• Title/Summary/Keyword: Concrete member

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A Study on the Similitude of Member Behavior for Small-Scale Modeling of Reinforced Concrete Structure (철근콘크리트 축소모델의 부재거동 상사성에 관한 연구)

  • 장진혁;이한선
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.187-192
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    • 1995
  • Four types of experiments were performed to check the similitude of member behavior between prototype and 1/10 scale models:(1) Test of slender columns with P- effect, (2)Test of short columns with and without confinement steel, (3)Test of simple beams without stirrups, and (4)T-beam test. Based on the results of experiments, the conclusions were made as follows : (1) The P- effect of slender columns can be almost exactly represented by 1/10 acale model. (2)The effect of confinement on short columns by the hoop steel can also roughly simulated by 1/10 scale model. (3)The failure modes of simple beams models were the yielding of tension steel followed by large diagonal tension cracking+compressive concrete failure. (4)The behaviors of prototype and 1/10 scale model in T-beams appear very similar.

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Blast Resistance Performance of Concrete Member with Intermediate Space by Fiber Reinforced Mortar Panel (섬유보강 모르타르 패널에 의해 중공층을 형성한 콘크리트 부재의 내폭성능 향상효과)

  • Nam, Jeong-Soo;Kim, Gyu-Yong;Miyauchi, Hiroyuki;Lim, Chang-Hyuck;Park, Jong-Ho;Jeong, Yong
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.427-428
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    • 2010
  • Recently, building structure damage and number of lives lost by bomb terror is increasing. Therefore, in this study, it is aimed to present basic data for blast resistance performance of concrete member with intermediate space by fiber reinforced mortar panel by explosion test.

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An Analysis on the Early Frost Damage According to the Component Thickness Changes of the Normal Strength Concrete Slab in Winter (겨울철 보통강도 콘크리트의 부재 두께 변화에 따른 초기동해 피해분석)

  • Kim, Tae-Woo;Lee, Yong-Jun;Kim, Dong-Gyu;Kim, Dae-Gun;Han, Min-Cheol;Han, Cheon-Goo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2018.05a
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    • pp.145-146
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    • 2018
  • In this study, the purpose of the study is to determine the depth of damage caused by early frost damage in concrete slab structures under the conditions of external temperature during winter. In other words, we intend to analyze the depth variation of the early frost damage as the thickness of the normal strength concrete slab members changes. As a result, the thinner the component was, the deeper the early frost damage was found to be, and the resulting increase in brightness of the concrete was delayed. and It is analyzed that under this test condition, an early frost damage was created with a thickness of 50 mm for the member and a thickness of 39 mm for the member of 300 mm.

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Cracking Analysis of RC Tension Members Using Polynomial Strain Distribution Function (다항식 변형률 분포함수를 이용한 철근콘크리트 인장부재의 균열해석)

  • 곽효경;송종영
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2001.04a
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    • pp.267-274
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    • 2001
  • In this paper, a analytical model which can simulate the post-cracking behavior and tension stiffening effect in a reinforced concrete(RC) tension member is proposed. Unlike the classical approaches using the bond stress-slip relationship or the assumed bond stress distribution, the tension stiffening effect at post-cracking stage is quantified on the basis of polynomial strain distribution functions of steel and concrete, and its contribution is implemented into the reinforcing steel. The introduced model can be effectively used in constructing the stress-strain curve of concrete at post-cracking stage, and the loads carried by concrete and by reinforcing steel along the member axis can be directly evaluated on the basis of the introduced model. In advance, the prediction of cracking loads and elongations of reinforced steel using the introduced model shows good agreements with results from previous analytical studies and experimental data.

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A Study on the Analysis of PSC Box Girder Bridge Considering Construction Stage in Box Section (시공단계를 고려한 콘크리트-콘크리트 합성형 PSC 박스거더 교량의 해석)

  • 김영진;김병석;강재윤
    • Proceedings of the Korea Concrete Institute Conference
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    • 1998.10b
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    • pp.694-700
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    • 1998
  • PSC box bridge by MSS construction method may not be set at cross section at one step. Web and bottom flange(U member) would be set at first, top flange will be set later with a time lag. In this case, U member and top flange concrete have different strain history. As two different aged section behaves as the composite section, there would happen the redistribution of stress. This is come from time-dependent strain characteristics of concrete itself. In this study, two models are considered, one with considering the set time of cross section and the other without. By performing longitudinal analysis of two models on considering construction stage, the stress differences of two are compared. As the analysis results show a considerable differences in the stresses of cross section between two models, the set time of cross section is needed for rational design f PSC box girder bridge.

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Anchorage Zone Reinforcement for Unbonded Post-Tensioned Circular Anchorage for Single Tendon (비부착식 단일 강연선용 원형 정착구를 적용한 포스트텐션 정착 구역의 보강)

  • Kim, Min Sook;Ro, Kyong Min;Lee, Young Hak
    • Journal of Korean Association for Spatial Structures
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    • v.18 no.3
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    • pp.117-124
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    • 2018
  • In the post-tensioned concrete member, additional reinforcement is required to prevent failure in the anchorage zone. In this study, the details of reinforcement suitable for the anchorage zone of the post-tensioned concrete member using circular anchorage was proposed based on the experimental results. The tests were conducted with the compressive strength of concrete and reinforcement types as variables. The experimental results indicated that the additional reinforcement for the anchorage zone is required when the compressive strength of concrete is less than 17.5 MPa. U-shaped reinforcement shows most effective performance in terms of maximum strength and cracks patterns.

Shear behavior of multi-hole perfobond connectors in steel-concrete structure

  • Xing, Wei;Lin, Xiao;Shiling, Pei
    • Structural Engineering and Mechanics
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    • v.56 no.6
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    • pp.983-1001
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    • 2015
  • This study focuses on the load carrying capacity and the force transfer mechanism of multi-hole perfobond shear connectors in steel-concrete composite structure. The behavior of multi-hole perfobond shear connector is more complicated than single-hole connector cases. 2 groups push-out tests were conducted. Based on the test results, behavior of the connection was analyzed and the failure mechanism was identified. Simplified iterative method and analytic solution were proposed based on force equilibrium for analyzing multi-hole perfobond shear connector performance. Finally, the sensitivity of design parameters of multi-hole perfobond shear connector was investigated. The results of this research showed that shear force distribution curve of multi-hole perfobond shear connector is near catenary. Shear forces distribution were determined by stiffness ratio of steel to concrete member, stiffness ratio of shear connector to steel member, and number of row. Efficiency coefficient was proposed to should be taking into account in different limit state.

Thermal Analysis of Reinforced Concrete Members at High Temperature (고온하에서 철근콘크리트부재의 온도해석)

  • Lee, Tae-Gyu
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1102-1105
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    • 2008
  • In this paper, the prediction method of internal temperature for high strength concrete members at high temperature is presented. Finite element method is employed to facilitate thermal analysis for any position of member. In case of water evaporates inside the concrete member by high temperature, the evaporation heat that absorb surrounding temperature is occurred. This effect of the evaporation heat is applied. And the model equations of the material characteristics of high strength concrete by high temperature are proposed. To demonstrate the validity of this numerical procedure, the prediction by the proposed algorithm is compared with the test results of other researchers. The proposed algorithm is good agreement with experimental results including the phenomenon that temperature by the evaporation heat is lost.

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An Experimental Study on Freezing-Thawing and Mechanical Properties of Lightweight Foamed Concrete Using Micro Foaming Agent (기포제를 사용한 경량 콘크리트의 역학적 특성 및 동결융해 평가에 관한 실험적 연구)

  • Min, Tae-Beom;Woo, Young-Je;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2009.11a
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    • pp.69-72
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    • 2009
  • This research is focused on the applying of the foaming agent which can make the independent pore in the concrete structure in order to make a lightweight concrete structure. This lightweight foamed concrete can satisfy both the required strength and the mechanical properties as structural members. In addition, anti freezing-thawing properties also required. As a result of the unit volume-weight measurement, when the foaming agent mixed at 0.5% to 1%, the lightweight foamed concrete can be applied for the structural member. Also the density and compressive strength measurement results reveals that it will be suitable as structural member with 21MPa strength, when the density is betweenity8 to 1.9 and foaming agent quantities are 0.5% to 1%. Finally the result of freezing-thawing experiment, the effect freezing-thawing damage reduced according to adding foaming agent because those foaming agent make micro-pores in the structure which are not seen in the ordinary concrete structure.

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Push-out tests on stud shear connectors with constrained structure of steel-concrete composite beams

  • Qi, Jingjing;Xie, Zuwei;Cao, Hua;Huang, Zhi;Lv, Weirong;Shi, Weihua
    • Structural Engineering and Mechanics
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    • v.83 no.6
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    • pp.789-798
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    • 2022
  • The stud shear connector is the main force transfer member in the steel-concrete composite member, and the mechanical behavior is very complicated in the concrete. The concrete around the stud is subjected to the pry-out local pressure concentration of the stud, which can easily produce splitting mirco-cracks. In order to solve the problem of pry-out local splitting of stud shear connector, a kind of stud shear connector with constraint measure is proposed in this paper. Through the push-out test, the interface shear behavior of the new stud shear connector between steel and concrete flange plate was studied, and the difference between the new stud shear connector and the traditional stud connector was compared. The results show that the stud shear connector with constraint measure can effectively avoid the adverse effect of local pressure splitting by relying on its own constraint measure. The shear stiffness of the interface between steel and concrete flange plates is greatly improved, which provides a theoretical basis for the design of strong connection coefficient of steel-concrete composite structures.