The authors present an experimental and analytical investigation of the modularized hybrid system (MHS) that utilizes the composite structure described in previous studies, that of a wide steel flange and precast concrete. The objective of this paper was to introduce the application of the MHS structural system to a high‐rise building in which one additional floor was added while the overall building height was maintained. The 68‐m‐tall, 18‐storey steel building was redesigned to a 19‐storey building using the composite beams, which combine the merits of ductile steel and concrete components to withstand external loading while reducing floor height. The bottom flange of the steel beam is reinforced with concrete at a manufacturing plant, eliminating the use of temporary pour forms. The erection process of the composite beams is identical to that of traditional steel construction. This paper also describes more than 30 potential applications of high‐rise composite construction using the MHS frames. The advantages of the MHS are presented in terms of reduced structural steel tonnage and shortened construction schedules. Copyright © 2009 John Wiley & Sons, Ltd.

An experimental investigation of composite beams composed of wide flange steel and precast concrete is presented. The bottom flange of the steel section is encased in precast concrete. Utilizing the merits of both steel and concrete material, the size of the steel beams can be reduced without sacrificing performance. The bottom flange of the steel beam is reinforced with concrete at a manufacturing plant, eliminating the use of temporary pour forms. The composite beams were tested to investigate how the size of the wide flange steel and how the top and bottom reinforcements influence the behaviour of the beams. Flexural load carrying capacity, load displacement relationships and failure modes were examined. The test specimens were T‐shaped composite beams with slabs, each measuring 10‐m long. The flexural moment strength of all of the composite beams—at both the yield limit state and the maximum load limit state—was measured and compared with the analytical flexural capacity. The stiffness degradation, ductility and dissipating energy capabilities of the composite beams were investigated based on the hysteresis curves. The composite beams tested in this study successfully reduced both the floor height of the building and the size of the steel beams needed to meet code requirements. Copyright © 2008 John Wiley & Sons, Ltd.