矩形RC梁採碳纖維包覆暨碳纖維錨栓耐震補強研究

Seismic Retrofit of Rectangular RC Beams Using CFRP Wrapping and CFRP Anchors

黃志豪(Jhih-Hao Huang)

指導教授 ： 林至聰 ； 林敏郎

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00023

摘要

國內外研究結果顯示，採用碳纖維強化高分子複合材料(CFRP)包覆補強鋼筋混凝土梁之剪力強度時，常因介面剝落(Debonding)破壞造成補強失敗，本研究針對此缺點提出以碳纖維包覆配合所研發之碳纖維錨栓(CFRP Anchor)之補強工法，讓鋼筋混凝土梁在不改變維持原外觀下，所包覆之碳纖維貼片得以充份發揮其材料強度。
本研究針對剪力強度不足之老舊鋼筋混凝土梁構件進行耐震補強試驗，採用四點式載重試驗法，以單向加載方式進行試驗，實尺寸RC梁試體之箍筋配置依舊規範進行配置，無法滿足現行規範之耐震特別規定要求，試驗共製作六座試體進行補強試驗，規劃一組為標準試體，預期之破壞模式為剪力破壞；補強試體共計五座，全部用U形包覆方式，一組採用U形包覆不加任何錨定預期產生剝落破壞，另一組額外採用國內工程使用的化學錨栓進行碳纖維貼片錨定，另三組則採用碳纖維錨栓進行碳纖維貼片與原RC梁間之錨定。試驗過程中除使用傳統量測外，亦使用影像量測技術進行梁試體大範圍位移場及應變場量測。
試驗結果顯示，標準試體如預期為非韌性之剪力破壞，碳纖維貼片U形包覆補強試體亦証實因介面剝落破壞於小位移時即發生而使補強材未能發展出其材料強度；於樓板底部使用鋼條配合化學錨栓錨定並無法有效增加介面強度，因此其破壞仍為剪力造成貼片剝落破壞，但韌性表現有所提升；採用碳纖維貼片U形包覆配合碳纖維錨栓使用之補強試體，確實有效提高介面強度，避免介面剝離之發生，而使試體發展出良好的韌性行為，大量提升梁構件之韌性能力，破壞模式也由剪力破壞轉變為撓曲破壞，本研究所發展之碳纖維包覆暨碳纖維錨栓補強工法與設計理論之合理性與實用性也因此獲得証實。而經比較傳統量測與影像量測之量測結果發現，於碳纖維剝落破壞前，碳纖維表面應變量測值接近，顯示影像量測技術之準確性，且影像量測尚可以獲得大範圍平面應變場變化情形。

關鍵字

剪力補強 ； 碳纖維包覆 ； 碳纖維錨栓 ； 矩形RC梁 ； 影像量測

並列摘要

CFRP (Carbon Fiber Reinforced Polymer) with high tensile strength, high durability and reinforcement components do not change the appearance of retrofitted member and so on. Results of previous studies show that the RC beams shear retrofitted by externally wrapping CFRP sheets were often unable to take full advantage of the expected CFRP high strength cause of the spalling due to interface failure (Debonding) between the RC surface of the beams and the CFRP sheets. Therefore, this paper proposes the use of anchored mechanism to overcome this problem.
In this study, a total of six full-scaled rectangular RC beam specimens were designed for the four-point bending tests in National Center for Research on Earthquake Engineering (NCREE) and the advanced “image-based measurement” was used in this research to obtain the global strain field of the external wrapping CFRP sheets. One of these specimens is the bench mark specimen was designed to subject the brittle shear failure whiling the monotonic loading tested. The other specimens retrofitted by different externally CFRP U-shaped wrapping were divide into three groups. The first one group is pure CFRP U-shaped wrapping specimen, the second group specimen is CFRP retrofitted specimen with adhesive anchors and the third group includes three specimens retrofitted by CFRP sheets with the different use amounts of CFRP anchors.
Test results indicated that the debonding between concrete surface of the beam and CFRP sheet occurred at the above of central line of beam section in the shear region caused by the shear crack of the specimen effect the strength of CFRP wrapping retrofitted. The strength of the retrofitted specimen with the use of adhesive anchors was increased but the failure behavior was still brittle shear failure. The CFRP retrofit specimens using CFRP anchors not only increase the strength but also the ductility. The failure behaviors of these three specimens used different amounts of CFRP anchors were flexural failure with huge deformation. The local strain data from the traditional strain gauge use on the surface of CFRP sheets was similar to the strain data from image-based measurement.The research of the CFRP anchor design procedures, the proposed working method of the RC beam retrofitted demonstrated effect and the used of advanced image-based measurement in this study is acceptable.

並列關鍵字

CFRP ； CFRP Anchor ； Shear Retrofit ； RC Beam ； Image-based Measurement

參考文獻

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[23] 陳北亭，「數位影像量測於結構實驗之應用」，碩士論文，私立中原大學土木工程學系，2009，桃園。

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