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The exceptional structural performance of steel‐concrete composite structures, which harness the advantages of both steel and concrete, has garnered considerable attention. Following a summary of the fundamental time‐dependent characteristics of concrete, this paper reviews the existing studies about the long‐term behaviour of various steel‐concrete composite components, including slabs, beams, columns and walls. For composite slabs, nonuniform shrinkage occurs along the thickness direction. The long‐term behaviour of composite beams is significantly affected by the degree of shear connection. While the creep and shrinkage effects of composite columns are substantially reduced in comparison to reinforced concrete columns, stress redistribution may cause yielding or buckling of the steel tube. However, there is currently limited research available on the long‐term behaviour of composite walls with profiled steel plates, and no studies have been conducted on composite walls made of double‐skinned flat steel faceplates infilled with concrete. This lack of knowledge may lead to design uncertainties for composite coupled wall‐frame structures. To bridge this gap, the authors are currently conducting a corresponding long‐term experimental program. [ABSTRACT FROM AUTHOR]

The emerging modular building construction technique is gaining attention by researchers and investors because of its benefits such as short construction time, better quality control, minimal environmental effect and more economical. Composite modules have many advantages, including size reduction and improved fire resistance, over the steel modules, which encourage the application of modular construction on tall buildings. Current state‐of‐art lacks the proper connection technique for composite modular tall buildings. This paper presents novel inter‐module connection for composite modular tall buildings. Purposed inter‐module connection is very simple in geometric design, adequately strong to bear loads for tall buildings, easy to connect and disconnect, and applicable with internal joints and composite modules. Bolts through bolt holes connect modules vertically whereas gusset plate connects horizontally. Firstly, prototype is developed, and workability is confirmed. Performance and failure mechanism of proposed connector under tensile load are evaluated considering the effect of different parameters such as thickness of base plate, size and material of bolt. Results can be used to develop the design guideline for proposed inter‐module connection. [ABSTRACT FROM AUTHOR]

In this research, an attempt has been made to evaluate the structural response of multi‐storey composite modular buildings when subjected to lateral wind loads. Finite element (FE) models were developed in Abaqus for a general 10 storey composite modular building, with and without the consideration of lateral load resisting mechanisms of composite shear walls. Concrete filled steel tubular (CFST) columns and composite shear walls were proposed in place of conventional elements to improve the structural resistance, modularity, and construction timeframe. It was observed that under the effect of wind loads, the forces between the modules are transferred primarily by horizontal axial forces. When the effect of sudden module removal is considered along with the wind, the vertical shear forces in the horizontal inter‐module connection increase and the connection becomes critical in shear. Even though the probability of occurrence of critical wind loads and a sudden module loss is rare, it was concluded that the wind forces do not influence the overall stability of the structure in the event of progressive collapse by sudden module removal if an effective lateral load resisting mechanism has been designed. [ABSTRACT FROM AUTHOR]

This study examines the use of steel fibers in enhancing the ductility of an economical ultra‐high strength concrete (UHSC). The addition of fibrous material with very small geometry in this mixture is an effective solution to improve its ductility and prevent its brittle failure which is a common characteristic of UHSC. Different mechanical properties of reinforced and unreinforced concrete (e.g., slump flow, compressive, splitting tensile strength tests, and failure modes) were taken into account to find out the efficiency of micro steel fibers. The test results showed that concrete containing 25 mm length and 0.20 mm diameter steel fibers at a volume fraction of 0.5% not only presented a reasonable improvement in ductility performance but also ensured cost‐effectiveness. The cost evaluation conducted on several existing mix designs is also introduced in this study to investigate the influence of various steel fiber contents on the total cost of concrete so that figure out the lowest budget solution. The evaluation shows the high price of fiber reinforcement in which an addition of steel fibers by 5% volume could increase 7% of the total concrete cost. [ABSTRACT FROM AUTHOR]

Summary: This paper investigates the behavior of high‐rise composite buildings with composite shear walls and concrete‐filled steel tubular (CFST) columns using a numerical model in OpenSees. In the model, the geometric and material nonlinearity of structural elements are captured by utilizing a fiber force‐based beam‐column elements with rigorously modified material stress–strain relationships. Besides, the confining effect of the concrete core, the semi‐rigid connections, and the coupling effect of composite shear walls is carefully taken into consideration. Finally, the case study of a 42‐storey composite building is conducted using the proposed model to provide a thorough understanding about the behavior of this kind of building. It shows that this innovative building has high loading capacity and significantly reduces the dimension of structural members (up to 50%) compared with the conventional RC building at the same loading capacity. Through the validation with test data, the suggested constitutive laws have shown the simplicity and high accuracy since the value of model error is only around 7%. In addition, the simulation results also indicate that the model can capture well the nonlinear behavior of tested specimens, especially, the failure and the formation of plastic hinges of coupling composite shear walls implicitly. [ABSTRACT FROM AUTHOR]