• 제목/요약/키워드: reinforced concrete, reinforcement

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FRP Rods로 보강한 콘크리트 보의 전단 내하력의 평가 (Estimation of Shear Carrying Capacity on Concrete Beams, Reinforced with FRP Rods)

  • 최익창;연준희;고재용
    • 한국해양공학회지
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    • 제18권1호
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    • pp.63-68
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    • 2004
  • The purpose of this study is to estimate the contribution of concrete and shear reinforcement, in shear carrying capacity, on concrete beams, reinforced with steel and/or FRP rods. The experimental tests for 12 concrete beams, reinforced with steel and/or FRP rods, are carried out. Experimental parameters includes the mechanical properties of reinforcements in shear and bending, and the ratio of shear reinforcement. This study compares the experimental results of shear carrying capacity in concrete beams, reinforced with steel and/or FRP rods, with the proposed equations. According to the experimental results, the effect of the concrete in concrete beams reinforced with FRP rods is decreased with decreasing Young's modulus of longitudinal tensile reinforcement. This results from the large deflection of concrete beams reinforced with decreasing Young's modulus of longitudinal tensile reinforcement. Also, the contribution of shear reinforcement is smaller than the calculated value, using the truss analogy. This results from the fact that the stress redistribution is not exhibited after the break of shear reinforcement.

편심하증을 받는 고강도 철근콘크리트 기둥의 역학적 특성 (Mechanical Characteristics of Eccentrically Loaded High Strength Reinforced Concrete Columns)

  • 김인식;최봉섭;권영웅
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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    • pp.399-404
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    • 2000
  • This paper are the mechanical characteristics of eccentrically loaded normal strength and high strength reinforced concrete columns based on the test results. The columns are $120\times120$mmat the mid-section and are haunched at the ends to apply the eccentric loading and prevent premature failure. Variables are concrete strengths(361, 672, 974 kgf/$\textrm{cm}^2$), $\textrm{cm}^2$longitudinal reinforcement ratios (1.98, 3.54, 1 5.53%), spacing of lateral reinforcement (30, 60, 120mm), and eccentricities (24, 40mm). As a results, the main conclusions obtained from the comparison and analysis for the strength tendency, deformation and ductility of high strength reinforced concrete columns with variables are as follows; As the concrete compressive strength concrete and lateral reinforcement increases, the ductility index of high strength reinforced concrete columns decrease, but it increase with the increase of eccentricity and longitudinal reinforcement ratio. The confinement ratio must be greater than 20 percent in order for the level of ductility between high strength reinforced concrete columns and normal strength reinforced concrete columns to be almost equal.

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FRP보강근-콘크리트보의 휨성능과 휨설계식의 평가 연구 (A Study on the Evaluation of Flexural Capacity and Design Equation of FRP Reinforcement-Concrete Beams)

  • 고동우
    • 한국공간구조학회논문집
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    • 제22권1호
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    • pp.59-66
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    • 2022
  • In this paper, the flexural capacity equation of FRP-bar reinforced concrete beams was verified by comparing the experimental results and flexural capacity obtained according to the ACI procedure. And, also the economic feasibility of FRP-bar reinforced concrete beams was analyzed by comparing nominal moment capacity of beams. The results of analysis were as follows, 1) GFRP concrete beams have lower flexural performance than reinforced concrete beams, whereas CFRP concrete beams have similar flexural performance to reinforced concrete beams under the same reinforcement ratio 2) Although the design moment increased as the compressive strength of concrete increased, the flexural performance of GFRP reinforced concrete beams was found to be lower than the reinforced concrete beams for all reinforcement ratios.

Evaluation of Bamboo Reinforcements in Structural Concrete Member

  • Siddika, Ayesha;Al Mamun, Md. Abdullah;Siddique, Md. Abu Bakar
    • Journal of Construction Engineering and Project Management
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    • 제7권4호
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    • pp.13-19
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    • 2017
  • This study is based on the use and performance of bamboo reinforcements in construction of low-cost structures. This study investigated the physical and mechanical properties of bamboo reinforcements. Bamboo reinforced concrete beam specimens were tested with different reinforcement ratios and observed the load capacity, deflection and failure patterns. It was observed that, flexural strength of bamboo reinforced column is sufficient higher than plain cement concrete and comparable to steel reinforced concrete beams. Bamboo reinforced concrete columns with different reinforcement ratio also tested and observed the ultimate compressive strength and failure pattern. It found, all columns failed in a similar pattern due to crushing of concrete. According to cost analysis, bamboo reinforced beams and columns with moderate reinforcement ratio showed the best strength-cost ratio among plain cement concrete and steel reinforced concrete.

부식전위 기준에 의한 철근콘크리트 구조물의 부식진단의 위험성에 관한 고찰 (Consideration on the Risk of Corrosion Assessment in Reinforced Concrete Structure by Corrosion Potential Criterion)

  • 정진아
    • Corrosion Science and Technology
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    • 제14권3호
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    • pp.147-152
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    • 2015
  • Corrosion of steel reinforcement is a major factor in the deterioration of harbour and bridge structure. Steel corrosion in concrete must be checked for assessing the condition of a reinforced concrete structure. There are several ways how to measure the corrosion condition of reinforced concrete, but the corrosion potential measurement is a very simple, rapid, cost-effective and non-destructive technique to evaluate the severity of corrosion in reinforced concrete structure, therefore commonly used by engineers. However some particular situations may not relate to the reinforcement corrosion probability and a simple comparison of the corrosion potential data with the ASTM C876 Standard on steel reinforcement corrosion probability could be meaningless and not give reliable informations because of environment factors as oxygen concentration, chloride content, concrete resistance. Therefore this paper explains the risk of corrosion assessment in reinforced concrete structure and how many factors can affect the reliability of the corrosion potential data.

Study on fracture characteristics of reinforced concrete wedge splitting tests

  • HU, Shaowei;XU, Aiqing;HU, Xin;YIN, Yangyang
    • Computers and Concrete
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    • 제18권3호
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    • pp.337-354
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    • 2016
  • To study the influence on fracture properties of reinforced concrete wedge splitting test specimens by the addition of reinforcement, and the restriction of steel bars on crack propagation, 7 groups reinforced concrete specimens of different reinforcement position and 1 group plain concrete specimens with the same size factors were designed and constructed for the tests. Based on the double-K fracture criterion and tests, fracture toughness calculation model which was suitable for reinforced concrete wedge splitting tensile specimens has been obtained. The results show that: the value of initial craking load Pini and unstable fracture load Pun decreases gradually with the distance of reinforcement away from specimens's top. Compared with plain concrete specimens, addition of steel bar can reduce the value of initial fracture toughness KIini, but significantly increase the value of the critical effective crack length ac and unstable fracture toughness KIun. For tensional concrete member, the effect of anti-cracking by reinforcement was mainly acted after cracking, the best function of preventing fracture initiation was when the steel bar was placed in the middle of the crack, and when the reinforcement was across the crack and located away from crack tip, it plays the best role in inhibiting the extension of crack.

RCC frames with ferrocement and fiber reinforced concrete infill panels under reverse cyclic loading

  • Ganesan, N.;Indira, P.V.;Irshad, P.
    • Advances in concrete construction
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    • 제5권3호
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    • pp.257-270
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    • 2017
  • An experimental investigation was carried out to study the strength and behavior of reinforced cement concrete (RCC) frames with ferrocement and fiber reinforced concrete infill panel. Seven numbers of $1/4^{th}$ scaled down model of one bay-three storey frames were tested under reverse cyclic loading. Ferrocement infilled frames and fiber reinforced concrete infilled frames with varying volume fraction of reinforcement in infill panels viz; 0.20%, 0.30%, and 0.40% were tested and compared with the bare frame. The experimental results indicate that the strength, stiffness and energy dissipation capacity of infilled frames were considerably improved when compared with the bare frame. In the case of infilled frames with equal volume fraction of reinforcement in infill panels, the strength and stiffness of frames with fiber reinforced concrete infill panels were slightly higher than those with ferrocement infill panels. Increase in volume fraction of reinforcement in the infill panels exhibited only marginal improvement in the strength and behavior of the infilled frames.

지하 철근 콘크리트 박스 구조물의 내진해석방법 및 철근 배근 상세에 관한 연구 (The Study of detailng for concrete reinforcement and Seismic Analysis Method for Underground Reinforced Concrete Box Structures)

  • 이명수;한상철
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2005년도 추계학술대회 논문집
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    • pp.1215-1222
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    • 2005
  • The object of this thesis is an study on detailing for concrete reinforcement and analytical study for seismic behavior of underground reinforced concrete box structures using the established seismic analytical method. Using the established seismic analytical method that has been presented in various documents seismic behavior of buried reinforce concrete box structures is compared. From the comparsion, it is shown that feasibility and detailing detailng for concrete reinforcement and seismic method for seismic analysis of buried reinforced concrete box structures.

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철근콘크리트 보의 최소전단철근비 예측 (Evaluation of Minimum Shear Reinforcement Content of Reinforced Concrete Beams)

  • 윤성현;이정윤;김상우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.253-258
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    • 2002
  • An evaluation equation of the minimum shear reinforcement content for reinforced concrete beams was theoretically proposed. The proposed equation takes into account the effects of compressive strength of concrete, longitudinal reinforcement content and shear span ratio. The proposed equation was compared with the current ACI 318-99 and CSA A23.3-94 codes.

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Finite element modelling of reinforced concrete structures with laboratory verification

  • Cheng, Y.M.
    • Structural Engineering and Mechanics
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    • 제3권6호
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    • pp.593-609
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    • 1995
  • The presence of reinforcement has a significant influence on the stress-strain behaviour of reinforced concrete structures, expecially when the failure stage of the structures is approached. In the present paper, the constrained and non-constrained zones of concrete due to the presence of reinforcement is developed and the stress-stress-strain behaviour of concrete is enhanced by a reinforcement confinement coefficient, Furthermore, a flexible method for the modelling of reinforcement with arbitrary orientation and not passing the nodes of concrete element is also proposed. Numerical examples and laboratory tests have shown that the coefficient and the modelling technique proposed by the author are satisfactory.