• 레미콘
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• no.6 s.20
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• pp.107-113
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• 1989

• 레미콘
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• no.4 s.87
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• pp.44-50
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• 2006

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2004.04a
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• pp.222-225
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• 2004

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.7-8
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• 2017

As the importance of maintenance of reinforced concrete structure recently has emerged, the attention of durability of structure has been increasing. There are many studies about durability decline especially due to the carbonation. In order to study carbonation progress after surface repair of carbonated concrete, each carbonation penetration velocity from different repair materials of concrete structure is compared through the experiment of carbonation accelerating CO₂ concentration to 5%. As carbonation infiltration progress is predicted through this study, the counterplan of service life evaluation will be prepared on selection of repair materials of concrete structure.

• Magazine of the Korea Concrete Institute
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• v.26 no.1
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• pp.30-34
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• 2014

• Fire Science and Engineering
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• v.25 no.6
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• pp.89-97
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• 2011

This study is for evaluating the fire resistance performance (1~2 h) of the RC Structure void slab using the Lightweight Hollow Sphere, which can reduce the unnecessary dynamic part of removing the central concrete. For this experiment, we set up depth of concrete cover, live load, and span length as the factors. The result comes out with all the slabs under those conditions can ensure the goal fire resistance performance (120 min). And among these factors, the resisting capability changes more sensitively with the live load rather than the thickness of cover. And the shorter span length could assure the better the fire resistance performance. The result observing the character in high temperature of the Lightweight Hollow Sphere which does not used as existing RC structure slab, a delay section in temperature change is occurred due to the Glass Transition in $100^{\circ}C$. And heat transfer by conduction does not occur at lightweight hollow sphere because the polystyrene in EPS (Expanded Polystyrene) melts point in $185^{\circ}C$. Therefore temperature at lightweight hollow sphere is lower than the concrete and rebar.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.247-249
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• 2013

열화한 철근콘크리트 구조물에 대하여 성능회복을 위하여 전기화학적 방식, 단면복구공법, 균열보수공법, 표면마감공법 등이 상용되고 있다. 본 연구에서는 단면복구공법의 적용과 성능예측을 위한 해석 모델의 입력값으로 사용될 보강철근과 단면복구재의 부착특성을 평가하기 위하여 철근인발실험을 실시하였다. 폴리머시멘트몰탈이 사용되었으며 부착요소의 강성과 강도를 구하여 비선형 해석을 실시하여 상당한 정확도의 예측값을 도출하였다.

• Journal of Korean Society of Steel Construction
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• v.17 no.2 s.75
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• pp.151-159
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• 2005

This study investigated the capacity evaluation of composite beam of the end-reinforced concrete, the center steel with attached main-bar of stud-bolt welting and flange with main parameter, such as shear span depth ratio (a/d=1.5, 2.5, 3.5), reinforcing method, reinforcing length, and steel main-bar ratio. The test results are summarized as follows: As the RC section becomes longer, the capacity ratio of Vsrc, test/Vsrc, the gradually decreased, with the tendency of decrease being remarkably more than a/d=3.5. The reinforcing method showed superior result both vertically and horizontally. And, capacity increase ratio displayed tendency that main-bar fixing length is obvious in 0.15L, and underestimate experimental value usually in Vsrc, Eq(3)~(5) equation. The capacity estimation was proposed equation by regression analysis with change of shear span depth ratio and main-bar fixing, steel main-bar ratio.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.368-372
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• 2007

Recently, construction companies prefer to use large scale system forms to prepare for lacking of skilled workers, aging and the chances of application of pre-build&post-sale policy. In result of the effort and interest, the duration for framework of domestic high rise buildings has been accomplished to 3-4days per floor but for the apartment housing which form over 90% of the domestic construction industry, and especially the middle story RC apartments which is the main part, the duration for framework is only about 6-8days per level. This is only about 50% of the duration per level of RC residential buildings in North America. In previous researches elementary technology, which has potential of duration reduction, was proposed and this research suggest the applicability in construction sites and ways to improve it using elementary technology applied Mock-up Test. Furthermore, we analyze the productivity and T/C usage rate of the 6day-Cycle and suggest an improved model.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.196-201
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• 2006

In general, the vertical vibration problems for strength of members and serviceability of building structures are not considered in structural design process, but the prediction of the vertical vibration is very important and essential to structural design process. This study aims to investigate the characteristics of vertical vibration in terms of the transfer of horizontal directions on the rahmen building structures and the shear wall building structures. In order to examine the characteristics of vertical vibration, the modal test and the heel-drop excitation experiments were conducted several times on the two type building structures. The results from the experiments are analyzed and compared with the results. The results of this study suggest that the characteristics of vortical vibration transfer in horizontal way are effected from the fundamental frequency of the slabs and excitation forces and are effected the shear wall on the path of the vibration transfer.