• Journal of the Korean Society of Safety
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• v.19 no.4 s.68
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• pp.161-165
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• 2004

Safety and efficiency in the construction of RC structures mainly depends on optimal operation of shore-slat systems. The disasters in RC construction are mainly due to excessive load applied to falsework and premature removal of supports. Development of sufficient compressive strength of early-age connote is essential for the safety of structures during construction. Most of studies on shore-slab interaction have focused on flat slab structures. In this study, load distributions in floor slabs and supports during the construction of shear wall-type RC apartment building structures is investigated using finite element analysis.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.3-11
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• 2008

An experimental investigation was conducted with half-scale representations of the reinforced concrete shear walls with the opening subjected to cyclic loads. Specimens were half scale representations of a one-story wall in the apartment built in 1980. The area ratio of the opening section, as well as the size and critical section of coupling slabs, were decided based on results from a previous researches. The test result of WS-0.23 specimen, which has artificial damages to install the opening, the strength of the wall decreased due to the opening. It is apparent that influence of cutting reinforcing bars and decrease of effective section area lead to early first yield of the reinforcing bars before the allowable limit of drift ratio of the shear walls was reached. Therefore, proper reinforcing method is needed to prevent this. The decrease of strength of the shear walls by installation of openings shows a great deal of difference compared to previous researches. This is because flexural capacity of the slabs is working as coupling elements for the shear walls. The critical section of coupling slabs that works as coupling elements for shear walls was a little different from the results of previous researches.

• Journal of the Korea Concrete Institute
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• v.14 no.1
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• pp.83-91
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• 2002

A common form of construction for apartment buildings consists of walls and coupling elements. But, the structural behavior of coupling elements are very complex and affected by the properties of coupling elements. The objective of this study is to estimate the behavior of coupling elements in wall-dominant systems. For the purpose of this study, two wall-slab specimens and two wall-beam specimens were tested. The specimens with different reinforcement layouts were subjected to reversed cyclic loading, consistent with coupling action, with increasing imposed inelastic deformations. From the results of this study, 1) in coupling slabs, the stresses were not uniform across the width, 2) the effective width of coupling slabs was found smaller than that of predicted from previous studies, 3) diagonally reinforced coupling beam with slab showed larger ductility and more amount of energy dissipation to be attained compared with conventionally reinforced coupling beam.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.1
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• pp.141-147
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• 2002

국내 주거의 주종인 아파트의 구조형식은 벽식 철근콘크리트조로 경제성 때문에 대부분 고층으로 지어지고 있다. 철근 콘크리트구조 건물을 구체공사비중 상당부분이 거푸집공사에 투입되고 있다. 구체공사의 공기(工期)는 층당 소요일수로 산정할 수 있는데 공사비 절감 및 공기단축을 통한 시공효율상의 향상을 위해서는 지주시스템의 효율적인 전용(轉用)이 필수적이라 할 수 있다. 본 연구에서는 벽식구조 아파트의 현장조사를 토대로, 현재 사용되고 있는 지주시스템 및 바닥슬래브에 대한 응력해석을 수행하고, 이를 분석하여 공기단축의 가능성을 검토하였다.

• Korean Journal of Construction Engineering and Management
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• v.6 no.3 s.25
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• pp.72-80
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• 2005

The number of apartments has been increased, and it is time to activate the remodeling or reconstruction. Recently remodeling has been preferred to reconstruction, because reconstruction might cause many problems. At this point of time, remodeling could save resources, preserve environment, and expand the construction market places. However, most research for remodeling is aimed to improve the financial value, and structural effects being caused by floor plan modification has not been done yet quantitatively. Remodeling naturally brings to floor plan modification, and it can cause serious problems of structural side. So we made apartments an object of study, then analyzed stress variation of structural elements according to the removal of shear wall, supposing the floor plan modification. For this purpose, we selected a sample of universal apartment floor plan and extracted floor plan modification factors. Then we applied the factors to sample floor plan and organized the results of stress variation of structural elements. As results, walls are most harmful when the independent walls are removed, and in case of slabs, it is most critical when continuous walls are removed.

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.312-318
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• 2014

Recent building structures are superior in its ability but they are light weight and long span, and so have problems of vibration. In general, the serviceability of RC slabs was known to be good against vibration because of its hardness. However, recent high-rise apartment slabs are mostly light and long, the serviceability of RC slabs due to vibration could be a problem. In this paper, a basic investigation about vibration problems of RC slabs was performed. Basic information and its influence on vibrations of RC slabs were revealed. Also, its serviceability against vibration was examined. Many tests were conducted for natural frequency of building, for example load of two persons walking and one person leaping etc.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.117-124
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• 2007

An experimental research has been performed to evaluate the load transfer capacity for the planar joints between existing and new slab in an apartment remodelling constructions expecially for enlarging the interior space. Post-installed dowel bars were used as a joint connector. The existing slabs were obtained from the existing apartment housing which will be demolished, and were retrofitted with carbon fiber plate. Test results showed that the planar joints with post-installed dowel bars behaved in full composite modes until ultimate capacity of test specimens, so sufficient ultimate and serviceability performance are confirmed.

• Land and Housing Review
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• v.7 no.4
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• pp.323-328
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• 2016

There are small box opening for inserting of electric lamp box in the slab of apartment. Around this box opening, we normally use the detailing of WWF or plastic ring strengthening to protect cracks induced by shrinkage. The shrinkage amount of slab box around was measured and analysed in order to consider validity of these strengthening methods and to find out economical alternative. Alternative of strengthening methods are normally used strengthening methods in construction companies, which are WWF strengthening, plastic ring strengthening and no strengthening methods. The shrinkage amount was measured using contact guage at the spot of tip attached around the box on slab of small area unit apartment which have small exclusive area below $59m^2$. Measured data shows that there are no big differences between all the 3 strengthening methods and Measure data range is $-264{\mu}{\varepsilon}{\sim}+216{\mu}{\varepsilon}$. Measured shrinkage is on trend slightly increase till 3~5weeks after removal of forms and then decrease. But amount of shrinkage are very low for all the slabs and there are no probabilities of concrete crack by shrinkage.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.315-329
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• 2018

Recently, RC transfer slab systems have been used widely to construct high-rise wall-type apartments for securing parking space or public space. However, it is problem that the design method and structural performance evaluation method developed for thin RC flat slab are still used in the design of the transfer slab whose thickness is very thick and therefore structural behavior is expected to be different from RC flat slab. Thus, for the rational design of the transfer slab, the ultimate shear behavior of the RC transfer slab system is required to be analyzed properly. Accordingly, in the present study, the two-way shear behavior of the transfer slab was analyzed using nonlinear FEM according to various design parameters such as thickness of the transfer slab, strength of concrete, shear span ratio, and reinforcement ratio. In addition, the two-way shear strength evaluations of RC transfer slab by the existing evaluation methods were verified by comparing those with the results of nonlinear FEM analysis.

• Journal of Korean Society of Steel Construction
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• v.16 no.1 s.68
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• pp.91-101
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• 2004

This study sought to suggest a structural design guide and to investigate the structural performances of the new beam-slab system in order to decrease the height of floors in high-rise steel structure apartments. Experiments were performed to assess the capacity of the new beam-slab system in a steel structure with 9.8-m span, particulary structural material test, pure bending test of composite beam, three-point bending test of composite beam, and bending and shearing tests. Results showed that the suggested composite beam had stable structural behavior when stud connectors were located in the upper flange, and upper bars were calculated normally according to the design of the slab.