외부 긴장된 탄소섬유판으로 보강된 실물모형 RC보의 휨 보강 (Flexural Strengthening of Full-scaled RC Beams with Externally Post-Tensioned CFRP(Carbon Fiber Reinforced Polymer) Strips)

서지정보

· 발행기관 : 대한건축학회
· 수록지 정보 : 대한건축학회논문집 구조계 / 24권 / 9호 / 21 ~ 28페이지
· 저자명 : 유영찬, 최기선, 김긍환

초록

A full-scaled model test has been performed in order to investigate the behavior of RC beams strengthened with externally post-tensioned CFRP(Carbon Fiber Reinforced Polymer) system. At the same time, flexural strengthening test results obtained from a series of small-scaled RC beam with respect to many parameter in the previous studies were verified. A total of 4 specimens have been manufactured including unstrengthened control beam. The specimens strengthened with post-tensioned CFRP strips consist of bonded and unbonded systems with 2 different types of mechanical anchorages. The post-tensioning force of 50% of CFRP tensile strength which is considered optimum in the previous studies was applied. From the test results, it was found that all the specimens strengthened with post-tensioned CFRP strips finally failed by the rupture of CFRP strips regardless of post-tensioning system because the anchorage can clamps the CFRP strips up to its rupture strength. On the contrary, specimens strengthened with simply bonded CFRP strips showed debonding failure below 50% of CFRP tensile strength due to premature debonding. Also Increase in cracking load, yielding load and nominal strength were observed at the specimen strengthened with post-tensioned CFRP strips, resulting in improved strengthening performance. Therefore, the full strength of CFRP strips can be utilized in strengthening by introducing post-tensioning of 50% of its tensile strength.

영어초록

A full-scaled model test has been performed in order to investigate the behavior of RC beams strengthened with externally post-tensioned CFRP(Carbon Fiber Reinforced Polymer) system. At the same time, flexural strengthening test results obtained from a series of small-scaled RC beam with respect to many parameter in the previous studies were verified. A total of 4 specimens have been manufactured including unstrengthened control beam. The specimens strengthened with post-tensioned CFRP strips consist of bonded and unbonded systems with 2 different types of mechanical anchorages. The post-tensioning force of 50% of CFRP tensile strength which is considered optimum in the previous studies was applied. From the test results, it was found that all the specimens strengthened with post-tensioned CFRP strips finally failed by the rupture of CFRP strips regardless of post-tensioning system because the anchorage can clamps the CFRP strips up to its rupture strength. On the contrary, specimens strengthened with simply bonded CFRP strips showed debonding failure below 50% of CFRP tensile strength due to premature debonding. Also Increase in cracking load, yielding load and nominal strength were observed at the specimen strengthened with post-tensioned CFRP strips, resulting in improved strengthening performance. Therefore, the full strength of CFRP strips can be utilized in strengthening by introducing post-tensioning of 50% of its tensile strength.

참고자료

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