• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.665-670
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• 2000

In this study mechanical properties of various fiber reinforced permeability concrete mixtures are investigated. Several mixes with fiber kinds(steel fiber, polyprophylen fiber, carbon fiber) and different fiber content(steel fiber : 0.3~0.9vol.%, polyprophylen fiber : 0.1~0.5vol.%, carbon fiber : 0.2~0.7vol.%) were studied. Test results are presented in terms of compressive strength, tensile-flexural strength and load-deflection behavior. The effect of fiber reinforcement does not increase the compressive strength of permeability concrete without fiber. Also, the tensile-flexural strength using various fibers are appeared good strength increase as conventional fiber reinforced concrete. Therefore, use of fiber for permeability concrete is necessary to improve of tensile-flexural properties and deformation performance(toughness).

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.671-676
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• 2000

This study was to determine the technical feasibility of using wastepaper fibers, obtained through dry processing of wastepaper, as reinforcement in thin cement produces. Dry-processed waste papers have high levels of noncellulosic impurities, and the recycling process also breads and damages the fibers. To produce wastepaper fiber-cement composites, first the influential variables in the slurry-dewatering method of processing the composites were identified in an experimental study based on factorial design. Among the proportioning and processing variables investigated, fiber mass fraction and level of substitution of virgin fibers with recycled ones were found to have statistically significant effects on mechanical and physical properties of composites. Subsequently, response surface analysis techniques were used to devise an experimental program that helped determine the optimum combinations of the selected influential variables based on mechanical and physical properties, and cost.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.699-702
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• 2005

This study evaluates the properties of porous concrete for pavement according to content of silica fume and steel fiber. The results of the test indicate that in every condition, the void ratio and the coefficient of water permeability of porous concrete for pavement satisfy both the domestic standards and proposition values. Among the properties of strength, the compressive strength satisfies the standards in the specification of KNHC as for every factor of mixture but in the case of the flexural strength, more than $0.6vol.\%$ of steel fiber satisfied the JCI proposition values. The case when silica fume and steel fiber are used simultaneously presents the strongest durability and Noise Reduction Coefficient is 0.48 to prove that it possesses almost $50\%$ sound absorption.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.161-164
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• 2005

The flexural behavior of a strengthened beam, that is a reinforced. concrete beam with externally bonded fiber sheets, was theoretically and experimentally investigated. The effects of the amount of glass fiber sheets varying from 1 to 4 plies on the flexural capacity of the strengthened beam are also examined. The flexural rigidity of the strengthened beam was enhanced compared with RC beam. In addition, the failure mode and load-deflection relationship for the strengthened beam and the comparison of analysis with experiment are extensive investigated. Finally, the determination of the nominal moment capacity $M_n$ of the strengthened beam will be discussed

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.575-578
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• 2005

Recently, various concrete reinforcing fibers have been used to reduce the plastic shrinkage cracking which occurs before the concrete hardens. In this study, the physical properties of nylon fiber reinforced concrete such as slump, air content, compressive strength and tensile strength were investigated. In addition, the performance of nylon fiber in the plastic shrinkage cracking reduction of mortar has been estimated in comparison with polypropylene fiber and cellulose fiber. Nylon fiber showed considerable advantages in terms of the workability of concrete and the plastic shrinkage cracking reduction of mortar compared with polypropylene fiber and cellulose fiber.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.579-582
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• 2005

Tunnel lining is the final support of a tunnel and reflects the results of the interaction between ground and support system. Recently it is very difficult to support and manage the tunnel because the cracks on tunnel lining cause problems in supporting and managing tunnels. Therefore the analysis of the cracks is quite strongly required. The major role played by the steel fiber occurs in the post-cracking zone, in which the fibers bridge across the cracked matrix. Because of its improved ability to bridging cracks, steel fiber reinforcement concrete(SFRC) has better crack properties than that of reinforced concrete. In this study, mechanical behaviour of a tunnel lining was examined by model tests. The model tests were carried out under various conditions taking different loading shapes, thicknesses and leakage of lining, and volume content of steel fiber. From these model test, the cracking load, the failure load, defection and cracking position and type were examined and the characteristics of deformation and failure for tunnel lining were estimated and researched.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.373-376
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• 2006

The purpose of this study was manufactured and evaluated the bond performance of recycled polyethylene terephthalate(PET) bottle fiber reinforced concrete. Four deformed recycled PET bottle fibers were manufactured and pullout test was conducted in accordance with the JCI-SF 8. Test parameters included four different type of fiber geometry and two types of mortar specimens. According to bond test results, it was found that embossing type recycled PET bottle fiber was significant improving the pullout load and interface toughness.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.393-396
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• 2006

This study present the experimental research investigating the influence of material factors such as a type or amount of superplasticizer, velocity agent, mineral admixture and steel fiber on the construction performance of fiber reinforced cementitious composites. As for the test results, it was found that the workability of fiber reinforced cementitious composites can be improved when the material factors were matched properly in amount and composition. Furthermore, it was shown that the smaller value of the aspect ratio of fiber improved the workability of fiber reinforced cementitious composites. And the fiber reinforced cementitious composites with better workability showed the enhanced compressive strength and flexural strength.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.66-69
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• 2006

Three reinforced concrete rigid frames and infilled rigid frames with new retrofitting system were tested under both vertical and cyclic loadings, Experimental programs were carried out to evaluate and improve the seismic performance of such test specimens, such as the hysteretic behavior, the maximum horizontal strength, crack propagation, and ductility etc. under load reversals. All the specimens were modeled in one-third scale size. For specimens(RFHPC, RFAR) designed by the improving of seismic performance of the rigid frame using the high ductile fiber composite PC panel and ALC panel system, load-carrying capacities were increased $1.45{\sim}2.28$ times, and hysteretic behavior was very stable during the final tests in comparison with the standard specimen(SRF).

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.326-329
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• 2006

Strengthening method using CFS have been developed for the rehabilitation of structures. However, it is very difficult to estimate their resistance capacity after retrofit. Therefore, damage information for strengthened structure with CFS investigated and the estimation method structural capacity by using the damage information is developed. The final objective of this research work is to propose the guideline and method for resistance capacity estimate of structure. In this paper, experimental study result with test parameters of number of carbon fiber sheets and bonding ratio is introduced.