矩形RC柱採碳纖維包覆暨碳纖維錨栓耐震補強研究

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

吳穎涵(Ying-Han Wu)

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(2008年)

https://doi.org/10.6841/NTUT.2008.00135

摘要

碳纖維強化高分子複合材料（Carbon Fiber Reinforced Polymer、簡稱CFRP）具備高拉力強度、高耐久性和不改變補強構件外觀等優點，過去研究成果顯示，若RC柱尺寸過大，將無法提供有效圍束而發生面外鼓出現象影響圍束效果，因此本研究提出以碳纖維包覆配合使用所研發之碳纖維錨栓(CFRP Anchor)之補強工法以克服此缺點，同時維持柱體補強後外觀。
本研究試驗針對老舊建築RC柱構件承受雙曲率彎矩和0.2f’cAg固定軸壓力進行補強研究，箍筋少量配置且無法滿足現行規範之耐震特別規定要求；試驗共製作五組試體分兩類進行補強試驗，第一類兩組試體為碳纖維包覆和碳纖維包覆搭配碳纖維錨栓補強剪力和韌性，第二類兩組試體為雙向碳纖維包覆搭配碳纖維錨栓補強剪力、韌性和彎矩強度，另規劃一組為標準試體。
試驗結果標準試體如同一般老舊建築柱為脆性撓剪破壞型式；第一類針對剪力強度與韌性能力進行補強試體之試驗結果顯示，碳纖維包覆配合使用碳纖維錨栓之補強工法，可提升補強柱構件韌性與消能能力，延後碳纖維貼片斷裂發生，並改善碳纖維非預警性炸開之破壞模式；第二類針對剪力強度、韌性及彎矩強度補強試體試驗結果顯示，補強試體初始勁度有所提升，但因試驗過程中發生縱向碳纖維和基礎鍊結之碳纖維錨栓斷裂破壞而使彎矩強度無法提升至設計目標。
根據上試驗結果，本研究發展之碳纖維包覆暨碳纖維錨栓補強工法與設計理論、碳纖維錨栓設計與製作方法已經大尺寸補強試驗驗證其合理性與實用性，可供工程實務設計參考與使用。

關鍵字

耐震補強 ； 碳纖維包覆 ； 碳纖維錨栓 ； 雙曲率 ； 矩形RC柱

並列摘要

External confinement by the wrapping of CFRP sheets (or CFRP jacketing) provides a very effective method for the retrofit of reinforced concrete (RC) columns subject to either static or seismic loads. Research result showed that retrofitting of rectangular columns by CFRP wrapping was ineffective because of crushed column concrete cause of bulging of column sides, thus, this study propose “CFRP wrapping conjugate CFRP anchors” rehabilitate method.
The objective of this study was to research, develop the CFRP Anchor and to evaluate the efficacy of seismic retrofit of rectangular columns by CFRP wrapping and CFRP Anchors. Five specimens of retangular reinforced concrete columns were tested by cyclic lateral force under reversed bending and constant axial load (0.2f’cAg.). Two different techniques of using CFRP wrapping and CFRP Anchors to improve concrete confinement, shear strength and moment strength in these specimens. These specimens were divided into two groups. Two specimens of group 1 were retrofitted shear strength and ductility by CFRP wrapping and CFRP anchors and two specimens of group2 were retrofitted moment strength by longitudinal CFRP sheets and CFRP anchors and shear strength, ductility by CFRP wrapping.
From test result of group 1, the behavior and effectiveness indicated that comparing with test conducted on the specomen wrapping by CFRP without anchor, anchoring techniques used were effective in improving the column confinement and in increasing the ability of energy disspation.
From test result of group 2, the initial elastic modulus increase cause of logngitudinal CFRP sheets linked the foundation by CFRP anchor. But it’s failure in linking mechanism of CFRP anchors by low cycle fatigue to do justice to moment strength.
The research and develop of CFRP anhor in this study of it’s used methods and theorem in rehabilation had reinforcement effect.The study of CFRP anchor is referable for seismic retrofit engineerings.

並列關鍵字

Seismic Retrofit ； CFRP Wrapping ； CFRP Anchor ； Double Curvature ； Rectangular RC Column

參考文獻

[17] 李有豐、林至聰、林彥傑，「中輕度受損非韌性RC構件快速修復與補強之研究(II)」，國家地震工程研究中心，2002，報告編號：NCREE-03-014，台北。

[1] ASCE-ACI Committee 426, "Shear Strength of Reinforced Concrete Menbers," ACI 426R-74, Reapproved 1980, Chapters1 to 4, Proceeding, ASCE, vol.99, no.ST6, June 1973, pp. 1148-1157.

[2] ACI 440.2R-02, "Guide for the Design and Construction of Externally Bounded FRP Systems for Strengthening Concrete Structrues," American Concrete Institue, Detroit, USA.

[3] A. Ghobarah, A. Said, "Shear strengthening of beam-column joints," Engineering Structures, 2002, vol.24. pp. 881-888.

[4] A. Ghobarah and K. Galal, "Seismic Rehabilitation of Short Rectangular RC Columns," Journal of Earthquake Engineering, vol. 8, no.1, 2004, pp.45-68.