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火灾中带裂缝钢筋混凝土梁的承载能力研究可为工程实际应用提供参考。文章利用有限元分析软件ABAQUS对火灾中带裂缝钢筋混凝土梁内部的温度场进行分析,阐明了火灾中带裂缝钢筋混凝土梁内部温度场的分布规律,根据其分布规律确定了在不同耐火时刻有裂缝钢筋混凝土梁300和800℃的等温线,结合已有的高温下钢筋混凝土梁承载力计算公式,提出了火灾中带裂缝钢筋混凝土梁承载力计算公式。结果表明:在同样的受火条件下有裂缝时钢筋混凝土梁中钢筋位置的温度比是无裂缝时钢筋混凝土梁中钢筋位置的温度高55%~144%;有五条裂缝的钢筋混凝土梁中钢筋位置的温度比有一条裂缝的钢筋混凝土梁中钢筋位置的温度高2.7%~11.5%;带裂缝钢筋混凝土梁的承载力比无裂缝钢筋混凝土的承载力低47%~82%。
Study on bearing capacity of cracked reinforced concrete beams in fire can provide reference for engineering application. In this paper, the finite element analysis software ABAQUS is used to analyze the temperature field inside the cracked RC beams with fire, and the distribution of the temperature field inside the cracked RC beams with fire is clarified. According to the distribution law, Based on the existing 300 ℃ and 800 ℃ isothermal curves, the formula of bearing capacity of reinforced concrete beams with fire in high temperature was put forward. The results show that the temperature of rebar location in RC beams is 55% ~ 144% higher than that of RC beams without cracks under the same fire conditions. The rebar with five cracks in RC beams The temperature at the location is 2.7% ~ 11.5% higher than the location of the rebar in the reinforced concrete beam with a crack. The bearing capacity of the cracked reinforced concrete beam is 47% -82% lower than that of the non-cracked reinforced concrete.