Steel-concrete Composite Buildings Research Articles

Assessment of the Tall Buildings Dynamic Response Considering the Geometric Nonlinearity and the Aerodynamic Damping

This research work aims to evaluate the dynamic structural behaviour of tall buildings when subjected to wind loads considering the effect of the geometric nonlinearity and also the aerodynamic damping, due to the relative movement between the structure and the wind action. This way, the project associated to a steel-concrete composite building with 48 floors and 172.8 m height is investigated, when subjected to wind nondeterministic dynamic actions. The composite building finite element model was developed based on the use of the Finite Element Method (FEM), utilising the ANSYS computational program, and considering the soil-structure interaction effect, aiming to obtain a realistic representation of the dynamic behaviour. The building dynamic response was obtained based on the displacements and accelerations values, determined having in mind a wind velocity range between 5 m/s [18 km/h] and 45 m/s [162 km/h]. The conclusions of this investigation pointed out to the fact that when the geometric nonlinearity effect was considered in the analysis the investigated building dynamic response presented relevant differences, with maximum differences up to 30% to horizontal translational displacements and up to 45% to accelerations. On the other hand, when the aerodynamic damping was considered the contribution was not significant to the structure dynamic response, with maximum differences up to 5% for the displacements and up to 10% for the accelerations.

Hybrid Bayesian-Copula-based damage probability estimation for steel-concrete composite tall buildings under concurrent seismic and wind loads

Hybrid Bayesian-Copula-based damage probability estimation for steel-concrete composite tall buildings under concurrent seismic and wind loads

Study and Analysis of Steel, RCC, and Composite Structure Comparison

In India, plain concrete is a common building material, especially for medium- and low-rise buildings. Even while steel is still widely used in high-rise structures and composite construction is less frequent, it's possible that composite construction could prove more beneficial in these projects. Reinforced concrete is often used in construction projects. Steel beams are put into concrete to make reinforced concrete, an efficient composite material. The distinguishing feature of composite construction is the secure joining and bending of two load-bearing structural elements into a single piece. When compared to RCC most steel frames, composite constructions are considered to be some of the least expensive and transient building materials. The main component of a composite construction is an I-section column embedded or encased in building materials, or a tube of steel filled with steel and concrete. Composed of cold steel plates plus mortar, Part I consists of a beam plus a plate for the deck. The beams are connected to the top slab using fire-resistant and robust shear connections. Keywords— Steel Concrete Composite Building, RCC building, Seismic Analysis etc.

Seismic evaluation of existing reinforced cement concrete building and steel–concrete composite building

Seismic evaluation of existing reinforced cement concrete building and steel–concrete composite building

Experimental Study of Novel Demountable Shear Connectors for Steel-concrete Composite Buildings

Sustainable composite structures in building construction are assembled using demountable structural elements that can be reused in the circular economy. The current research and development project, in cooperation with Budapest University of Technology and Economics and KÉSZ Group, bim.GROUP Ltd., Hungary, aims to design a novel demountable steel-concrete composite slab and frame system for buildings. The key component of this construction is the demountable shear connector. In the current research, novel bolted shear connectors with embedded bolts and threaded rods are developed and studied that can fit the applied technology of the industrial partner. One of the leading aspects of this connection is the consideration of bolt hole clearance, since it occurs initial slip and stiffness reduction of the composite beam. In the first phase of the research program, demountable and economical structural details were developed, which can reduce the stiffness reduction with the proper resistance and ductility features. To study the behavior of these shear connections, a push-out experimental program was designed and completed in March and April 2023. It is observed that novel shear connectors have a proper behavior with sufficient resistance and ductility, which is applicable according to the Eurocode 4 standard and fits the objectives of the research and development project. In the paper, the developed structural details and the push-out experimental program are presented with general results and statements besides a detailed evaluation of a specified specimen type.

Research on section dimension optimization of high-rise steel–concrete composite buildings based on improved dividing rectangle algorithm and combined response surface model

Optimizing the design of high-rise steel–concrete composite buildings poses significant challenges due to the diverse range of components and complex arrangement. To optimize this type of structure while considering both optimization efficiency and structural reliability, an optimization method based on an improved DIviding RECTangle algorithm and combined response surface models is proposed herein. Firstly, the standardized section number of components with the same initial section dimension and material strength grade is treated as a variable. Each variable represents a dimension of the initial hyperrectangle, and the subdivision sequence is determined based on the design priority index. Subsequently, after each subdivision, potential optimal hyperrectangles are identified by evaluating the objective function value with constraint penalties at hyperrectangle center points and the distance from the points to the vertices. By continuously subdividing the potential optimal hyperrectangles, initial sampling points are obtained. Furthermore, combined response surface models for the objective and constraint functions are constructed. Finally, by continuously solving the sub-optimization problem to update the response surface models until the algorithm converges, the optimization of structural cost can be achieved. The case studies demonstrate that this method is capable of satisfying the structural constraints while efficiently optimizing the section dimension of high-rise building components.

Shake table tests of a full-scale two-story plate-type modular composite building with semi-rigid corner connections

To study the dynamic characteristics and seismic response of a novel plate-type modular steel–concrete composite building with different semi-rigid corner connections under different seismic levels, a full-scale two-story two-room test model with L-shaped and T-shaped II corner connections was designed and built according to the Chinese typical area with an eight-degree seismic precautionary intensity and a design basic acceleration of ground motion of 0.2 g. The test model was subjected to white-noise tests and horizontal biaxial seismic tests by applying two natural seismic waves (the EL Centro wave and the Chi-Chi Taiwan wave) and one artificial wave on a shake table. The test program and the results were presented in detail in this paper. The experimental phenomena were analyzed, and the dynamic characteristics (fundamental frequency and damping ratio) and seismic performance (acceleration dynamic amplification factor, global lateral displacement, building drift, shear force distribution, and strain response at key positions) were investigated and discussed. The test results showed that the full-scale two-story plate-type modular composite building has good seismic performance and little damage under a severe earthquake due to the strong diaphragm action of the exterior glass fiber-reinforced concrete wall panels.

Evaluation of Seismic Response of Composite Buildings under Near-Field Earthquakes

This paper represents the effectiveness of the bracing system concerning the seismic performance of steel-concrete composite buildings by comparing 5-storey composite buildings with and without bracings subject to extreme earthquake loads. The nonlinear time history analysis (NTHA) is carried out on the specific building models considered for this study. The seismic response is obtained in terms of different seismic response parameters which are further compared to determine the effect of the bracing system. The results obtained by applying real earthquake records of different near-field & far-field earthquakes were compared for three earthquake response parameters which include base shear, inter-storey drifts, and storey displacements. The bracing system is very effective in resisting the seismic force when subjected to extreme earthquakes as it increases the overall stiffness of the building. The bracing system improves the overall performance of the composite building by reducing the inter-storey drifts and maximum storey displacement under extreme earthquakes.

Performance evaluation of steel-concrete composite structures designed in poorly graded soils

In this study, the seismic behavior of steel concrete composite buildings in a specific region was investigated. For this purpose, 5-, 10-, 15- and 20-storey composite moment-resisting framed structures were designed. Moment-resisting composite framed structures are modeled with concrete-filled steel tube columns and designed and modeled using composite beams. The buildings are designed according to ÇYTHYE-2016 and TBEC-2018 regulations at design levels with high ductility. In the design of the designed structures, the peak ground acceleration value is 0.79 g, and the design ground is planned as ZE class. SeismoStruct software was used for the design and performance evaluation of the structures. During the performance evaluations of the structures, nonlinear static pushover and incremental dynamic analyzes were used. Uniform and triangular load distributions are adopted in the static pushover analysis and 16 earthquake ground motions are used in the incremental dynamic analysis. Evaluation of the effect of the number of stories on the earthquake behavior of composite moment-resisting framed structures was investigated using the non-linear analyzes mentioned. Accordingly, lateral response, overstrength factors, ductility, and dynamic behavior factor values for composite frame structures were calculated and presented using the relevant analysis results. It has been calculated that the behavior factor of all moment-resisting composite framed structures can perform well above the design assumptions, whereas moment-resistant composite framed structures absorb seismic energy by using inelastic deformations. Ductility is almost 30% higher than the design assumption for international standards. As a result, it was concluded that these structures could continue to serve theoretically.

Analysis and Design of Steel Concrete Composite Structure and Its Comparison with RCC Structure

Abstract: Composite Structure is quickly gaining acceptance in India's non-residential multi-story building sector. The reason for considering composite construction is simple: Steel is best in tension and concrete is best in compression. Combining these two materials strengthens their structural properties, which can be used to create a highly effective and lightweight design. Steelconcrete composite building systems are formed by connecting the steel beams to the profiled deck slab using shear connectors so that they function as a single unit, and for columns steel section is encased in concrete. In this present work, comparative study of G+15 R.C.C and composite multistorey commercial building located in Earthquake zone IV is Considered by Equivalent Static Method of Analysis. ETABS 2018 Software is used for modelling of both the structure. Storey Displacement, Storey Drift, Storey Shear, Self weight, Axial force, Bending moment and Shear force are considered as parameters. When the results are compared, it is observed that the Composite structure is superior in every aspect. Keywords: Composite Structure, Composite Column, Composite beam, Deck slab, Shear connectors, Equivalent Static Analysis, ETABS 2018

Parametric Analysis of the Performance of Steel-Concrete Composite Structures Designed with TBDY 2018

In this study, the seismic behavior of steel-concrete composite buildings designed using ÇYTHYE 2016 and TBDY 2018 was investigated. For this purpose, composite moment resisting frame buildings with concrete filled steel tube columns and composite beams with 5, 10, 15 and 20 stories are modeled. Buildings are designed at high ductility (DCH) levels. During the design of the DCH class structures, the design was carried out for the ZA soil class for 0.79 g PGA in the region selected from the earthquake map given in the regulations. Within the scope of the study, SeismoStruct software was used during the design and performance evaluation of the structures. Incremental dynamic analyzes were used along with nonlinear static pushover analyses. In the static pushover analysis, uniform and triangular load distributions of the lateral load are adopted. In the dynamic analysis, 16 earthquake ground motions were obtained from AFAD earthquake acceleration databases according to the relevant design area and used. The variation of the seismic behavior of CMRFs depending on the variation of the floor number was investigated using nonlinear analysis results. Accordingly, the variation in lateral response, overstrength factors and ductility factors for CMRF structures are presented comparatively. In addition, the section deformation capacities were investigated during the IDR changes during dynamic and static nonlinear analyses. The behavior factor of all CMRFs, especially the CMRFs studied in the case study, demonstrated above-expected performance according to the design assumptions.

Seismic response reduction of high rise steel-concrete composite buildings equipped with base isolation system

This study presents the effectiveness of the high-rise multi-storey buildings in reducing the seismic response induced during the earthquake events with the implementation of the Base Isolation system. For this, two base-isolated steel–concrete buildings are considered for the analysis having twelve and fifteen storey levels. The lead rubber bearing isolators are used for providing the base isolation system for these buildings. For the sake of comparison of the seismic responses of composite base-isolated buildings, their fixed base Reinforced Concrete and Composite counterparts are also modelled. The Seismic responses are evaluated by performing the response spectrum method for the highest seismic zone as per Indian Code. The results of the study indicate that that base isolation provided with the lead rubber bearing isolators is effective in reducing the overall seismic responses of the composite buildings in the range of 50% - 60%. The effectiveness of the base isolation is more in the case of 15 storeyed building. The reduction of approximately 50% is found in the storey drift and displacements of the base isolated composite building in comparison to reinforced concrete building.

Assessment of Seismic Behavior Factor of Code-Designed Steel–Concrete Composite Buildings

In this study, the seismic behavior factor of steel–concrete composite buildings was examined. For this purpose, 5-, 10-, 15- and 20-story composite moment-resisting frame (CMRF) buildings having concrete-filled steel tube columns and composite beams were designed at medium ductility (DCM) and high ductility (DCH) levels as per the regulations of Eurocode 8. Examined DCM structures were designed for a PGA of 0.2 g while DCH structures were designed for a PGA of 0.4 g. SeismoStruct software was utilized in the design and performance assessment of the case study structures. Nonlinear static pushover and incremental dynamic analyses were used. In the pushover analysis, the uniform and triangular load distributions were adopted while 12 earthquake ground motions were employed in the dynamic analysis. The effect of ductility levels and number of stories on the seismic behavior of CMRFs was studied using the results of the nonlinear analysis. To this, the variation in the lateral response, global yielding value, code-based behavior factor and component, and dynamic behavior factor were presented for CMRF structures with DCM and DCH. It was observed that the behavior factor of all CMRFs exhibited well above the design assumptions, especially DCM class CMRFs.

Parametric Study of G+15 R.C.C , Steel and Steel Concrete Composite Building based on Seismic Analysis

Parametric Study of G+15 R.C.C , Steel and Steel Concrete Composite Building based on Seismic Analysis

Optimized seismic retrofit of steel-concrete composite buildings

This work is focused on comparatively assessing the cost-effectiveness of three seismic retrofit approaches for non-code-conforming frame buildings with steel-concrete composite columns. The first two of the assessed retrofit approaches aim in indirectly enhancing structural system performance by strengthening individual composite columns using reinforced concrete jackets or concrete-covered steel cages. The third retrofit approach considered aims in upgrading the composite building frame at hand by installing steel bracings at selected bays. A specially developed structural optimization procedure is used to perform an objective comparison of the cost-effectiveness of the three retrofit approaches. The objective of the optimization procedure is to minimize the total retrofit material cost, while constraints are imposed to ensure the satisfaction of design requirements for the retrofitted structure regarding member capacities (according to Eurocodes 3 and 4 for steel beams and composite columns, respectively), structural system performance under horizontal loading (based on interstorey drifts calculated by pushover analyses) and fundamental periods (obtained from eigenvalue analyses). By defining 30 cases of under-designed 2-storey, 4-storey and 6-storey composite buildings (i.e. buildings with steel-concrete composite columns), an extensive numerical investigation involving 120 retrofit optimization runs was conducted. The results obtained provide insight into the relative cost-effectiveness of the three seismic retrofit approaches and reveal certain conditions under which each approach is economically most viable.

Progressive Collapse Analysis of Three-Dimensional Steel–Concrete Composite Building due to Extreme Blast Load

AbstractThis paper investigated the behavior of three-dimensional (3D) steel-concrete building under external explosion considering the slab and connection rigidity. Most of the work carried out so...

Behavior of an Advanced Bolted Shear Connector in Prefabricated Steel-Concrete Composite Beams.

The high-strength bolt shear connector in prefabricated concrete slab has advantages in applications as it reduces time during the construction of steel-concrete composite building structures and bridges. In this research, an innovative and advanced bolt shear connector in steel-concrete composite structures is proposed. To investigate the fundamental mechanical behavior and the damage form, 22 static push-off tests were conducted with consideration of different bolt dimensions, the reserved hole constraint condition, and the dimension of slab holes. A finite element (FE) model was established and verified by using test results, and then the model was utilized to investigate the influence of concrete strength, bolt dimension, yield strength, bolt pretension, as well as length-to-diameter ratio of high strength bolts on the performances of shear connectors. On the basis of FE simulation and test results, new design formulas for the calculation of shear resistance behavior were proposed, and comparisons were made with current standards, including AISC, EN 1994-1-1, GB 50017-2017, and relevant references, to check the calculation efficiency. It is confirmed that the proposed equation is in better agreement with the experimental results.

Research on Application of Uplift-Restricted Slip-Permitted (URSP) Connectors in Steel-Concrete Composite Frames

Tensile stresses and cracks in concrete slabs induced by a hogging moment have always been a disadvantage of steel-concrete composite structures and key issue of concern in the design of such structures. To reduce the tensile stress and control the crack width of the reinforced concrete (RC) slab, a new type of connector, called the uplift-restricted and slip-permitted (URSP) connector has been proposed and successfully applied in the area subjected to a negative bending moment in steel-concrete composite bridges. The feasibility of the URSP connector in steel-concrete composite frame buildings is investigated in this study based on a comprehensive parametric analysis. The effects of URSP connectors on the cracking behavior, as well as the stiffness and strength of composite frames, are systematically analyzed using an elaborate finite element model, which resembles a typical composite beam-column joint subjected to both lateral loads and vertical loads. In addition, an optimized arrangement length of URSP connectors is proposed for practical design. The research findings indicate that the application of URSP connectors greatly improves the crack resistance of RC slabs without an obvious reduction of the ultimate capacity and lateral stiffness of the composite frame. It is recommended that the distribution length of URSP connectors at each beam end should be 20–25% of the frame beam length.

Influence of repairable bolted dissipative beam splices (structural fuses) on reducing the seismic vulnerability of steel-concrete composite frames

After a strong earthquake, repair work of conventional steel-concrete composite buildings can be very expensive, and very often, impossible due to practical problems. Within the EU-funded research project FUSEIS, a new steel-concrete composite frame type has been developed, as a cost-effective and robust alternative to conventional earthquake resistant structures. In this new frame type, damage concentrates mainly in the bolted dissipative beam splices acting as “structural fuses”, which can be easily and inexpensively replaced after strong seismic events. After the replacement, the building can be restored to its original form. This paper studies a benchmark building frame with and without bolted dissipative beam splices. The performance of both innovative and conventional structures has been quantified in terms of energy dissipation, floor displacements and inter-story drifts, as a result of nonlinear transient dynamic analysis. Different than similar studies in the literature, the numerical models explicitly consider the presence of reinforced concrete slab by means of fiber-based distributed plasticity approach. They have been calibrated according to the experiments, both provided in the literature and performed in the FUSEIS research project. The models allowed the quantification of the energy dissipated by each component of a steel-concrete composite frame (structural fuses, steel elements, concrete slab and steel reinforcement), which gave an insight on redistribution of dissipated energy in the case of adopting the structural fuses with respect to the traditional steel-concrete composite buildings. Based on the results of the numerical analysis, the reparability aspect has been discussed.

Vibration analysis of steel–concrete composite floors when subjected to rhythmic human activities

The main objective of this research work is to investigate the dynamic structural response of floors, when subjected to rhythmic human activities (aerobics), based on experimental tests and numerical modelling. The focus of this investigation is to assess the human comfort of floors, initially, simulating the individuals by traditional “force only” models and after that the effect of the people–structure dynamic interaction is considered based on the modelling of SDOF biodynamic models (mass–spring–damper systems). This way, the analysed structural model is related to a steel–concrete composite building, which is composed of three floors, with dimensions of 20 × 20 m, total area of 1200 m2 (3 × 400 m2) and a ceiling height of 4 m. The numerical modelling of the structure was performed based on the use of the ANSYS computational program and utilising the Finite Element Method (FEM) simulations. Aiming to evaluate the human comfort of the investigated composite floors, the dynamic characteristics of the individuals (mass, damping and stiffness) were experimentally obtained to introduce them into the developed biodynamic modelling. Thus, the dynamic response of the investigated composite floors was evaluated in terms of the peak accelerations, RMS and VDV values, based on current human comfort criteria. The results found along this investigation have indicated significant reductions of the peak accelerations values, when the biodynamic systems were considered in comparison with the results provided by the “force only” models.