對於鋼筋混凝土結構元件之補強,若以包覆FRP的方式處理,其所使用的界面粘接材料多以環氧樹脂為主,而環氧樹脂的不耐高溫性質卻是當前亟待解決的問題。前期研究曾嘗試以近年新開發之無機聚合樹脂(geopolymer)取代環氧樹脂作為粘接材料,探究RC梁包覆FRP之剪力及撓曲補強成效,初步發現其效果雖稍遜但仍有相當的競爭力。本研究則更進一步,針對RC梁的撓曲補強,探討其在高溫下之效果。首先,製作彎矩控制之RC矩形梁,以在梁底分別包覆玻璃纖維(GFRP)及碳纖維(CFRP)之方式進行正彎矩補強,且採用不同包覆型式,最後藉由四點抗彎試驗分別探討常溫及高溫下彎矩補強的成效。結果顯示RC梁以包覆纖維方式撓曲補強有其效益但有所限度,且對梁之韌性容量有影響。因此,在實務上之應用宜更審慎。
While using FRP as a wrapped material for jacket strengthening of RC elements, the most common bond material was epoxy. However, its poor heat resistant property remains an unsolved problem. Previous researches have replaced the bond material by a newly developed material, namely geopolymer, to investigate the effect of shear and flexural strengthening of RC beams by FRP jacket. At first, GFRP and CFRP were wrapped at the bottom of RC beams to process strengthening for positive bending moment with different cover types. Finally, the effect of flexural strengthening of reinforced concrete beams with FRP jacket by using geopolymer as bond material under room temperature and poor temperature was investigated because of experiment. The results revealed that the strengthened effect was a bit lower than those of using epoxy. In the present work, further steps is taken to investigate the flexural strengthened effect of FRP jacket RC beams under high temperatures. The results show that the flexural strengthened effect of FRP jacket RC beams is assured but limited. And moreover, the capacity of toughness is declining. Therefore, it is advisable that more prudent should be taken while applying in the practice.