• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.82-87
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• 1992

In this thesis, the fatigue tests were performed on a series of SFRC (steel fiber reinforced concrete)to investigate the flexural tensile behavior of SFRC varying with the steel fiber contents and the steel fiber aspect ratios. Beam specimens of 10$\times$10$\times$60cm are used. the specimen series are classified according to the steel fiber contents varying 0.5. 1.0, 1.5%, and to the steel fiber aspect ratios varying 60, 80, 100. The three point loading system was used in the fatigue tests. The minimum value of repeated loading was fixed at 10.0kgf and maximum value was 75% to static ultimate strength for periodically using concrete strain gages located at the lower end of the mid-span, and the stress-strain curves were drawn for each specimens, respectively. From the tests result, it was found that the larger steel fiber content and the smaller the steel fiber aspect ratio is , the tensile strain of SFRC under fatigue load proportionally increases. By the regression analysis on these results, the empirical formulae to predict the tensile strain of SFRC were suggested. In comparison of the tensile elastic modulus under fatigue load, it was also found that the larger steel fiber content and the smaller steel fiber aspect ratio is , the smaller decreasing rate of the stiffness of SFRC under fatigue load decreased.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.241-242
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• 2009

This study showsUltra high performance concrete with steel fiber to obtain the high ductillity. the results of high strength concrete specimences with existing steel fiber and liquid metal fiber were compared with them of plain high strength mortal through bending test. The result that the ductility of high strength concrete with liquid metal fiber was superior to that with bundrex steel fiber was found through toughness test mathod like ASTM C 1018, JSCE-SF4.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.155-156
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• 2020

The purpose of this study is to evaluate tensile performance of cementitious composites reinforced with steel fiber. The tensile performance of steel fiber reinforced cementitious composites is related to the tensile performance of reinforced fiber, and depends on the fracture or pull-out of fiber. Therefore, the tensile performance was compared and analyzed by conducting a direct tensile test on the tensile specimens of cementitious composites reinforced with hook-type steel fiber and amorphous steel fiber.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.23-28
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• 2001

Since the steel fiber used in concrete to improve shear and ductility capacity, a number of laboratory tests have been studied to define shear strengthening effect according steel fiber contents in concrete. This study investigates shear strengthening effect of steel fiber in RC columns according to compression strength of concrete. From the structural performance test, following conclusions can be made; the maximum enhancement of shear strengthening effect can be achieved at about 1.0 %~l.5 % of steel fiber contents in comparison with shear capacity ratio, and ductility capacity slightly improved as steel fiber contents increased.

• Magazine of the Korean Society of Agricultural Engineers
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• v.41 no.3
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• pp.73-80
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• 1999

The objective of this study were to investigate the properties and to improve the disadvantages of the polymer concrete such as brittle fracture, large hardening shrinkage . In this paper, steel fiber reinforced polymer concrete is prepared with various steel fiber aspect ratios(ι/d), contents(vol.%), and their material characteristics were investigated experimentally . The aspect ration (ι/d) of the steel fiber was reversly proportional to slump value, and slump value tended to decrease as increase of steel fiber content . And harding shrinkage and impact resistance tended to be improved as the steel fiber content and aspect ration were increased.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.48-57
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• 2009

The quality control of tunnel support construction is very important to maintain a long term stability of tunnel. Especially, steel fiber reinforced shotcrete should be necessary to investigate practically the condition of quality control in the construction site. In order to perform this study, the design criteria and specifications relevant to steel fiber reinforced shotcrete are reviewed. And the comparison is made between the bearing capacity of the several shotcrete layers, based on the equivalence of the bending moments. Eight tunnel construction sites are also investigated carefully to examine and analyse the characteristics of steel fiber reinforced shotcrete especially including strength and mixing condition of steel fiber. Based on the results, it is founded the items to be improved in the future. In addition, the modification program for the specifications of steel fiber reinforced shotcrete is suggested.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.336-341
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• 1998

Steel fiber reinforced concrete(SFRC) is a composite material possessing many physical and mechanical properties which are distinct from unreinforced concrete. The use of steel fiber reinforcement to improve the flexural and tensile strengths, extensibility and toughness of ordinary cement concrete is well known at present, but reinforcement of polymer concrete with steel fibers has been hardly reported untill now. The objective of this study was to improve the properties of the polymer concrete by addition of steel fibers. In this paper steel fiber reinforced polymer concrete is prepared with various steel fiber contents and aspect ratio($\ell$ /d), and their mechanical properties were investigated experimentally.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.3
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• pp.129-137
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• 1999

Reinforced concrete structures using early age concrete were result in the degradation of structural performance due to crack, overload, unexpected vibration and impact load. It demands urgently that reinforced concrete structure using early age concrete should be improved the serviceability and structural performance with the application of new fiber materials. Therefore specimens, designed by the test varibles, such as with or without stirrup and percent of steel fiber incorporated, were constructed and tested to evaluate and develop the structural performance of reinforced steel fiber concrete beam. Based on the test results reported in this study, the following conclusions are made. Specimens, designed by the over 0.75% of steel fiber incorporated, were showed the ductile behavior and failed slowly with flexure and flexure-shear. Comparing with the load-displacement relationship of specimen BSS, designed by the recommendations of the Ministry of Construction and Transportation, reinforced steel fiber concrete beam using early age concrete, over 0.75% of steel fiber incorporated, gets enough load carrying capacity and ductility. Increasing the percent of steel fiber incorporated(0.25~2.0%), the ultimate shear stress of each specimen were increased 12~40% than that of control specimen SSS.

• Advances in concrete construction
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• v.16 no.3
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• pp.127-139
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• 2023

In this study, the steel fiber and the polypropylene fiber were used to enhance the mechanical properties of fully recycled coarse aggregate concrete. Natural crushed stone was replaced with recycled coarse aggregate at 100% by volume. The steel fiber and polypropylene fiber were used as additive material by incorporating into the mixture. In this test two parameters were considered: (a) steel fiber volume ratio (i.e., 0%, 1%, 1.5%, 2%), (b) polypropylene fiber volume ratio (i.e., 0%, 0.1%, 0.15%, 0.2%). The results showed that compared with no fiber, the integrity of cubes or cylinders mixed with fibers after failure was better. When the volume ratio of steel fiber was 1~2%, the width of mid-span crack after flexural failure was 5~8 mm. In addition, when the volume ratio of polypropylene fiber was 0.15%, with the increase of steel fiber content, the static elastic modulus and toughness of axial compression first increased and then decreased, and the flexural strength increased, with a range of 6.5%~20.3%. Besides, when the volume ratio of steel fiber was 1.5%, with the increase of polypropylene fiber content, the static elastic modulus decreased, with a range of 7.0%~10.5%. The ratio of axial compression toughness first increased and then decreased, with a range of 2.2%~8.7%. The flexural strength decreased, with a range of 2.7%~12.6%. On the other hand, the calculation formula of static elastic modulus and cube compressive strength of fully recycled coarse aggregate with steel-polypropylene fiber was fitted, and the optimal fiber content within the scope of the test were put forward.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.238-239
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• 2014

It is well known that the bond characteristics of fiber govern the performance of fiber reinforced composite material. A preliminary study was carried out to investigate the pull-out behavior of amorphous and conventional single fiber in cement mortar in accordance with the JCI(Japan Concrete Institute) SF-8. The test was performed under displacement control, and results showed that the bond strength decreased with increasing fiber length. In addition, the amorphous steel fiber showed much higher pull-out load per unit weight compared to conventional steel fiber.