碳纤维布与高温后混凝土界面黏结性能试验研究

发布时间：2018-01-05 12:05

  本文关键词：碳纤维布与高温后混凝土界面黏结性能试验研究　出处：《建筑结构学报》2015年08期 　论文类型：期刊论文

  更多相关文章： 混凝土 CFRP布 高温后加固 正拉试验 剪切试验 黏结性能 本构模型

【摘要】：通过35个正拉试件和44个单剪试件的试验研究,考察了CFRP布与高温后混凝土界面黏结性能受过火温度、恒温时间、冷却方式、粘贴长度、粘贴宽度、粘贴层数等参数的影响规律。根据试验结果进行回归拟合,建立了CFRP布与高温后混凝土界面正拉黏结强度与过火温度的关系式,提出了分别基于双曲线模型和基于Popovics模型的CFRP-高温后混凝土界面黏结滑移本构模型,并给出了曲线的特征参数值。结果显示:正拉黏结强度随过火温度的升高而降低,喷水冷却后试件的正拉黏结强度较自然冷却后的进一步降低,经历300℃、500℃高温作用后的混凝土试件,自然冷却和喷水冷却后正拉黏结强度较常温时分别降低了4.1%、30.8%和11.0%、40.4%。当过火温度小于500℃时,试件的极限黏结荷载随粘贴长度的加长呈先上升后下降的趋势,且在粘贴长度为130 mm时达到最大。当过火温度为500℃时,极限黏结荷载随粘贴长度的增加而增加,同时由于表层黏结剂渗入到混凝土孔隙内部进而提高黏结滑移性能,出现高温后极限黏结荷载大于常温下的情况。CFRP布与高温后混凝土间的界面黏结-滑移关系曲线经标准化处理后大体相同。
[Abstract]:Based on the experimental study of 35 normal tensile specimens and 44 single shear specimens, the interfacial bond properties of CFRP cloth and high temperature concrete are investigated, such as overfire temperature, constant temperature time, cooling mode, paste length and paste width. According to the experimental results, the relationship between the positive tensile bonding strength and the overfire temperature of the interface between CFRP cloth and high temperature concrete is established. Based on hyperbolic model and Popovics model respectively, CFRP- concrete interface bond slip constitutive model after high temperature is proposed. The characteristic parameters of the curve are given. The results show that the positive tensile bonding strength decreases with the increase of overheating temperature, and the positive bond strength of the sample after spray cooling decreases further than that after natural cooling, and goes through 300 鈩，

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