• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.631-636
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• 2002

It is common in multistory flat-plate structures that newly cast slabs are supported by a number of previously cast floors. Then the weight of newly cast slabs is imposed on shored previously cast floors as load, and this load may be large as double as dead load. Because early-age construction loads cause large immediate deflection and creep deflection with cracks, this loads influence long-term behavior of slabs. In current provision, the minimum thickness is required to satisfy serviceability But this minimum thickness based on historical precedent is determined by span length, therefore the minimum thickness of current provision can not includes properly the effect of construction scheme including the number of shored floors and construction cycle. In the present study, a minimum thickness criterion, which includes the effect of concrete strength, geometry of slabs and construction scheme, was developed from computer-based iteration using deflection calculation procedure of current code method.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.173-178
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• 2002

Flat plate is susceptible to punching shear failure at the slab-column connection, which may cause catastrophic structural collapse. To prevent such brittle failure, strength and ductility of the connection should be ensured. However, since it is very difficult to experimentally simulate the actual load and boundary conditions of the flat plate system, it is not easy to obtain reliable information and data regarding to the strength and ductility of the flat plate-column edge connection. In the present study, numerical studies were performed for edge connections of continuous flat plate. The results were compared with the existing experiments, and the variations of bending moment, drift, effective width around the connection were investigated. Based on tile findings of the numerical studies, the disadvantages of current design methods were discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.891-896
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• 2002

Flat plate is susceptible to punching shear failure at the slab-column connection, which may cause catastrophic structural collapse. To prevent such brittle failure, strength and ductility of the connection should be ensured. However, since it is very difficult to experimentally simulate the actual load and boundary conditions of the flat plate system, it is not easy to obtain reliable information and data regarding to the strength and ductility of the flat plate-column connection. In the present study, numerical studies were performed for interior connections of continuous flat plate. The results were compared with the existing experiments, and the variations of bending moment, shear, torsional moment around the connection were investigated. Based on the findings of the numerical studies, the disadvantages of current design methods were discussed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.48-51
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• 2004

This paper is to study the response of flat plate slab-column connections consisting of various types of shear reinforcement and steel plate subjected to gravity loadings, mainly punching shear forces using the non-destructive testing, spectral analysis of surface waves and structural experiments. The base specimen failed due to punching shear generated from the gravity. The three other types of slab shear reinforcement and steel plate showed effective in resisting punching shear for these types of connections under gravity loading. This study has focused in evaluating the velocity response of a Surface wave during the early age as the poured concrete specimens have been hardened, the possibility of damage detection in the slab-column connection and the relationship between the punching shear forces and the surface wave velocities under the condition that the punching shear forces had gradually increased until the flat plate slab in slab-column connection had been failed.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.272-275
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• 2004

This study is to propose a modified equivalent frame method under lateral loading. ACI 318-02 allows the equivalent frame method to conduct slab analysis subjected to lateral loads. However, current method can not predict the behavior of the slabs particularly under lateral loading because the equivalent frame method in the ACI 318 has been developed against gravity loads. This study provides more precise model for the analysis of the flat plate slabs under lateral loading. The model reflect the force transfer mechanism of slabs, column and torsional member more accurately than the existing model. The accuracy of this model is verified by compared with finite element method analysis results.

• Journal of the Korean Society for Advanced Composite Structures
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• v.5 no.1
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• pp.22-27
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• 2014

The flat plate slab system have many good features, which are design flexibilities, saving of story-height and economy of construction etc. But the study of flat plate slab system for H-steel column have been rare both at home and abroad. Recently high-rise residential and commercial buildings have been constructed in urban areas in Korea. The suggested dowel connection system is more likely to adoptable because it remarkably contribute to save inter story height and also to have many advantages compared with conventional steel works such as H-Steel frame + Deck plate slab system. This study aims at developing design method and program for connection between H-Steel column and flat plate slab system, which contribute to save significantly inter-story height.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.145-148
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• 2005

Recently the construction of high-rise reinforced concrete building is progressively increased as the social demands. It is significantly important factors such as economy, the safety of structure, and the flexibility of internal space. Therefore new structural system is also required to be attained the reduction of story height, the flexibility and efficient use of space. The most suitable structural system is with the economy and flexibility, flat plate slab system in high-rise reinforced concrete building. In this research, it was focused in the improvement of shear performance in the flat plate system using high ductile fiber reinforced mortar. It was evaluated the shear performance in the critical region of slab-column connection. The flat plate system, designed by the high performance and safety, was developed as a new technique in the application of high-rise R/C building.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.213-216
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• 2005

A numerical analysis was performed for interior connections of continuous flat plate to analyze the effect of design parameters such as column section shape, gravity load and slab span on the behavioral characteristics of the connections. Through the parametric study, the variations of shear stress distribution around the connection were investigated. According to the result of numerical analysis, as the length of the cross section of column in the direction of lateral load increases and gravity load increases, the effective area and the maximum shear strength providing the torsional resistance decrease considerably. And as the slab span loaded with relatively large gravity load increases, the negative moment around the connection increases and therefore the strength of connection against unbalanced moment decreases.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.30-33
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• 2006

The purpose of this research is to study the seismic behavior of interior column-slab connections with different column aspect ratio, when subjected to combined gravity and cyclic lateral loading. The control specimen had square column, while the other specimens had rectangular column with aspect ratio of 0.5 and 2.0. From the test results, all of the specimens sustain lateral drifts as high as 4% with no more than a 20% decrease in peak lateral load capacity. And it appears that KBC Code(2005) procedure may be unconservative for connections with different column aspect ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.161-162
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• 2009

In this study, the methodology of calculating the construction loads with considering effects of the shoring stiffness and slab cracks is proposed. Comparisons with the proposed method and the existing methods for construction load calculations were performed for measured shoring loads.