預應力CFRP布及預緊螺栓加固RC梁試驗研究

管延華 岳紅亞 孫仁娟 紀續 袁凱 劉傳波

摘要：為提高碳纖維布加固RC結構的效果及其可靠性，提出了預應力碳纖維布與預緊螺栓聯合加固技術。結合在役RC梁的損傷特點及目前的RC梁加固方法，分別采用不同的碳纖維布加固技術對完整梁和破壞梁的抗彎性能進行了對比試驗研究。針對目前碳纖維布張拉設備的缺陷，研發了便于現場應用的新型碳纖維布布張拉設備，分析了預應力大小對加固效果的影響。結果表明，預應力碳纖維布及預緊螺栓聯合加固技術是一種更可靠的橋梁加固方法，不僅能夠提高RC梁正截面的抗彎承載能力及正常使用階段的截面剛度，而且螺栓預緊錨固碳纖維布能夠很好地抑制其在混凝土表面的剝離，提高碳纖維布與混凝土表面之間粘結強度，對碳纖維布施加預應力能夠充分發揮其高強性能，有效抑制混凝土裂縫開裂和開展。

關鍵詞：預應力CFRP；預緊螺栓；加固技術；試驗研究；力學行為

中圖分類號：TU375.1；U445.7

文獻標志碼：A 文章編號：16744764（2016）02000110

Abstract：To improve the strengthening effect and reliability of concrete structure strengthened with carbon fiber sheets， a new hybrid bonding pre-stressed carbon fiber sheets technique is developed. This technique combines the pre-stressed carbon fiber sheets with mechanical fastening of pre-screwed bolts. In accordance with the fracturing characteristics and the strengthening method of aging RC beam bridges， different carbon fiber sheets strengthening technology were applied on the intact and destructive RC beams. And a series of experiments were conducted to examine and assess the flexural performance of RC beams. Then， a new type of tensioning equipment was invented to meet the need of tensioning carbon fiber sheets in practical engineering. The experiment results show that the hybrid bonding pre-stressed carbon fiber sheets is a more reliable strengthening technique which can not only improve the flexural capacity and the section stiffness of RC beams during normal use stage， but also can increase the cohesive force between carbon fiber sheets and concrete interface. It can make full use of the tensile strength of carbon fiber sheets and can restrain the opening and developing of the cracks.

Keywords：pre-stressed carbon fiber sheets；pre-screwed bolts；strengthening technology；experimental study；mechanical behavior

非預應力碳纖維復合材料（CFRP）加固技術已被廣泛應用于混凝土結構加固中[1-7]，但是鑒于CFRP材料的高強特性，非預應力CFRP加固混凝土結構不能充分發揮碳纖維的高強性能，造成材料的極大浪費。預應力CFRP技術不僅能夠克服非預應力CFRP技術的上述缺陷，而且能有效抑制橋梁裂縫的開裂及開展、提高混凝土結構的耐久性，是一種更有效的加固技術[8-9]。預應力碳纖維復合材料加固通常包括CFRP板和CFRP布兩種，而對鋼筋混凝土（RC）結構來說，采用預應力CFRP布加固技術是更經濟有效的加固方法[10-13]。……