• Title/Summary/Keyword: Steel-Fibers

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The effect of acid environment and thawing and freezing cycles on the mechanical behavior of fiber-reinforced concrete

  • A.R. Rahimi Chakdel;S.M. Mirhosseini;A.H. Joshagani;M.R.M. Aliha
    • Structural Engineering and Mechanics
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    • v.90 no.5
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    • pp.481-492
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    • 2024
  • This research examined the mechanical behavior of fiber-reinforced concrete at unstable environmental conditions. Concrete composites with varying percentages of steel and glass fibers were analyzed. Compressive, indirect tensile, and fracture toughness properties were evaluated using the Edge Notched Disc Bend (ENDB) test under freezing-thawing and acidic environments and the results were compared with normal conditions. Steel fibers decreased the strength in the specified cycles, while glass fibers showed a normal strength trend. The compressive, tensile and fracture toughness of the samples containing 1.5 vol.% fibers showed a 1.28-, 2.13- and 4.5-fold enhancement compared to samples without fibers, after 300 freezing-thawing cycles, respectively.

Enhancing the Performance of High-Strength Concrete Corbels Using Steel Fibers and Headed Bars (강섬유 및 헤디드 바를 활용한 고강도 콘크리트 내민받침의 성능 향상)

  • Yang, Jun-Mo;Lee, Joo-Ha;Shin, Hyun-Oh;Yoon, Young-Soo
    • Journal of the Korea Concrete Institute
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    • v.21 no.6
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    • pp.697-703
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    • 2009
  • High-strength concrete corbels with varying percentage of steel fibers and two different anchorage types (welding to transverse bar, headed) for the main tension tie were constructed and tested. The results showed that performance in terms of load carrying capacities, stiffness, ductility, and crack width was improved, as the percentage of steel fibers was increased. In addition, the corbel specimens in which headed bars were used as the main tension tie reinforcements showed superior load carrying capacities, stiffness, and ductility compared to the corbel specimens in which the main tension ties were anchored by welding to the transverse bars. From the test results, it is expected that load carrying capacities, durability, and constructibility of high strength concrete corbels would be improved by using steel fibers and headed bars. Experimental results presented in this paper were also compared with various prediction models proposed by researchers and presented in codes. The truss model proposed by Fattuhi provides fairly good predictions for fiber reinforced high-strength concrete corbels.

A Study on the Steel Anticorrosive Effect of Fiber-Reinforced Cement Composite (FRCC) by using Metal Fibers (금속섬유를 이용한 섬유보강 시멘트 복합재료(FRCC)의 철근 방식 효과)

  • Choi, Hyeong-Gil;Choi, Hee-Sup
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.23 no.4
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    • pp.23-30
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    • 2019
  • Fiber-Reinforced Cement Composite (FRCC) is known to be effective in mechanical effects such as cracking width control as well as steel anticorrosive effect. In this study, we examined about steel anticorrosive effect by using metal fibers including zinc fibers by accelerated corrosion test. Moreover, it was examined for salt penetration, sacrificial anode effect and formation of electric circuit that was significant effect on the steel anticorrosive effect. As a result, Steel anticorrosive effect was confirmed with mixed metal fibers on FRCC. Especially, In the case of zinc fibers with a high sacrificial anode effect, it was confirmed that the suppression of penetration and corrosion resistance were improved.

An Experimental Study on Structural Behavior of PSC Beams Reinforced with Steel Fibers (강섬유보강 PSC 보의 구조거동 실험연구)

  • Yang, In-Hwan;Joh, Chang-Bin;Kim, Byung-Suk;Joo, Kun-Hyung
    • Proceedings of the Korea Concrete Institute Conference
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    • 2010.05a
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    • pp.101-102
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    • 2010
  • The flexural performance of high-strength prestressed concrete (PSC) beams reinforced with steel fibers is described. This study aims at determining the structural behavior of steel fiber reinforced concrete beams such as failure mode, capacity in flexure, crack patterns, strains in concrete.

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Effects of Mixing Fiber Types on Electromagnetic Wave Shielding Effectiveness of Mortar (혼입섬유에 따른 모르타르의 전자파 차폐 효과)

  • Kim, Young-Jun;Yi, Chongku
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2015.05a
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    • pp.150-151
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    • 2015
  • In this study, the electromagnetic shielding performance of mortar with different metal fiber, as part of the development of a electromagnetic shielding construction material, was measured according to KS C 0304. The results showed that the amorphous steel fibers can shield electromagnetic effectively than the oter conventional steel fibers. The superior performance of the amorphous steel fiber may be attributed its plate shape geometry.

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Experimental Study on Mechanical Properties and Deformation Behavior of Concrete with Recycled Aggregates and Steel Fiber (순환골재 및 강섬유를 혼입한 콘크리트의 역학적 특성 및 변형 거동에 관한 실험적 연구)

  • Lee, Hyun-Ho;Lee, Tae-Wang
    • Journal of the Korea Concrete Institute
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    • v.28 no.3
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    • pp.357-363
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    • 2016
  • To solve the exhaustion problem of natural aggregate which were create the high value in construction and environmental industry, recycled aggregates have considerable benefits than other materials. However, even though many researches have been conducted with recycled aggregates, building structures with recycled aggregated are rarely constructed because it has lower quality than natural aggregates have. In this study, mechanical and strain properties of recycled aggregates concrete containing steel fibers have been reviewed in order to complement performance of recycled aggregates concrete. As results, recycled aggregates concrete showed lower compressive strength and elastic modulus than plain concrete. But, recycled aggregates concrete containing steel fibers showed equivalent performance with plain concrete. In review of drying shrinkage and creep coefficient, recycled aggregates concrete containing steel fibers showed similar behavior with plain concrete in the range of 0.5 Vol.% fiber content rate by internal restraint effect, moisture transport restraint effect and strength enhancement effect of steel fiber. Therefore, it is considered that mixing steel fibers with concrete is the effective method as a active application plan for recycled aggregates.

Cracking Behavior of RC Tension Members Reinforced with Amorphous Steel Fibers (비정질 강섬유로 보강된 철근콘크리트 인장부재의 균열거동)

  • Park, Kyoung-Woo;Lee, Jun-Seok;Kim, Woo;Kim, Dae-Joong;Lee, Gi-Yeol
    • Journal of the Korea Concrete Institute
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    • v.26 no.4
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    • pp.475-482
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    • 2014
  • This paper presents the experimental results concentrically reinforced concrete tension members and compares cracking behavior of amorphous steel fiber and normal steel fiber reinforced concrete members. Two kind of steel fibers were included as a major experimental parameter together with the six cover thickness to bar diameter ratio ($c/d_b$). The presence of amorphous steel fibers effectively controlled the splitting cracks initation and propagation. In the amorphous steel fiber reinforced specimens, no splitting cracks were observed that becomes higher with cover thickness to bar diameter ratio is 2.0. Crack spacing of the each specimens reinforced with amorphous steel fibers and normal steel fibers becomes larger with the increase in cover thickness, and also measured maximum and average crack spacing are significantly smaller than current design code provision. Based on the measured crack spacings, a relationships for predicting the crack spacing is proposed using the measured average crack spacing in amorphous steel fiber reinforced concrete tension members.

Fundamental Study of Behavior on Steel·Concrete Composite Beam Reinforced Steel Fiber (강섬유를 보강한 강상판 합성보의 거동에 관한 기초적 연구)

  • Seo, Seung-Tag
    • Journal of the Korean Society of Industry Convergence
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    • v.11 no.2
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    • pp.93-98
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    • 2008
  • Steel fibre reinforced concrete (SFRC) were considered a new technology for the construction industry. However today this technology has found wider acceptance among the construction industry. Currently, steel fibres are used in varied segments in many application areas across different segments in the construction industry, especially in tunneling, airports, warehouses, etc. Time and safety are the main factors are among the various advantages which renders steel fibres superior to the competing product. For fibers reinforcing, The maximum load carrying capacity is controlled by fibers pulling out of the composite because fiber reinforcing does not have a deformed surface like larger steel reinforcing bars. The study demonstrated that above concept is applicable and effective in concrete structure by analytical study. The analytical result appears that SFRP have the potential to significantly increase the strength of existing concrete structures, while at the same time dramatically improving their fracture energy characteristics.

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Tribology of friction materials containing different metal fibers (마찰재에 함유된 금속섬유의 종류에 따른 마찰 특성)

  • Ko, Kil-Ju;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.55-63
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    • 2001
  • Friction and wear properties of brake friction materials containing different metal fibers (Al, Cu or Steel fibers) were investigated using a pad-on-disk type friction tester. Two different materials(gray iron and Al-MMC)) were used for disks rubbing against the friction materials. Results from ambient temperature tests revealed that the friction material containing Cu fibers sliding against cast iron disk showed a distinct negative ${\mu}$-ν (friction coefficient vs. sliding velocity) relation implying possible stick-slip generation at low speed. The negative ${\mu}$-ν relation was not observed when the Cu-containing friction materials were rubbed against the. Al-MMC counter surface. As applied loads increased, friction materials showed higher friction coefficients comparatively. Friction materials slid against cast iron disks exhibited higher friction coefficients than Al-MMC disks during high temperature tests. On the other hand, high temperature test results suggested that copper fibers in the friction material improved fade resistance and the steel fibers were not compatible with Al-MMC disks showing severe material transfer and erratic friction behavior during sliding at elevated temperatures.

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Effect of Aligned Steel Fibers by a Solenoid on Flexural Fracture Behavior (솔레노이드에 의해 정렬된 강섬유가 휨파괴 거동에 미치는 영향)

  • Gyu-Pil Lee;Do-Young Moon
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.27 no.6
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    • pp.193-200
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    • 2023
  • This paper investigates the effect of directional alignment of steel fibers using an electromagnetic field on the flexural fracture behavior of steel fiber reinforced concrete. A specially designed and manufactured solenoid, capable of aligning steel fibers in the longitudinal direction of the beam specimen, was employed for this purpose. Beam specimens with a design strength of 30 MPa were produced, and failure tests were conducted on specimens exposed to electromagnetic fields and those without exposure. Experimental variables included the mixing ratio and aspect ratio of steel fibers. The results of the experiments revealed a slight increase in flexural strength and crack mouth opening displacement at the maximum load for specimens exposed to the electromagnetic field. Notably, a significant enhancement in fracture energy was observed.