考虑海洋环境损伤的钢筋混凝土框架节点受火性能试验研究

发布时间：2018-09-05 19:27

【摘要】：为了研究海洋环境下锈胀裂缝对钢筋混凝土框架节点受火性能的影响,设计了5个配筋相同的足尺钢筋混凝土框架节点试件,以沿梁、柱箍筋方向裂缝宽度最大值为损伤指标,通过快速氯离子侵蚀试验模拟海洋环境下氯离子侵蚀,使4个试件产生不同宽度的锈胀裂缝,然后对4个已损伤框架节点试件以及未损伤的对比节点试件进行火灾试验。结果表明:通过快速氯离子侵蚀试验产生了横向裂缝,其位置与箍筋位置大致相同,其间距与箍筋间距大致相等;初始裂缝宽度对构件高温下的梁、柱端位移变化速率影响显著,锈胀裂缝越宽,构件高温下梁、柱端位移变化速率越快;裂缝的存在加快了热量的传输,导致截面温度场发生畸变;裂缝的存在也会提高钢筋和混凝土的升温速度,加快其力学性能退化,对构件高温下的承载力退化影响显著。
[Abstract]:In order to study the effect of corrosion expansion crack on the fire behavior of reinforced concrete frame joints under marine environment, five specimens of full-scale reinforced concrete frame joints with the same reinforcement were designed. The maximum crack width along the beam and column direction was regarded as the damage index. The corrosion of chlorine ions in marine environment was simulated by rapid chloride ion erosion test. Four specimens with different widths of rust expansion cracks were induced. Fire tests were carried out on four damaged frame joint specimens and undamaged control joint specimens. The results show that the transverse crack is produced by rapid chloride ion erosion test, and its position is approximately the same as that of stirrups, and its spacing is approximately equal to that of stirrups, and the initial crack width is about the same as that of beams at high temperature. The change rate of displacement at the end of the column is significant, the wider the crack is, the faster the displacement changes at the end of the column under the beam at high temperature, and the existence of the crack accelerates the heat transfer, which leads to the distortion of the temperature field of the section. The existence of cracks will also increase the heating rate of steel bar and concrete, accelerate the degradation of mechanical properties, and have a significant effect on the degradation of bearing capacity of members at high temperature.
【作者单位】：青岛理工大学土木工程学院;北京工业大学建筑工程学院;
【基金】：国家自然科学基金项目(51179081)
【分类号】：TU375.4

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