• Title/Summary/Keyword: Reinforcing method

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Mock-up Test for Nuclear Power Plant Rebar Modulation Applying Febrication (선조립공법을 활용한 원전구조물 철근모듈화 Mock-up 실험연구)

  • Lim, Sang-Jun;Lee, Byung-Soo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.13-14
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    • 2015
  • To minimize construction of nuclear facility, it is required to reduce reinforcing bar amount and solve reinforcing bar concentration and for this, it is necessary to develop appication design technology and modular of high strength reinforcing bar. Hence, KHNP reduces excessive reinforcing bar amount which can cause possibility of poor construction of concrete through design standard development and modular of nuclear facility structure using high strength reinforcing bar to raise economics and has its purpose to maintain high-level safety and durability as they are. After reviewing the rebar drawing of the NPP structures and performing the mock-up test, the rebar modulation method in the various area of the NPP Structure has been established.

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Fire Resistance of High Strength Concrete followed by Thickness of Fireproof Plaster Board and Change of Adhesive Method (방화석고보드의 두께 및 접착방식 변화에 따른 고강도 콘크리트의 내화특성)

  • Jang, Ki-Hyun;Kim, Won-Ki;Jin, Hu-Lin;Lee, Jin-Woo;Yang, Seong-Hwan;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2008.05a
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    • pp.67-71
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    • 2008
  • The study analyzed on fire resistance of high strength concrete followed by thickness of fireproof plaster board and change of adhesive method. In spalling characteristics after fire resistance test, all four-side covering concretes were left out of testing screens. Thus, serious spalling was happened by exposing their internal reinforcing rods. in partial testing screens, spalling was happened till the internal concrete of main reinforcing rod. Only, temperature history didn't have special differences among changes of adhesive method. However, thickness of fireproof plaster board is very important. Namely, mock member reinforcing 25mm general adhesive + Bending was 583℃ in the highest temperature of surface part and 479℃ in the highest temperature of the main reinforcing rod, which was relatively good temperature history.

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Determination Technique of Cut-Slope Reinforcing Method Considering the Effect Factor (영향인자를 고려한 절토사면 보강공법 선정기법)

  • Han, Jung-Geun;Lee, Jong-Young;Lee, Myung-Ho;Choi, Poong-Kon
    • Journal of the Korean Geosynthetics Society
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    • v.6 no.2
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    • pp.27-32
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    • 2007
  • Analysis was performed using AHP (Analytic Hierarchy Process) technique for the determination of priority on the effect factors and the preferences on cut-slope reinforcing methods. The results from professional group, such as researchers, design engineers and construction engineers, show that stability, durability and environmental condition are the most important effect factors. The retaining wall and the cutting methods were predominant for stability, economical efficiency, and maintenance/management in the evaluation of preferences on the cut-slope reinforcing methods interpreted for the increasing method of safety factor.

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Corrosion Protection Method of Reinforcing Steel in Concrete by Using Corrosion Inhibitors

  • Bae Su-Ho;Chung Young-Soo;Kim Dae-Ho
    • KCI Concrete Journal
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    • v.14 no.4
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    • pp.145-150
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    • 2002
  • Reinforced concrete is inherently a durable composite material. When properly designed for the environment to be exposed and carefully constructed, reinforced concrete is capable of giving maintenance-free performance. However, unintentionally using improper materials such as non-washed sea sand having much salt together with poor controlled quality, or the concrete are placed in highly severe environment such as marine atmosphere, the corrosion of reinforcing steel in concrete becomes one of the most significant concerns of concrete. The purpose of this experimental research is to evaluate the performance of corrosion inhibitors for normal strength and high strength concrete, and to propose desirable measures for controlling corrosion of reinforcing steel in concrete. Test specimens in normal strength and high strength concrete were made with and without corrosion inhibitors. The accelerated corrosion test for reinforcing steel in concrete was adopted in accordance with JCI-SC3, which required the periodic 20 cycles for 140 days. One cycle includes 3 days for the wetting condition of $65^{\circ}C$ and $90\%$ RH, and 4 days for the drying condition of $15^{\circ}C\;and\;60\%$ RH. It was observed from the test that corrosion inhibitors in normal strength concrete and high strength concrete showed excellent corrosion resistance for reinforcing steel in concrete, but the silica fume in high strength concrete was found to have a negligible corrosion resistance if not used with corrosion inhibitors, since the chloride corrosion threshold limit in concrete containing silica fume without corrosion inhibitor was found to be considerably smaller than that of the case with corrosion inhibitor.

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A Study on Coupling Coefficient Between Rail and Reinforcing Bars in Concrete Slab Track (콘크리트 슬래브궤도에서 레일과 철근 사이의 결합계수에 대한 연구)

  • Kim, Min-Seok;Lee, Sang-Hyeok;Kwon, Jae-Wook;Lee, Jong-Woo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1169-1177
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    • 2008
  • The system of the railway signaling using the track transmits the approved speed to the location of a train and it. Referring to the way of transmitting train control information, there are the one transmitting it to the on-board system of a train using the direct track, the another transmitting it establishing an instrument, and the other transmitting an instrument by a railway track. The one is the method using the direct track as a conductor for composing the part of the track and attaining the information controlling a train by transmitting a signal to the track. It is used for the high-speed railway and the subway. The method using the track attains information by transmitting it to returned information, and the on-board system of a train attains it by magnetic coupling. Because many reinforcing bars on the concrete slab track are used, interaction between a rail and a reinforcing bar that is not produced on ballast track is made. Due to the interaction, the electric characteristic of rail is changed. In the current paper, we numerically computed the coupling coefficient between the rail and the reinforcing bar based on the concrete slab track throughout the model related to the rail and the reinforcing bar using the concrete slab track that is used in the second interval of the Gyeongbu high-speed railway, and we defined the coupling coefficient not changed in the electric characteristic of rail in the condition that there is no interaction between the rail and the reinforcing bar.

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A Study on Reinforcing Effect of Multi-Bar Spring Nailing (다철근 스프링 네일링 공법의 보강효과 검토에 관한 연구)

  • Lee, Choong-Ho;Jung, Young-Jin;Kim, Dong-Sik;Chae, Young-Su
    • Journal of the Society of Disaster Information
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    • v.3 no.2
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    • pp.147-169
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    • 2007
  • This study investigates the reinforcing effects of the Multi-bar Spring nails with respect to the conventional Soil-nails in artificial slopes. Based on wide experience related to design and construction, soil nails have been widely applied to reinforce slope in the world. Multi-bar spring nails are one of the improved soil nailing methods. These method maximizes bending, shearing, pull-out resistance for those multi-nails, not unit nail, that are inserted in the borehole using special spacer at regular intervals. In addition, because cutting plane is confined effect resulting from a pressured plate at the end of the nails with compression spring equipment, slope stability is secured using MS-nailing method. Analyzing bending, pull-out, shearing condition of MS-nail, it was examined throughly elastic region, load transfer capacity, reinforcing effect on cutting plate of MS-nails. In addition, Pilot and laboratory tests, numerical analysis were carried out to verify the superiority of MS-nailing method. In case, MS nailing method is applied to reinforce artificial slope, it was analyzed that bending, pull-out, shearing resistance was increased more than existing nailing method was applied. In this study, it was shown that surface failure was more or less prevented using MS-nailing method, confining effect on cutting plane using spring stuck to flexible equipment.

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A Safety Analysis of the BTR Method by Construction Sequence (BTR공법의 시공단계별 안전성 해석)

  • Chung, Kuang-Mo;Lee, Won-Hee;Lee, Sang-Hyun;Bang, Myung-Seok
    • Journal of the Korea Safety Management & Science
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    • v.14 no.1
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    • pp.101-108
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    • 2012
  • In this study was conducted numerical analysis to evaluate the stability of BTR(Built-in Timber Roof Tunneling Method), which is one of construction methods of underground structures in the non-opening state. The discretion method was applied to individually model reinforcing members of BTR, and the homogeneity analysis technic by area ratio was used to verify the feasibility comparing this result with that from conventional analysis method. The parameter study was performed to evaluate the effect varying ground depth, distance length of reinforcing supports and to verify the field applicability of new analysis method. The results showed the very precise value with allowable error, so this method can be applied in the field, The more length of supporting members caused the more vertical displacement and the top displacement increment of support members is larger than that of ground surace. The effect of ground depth was more impressive than that of distance length of reinforcing supports.

Capacity Evaluation of Composite Beams Composed of End-Reinforced Concrete and Center-Steel (단부 RC조 중앙부 S조로 이루어진 합성보의 내력 평가)

  • Lee, Seung Jo;Park, Jung Min;Kim, Ki Wook;Kim, Wha Jung
    • 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.

Pullout Characteristics of Reinforcing Body Using Pressure Re-injection Grouting Method (압력재주입 그라우팅 방식을 이용한 보강재의 인발특성)

  • Lee, Bongjik;Kim, Sangsu;Youn, Junsik;Lee, Jongkyu
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.10
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    • pp.25-31
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    • 2010
  • Anchor, soil nail, micropile have been widely used for slope reinforcement and foundation. These all methods need grouting work after placing reinforcing member. In domestic case, gravity fill techniques and pressure grouting techniques are mainly used. In contrast the pressure re-injection grouting method is not commonly used because grouting equipment and lack of practical application example is short and the verification of reinforcing effect is difficult. Pressure re-injection grouting is a kind of post grouting which technique increases the radial stresses acting on the grout body and causes irregular surface to be developed around bond length that tends to interlock the grout and the ground. In this study, the field test was performed to evaluate the reinforcing effect with the variation of grouting methods and pullout characteristics of reinforcing member placed by pressure re-injection grouting method. The test results showed that the post-grouting methods were useful to increase the pullout capacity.

A Study on the Gu-chim(九鍼) and Guan-chim(官鍼) of "Hwangje-Naegyeong(黃帝內經)" ("황제내경(黃帝內經)"의 구침(九鍼)과 관침(官鍼) 개념에 대한 소고(小考))

  • Baik, You-Sang;Kim, Do-Hoon
    • Journal of Korean Medical classics
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    • v.21 no.2
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    • pp.101-112
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    • 2008
  • Generally, we regard the concept of Guchim(九鍼) in "Naegyeong(內經)" as the a generic term of acupuncture means of nine kinds of forms and usages. However, it also contains the meaning of methods and transcriptures of acupuncture. The diversity of Guchim reflects that it has a high level diagnosis and treatment based on overall analysis of symptoms and signs. And among the treatments, reinforcing and reducing methods are prominent. The treatments of reinforcing and reducing methods, usually use Hochim(毫鍼), the filiform needle. The focus of Guchim, in reinforcing and reducing of Gi(氣), is reinforcing and reducing by way of drainage of Gi. And it mainly deals with diseases of Gi. From the research of the philosophic background of the number Nine in Chinese philosophy, number nine symbolizes the posterior and space, as number one symbolizes apriority and time. In this circumstances, Guchim became the supreme method of acupuncture. The concept of Gwanchim(官鍼), standardized needle in "Naegyeong" also expresses the Guchim as theory and skill in standardized traditional medicine. The period of materialization of Guchim and Gwanchim lies in from the era of Jeonguk[戰國時代, the age of civil wars] to Han dyansty[漢代], when the "Naegyeong" made a synthesis of the medicine in those days, as the society unified politically and ideologically. In this process, Guchim was sublimated in method of acupuncture which contained absolute authority.

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