• Title/Summary/Keyword: steel fiber ratio

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An Experimental Study on Eccentrically Loaded Steel Fiber Reinforced Concrete Columns (편심축하중을 받는 강섬유보강 콘크리트 기둥의 실험적 연구)

  • 박홍용;안영진
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10b
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    • pp.857-860
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    • 2000
  • An experimental study on the behavior of Steel Fiber Reinforced Concrete Columns under eccentric compression are presented. Forth-one columns were tested; the variables were column type, eccentricity of load, fiber contents, and longitudinal reinforcement ratio. The column size was $250\times160$ mm in cross section with an effective length of 1150 mm. Eccentricity of load was varied in the range from 1/6 to 1/2 times the column depth. This paper is to provides a framework for basic understanding of the steel fiber concrete columns.

Steel Fibers Efficiency as Shear Reinforcement in Concrete Beams (섬유보강콘크리트 보의 전단거동에 미치는 강섬유의 효과)

  • 문제길;홍익표
    • Magazine of the Korea Concrete Institute
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    • v.6 no.2
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    • pp.118-128
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    • 1994
  • There have been conducted a lot of works on shear behavior of steel fiber reinforced concrete beams. Fiber reinforced concrete beams without shear reinforcement were tested to determine their cracking shear strengths and ultimate shear capacities. Results of tests on 14 reinforced concrete beams (including 11 containing steel fibers) are reported. Two parameters were varied in the study, namely, the volume fraction of fibers and shear span-to-depth ratio.The effects of fiber incorporation on failure modes, deflections, cracking shear strength, and ul~imate shear strength have been examined. Resistance to shear stresses have been found to be improved by the inclusion of fibers, The mode of failure changed from shear to flexure when the shear span-to-depth ratio exceeds 3.4. Based on these investigations, a method of computing the shear strength of steel fiber reinforced concrete beam is suggested. The comparisons between computed values and expenmentally observed values are shown to verify the proposed theoretical treatment and steel fibers efficiency.

Estimation of Flexural and Shear Strength for Steel Fiber Reinforced Flexural Members without Shear Reinforcements (전단보강이 없는 강섬유보강 콘크리트 휨부재의 휨 및 전단강도의 평가)

  • Oh, Young-Hun;Kim, Jeong-Hae
    • Journal of the Korea Concrete Institute
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    • v.20 no.2
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    • pp.257-267
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    • 2008
  • Results of seventy-seven specimens tested by this study and previous research were collected and evaluated to propose the flexural strength and shear strength for flexural members with steel fiber concrete. For strength evaluation, structural parameters such as compressive strength, steel fiber content, tensile reinforcement ratio, and shear span to effective depth ratio are involved. The proposed equations for flexural and shear strength are regarded to give a good prediction for the strength of steel fiber reinforced composite and/or RC beams to compare with equations by previous researchers. Especially, the proposed shear strength equation in this study shows the lowest the mean value, the coefficient of variation and the error ratio among predictions by several equations. Therefore, equations for shear strength and flexure strength, which are proposed in this study are to be useful measure to predict the actual behavior and failure mode of steel fiber reinforced composite beams.

Evaluation of Stress-Strain Relationship and Elastic Modulus Equation of Steel Fiber Reinforced High-Strength Concrete (강섬유보강 고강도콘크리트의 응력-변형률 곡선 및 탄성계수 추정식 평가)

  • 장동일;손영현;조광현;김광일
    • Journal of the Korea Concrete Institute
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    • v.12 no.2
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    • pp.13-20
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    • 2000
  • In this study, the compression test of steel fiber reinforced high-strength concrete have been performed with varying strengths and volume factions of steel fiber. Three types of matrices including low strength concrete( c'=30 MPa), medium strength concrete( c'=50 MPa), and high strength concrete( c'=70 MPa) were selected. Five types of fiber fractions were studied including 0.0%, 0.5%, 0.75%, 1.0%, and 1.5% by volume. From the results of the compressive strength test, the post-peak characteristics of the stress-strain relationship were investigated, and the existing equations to predict the elastic modulus were experimentally evaluated.

Studies on the Properties of Fiber Reinforced Porous Concrete Using Polymer (섬유보강 폴리머 포러스콘크리트의 특성에 관한 실험적 연구)

  • Park, Seong-Bum;Lee, Byung-Jae;Lee, Jun;Son, Sung-Woo;Cho, Kwang-Yeon
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.581-584
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    • 2006
  • This study is analyzed mechanical properties and durability of permeability porous concrete to mix polymer and steel fiber for the enhance of performance and durability of porous concrete. It proves that void ratio and permeability are tallied with internal and external standard of paving porous concrete. A property of strength is increased according as the mixing rate of polymer and steel fiber increase, but it showed the tendency to be reduced on the contrary when mixed upwards of 20% of polymer mixing rate and 0.9vol.% of steel fiber mixing rate. As a result, it is possible to make an enhanced which increased 16% of compressive strength and 30% of flexural strength steel fiber reinforced polymer porous concrete at the mixing rate of 10vol.% of polymer and 0.6% of steel fiber.

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Fabrication and Mechanical properties of Steel Fiber Reinforced Polyester Resin Composites Utilizing by-Products (Fly Ash) (산업부산물을 이용한 강섬유보강 폴리에스터 수지복합체의 제조 및 역학적 특성)

  • 박승범;윤의식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.35-40
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    • 1992
  • Results of an experimental study on the manufacture, the workability and mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products are presented in this paper. The fly ash polyester resin composites using steel fiber, fly ash and calcium carbonic acid (CaCo3), unsaturated polyester resin, styrene monomer, cobalt octate and methyl ethyl ketone peroxide, fine and coarse aggregates are prepared with various filler~binder rations, binder rates and mixing conditions. As a test results, the workability of steel fiber reinforced polyester resin composites are considerably dropped with increasing fly ash-binder ratio and steel fiber volume. And compressive, flexural strength and bending toughness of the composites are remarkably improved with augmenting fiber contents.

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The combined reinforcement to recycled aggregate concrete by circular steel tube and basalt fiber

  • Zhang, Xianggang;Zhang, Songpeng;Chen, Xu;Gao, Xiang;Zhou, Chunheng
    • Computers and Concrete
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    • v.29 no.5
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    • pp.323-334
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    • 2022
  • In order to study the axial compression performance of basalt-fiber reinforced recycled concrete (BFRRC) filled circular steel tubular short columns, the axial compression performance tests of seven short column specimens were conducted to observe the mechanical whole-process and failure mode of the specimens, the load-displacement curves and the load-strain curves of the specimens were obtained, the influence of design parameters on the axial compression performance of BFRRC filled circular steel tubular short columns was analyzed, and a practical mathematical model of stiffness degradation and a feasible stress-strain curve equation for the whole process were suggested. The results show that under the axial compression, the steel tube buckled and the core BFRRC was crushed. The load-axial deformation curves of all specimens show a longer deformation flow amplitude. Compared with the recycled coarse aggregate (RCA) replacement ratio and the basalt fiber dosage, the BFRRC strength has a great influence on the peak bearing capacity of the specimen. The RCA replacement ratio and the BFRRC strength are detrimental to ductility, whereas the basalt fiber dosage is beneficial to ductility.

Hysteretic Behavior of Diagonally Reinforced Concrete Coupling Beams According to Aspect Ratio and Volume Fraction of Steel Fiber Under Cyclic Loading (반복하중을 받는 대각보강된 철근콘크리트 연결보의 강섬유 형상비와 혼입률에 따른 이력거동)

  • Choi, Ji-Yoon;Son, Dong-Hee;Bae, Baek-Il;Choi, Chang-Sik
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.3
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    • pp.84-91
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    • 2022
  • In this study, an experimental study was conducted to analyze the hysteresis behavior according to the steel fiber aspect ratio and volume fraction of diagonally reinforced concrete coupling beams under to cyclic loading. The aspect ratio and volume fraction of the steel fibers were set as the main variables, and 4 specimens were fabricated in which the amount of transverse reinforcement of the coupling beam suggested in the domestic building structural standard was relaxed by about 53%. In the experiment, cyclic loading experiments were performed in the displacement control method in accordance with ACI 374.2R-13, and as a result of the experiment, it was found that all specimens containing steel fibers exceeded the nominal shear strength suggested by the current structural standards. As the aspect ratio of the steel fibers increased, the steel fibers prevented the buckling of the diagonal reinforcement, and the bridging effect of the steel fibers held the crack surface of the concrete. The shear strength, stiffness reduction and energy dissipation capacity of the specimens containing steel fibers were superior to those of the Vf0 specimens without steel fibers. Therefore, it is judged that the steel fiber reinforced concrete can relieve the details of the transverse reinforced.

An Experimental Study of Improving Fire Performance with Steel-fibers for Internally Anchored Square Composite Columns (내화성능 개선을 위한 강섬유 보강 내부 앵커형 각형강관 합성기둥의 실험연구)

  • Kim, Sun Hee;Yom, Kong Soo;Kim, Yong Hwan;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.499-509
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    • 2014
  • This study focuses on mixing steel fiber in the concrete to improve the ductility and toughness of the columns. The purpose of the study is to evaluate the load capacity and deformation capacity associated with the amount of steel fiber and loading condition and to analyze the interplay between the steel fiber reinforced concrete and the welding built-up square tube in terms of structure and fire resistance performance. Reinforcement of concrete with steel fiber(Vf=0.375%), when cross-section shape and boundary condition (load ratio) remained unchanged, improved fire resistance performance by 1.1~1.3 times. It is deemed that the area resisting thermal load increased and fire resistance performance was improved since the concrete reinforced with steel fiber restrained cracking. In addition, the fact that the cross-sections of the concrete were barely damaged indicates that load share capacity was greatly improved.

Experimental analysis and modeling of steel fiber reinforced SCC using central composite design

  • Kandasamy, S.;Akila, P.
    • Computers and Concrete
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    • v.15 no.2
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    • pp.215-229
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    • 2015
  • The emerging technology of self compacting concrete, fiber reinforcement together reduces vibration and substitute conventional reinforcement which help in improving the economic efficiency of the construction. The objective of this work is to find the regression model to determine the response surface of mix proportioning Steel Fiber Reinforced Self Compacting Concrete (SFSCC) using statistical investigation. A total of 30 mixtures were designed and analyzed based on Design of Experiment (DOE). The fresh properties of SCC and mechanical properties of concrete were studied using Response Surface Methodology (RSM). The results were analyzed by limited proportion of fly ash, fiber, volume combination ratio of two steel fibers with aspect ratio of 50/35: 60/30 and super plasticizer (SP) dosage. The center composite designs (CCD) have selected to produce the response in quadratic equation. The model responses included in the primary stage were flowing ability, filling ability, passing ability and segregation index whereas in harden stage of concrete, compressive strength, split tensile strength and flexural strength at 28 days were tested. In this paper, the regression model and the response surface plots have been discussed, and optimal results were found for all the responses.