress distribution in each joint component, as well as the failure mode and ultimate bearing capacity, were analyzed in conjunction with the experimental results. Based on the findings from both the experimental and finite element analyses, an improved joint design is proposed. Additionally, parametric analysis was conducted on the enhanced joint configuration. The study findings indicate that the improved joint exhibits superior damage resistance, seismic performance, and enhanced assembly efficiency compared to the original design. This research contributes to the advancement of assembled bolted joints between precast RC columns and steel-concrete composite beams, offering valuable insights for practical applications in seismic regions.

Investigation on permanent deformation in steel-concrete composite beam bridge deck pavement under temperature-load coupling effect

Rutting is one of the common distresses observed in asphalt pavement, influenced by temperature and load conditions. To clarify the permanent deformation behavior of steel-concrete composite beam (SCCB) bridge deck pavement under temperature-load coupling effect and provide references for the distress cause analysis, five typical SCCB bridge deck pavements were selected. The temperature distribution and the temperature stress of the pavement structures were analyzed by numerical simulation under periodic temperature variations. In addition, considering the daily variation in traffic volume, the permanent deformation of the five pavement structures were calculated under temperature-load coupling effect. Finally, the influence of heavy load on the development of rutting distress was also investigated. The results show that the temperature field and temperature stresses within the SCCB bridge deck pavement exhibit periodic variations under periodic temperature variations. Additionally, after 500,000 times of standard axle load application, “EA + SMA” exhibits the smallest permanent deformation and the best resistance to rutting distress under temperature-load coupling effect. Finally, heavy load conditions have a great influence on the permanent deformation of SCCB bridge deck pavement. In areas with severe rutting distresses, it is recommended to use “EA + SMA” pavement structure in SCCB bridge.

Theoretical and Numerical Analyses of Steel-timber Composite Beams with LVL Slabs

Recently conducted studies have shown that significant benefits are to be gained by joining steel beams and timber slabs. Steel-timber composite beams present a sustainable solution for the construction industry because of their high strength and stiffness, and lower carbon footprint and self-weight than steel-concrete composite beams. The behaviour of steel-timber composite beams is still being investigated to reduce knowledge gaps. This paper presents theoretical and numerical analyses of steel-timber composite beams consisting of steel girders and laminated veneer lumber slabs. The elastic and plastic resistance to bending were estimated analytically based on the elastic analysis and the rigid-plastic theory. The impact of the composite action, the LVL slab thickness, the cross-section of a steel girder and the steel grade on resistance to bending was evaluated. The load-deflection curve of the composite beam was obtained using a 2D finite element model, in which timber failure was captured using the Hashin damage model. The results of the numerical simulation were in good agreement with the ones of the theoretical analyses.

Experimental study on fatigue behavior of UHPC joint in negative moment region of π-shaped steel–concrete composite beams

To improve the crack resistance of concrete bridge decks in the negative moment region of π-shaped steel–concrete composite beam, a novel ultra-high performance concrete (UHPC) joint was first proposed. Based on an actual bridge, a 1:2 scale model was then designed as the specimen. A fatigue test was conducted to investigate the variation of its structural properties during fatigue loading, and a static test was performed to evaluate its residual bearing capacity. The test results show that the new UHPC joint has good crack resistance under fatigue loading and can meet the engineering requirements. The stiffness of the specimen significantly decreases after 3 million fatigue cycles. However, without significant fatigue damage on the surface of specimen, plenty of stiffness is reserved. It is found that there is no significant slip between the concrete deck and steel girder, and between the UHPC and normal concrete in the static test after fatigue, indicating that the studs inside the π-shaped steel–concrete composite beam are arranged reasonably and the interaction of the overall structure is reliable. Furthermore, the ultimate bearing capacity of the specimen decreased by only 9.4% from its design value after being subjected to 3 million fatigue cycles. It is revealed that the application of UHPC in the composite beam effectively improves its crack resistance, resulting in a smaller reduction in bearing capacity. This paper can provide theoretical foundation for the preparation and application of the π-shaped steel–concrete composite beams with UHPC joints.

Experimental study and numerical simulation on shear behavior of steel and concrete composite beam with molybdenum tailing

To improve the flexural performance of steel–concrete composite beams and alleviate the problem of sand depletion caused by the application of concrete structures, this paper proposes a new type of steel-molybdenum tailings concrete composite beam. In order to further study the shear performance of the new type of steel-molybdenum tailings concrete composite beam, this paper couples molybdenum tailings replacement ratio (0%, 50%, and 100%) and shear span ratio (1 and 2) as research parameters, designs a total of six 1:2 scaled composite beam models, and conducts monotonic loading tests to study the failure process, failure mode, ultimate bearing capacity, deformation, and local strain of some typical measuring points of the new composite beam. The steel and concrete composite beam with the molybdenum tailing has the similar mechanical behavior for each ratio of the shear span to the effective depth with that of the steel and concrete composite beam. In addition, they have a little difference in the failure processes for each ratio of the shear span to the effective depth, whereas they show typical diagonal compression failure mode for the ratio of the shear span to the effective depth is equal to 1 and the representative shear-compression failure mode for the ratio of shear span to effective depth is 2, and have no obvious difference in failure mode for each ratio of the shear span to the effective depth. Their shear resistance mechanism is basically the same. Furthermore, based on the validated finite element model, this paper conducted a parameter extension analysis. The finite element results show that: The ultimate load bearing capacity of the steel and concrete composite beam with molybdenum tailing varies significantly with the beam section size (beam section width and beam depth), reinforcement ratio, and the ratio of the shear span to the effective depth; Whereas it has little relation to the steel plate thickness. This provides the necessity and feasibility to use the steel and concrete composite beam with the molybdenum tailing in engineering practice. The proposed equation in this study is based on the previous researches and the simulated and test results. The proposed equation is rigorous and thorough and the predicted results are highly accurate and effective.

Experimental study on fatigue damage of continuous steel–concrete composite beam by acoustic emission

To investigate the developing process and mechanism of internal fatigue damage of continuous steel–concrete composite (CSCC) beams, the fatigue test of two-span CSCC beams under cyclic loading was conducted, and the acoustic emission (AE) testing method was used to monitor the fatigue damage accumulation during loading. Internal AE propagation characteristics and residual deflection were compared to analyze the overall damage process as well as the boundary points of each fatigue stage. The fatigue failure mechanism of CSCC beams was deduced from an internal damage point of view. The fuzzy C-means algorithm was used to cluster the AE signals and extract the signals of the concrete structure. According to the energy accumulation-release signal of the fatigue crack tip, a novel method for fatigue damage location identification of the concrete structure was proposed, and the propagation characteristics of the fatigue crack along with the variation law of the AE wave velocity within the concrete slab were further investigated. Control parameters for fatigue damage, similar to the relationship between magnitude and frequency of earthquakes, were calculated, and the warning signs of fatigue failure of CSCC beams were inferred. The AE cumulative energy-based fatigue damage model was proposed to predict the damage status and fatigue life of the composite beam. Results have shown that the AE detection method is capable of continuously and accurately monitoring the fatigue damage within the composite beams in real-time as opposed to inspections that are solely based on appearance. The fatigue damage energy model also confirmed the fact that the fatigue damage growth follows an exponential function. The fatigue damage energy model and the AE method proposed based on AE attributes provided a more feasible and stringent method for fatigue damage prediction and analysis for CSCC beams.

Experimental study of innovative bolted shear connectors in demountable cold-formed steel–concrete composite beams

Although cold-formed steel (CFS) members have been widely used in structures, their application is limited due to the buckling and instability of these members. To enhance their strength and stiffness, they are often combined with other materials like concrete or timber. One of the main challenges in composite structures is ensuring proper connection between different components to facilitate safe shear load transfer. This is achieved through various types of shear connectors. Bolted shear connections are preferred over headed shear studs because they offer greater strength and can be easily dismantled. Headed shear studs welded onto a steel section are unsuitable for CFS members due to their low thickness.In this paper, we propose a novel demountable composite connection specifically designed for prefabricated CFS structures. The behavior of this connection was evaluated through fifteen push-out test specimens, with key variables including CFS section thickness and bolt diameter/strength. The ultimate load, stiffness, ductility, and failure modes of all specimens were determined. The results revealed that specimens with a higher thickness of CFS members experienced bolt fracture, exhibiting superior effective stiffness, strength, and ductility. Conversely, specimens with a lower thickness of CFS members failed due to distortional buckling of the CFS members. The test results underscore the importance of carefully designing and providing a proportionate CFS section thickness to ensure shear connectors fracture before the CFS members. This significantly improves the shear strength capacity of the composite connection with CFS sections and precast concrete slabs. Furthermore, the deconstructability of the connection at the end of its service life was investigated. The steel–concrete composite connection with precast concrete slabs and demountable bolted shear connections was also modeled using a 3D finite element method. The numerical model’s accuracy in simulating the observed structural behavior was confirmed against experimental data. Finally, appropriate and straightforward formulations for predicting the ultimate load of the CFS-concrete composite connection were proposed. It was concluded that the predictions of ultimate shear load capacity values by EC4, AISC, and AISI provisions for this composite connection are significantly less accurate.

Behavior and design of steel-UHPC composite beams subjected to negative moment

To improve the crack resistance of concrete deck slabs of steel–concrete composite beams in the negative moment regions, Normal Concrete (NC) and Ultra-high Performance Concrete (UHPC) were respectively used to cast the deck slab to investigate the effects of different slab materials on the failure modes, crack characteristics and flexural performance. The flexural performance tests under negative bending moment were conducted, and the impact of different slab materials on the mechanical performance of the composite beams were analyzed using the numerical simulation method verified by the tests. The method of calculating the ultimate flexural capacity of steel-UHPC composite beam, which considered the material micromechanics mechanism such as fiber distribution, orientation, burial depth and interfacial bond strength, was proposed based on the simplified plasticity theory and were verified with existing method by the test results of related literature. The results show that the force characteristics of the two composite beams were similar, and the failure modes were both flexural failures. Compared with the steel–concrete composite beam, the cracks of the steel-UHPC composite beam were more evenly distributed and narrower, with larger crack distribution spacing and fewer secondary cracks. The cracking resistance of composite beam can be effectively improved by using UHPC slab, and the flexural capacity improved slightly. The cracking load of the deck slab of the steel-UHPC composite beam was improved by 500%, the corresponding load when the crack width reached 0.2 mm was improved by 37.5%, and the ductility and ultimate flexural capacity were improved by 30% and 5 %. In addition, the ultimate flexural capacity of steel-UHPC composite beam should consider the tensile contribution of UHPC, and the proposed calculation method is suitable for steel-UHPC composite beam with different UHPC mix ratios.

Analysis of the layered steel-concrete pervious composite beam under moving point load

Analysis of the layered steel-concrete pervious composite beam under moving point load

High‐Performance Pre‐engineered Steel‐Concrete Composite Beams for Sustainable Construction – Mechanical Behaviour of the Full‐Scale Beams

AbstractThis paper presents an experimental study on the behaviour of high‐performance pre‐engineered steel‐concrete composite beams. The slab is constructed with green concrete of grade C55/67 made using recycled concrete aggregates to replace 20% of natural aggregates, and GGBS together with silica fume as supplementary ce‐mentitious materials to replace 25% of the Ordinary Portland Cement (OPC). Pre‐engineered (built‐up) structural steel asymmetric section of grade S460M is adopted for optimised structural efficiency. To verify the compatibility among the three different materials used, i.e., the S460M structural steel, green C55/67 concrete, and the shear studs, shear connection specimens were designed and tested with reference made to EC4. Subsequently, 2 full scale steel concrete composite beams are tested until failure. The results showed that the EC4 design equations for predicting the shear resistance and the bending moment resistance are still conservative for the materials and full‐scale beams.

A Parametric Study on the LDB Strength of Steel-Concrete Composite Beams

Lateral distortional buckling (LDB) is an instability phenomenon characteristic of steel-concrete composite beams (SCCB) that occurs in the presence of hogging moments in regions close to internal supports. The LDB behavior in SCCB is not yet fully understood. The procedures for determining the LDB strength are based on the classic lateral torsional buckling theory or on the inverted U-frame model. In addition, the standard procedures make use of the classic design curves of the SSRC (Structural Stability Research Council) and ECCS (European Convention for Constructional Steelwork) developed to analyze the stability behavior of steel elements. However, studies indicate that the use of the same empirical curves obtained for the analysis of steel elements leads to the conservative results of the LDB strength in SCCB. Therefore, this article aims to assess the LDB strength in SCCB through the development of post-buckling numerical analysis using the ABAQUS software. In the parametric study, four types of steel with different mechanical properties were analyzed. In addition, the I-section, the unrestrained length, and the reinforcement rate in the concrete slab were varied. The results showed the influence of the steel type on the LDB strength and deviations from the standard procedures. A small influence of the longitudinal reinforcement area variation was verified in the LDB strength in the FE analyses; however, this factor is significantly important in the standard procedures, causing considerable divergences. These results can provide a reference for future research and specification reviews.

Mechanical behavior of asphalt pavement on steel-concrete composite beam bridge under temperature-load coupling

Over the past few decades, steel–concrete composite beam (SCCB) bridges have been gaining popularity all over the world. However, distresses such as rutting, delamination and cracking may occur on the corresponding bridge pavement structure soon after open traffic. To alleviate pavement distresses and clarify the applicability of different pavement structures and materials, in this study, a targeted research method for the mechanical properties of SCCB bridge deck pavement under temperature-load coupling was proposed. The research elements and procedures of the SCCB bridge deck pavement were structurally analyzed and synthesized. In addition, a temperature-load coupling model of SCCB bridge deck pavement was established. The permanent deformation under different cumulative axle load action times was calculated and fitted, and then compared with the actual detected data. Finally, the mechanical response of pavement structures commonly used for SCCB bridges was analyzed. The results show that the absolute error of rutting depth between the field test and fitting result was small, which proved the rationality of the proposed method. Besides, for SCCB bridges, “AC + SMA” and “double-layer SMA” have better road performance. The conclusion of this paper provides reliable support for the maintenance and distress causes analysis of SCCB bridge deck pavement.

Numerical and analytical investigations on the flexural behaviours of composite beams of inverted-T steel section and ultra-high-performance concrete (UHPC) slab

This study numerically and analytically investigates the flexural performance of a new form of steel–concrete composite beam, where an inverted-T section is connected to ultra-high-performance concrete (UHPC) slab that serves as the compression chord. Such arrangement eliminates the necessity for the top flange and absorbs the compressive stresses when the beam is under construction. Thus, the aim of this study is to develop a comprehensive finite element (FE) model for the proposed inverted-T steel-UHPC composite beam in ABAQUS by considering both geometric and material nonlinearities. The developed FE model was validated against the existing experimental results, and afterwards the validated FE model was employed to conduct an extensive parametric study. In the parametric study, the effects of different design parameters including slab thickness, concrete compressive strength, stud spacing, stud diameter, effective width of slab and web penetration depth were investigated in terms of the load–deflection, bond-slip, and damage patterns. Furthermore, the load–deflection and load-slip behaviors of the proposed beam were compared with the conventional steel–concrete composite beam. Finally, an analytical procedure was developed to determine the flexural resistance of the inverted-T steel-UHPC composite beam. The results of this study will pave the way toward a practical application that is expected to decrease the construction time and cost.

Influence of longitudinal prestress on the shear resistance of prefabricated shear stud connectors

In order to meet the requirements of accelerated bridge construction (ABC), the structure of steel–concrete composite bridges presents a development trend of the entire assembly. A Prefabricated Composite Shear Studs (PCSS) is proposed to speed up the assembly efficiency of traditional steel–concrete composite beams and improve the effectiveness of the prestress of prefabricated concrete decks in the negative moment zone. A finite element model (FEM) of the PCSS shear connector is established by considering the stress characteristics of different assemblies, thirty different steel tendon quantities, and relative arrangements are selected to analyse the impact of longitudinal prestress on the shear resistance of PCSS, the effectiveness of finite element model is verified this through test results. It is revealed that the steel tendon arrangement and quantity will change the shear resistance of the PCSS shear connectors. However, the magnitude, positive and negative effects are related to the position of the steel tendon along the deck height. When the steel tendon deviates downward from the neutral axis of the deck, the shear bearing capacity and shear stiffness increase; in addition, its force transfer mechanism is that the longitudinal prestress changes the lateral restraint effect of the PCSS on the concrete. Under the combined action of prestressing and transverse restraint of steel plate, the cooperative working ability of the stud and surrounding concrete can be enhanced or weakened. Thus, the yielding of stud and concrete damage can be delayed or accelerated, significantly affecting the shear bearing capacity and stiffness.

Investigating the behavior of composite steel–concrete beams with X-HVB shear connectors exposed to various fire temperature levels

Investigating the behavior of composite steel–concrete beams with X-HVB shear connectors exposed to various fire temperature levels

Numerical method and validation using ANN of composite steel–concrete beam for optimized geometry and emplacement of web opening

Numerical method and validation using ANN of composite steel–concrete beam for optimized geometry and emplacement of web opening

Influence of loading direction on X-HVB shear connectors in partially composite steel–concrete beams exposed to fire

Influence of loading direction on X-HVB shear connectors in partially composite steel–concrete beams exposed to fire

Bending Analysis of Steel-Concrete Composite Beams with Porosity

This study investigated the bending behavior of a simply supported pervious composite beam using the finite element method based on cubic order beam theory. The cubic order axial displacement was assumed and solved using shear stress-free conditions on the extreme surfaces of the composite beam. For simplicity, this study considered one-dimensional axial displacement. Three nodded finite elements were assumed, and each node had eight unknowns. Shear locking was eliminated in the present model by numerical integration of the stiffness matrix. A uniform porosity distribution was implemented in the upper layer of the composite beam. The damping ratio was also considered for the bending analysis. The accuracy of the present model makes it robust for the analysis of composite beams.

Lateral distortional buckling of continuous composite beams in fire situation: Experimental and numerical analyses

In continuous steel-concrete composite beams, hogging moments may occur near the internal supports. This type of bending causes compression in the bottom flange, which may buckle laterally in an ultimate limit state known as lateral distortional buckling. Despite the consideration that continuity may result in an economic design, no research had yet been conducted on the possibility of lateral distortional buckling in continuous composite beams in fire situation. This paper presents an experimental and numerical study on the lateral distortional buckling of steel concrete composite beams. Four real scale fire tests were conducted and proved that it may indeed occur. A parametric study was also developed. It has been shown that this buckling mode may lead to a reduction in the strength of composite beams of up to 50% when compared to the plastic moment. It was also noted that this buckling mode is usually accompanied by local buckling, which may occur even in compact sections, leading to a decrease in bearing capacity. These results indicate a need of reviewing the design codes to consider the possibility of lateral distortional buckling at high temperatures, as it may be more than at ambient temperature.

Experimental and theoretical investigation of concrete filled and encased steel column under compression loading

Steel-concrete composite beams find extensive usage in high-rise buildings and bridges. The primary advantages of composite beams are high strength, high ductility, and fire resistance. In this research, the effect of the position of steel tube such as concrete encased and filled steel tube column and concrete filled steel tube column. The author bought Fe250 grade steel from the local market. The steel tube comes in two shapes: circular and rectangular. The entire column was subjected to a concentrated load until it failed. Compared to the concrete encased and filled steel tube column, the concrete filled steel tube column has a higher value of Young's modulus. The theoretical load carrying capacity of CFST is 367.74 kN, which is 19.64% lower than the experimental load carrying capacity. The theoretical load carrying capacity of CFCT is 206.80 kN, which is 28.43% lower than experimental CFCT. Theoretical load carrying capacity of CFST is 26.05% higher than the theoretical load carrying capacity of CFEST. Theoretical load carrying capacity of CFCT is 60.29% higher than theoretical load carrying capacity of CFECT. The theoretical vs experimental load difference is not less than 0.72.