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目前,基于灾后损伤混凝土结构需要加固及损伤程度对加固后结构影响程度的研究尚属空白,按1/3缩尺模型,设计制作了钢筋混凝土框架试件。分别对3榀框架施加水平低周反复荷载,使其处于不同损伤状态(截面开裂、钢筋屈服),保持竖向荷载不变,对其进行碳纤维布加固,再对加固框架进行同样试验至破坏。基于试验结果,分析了损伤程度对加固框架开裂荷载、极限荷载、位移延性、裂缝宽度及碳纤维布应变滞后的影响;比较了碳纤维布加固不同损伤混凝土框架的抗震性能。结果表明,随着损伤程度的增加,碳纤维布加固后框架的最大裂缝宽度越大、碳纤维布应变滞后也越大;当损伤程度达到严重时,加固后的结构延性减小。总体上,碳纤维布加固的不同损伤钢筋混凝土框架均具有良好的抗震性能,为大震后损伤混凝土框架加固提供理论依据。
At present, based on the 1/3 scale model, the reinforced concrete frame specimens are designed and manufactured based on the degree of reinforcement and damage that the post-disaster concrete structures need to be reinforced and the degree of damage to the strengthened structures. The horizontal low-cycle repeated load was applied to the 3-nd frame to make it in different damage state (cracking in section and yielding in steel bar), keeping the vertical load unchanged, reinforcing it with carbon fiber cloth and carrying out the same test on the reinforced frame to destroy it. Based on the test results, the influence of the degree of damage on the cracking load, ultimate load, displacement ductility, crack width and strain hysteresis of CFRP frame is analyzed. The seismic behavior of CFRP-reinforced concrete frame with different damage is compared. The results show that as the degree of damage increases, the maximum crack width of the frame after CFRP strengthening increases the strain hysteresis of the CFRP. When the degree of damage is serious, the ductility decreases. In general, the reinforced concrete frames with different damage strengthened by CFRP have good anti-seismic performance, which provides a theoretical basis for strengthening the damaged concrete frame after the earthquake.