• 한국구조물진단유지관리공학회 논문집
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• 제8권3호
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• pp.141-148
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• 2004

본 논문에서는 고성능 감수제, 증점제, 광물질 혼화재 및 강섬유의 양과 종류가 고강도 섬유보강 시멘트 복합체의 워커빌리티에 미치는 영향을 실험적으로 검토하였다. 그 결과, 고강도 강섬유 보강 시멘트 복합체의 워커빌리티는 고성능 감수제, 증점제 및 광물질 혼화재를 적절히 사용함으로써 향상된다. 그리고 강섬유의 형상계수가 작을수록 섬유보강 시멘트 복합체의 워커빌리티가 향상되었으며, 또한 워커빌리티가 향상된 강섬유 보강 시멘트 복합체의 압축강도와 휨강도는 향상되는 것으로 나타났다.

• Steel and Composite Structures
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• 제23권5호
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• pp.611-621
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• 2017

This paper presents an investigation on the fire resistance of high strength fiber reinforced concrete filled box columns (CFBCs) under combined temperature and loading. Two groups of full-size specimens were fabricated. The control group was a steel box filled with high-strength concrete (HSC), while the experimental group consisted of a steel box filled with high strength fiber concrete (HFC) and two steel boxes filled with fiber reinforced concrete. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The test results show that filling fiber concrete can improve the fire resistance of CFBC. Moreover, the configuration of longitudinal reinforcements and transverse stirrups can significantly improve the fire resistance of CFBCs.

• Computers and Concrete
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• 제5권1호
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• pp.21-36
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• 2008

Steel fiber reinforced concrete is increasingly used day by day in various structural applications. An extensive experimentation was carried out with w/cm ratio ranging from 0.25 to 0.40, and fiber content ranging from zero to1.5 percent by volume with an aspect ratio of 80 and silica fume replacement at 5%, 10% and 15%. The influence of steel fiber content in terms of fiber reinforcing index on the compressive strength of high-performance fiber reinforced concrete (HPFRC) with strength ranging from 45 85 MPa is presented. Based on the test results, equations are proposed using statistical methods to predict 28-day strength of HPFRC effecting the fiber addition in terms of fiber reinforcing index. A strength model proposed by modifying the mix design procedure, can utilize the optimum water content and efficiency factor of pozzolan. To examine the validity of the proposed strength model, the experimental results were compared with the values predicted by the model and the absolute variation obtained was within 5 percent.

• 콘크리트학회논문집
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• 제20권4호
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• pp.531-539
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• 2008

본 연구에서는 강섬유보강 고강도콘크리트의 휨강도와 휨인성을 평가하기 위하여 실험을 수행하였으며, 이러한 실험 결과와 기존 연구자들의 실험 결과를 추가하여 강섬유보강 고강도콘크리트의 휨거동 특성을 분석하였다. 고강도 강섬유 콘크리트의 휨거동 특성은 강도와 인성으로 평가할 수 있으며, 이러한 특성은 콘크리트의 압축강도, 강섬유 혼입률 및 형상비, 강섬유계수와 같은 요소에 의해 영향을 받는 것으로 파악되었다. 아울러 기존 연구자에 의해 제안된 휨강도 산정식의 유효성을 평가하였으며, 강섬유 콘크리트의 휨강도는 콘크리트의 압축강도, 강섬유 혼입률 및 형상비, 강섬유계수와 같은 구조변수의 영향을 모두 고려하여 평가하는 것이 합리적이라고 판단되었다. 최종적으로 본 연구에서는 강섬유 혼입에 따른 휨강도의 상승분과 주요 구조변수간의 상관관계를 분석함으로써 보다 합리적인 휨강도 산정식을 제시하였다.

• 콘크리트학회논문집
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• 제11권4호
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• pp.137-145
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• 1999

The use of steel fiber reinforced to improve the strength and flexural toughness of concrete is well known, but reinforcement of polymer concrete with steel fibers has been hardly reported till now. Polymer concrete has high strength, durability and freeze-thaw resistance than that of cement concrete, but it has disadvantage such as low flexural toughness. In this paper, the strength characteristics and flexural toughness of steel fiber reinforced polymer concrete are investigated experimentally with various steel fiber aspect ratios($\ell$/d), and contents(vol.%). As the result, the flexural and splitting tensile strengths and flexural toughness were increased aspect ratio, and reach the maximums at a aspect ratio of 50. The relationship between the compressive, flexural and splitting tensile strength were high. And the relationship between flexural strength and strain energy was approximately linear.

• Computers and Concrete
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• 제9권2호
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• pp.153-169
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• 2012

The contribution of steel fibers on the 28-day compressive strength of high-performance steel fiber reinforced concrete was investigated, is presented. An extensive experimentation was carried out over water-cementitious materials (w/cm) ratios ranging from 0.25 to 0.40, with silica fume-cementitious materials ratios from 0.05 to 0.15, and fiber volume fractions ($V_f$= 0.0, 0.5, 1.0 and 1.5%) with the aspect ratios of 80 and 53. Based on the test results of 44 concrete mixes, mathematical model was developed using statistical methods to quantify the effect of fiber content on compressive strength of HPSFRC in terms of fiber reinforcing index. The expression, being developed with strength ratios and not with absolute values of strengths, is independent of specimen parameters and is applicable to wide range of w/cm ratios, and used in the mix design of steel fiber reinforced concrete. The estimated strengths are within ${\pm}3.2%$ of the actual values. The model was tested for the strength results of 14 mixes having fiber aspect ratio of 53. On examining the validity of the proposed model, there exists a good correlation between the predicted values and the experimental values of different researchers. Equation is also proposed for the size effect of the concrete specimens.

• 콘크리트학회지
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• 제2권4호
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• pp.53-60
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• 1990

전단보강된 고강도콘크리트 보의 역학적 거동을 알아보기 위하여 총9개의 시험체가 제작되었다. 콘크리트 압축강도가 800kg/$\textrm{cm}^2$ 전단스팬비가 3 그리고 주근비가 0.5Pb로 일정할 때 주요변수로서 전단보강비(Vs=0,25,50%)와 섬유첨가율(Vf=0,0.5,1%)로 두었다. 시험결과로 섬유첨가율의 증가에도 극한강도의 변화는 별반 없었으나 연성 능력을 향상시켰으며, 전단보강철근으로의 대체성을 보여주었다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.132-133
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• 2020

The aim of this study is to evaluate the combination effect of amorphous steel fiber and polypropylene fiber on spalling of the 150MPa level ultra high strength concrete. Considering spalling has a great relationship with water vapor pressure, this paper is focusing on water vapor pressure. The test specimens were heated accordance with ISO-834 Standard Curve using electric heating furnace, the depth of 10mm water vapor pressure formation was tend to get faster and spalling damage become severe when the mixing proportion of amorphous steel fiber increase. When using ultra high strength concrete reinforced with amorphous steel fiber, further research about proper mixing proportion of polypropylene fiber.

• 콘크리트학회논문집
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• 제27권3호
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• pp.283-290
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• 2015

이 논문에서는 하이브리드 강섬유로 보강된 콘크리트의 부재의 휨강도를 예측하기 위한 수치해석기법을 제시하였다. 이를 위해 휨을 받는 하이브리드 강섬유 보강 콘크리트 실험과 수치해석연구를 수행하였다. 부피비 1.5%의 하이브리드 강섬유 보강 초고강도 콘크리트의 휨거동 특성 실험을 수행하였다. 강섬유보강 콘크리트의 인장연화특성은 구조적 거동에 매우 중요한 역할을 하며, 하이브리드 강섬유 보강 초고강도 콘크리트의 하중-균열개구변위 실험결과를 반영하여 가상균열모델에 근거한 역해석에 의해 인장연화모델링을 수행하였다. 제안기법에 의한 콘크리트 보의 모멘트-곡률 수치해석결과를 실험결과와 비교하였으며, 수치해석결과와 실험결과는 전반적으로 잘 일치하고 있다. 따라서, 제안기법에 의해 강섬유 보강 초고강도 콘크리트 보의 휨강도를 합리적으로 예측할 수 있다고 판단된다.

• 한국농공학회지
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• 제44권1호
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• pp.93-102
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• 2002

Steel fiber and polymer are used widely for reinforcement material of RC structures because of its excellences of the durability, serviceability as well as mechanical properties. The purpose of this study is to investigate the shear behavior of polymer cement high strength concrete beams mixed with steel fiber. The compressive strength of concrete was based on the 100$\times$200 mm cylinder specimens. The compressive strength of concrete are 320$kgf/cm^2$, 436 $kgf/cm^2$ and 520 $kgf/cm^2$ in the 28 days. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns and fracture modes. Also, load-strain and load-deflection examined. During the test cracks were sketched against the load values according to the growth of crack. result are as follows; (1) The failure modes of the specimens are increased in rigidity and durability with mixing steel fiber and polymer. (2) The load of initial crack was similar a theory of shear-crack strength. (3) The deflection and strain at failure load of Polymer-steel fiber high strength concrete beams were increased, improving the brittleness of the high strength concrete.