• Journal of the Korea institute for structural maintenance and inspection
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• v.2 no.3
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• pp.161-167
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• 1998

A problem of frequency in the field of low-frequencies such as high-rise apartment building or construction vibration are often found. In this study, damage reason of a 25 stories apartment building was searched on the basis of actual damage. To find the damage reason, structural design procedure were reviewed and low-frequency vibration test was conducted. The results indicate that the main damage reason is not by the low-frequency vibration but the asymmetrical plan of that building.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.425-430
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• 1996

The purpose of this study is to investigate the behavior of the bearing precast concrete (pc) wall structure with hollow core based on experimental tests. In order to evaluate the cyclic performance of the pc walls. Too one story pc walls and ond one reinforced concrete wall are made. The experimental results of pc walls were compared with those values of reinforced concrete (rc) wall. The structural behaviors of pc wall structure with hollow core are similar to those of reinforced concrete bearing wall structure. This study shows that the pc wall with hollow core could be treated as rc wall when designs the pc wall structure against lateral loads

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.508-513
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• 1996

The purpose of this paper, having chosen the connection method, filled by High-strength mortar, in conncetion of PC member, is to study the mechanical behaviour and practical usage of the method. The paper estimates the connection ability of Reinforced-bar, that is, Sleeve considering the effect of Reinforced-bar's dimeter. Sleeve's length and diameter in the structural behaviour of mortar-filled connection, therefore the behaviour of Splice-Sleeve exists in concrete practically. This paper discusses the effect of the concrete in Splice-Sleeve. Also, to estimate structural behaviour in a practical wall panel, the upper and bottom wall panels are produced and the behaviour of Splice-Sleeve is discussed. And then Vertical Tie Bar being designed by using Precast method, this paper presents the various application and the practicable method using Splice-Sleeve.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.605-610
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• 1997

An experimental investigation was conducted to examine the feasibility of Carbon Fiber Sheet(CFS), a kind of high strength fiber, for a repair and reinforcement method of concrete structures. The experimental program included tests of flexural beams different in wrapping method and amount of CFS. The beams were subjected to monotonic loading. Although the flexural strength for concrete members increases with wrapping methods of CFS., the reduction factor due to the distribution, amount bond of CFS should be completely examined. This study approached the effectiveness and application of CFS, along with reinforcement effects of CFS on reinforced concrete beams through tests. Test results indicated that the increase in the number of CFS layer caused the increase in strength of beams in strength.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.657-662
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• 1997

In these day, there have been shortage of construction workers and an increase of labor cost in our county. In order to overcome these problems, prefabricated and mechanized system of bar placing have been used in the construction fields. As a part of this tendency, welded wire fabric(WWF) reinforcement were studied several years ago. In this study, the required working hour. the labor power and the construction process of WWF reinforcement for the apartment building slabs are reported. From the result of field investigations, it is showed that the WWF reinforcement facilitates the field placing and the working time of WWF placing is saved, and then the labor cost of WWF reinforcement is less than that of the conventional bar reinforcement.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.239-242
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• 2005

The purpose of this research was focused on substantiating an effects of tendon-layouts and compressed stress($=f_{pc}$) induced by post-tensioning on seismic performance of post-tensioned flat plate slab-column connection designed as non-participating system. To accomplish this purpose, an experimental research of flat plate exterior slab-column connections subjected to gravity load and reversed lateral displacement history are presented. As a result, tendon-layout is a main variable to influence failure mechanism, dissipated energy and lateral deformation capacity. Furthermore, compressed stress ($=f_{pc}$) induced by post-tensioning enhanced the seismic performance of flat plate slab.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.107-110
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• 2005

In general, post tensioned (PT) flat plate slab systems have been used as a Gravity Load Resisting System (GLRS) in buildings. Thus, these systems should be constructed with Lateral Force Resisting Systems (LFRS) such as shear walls and moment resisting frames. When lateral loads such as winds or earthquakes occur, lateral load resisting systems undergo displacement by which connected gravity systems experience lateral displacement. Therefore, GLRS should have some lateral displacement capacity in order to hold gravity loads under severe earthquakes and winds. Since there are the limited number of researches on PT flat plate slab systems, the behavior of the systems have not been well defined. This study investigated the cyclic behavior of post tensioned flat plate slab systems. For this purpose, an experimental test was carried out using 4 interior PT flat plate slab-column specimens. All specimens have bottom reinforcement in the slab around the slab-column connection. Test variables of this experimental study are vertical load level and tendon distribution patterns.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.171-174
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• 2005

In this study, new moment-resisting precast concrete beam-column joint is proposed for moderate seismic regions. It has the connection reinforcing bars, penetrated the joint and lap-spliced with the bottom bars of precast U-beam. To evaluate the performance for noncontact lapped splice, analytical works were conducted. Major variables for FEM analysis are the length of lap, the diameter of connection reinforcing bars, and the distance between lapped bars. The results of this study show thar the these variables has much influence on strength and deformation of lapped joint.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.223-226
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• 2005

The purpose of this study is to discuss how strength and ductility of each system in low-rise R/C buildings combined with extremely brittle, shear and flexural failure systems have influence on seismic capacities of the overall system, which is based on seismic response analysis of SDOF structural systems. To simulate the triple lateral-load resisting system, structures are idealized as a parallel combination of two modified origin-oriented hysteretic models and degrading trilinear hysteretic model that fail primarily in extremely brittle, shear and flexure, respectively. Stiffness properties of three models are varied in terms of story shear coefficients, and structures are subjected to two ground motion components. By analyzing these systems, interaction curves of required strengths of the triple systems for various levels of ductility factors are finally derived for practical purposes.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.443-446
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• 2005

The shear strength equations of the joint with RC column and steel beam are used the proposed equations of ASCE, Kanno and AIJ but there are not applied variable joint details. Until now the variable experimental studies are practiced but the studies of predicted shear strength equation are not integrated and only the applicable equations to each case are proposed. The purpose of this study is statistical analysis for the proposed equations applied existing experiments. The proposed equations are ASCE, Kanno, M-Kanno, AIJ and M-AIJ. The 47 of shear failure experiments are used in this study The consequence is that the Kanno's equation is very analogized with the experimental result but ASCE equation underestimates about 42$\%$. AIJ and M-AIJ are not proper equations for estimating the shear strength of RCS joint.