CFRP布加固火灾后钢筋混凝土柱的试验研究

Experimental Research on Rehabilitation with CFRP Sheets for Reinforced Concrete Columns After Exposure to Fire

通过3根碳纤维增强复合材料(CFRP)布加固ISO 834标准火灾作用后钢筋混凝土柱的性能试验以及3根ISO 834标准火灾作用后未加固的钢筋混凝土柱和3根常温下钢筋混凝土柱的对比试验,研究了CFRP布加固火灾后钢筋混凝土柱的有效性。试验结果表明:CFRP布加固对火灾后钢筋混凝土柱的刚度修复有一定作用,但刚度提高程度有限,从开始加载到荷载达到80%极限荷载的不同加载水平下,加固后轴压试件的轴压刚度与常温下试件刚度的比值在0.25～0.39之间,偏压试件的抗弯刚度与常温下试件刚度的比值在0.14～0.31之间。CFRP布加固对火灾后试件的承载力提高作用较为显著,能将试件的承载力提高至受火后承载力的1.67～2.37倍,但与常温下试件的承载力相比,依然有一定差距,加固后试件的承载力水平为常温下试件的0.54～0.67倍。

By tests on three reinforced concrete columns repaired by carbon fiber reinforced polymer （CFRP） sheets after exposure to ISO 834 standard fire and three reinforced concrete columns without being repaired after exposure to ISO 834 standard fire as well as three reinforced concrete columns without exposure to fire, the rehabilitation effectiveness of CFRP sheets was investigated. Experimental results show that the rigidity of the reinforced concrete columns after exposure to fire can be enhanced to some extent by CFRP sheets, but the enhancement is not apparent. In various loading stages from the initial loading to 80G ultimate load, the ratio of axial rigidity of axial compression specimens rehabilitated by CFRP sheets and that at normal temperature ranges from 0.25 to 0.39, and the ratio of flexural rigidity of the eccentric specimens times to 0.67 times.