• Title/Summary/Keyword: 탄소 섬유 보강근

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Self-Diagnosis for Fracture Prediction of Concrete Reinforced by New Type Rib CFGFRP Rod and CF Sheet (신형 리브재 CFGFRP 보강근 및 CF 보강시트로 보강된 콘크리트의 파괴예측 자가진단)

  • Park, Seok-Kyun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.27 no.2
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    • pp.115-123
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    • 2007
  • For investigating self-diagnosis applicability, a method based on monitoring the changes in the electrical resistance of carbon fiber reinforced concrete has been tested. Then after examining change in the value of electrical resistance at each flexural weight-stage of carbon fiber in CFGFRP (carbon fiber and glass fiber reinforcing plastic) with new type rib and carbon sheet for concrete reinforcing, the correlations of electrical resistance and load as a function of strain, deflection were analyzed. As the results, it is clarified that when carbon fiber rod, rib and sheet fracture, the electrical resistance of it increase largely, and specially in case of CFGFRP, afterwards glass fiber tows can be resist the load due to the presence of the hybrid (carbon and glass) reinforced fiber. Therefore, it can be recognized that reinforcing bar and new type rib of CFGFRP and sheet of CF could be applied for self-diagnosis of fracture in reinforced FRP concrete.

Applicability of Hyblid FRP Reinforcing Bar for Self-diagnosis of Concrete Fracture (콘크리트 파괴 자가진단을 위한 하이브리드 FRP 보강근의 적용 특성)

  • Park, Seok-Kyun;Kim, Dae-Hoon
    • Journal of the Korea Concrete Institute
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    • v.18 no.3 s.93
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    • pp.439-445
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    • 2006
  • For investigating self-diagnosis applicability, a method based on monitoring the changes in the electrical resistance of hybrid FRP(having electrical property) reinforced concrete has been tested. Then after examining change in the value of electrical resistance of carbon fiber in CFRP(non-hybrid type), CFGFRP and CFAFRP(hybrid type) before and after the occurrence of cracks and fracture in non-hybrid and hybrid FRP reinforced concrete at each flexural weight-stage, the correlations of each factors(the changes in electrical resistance and load as a function of strain, deflection) were analyzed. As the results, it is clarified that when the carbon fiber tows fracture, the electrical resistance of it increase largely, and afterwards hybrid FRP composites can be resist the load due to the presence of the reinforced fiber, for example, glass fiber or aramid fiber tows. Therefore, it can be recognized that hybrid FRP(including carbon fiber) reinforcing bar could be applied for self-diagnosis of fracture in reinforced FRP concrete fracture.

Evaluation of Residual Bond Stress between Carbon-fiber Reinforced Polymer and Steel Rebar Using Ultra-High-Performance-Concrete after Elevated Temperature (초고강도 콘크리트를 활용한 고온가열 이후의 탄소 보강근과 철근의 잔류 부착성능 평가)

  • Yoo, Sun-Jae;Lee, Ho-Jin;Yuan, Tian-Feng;Yoon, Young-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.6
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    • pp.169-176
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    • 2021
  • In this study, pull-out tests were conducted at room temperature, 150 ℃ and 250 ℃ to evaluate the residual bond strength of carbon fiber reinforcement polymer, CFRP after elevated temperature and deformed steel rebar of D10 and D13 were also evaluated after the high temperature heating for comparison. As a result of the experiment, the bond strength of the CFRP after 150 ℃ and 250 ℃ decreased by 9.94 % and 41 %, respectively. On the other hand, after thermal heating, both the steel rebar of D10 and D13 had a lower rate of reduction in bond strength than that of the CFRP. Also slip at the maximum bond strength also decreased after the heating for both the CFRP and the rebars. Through it, the correlation between the bond strength and the slip reduction due to thermal heating was confirmed and bond slip models were presented. Finally the experimental result was evaluated as relative bond strength to identify the residual bond performance of the CFRP and the rebar after the heating was confirmed by comparing with the existing test result of the bond strength after elevated temperature.

Experimental Verification of Reinforced Concrete Beam with FRP Rebar (FRP 보강콘크리트 보의 휨거동에 관한 실험적 연구)

  • Oh, Hong Seob;Ahn, Kwan-Yeol
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.12 no.3
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    • pp.93-100
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    • 2008
  • The use of fiber reinforced polymer (FRP) composites is significantly growing in construction and infrastructure applications where durability under harsh environmental conditions is of great concern. In order to examine the applicability of FRP rebar as a reinforcement in flexural member, flexural tests were conducted. 12 beams with different FRP materials such as CFRP, GFRP and Hybrid FRP and reinforcement ratio were tested and analyzed in terms of failure mode, moment-deflection, flexural capacity, ductility index and sectional strain distribution. The test results were also compared with the theoretical model represented in ACI 440.1R06. Test results indicate that the flexural capacity of the beams reinforced by FRP bars can be accurately predicted using the ultimate design theory. They also show that the current ACI model for computing the deflection overestimates the actual deflection of GFRP series and underestimates the deflection of CFRP series.

Pre-stress Effect of Geosynthetics-reinforced Soil Structure (토목섬유로 보강된 구조물의 프리스트레스효과)

  • Kim Eun-Ra;Kang Ho-Keun
    • Journal of the Korean Geotechnical Society
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    • v.21 no.6
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    • pp.53-65
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    • 2005
  • This paper presented a mechanism of the soil structure reinforced by geosynthetics, in which the reinforcing mechanism is treated as the effect arising from the reinforcement process to prevent the dilative deformation of soil under shearing. A full-scale in-situ model test was carried out by introducing the prestress method to enhance the geosynthetic-reinforcement, and the prestress effect through the FEM is also examined. The elasto-plastic model and the initial parameters needed in the FEM are presented. Moreover, the theoretical prediction is compared with the experimental results, which were obtained by a full-scale in-situ model test.

A Degradation Characteristic of FRP Rebars Attacked by Combined Environmental Factors (복합환경인자에 의한 FRP 보강근의 성능저하 특성)

  • Oh, Hong Seob;Moon, Do Young
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.16 no.3
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    • pp.1-10
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    • 2012
  • In spite of high resistant to corrosion and its strength, over the last two decades, concerns still remain about the durability of FRP materials under severe environmental and thermal exposures. In this paper, authors experimentally examine the combined degradation by thermal and chemical attacks in heterogeneous FRP rebar be made up with various fibers and resins. Five types of Carbon, Glass and Hybrid FRP rebars had manufactured by different process and surface patterns are adopted for the experiments such as weight change, interlaminar shear strength, SEM and FT-IR analysis. FRP specimens were immersed in alkaline or distilled solution up to 150 days and then thermal exposed on 60, 100, 150 and $300^{\circ}C$ for 30 minutes. From the test results, the degradation of FRP bars are influnced by the resin type and manufacturing process as well as the fiber, and ILSS of exposed FRP bar in solutions is slightly increased in initial stage and then decresed with the passing of immersed time. But, in this test, it is observed that the discrepancy of ILSS between degraded by alkaline solution and distilled water is negligible value.

A Study on the Failure Behavior of Overhanging Geosynthetic-Reinforced Soil Structure Considering Dilatancy Characteristics of Compacted Soil (다짐토의 다일러턴시 특성을 고려한 역경사형 토목섬유 보강토 구조물의 파괴 거동 분석)

  • Kim Eun-Ra;Kang Ho-Keun
    • Journal of the Korean Geotechnical Society
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    • v.20 no.9
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    • pp.65-75
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    • 2004
  • In this paper, a mechanism of the soil structure reinforced by geosynthetics is discussed. The reinforcing mechanism is interpreted as an effect arising from the reinforcement works preventing the dilative deformation (negative dilatancy) of soil under shearing. A full-scale in-situ model test was carried out in Kanazawa of Japan (1994), and in the laboratory test the strength and the characteristics of deformation conducting a constant volume shear test are examined. The parameters needed in the FEM are also applied by using the experimental data. The elasto-plastic finite element simulation is carried out, and the results are quantitatively compared with that of experiment. As a results, it is known that the theoretical predictions could explain effectively the experimental results which are obtained by a full-scale in-situ model test.