• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.5
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• pp.111-118
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• 2020

The U-shaped composite beam used in this study consist of a reinforced concrete structure, a beam steel structure supporting the slab, a reinforced concrete structure, and a U-shaped steel plate. The U-shaped composite beam was developed for the purpose of using it as a parking lot because it is highly constructible and has low floor height and long span. For the improvement of constructivity, the U-shaped composite beam ends are planned with standardized H-shaped steel and connected directly to the columns, and the middle of the U-shaped composite beam consists of U-shaped steel plates folded in U-shaped form using thin steel plates (t=6) instead of H-shaped steel. In the middle of the composite beam, where U-shaped steel plates are located, the depth of U-shaped beam may be planned to be small so as to satisfy the height limit of the parking lot. It is important to grasp the structural performance according to the change of depth because low beam depth is advantageous for the reduction of the floor height, but it is a inhibitor to the structural behaviors of U-shaped composite beam. In addition, since U-shaped composite beams are a mixture of steel frame structures, reinforced concrete structures and U-shaped steel plates, securing unity has a great influence on securing structural performance. Therefore, in this study, a structural experiment was conducted to understand the structural performance according to the depth change for U-shaped composite beam. A total of three specimens were planned, including two specimens that changed the depth using a criteria specimen planned for a general parking lot. The results of the experiment showed that the specimens who planned the depth greatly had better structural performance such as yield strength, maximum strength, and energy than the standard specimen.

• Magazine of RCR
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• v.14 no.2
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• pp.54-58
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• 2019

• Steel and Composite Structures
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• v.9 no.3
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• pp.255-274
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• 2009

This paper presents an experimental study of a newly developed composite floor system, built up from thin-walled C-profiles and upper concrete deck. Trapezoidal sheeting provides the formwork and the fastening of the sheet transmits the shear forces between the C-profiles and the deck. The modified formation of the standard self-drilling screw in the beam-to-sheet connection is applied as shear connector. Push-out tests are completed to study the composite behaviour of the different connection arrangements. On the basis of the test results the behaviour is characterized by the observed failure modes. The design values of the connection stiffness and strength are calculated by the recommendation of Eurocode 4. In the next phase of the experimental study six full-scale composite beams are tested. The global geometry is based on the proposed geometry of the developed floor system. The applied shear connections are selected as the most efficient arrangements obtained from the push-out tests. The experimental behaviour of the composite beams are discussed and evaluated. As a conclusion of the experimental study the Eurocode 4 plastic design method is validated for the developed composite floor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1998.04a
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• pp.371-376
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• 1998

As the requirement of high-rise buildings in big cities increases, steel structural system becomes more popular in spite of the relatively higher material cost compared to that of the concrete structural system. Most of the steel structure adopts metal deck floor system because of the easiness in construction. However, the metal deck floor system has a weakness on vibration which became very important factor in office buildings, hotels and residential buildings as the more sensitive machines being used. Therefore, most, of the building codes in many countries restrict the natural frequency of the each floor should be higher than or equal to 15 Hz. Floor vibration of the KEM deck composite floor system which has been , developed recently from the engineers and scientists in Korea was measured. Also, the simplified analytical derivation of natural frequency for each floor was studied according to the measured natural frequency for each different boundary condition of the floor. As the length of the slab gets bigger, the natural frequency of the slab becomes lower even though the structural designer still considers it as a one-way slab.

• International Journal of High-Rise Buildings
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• v.6 no.1
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• pp.33-47
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• 2017

This mixed-use Raffles City (RCH) development is located near the Qiantang River in Hangzhou, the capital of Zhejiang province, located southwest of Shanghai, China. The project incorporates retail, offices, housing, and hotel facilities and marks the site of a cultural landscape within the Quianjiang New Town Area. The project is composed of two 250-meter-tall twisting towers with a form of vibrant waves, along with a commercial podium and three stories of basement car parking. It reaches a height of 60 stories, presenting views both to and from the Qiantang River and West Lake areas, with a total floor area of almost 400,000 square meters. A composite moment frame plus concrete core structural system was adopted for the tower structures. Concrete filled steel tubular (CFT) columns together with steel reinforced concrete (SRC) beams form the outer moment frame of the towers' structure. The internal slabs and floor beams are of reinforced concrete. This paper presents the engineering design and construction of this highly complex project. Through comprehensive discussion and careful elaboration, some conclusions are reached, which serve as a reference guide for the design and construction of similar free-form, hybrid, mix-use buildings.

• Steel and Composite Structures
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• v.20 no.2
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• pp.431-445
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• 2016

Seismic behavior of new composite structural system with a fabricated floor was studied. A two-bay and three-story structural model with the scale ratio of 1/4 was consequently designed. Based on the proposed model, multiple factors including energy dissipation capacity, stiffness degradation and deformation performance were analyzed through equivalent single degree of freedom pseudo-dynamic test with different earthquake levels. The results show that, structural integrity as well as the effective transmission of the horizontal force can be ensured by additional X bracing at the bottom of the rigidity of the floor without concrete topping. It is proved that the cast-in-place floor in areas with high seismic intensity can be replaced by the prefabricated floor without pouring surface layer. The results provide a reliable theoretical basis for the seismic design of the similar structural systems in engineering application.

• Steel and Composite Structures
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• v.47 no.4
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• pp.489-502
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• 2023

The strong column-weak beam (SCWB) moment ratio is specified in AISC 341 to prevent an abrupt column sway in steel special moment frames (SMFs) during earthquakes. Even when the SCWB requirement is satisfied for an SMF, a column-sway can develop in the SMF. This is because the contribution of the composite beam action developed in the concrete floor slab and its supporting beams was not included while calculating the SCWB moment ratio. In this study, we developed a new method for calculating the SCWB moment ratio that included the contribution of composite beam action. We evaluated the seismic collapse performance of the SMFs considering various risk categories and building heights. We demonstrated that the collapse performance of the SMFs was significantly improved by using the proposed SCWB equation that also satisfied the target performance specified in ASCE 7.

• Steel and Composite Structures
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• v.51 no.3
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• pp.289-304
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• 2024

The seismic performance of traditional steel frame-shear wall structures was significantly improved by the application of self-centering steel-reinforced concrete (SRC) wall-panel structures in the steel frames. This novel resilience functionality can rapidly restore the structure after an earthquake. The presented steel frame with steel-reinforced concrete self-centering wall-panel structures (SF-SCW) was validated, indicating its excellent seismic performance. The seismic design method based on bear capacity cannot correctly predict the elastic-plastic performance of the structure, especially certain weak floors that might be caused by a major fracture. A four-level seismic performance index, including intact function, continued utilization, life safety, and near-collapse, was established to achieve the ideal failure mode. The seismic design method, based on structural displacement, was proposed by considering performance objectives of the different seismic action levels. The pushover analysis of a six-floor SF-SCW structure was carried out under the proposed design method and the results showed that this six-floor structure could achieve the predicted failure mode.

• Journal of Korean Society of Steel Construction
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• v.19 no.4
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• pp.413-423
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• 2007

Slimfloor composite-beam systems could considerably reduce the story height of a building if the steel beam would be installed deep into the concrete floor slab. However, as the depth of the steel beam's installation is limited, it cannot cope with the various demands of building systems. To address this problem, a profiled steel beam section that can control the depth of the steel beam's and slabs' installation was developed in this study. Presented herein are the results of an experiment that was conducted focusing on the flexural behavior of the partially connected composite beams with profiled steel beams encased in composite concrete slabs. Five full-scale specimens with different slab types, with or without shear connection and reinforcement bars, were constructed and tested in this study. As a result, the shear bond stress without an additional shear connection was found to be $0.20{\sim}0.76N/mm^2$due to the inherent mechanical and chemical bond stress.

• Journal of Korean Society of Steel Construction
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• v.26 no.3
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• pp.241-250
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• 2014

The purpose of this study is to propose structural technologies on the light-weight composite floor systems in the unit modular and to evaluate structural performance of the composite floor through flexural experiments. The flexural experiments were carried out on total nine specimens(each three type in shape) using steel flat deck and truss deck. From the results of test, all specimens showed the same failure patterns which exhibited deflection at the center of the specimens due to flexural deformation before concrete crushing at the upper of specimens. Also, we know that the proposed floors satisfied in serviceability and would be safe sufficiently. The ratio of experimental yield load by theoretical nominal load was the distribution of 0.86 to 1.27 with an average 1.04. Coefficient of variation in distribution showed good agreement.