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考虑不同的的孔洞大小,对剪弯段开孔混凝土梁及采用水泥基灌浆材料(CGM)填补孔洞与碳纤维布加固孔边两种情况下的开孔梁进行了试验研究。研究结果表明:梁开孔致使其挠度增长加快,裂缝宽度增大,承载力显著降低,破坏形态变为脆性的剪切破坏,严重影响梁的安全性,且孔洞越大,破坏越严重;当孔洞尺寸在一定范围内时(d0≤0.4h),采用CGM灌浆料填补孔洞及采用碳纤维布加固孔边,均可有效提高开孔梁的承载力,减缓跨中挠度的增长速度,并使底部钢筋达到屈服,梁的破坏形态恢复至弯曲破坏,其各项力学性能都可恢复至未开孔梁的状态,从而可保证开孔梁的安全性。但采用碳纤维布加固后,随着孔洞的增大,破坏时孔洞处裂缝宽度增大。
Considering the different hole sizes, the perforated beams with cut-away section of open concrete beams and the use of cement-based grouting material (CGM) to fill holes and CFRP reinforcement holes were tested. The results show that the beam opening increases the deflection, the crack width increases, the bearing capacity decreases significantly, the failure mode becomes brittle shear failure, which seriously affects the safety of the beam. The larger the hole, the more serious the damage. When When the hole size is within a certain range (d0≤0.4h), filling the hole with CGM grouting material and reinforcing the hole edge with the carbon fiber cloth can effectively increase the bearing capacity of the perforated beam, slow down the growth rate of the mid-span deflection, and make the bottom Reinforcement to yield, the destruction of the beam to restore the form of bending damage, and its various mechanical properties can be restored to the state of unopened beams, which can ensure the safety of the beam. However, with CFRP reinforcement, as the hole increases, the crack width increases when the hole is damaged.