RC梁應用環氧樹脂貼覆CFRP剪力補強之耐高溫研究

On the Heat Resistance of Shear Strengthened RC Beam with CFRP Jacket by Epoxy Resin

陳建任(Jian-Ren Chen)

指導教授 ： 吳傳威

國立臺北科技大學/工程學院/土木與防災研究所/碩士(2009年)

https://doi.org/10.6841/NTUT.2009.00162

摘要

環氧樹脂具有優異的黏著性能，為當前結構構件複合纖維貼片補強最常採用的黏結材料，但其不耐高溫之性質亦一直為人所質疑。先前之相關研究包括將混凝土圓柱試體與鋼筋混凝土矩形梁以環氧樹脂包覆FRP補強後進行高溫試驗，顯示之結果確實令人擔憂。然因先期研究在採試溫度方面有部分不完整，故而並未確認補強失效之溫度。本研究則延續前期，將鋼筋混凝土矩形梁使用環氧樹脂為黏結材料包覆碳纖維(CFRP)剪力補強之高溫性能做一完整之探討，以期完成最後論述。
本試驗研究之矩形梁試體採剪力控制設計，尺寸為150×20×15(cm)。混凝土強度約為140kgf/cm2。剪力補強以單向U型貼覆碳纖維為主，包覆層數包括一層及兩層，採試之溫度分別為常溫、100℃、250℃、450℃、550℃、及650℃。另為探查試體之破壞溫度，另補充710℃及900℃兩組溫度環境試驗原型梁。結果顯示，CFRP貼片補強於高溫450℃時達到其耐高溫極限，於450℃至550℃間補強效果開始快速衰退，於550℃時補強完全失效。於650℃時，環氧樹脂似因溫度過高而完全消失。因此，以環氧樹脂作為黏結材料貼覆CFRP補強之結構構件，其耐高溫之性能表現的確不佳，在實務應用上宜予節制。

關鍵字

剪力補強 ； 高溫 ； 環氧樹脂 ； 碳纖維

並列摘要

Epoxy resin, known for its fine adhesive property, is the most common bonded material used in the practical structural retrofit. However, its poor heat resistant property is also well known. The previous studies including the heat resistant tests on FRP jacketed concrete cylinders and RC beams revealed that the results were worrisome. Nevertheless, the preceding works existed some gaps such as the test temperatures, so that the temperature of losing the strengthened effect was not certain. The present work is thus aimed at completing the study of investigating the heat resistant effect of shear strengthened RC beams by CFRP jacket with epoxy resin as the boned material.
The RC beams used in the test were designed as shear insufficient. The size of the test beam specimen was 150*20*15(cm), and the concrete strength used was around 140kgf/cm2. The shear strengthening was applied by one-way U type CFRP jacket with both one and two layers. Six testing temperatures were set, i.e. room temperature, 100℃, 250℃, 450℃, 550℃ and 650℃. Two additional temperatures, 710℃ and 900℃, were applied to the original beams for searching the temperature of final failure of the specimen. The results indicate that he temperature limit for maintaining the effect of strengthening is 450℃. The effect of strengthening declines rapidly between 450℃ and 550℃, while reaches totally failed at 550℃. The epoxy resin layer seemed disappear at 650℃. It is clear now that the heat resistant effect of shear strengthened RC beams by CFRP jacket with epoxy resin is quite unfavourable, and therefore should be restricted in the practice.

並列關鍵字

Shear strengthening ； High temperature ； CFRP ； Epoxy Resin

參考文獻

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