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对在汶川地震的震损建筑中拆下的强度等级约C13的钢筋混凝土梁,加载到相同损伤程度后,进行8种加固方法 22个钢筋混凝土梁单调加载试验,探讨梁的极限承载力、破坏模式、裂缝开展和应变变化等力学性能。结果表明:1)采用剔槽植入钢筋置换混凝土灌胶再粘贴碳纤维布(CFRP)的复合加固方案,加固梁的开裂荷载、极限承载力与直接粘贴CFRP布比有显著提高。2)剔槽植筋复合加固方案中的CFRP布上的应变值比简单粘贴CFRP布后应变值增大更多,新旧混凝土间协同工作性强,可以很好地发挥CFRP布高强作用。3)采用复合工艺加固的梁,如适当提高碳纤维布的用量,可以进一步改善钢筋的受力状态,有效地提高梁的开裂荷载和极限荷载。
After the reinforced concrete beams with strength grade of about C13 dismantled in the earthquake-damaged buildings in Wenchuan earthquake were loaded to the same degree of damage, the monotonic loading tests of 22 reinforced concrete beams of 8 kinds of strengthening methods were carried out to investigate the ultimate bearing capacity of the beams and destroy Mode, crack development and strain changes and other mechanical properties. The results show that: 1) The composite reinforcement scheme of CFRP with replacement of concrete by slotting is adopted to reinforce the girder. The cracking load, ultimate bearing capacity and CFRP ratio of the reinforced beam are obviously improved. 2) The strain value of the CFRP cloth in the composite plan of trenching and planting reinforcement increases more than the strain value of the CFRP cloth after the simple paste, and the new and old concrete work well together and can exert the high strength effect of the CFRP cloth well. 3) The beam strengthened by the composite process, if properly increased the amount of carbon fiber cloth, can further improve the stress state of the rebar, effectively improve the beam cracking load and ultimate load.