• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
• /
• pp.341-344
• /
• 2004

In the present research, slump, modulus of rupture (MOR) and flexural toughness $(I_{30})$ of high performance hybrid fiber reinforced concrete (HPHFRC) mixed with micro-fiber (carbon fiber) and macro-fiber (steel fiber) and replaced with silica fume were assessed with the analysis of variance (ANOVA). Steel fiber was a considerable significant factor in aspect of the response values of MOR and boo Based on the significance of factors related to response values from ANOVA, following assessments were available; Slump decrease: carbon fiber >> steel fiber > silica fume; MOR: steel fiber > silica fume > carbon fiber; $I_{30}$: steel fiber > carbon fiber > silica fume. Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $5.0\%$, and Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $2.5\%$ were obtained as the most optimum mixture.

• 한국전산구조공학회논문집
• /
• 제25권5호
• /
• pp.381-388
• /
• 2012

본 연구에서는 Steel Fiber를 원전 격납건물에 적용하기 위한 적용성 평가를 위해서 Steel Fiber가 삽입된 격납건물에 대한 지진위험도 평가를 수행하였다. Steel Fiber를 콘크리트에 삽입함으로써 콘크리트의 구조적 성능에서 취약점인 인장성능을 향상시킬 수 있고, 압축강도 및 전단강도도 증가시킬 수 있는 장점이 있기 때문이다. 그러나 아직까지 원전 격납건물에 Steel Fiber를 적용하기 위한 노력은 진행되고 있지 않다. 재료적 우수성에도 불구하고 원전에 적용하기 위해서는 좀 더 많은 사용경험과 성능검증이 이루어져야 가능할 것이다. 따라서 본 연구에서는 원자력발전소 격납건물에 Steel Fiber를 사용하였을 경우, 격납건물의 지진안전성의 변화를 살펴보기 위하여 기존의 실험자료를 이용하여 취약도 평가를 수행하였다. 분석결과 Steel Fiber의 함유로 인하여 전단성능과 연성능력이 증가하여 지진취약도의 향상으로 나타났다. Steel Fiber함유량이 1.0%인 경우 지진내력이 10%가량 증가하는 효과를 얻을 수 있었다. 그러나 본 연구의 결과는 제한된 기존의 실험결과를 이용한 예비해석이므로 Steel Fiber의 실제 적용성을 적확하게 분석하기 위해서는 Steel Fiber가 함유된 다양한 콘크리트 부재실험을 통하여 그 물성의 변화를 파악하여야 할 것이다.

• 한국터널지하공간학회 논문집
• /
• 제13권1호
• /
• pp.71-82
• /
• 2011

본 논문에서는 강섬유 형상에 따른 인발력 거동에 대한 연구를 수행하였다. 최적의 강섬유 형상을 도출하기 위하여 매입 된 강섬유가 이루는 각도와 길이를 변화시켜가며 인발실험을 시행하였다. 또한 인발실험 결과를 모사하기 위해 수치 해석을 수행하였다. 그 결과 강섬유 형상에 있어서 hook 각도와 설치각도 클수록 인발력이 뛰어나며, 특히 강섬유의 길이가 짧아짐에 따라 인발력도 뛰어난 것으로 판단되어졌다.

• 한국농공학회논문집
• /
• 제46권7호
• /
• pp.55-67
• /
• 2004

In this paper, the flowability, strengths, impact resistance and sulfuric acid resistance of steel fiber reinforced high performance concrete (SFHPC) for the steel fiber content and fly ash and blast furnace slag as admixtures were presented. For evaluating flowability particularly, tests of slump flow, box-type passing ability and L-type filling ability were performed. The slump flow of SFHPC was some decreased with increase of the steel fiber content. At the box-type passing ability, the difference of box height of SFHPC is greatly increased with increasing the fiber content. The L-type filling ability of SFHPC was not excellent above $0.75\% of the steel fiber content. Also, the compressive strength of SFHPC was decreased with increase of the steel fiber content, but the flexural strength of SFHPC was much higher than that of the concrete without the steel fiber. At the impact resistance, drop number of SFHPC for reaching final fracture was increased with increase of the fiber content. Also, the drop number for reaching initial fracture of lmm was increased with increase of the fiber content. At the sulfuric acid resistance, 4-week weight change of SFHPC with the steel fiber was almost similarity that of HPC without the steel fiber and was in the range of 73.6 to 81.5.

• 한국농공학회지
• /
• 제27권2호
• /
• pp.47-56
• /
• 1985

Wasting fiberous residues from the cutting processes of steel materials at an iron-Works were mixed with concrete. The strength and toughness of steel fiber concrete with different steel contents were tested in a laboratory. The test results showed that the steel fiber residues can be used for the reinforcement of concrete. The potential applications of such product include floor constructions for facilities like dairy barns, grain storages, and machinery shops. The test results are as follows. 1. The compressive strengths of steel fiber concrete with one percent steel content by volume were 20 percent greater than that of plain concrete. The treatments also increased the concrete toughness by 96 percent. 2. When applied to tensile forces, the steel fiber concrete showed the increased strengths by 20 percent, and the toughness by 48 percent. 3. The steel content levels greater than or equal to 1.5 percent by volume resulted in the decreases of the compressive and tensile strengths of steel fiber concrete by 10 percent as compared to plain concrete. The concrete toughness increased with the steel contents. 4. The reinforcement effects of steel fiber depend on the quality of fiber material being used. Good steel fiber for concrete reinforcement appears to be uniform in shape and component, fine and long, and round-shaped.

• International Journal of Concrete Structures and Materials
• /
• 제11권1호
• /
• pp.29-43
• /
• 2017

This study investigates the blast resistance of fiber-reinforced cementitious composite (FRCC) panels, with fiber volume fractions of 2%, subjected to contact explosions using an emulsion explosive. A number of FRCC panels with five different fiber mixtures (i.e., micro polyvinyl alcohol fiber, micro polyethylene fiber, macro hooked-end steel fiber, micro polyvinyl alcohol fiber with macro hooked-end steel fiber, and micro polyethylene fiber with macro hooked-end steel fiber) were fabricated and tested. In addition, the blast resistance of plain panels (i.e., non-fiber-reinforced high strength concrete, and non-fiber-reinforced cementitious composites) were examined for comparison with those of the FRCC panels. The resistance of the panels to spall failure improved with the addition of micro synthetic fibers and/or macro hooked-end steel fibers as compared to those of the plain panels. The fracture energy of the FRCC panels was significantly higher than that of the plain panels, which reduced the local damage experienced by the FRCCs. The cracks on the back side of the micro synthetic fiber-reinforced panel due to contact explosions were greatly controlled compared to the macro hooked-end steel fiber-reinforced panel. However, the blast resistance of the macro hooked-end steel fiber-reinforced panel was improved by hybrid with micro synthetic fibers.

• 한국농공학회지
• /
• 제29권4호
• /
• pp.124-131
• /
• 1987

The aims of this study was to determine the mechanical properties of steel-fiber reinforced concrete under direct tensile loading, and also to insestigate the mechanism fiber reinforcement in order to improve the possible applications of steel-fiber reinforced concrete. In this study the major variables of experimental investigation were fiber conntents, and the lengths and diameters of fibers. The major results obtained are summarized as follows : 1. The strength, elastic modulus and energy absorption capability of steel-fiber reinforced concrete under direct tensile loading were improved as increasing of fiber contents. 2. The direct tensile strength of steel-fiber reinforced concrete was not influenced by the lengths of fiber, but was decreased as increasing of fiber diameters. 3. The direct tensile strength of steel-fiber reinforced concrete was not influenced by the fiber aspect-ratio, but this was because the fiber contents were below the critical value of fiber content. 4. The correlation of direct tensile strength and combined parameter, Vf l/d, was not good. 5. Mutiple cracking and post-crack resistance were investigated at stress-strain curves in direct tensile test. 6. The effect of fiber reinforcement can be influenced by fiber orientation and the bond strength between fiber and matrix. 7. The improvement of mechanical properties of steel-fiber reinforced concrete under direct tensile loading can be theoretically explained by the concept of composite materials.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(II)
• /
• pp.337-340
• /
• 2005

In this study, an effect of fiber blending on material property of Hybrid Fiber Reinforced Concrete (HFRC) was evaluated. Also, Compare and evaluates collating and mechanical property by the mixing rate of fiber for HFRC was determine. Modulus of rupture and strength effectiveness of Hybrid Fiber Reinforced Concrete mixed with macro-fiber(steel fiber) and micro-fiber(glass fiber, carbon fiber, cellulose fiber). Test result shows, in the case of mono fiber reinforced concrete. As the steel fiber mixing rate increases to 1.5$\%$, the strength effectiveness promotion rate rises. However, when is 2.0$\%$, strength decreases. In the case of hybrid fiber reinforcement concrete, synergy effect of micro fiber and macro fiber happens and higher Modulus of rupture and strength effectiveness appears than mono-fiber reinforcement concrete. Use of hybrid fiber reinforcement in concrete caused a significant influence on its fracture behavior; consequently, caused increase by mixing rate of steel fiber + carbon fiber and contributed by steel fiber + glass fiber, steel fiber + celluloid fiber in reinforcement effect in order. And was expose that steel fiber(1.5$\%$) + carbon fiber(0.5$\%$) is most suitable association.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2020년도 봄 학술논문 발표대회
• /
• pp.191-192
• /
• 2020

The purpose of this study is to measure the electrical conductivity of cementitious composites as an early step to obtain shielding performance by mixing various type of steel fiber into cementitious composites, the main building material of protection facility, to shield electromagnetic pulse (EMP) damage. Fiber such as conductors as amorphous metallic fiber, hooked steel fiber, and smooth steel fiber are mixed into cementitious composites to give electrical conductivity and measure the impedance of concrete using LCR meter. By doing this, the electrical conductivity of each type of steel fiber reinforced cementitious composites (FRCC) is compared.

• Advances in concrete construction
• /
• 제16권1호
• /
• pp.1-20
• /
• 2023

This study presents the experimental results performed to evaluate the effects of Polyvinyl-alcohol (PVA) and Polypropylene (PP) fibers on the fresh and residual mechanical properties of the hybrid fiber reinforced SCC before and after the exposure of 250℃, 500℃ and 750℃ temperatures. The compressive and splitting tensile strength, modulus of rupture (MOR), ultrasonic pulse velocity (UPV) as well as toughness and weight loss were investigated at different temperatures. PVA and PP fibers were added into SCC mixtures having only macro steel fiber and also having binary hybridization of both macro and micro steel fiber. The results showed that the use of micro steel fiber replaced by macro steel fiber improved the fresh and hardened properties compared to the use of only macro steel fiber. Moreover, it was emphasized that PVA or PP enhanced the residual flexural performance of SCC, generally, while it negatively influenced the workability, weight loss, UPV and the residual strengths with regards to the use of single steel fiber and binary steel fiber hybridization. Compared to the effect of synthetic fibers, PP had slightly more positive effect in the view of workability while PVA enhanced the residual mechanical properties more.