火灾后钢筋混凝土梁抗剪承载力

研究火灾后钢筋混凝土梁抗剪承载力,建立了钢筋混凝土梁的非线性有限元模型,对其在火灾后的抗剪性能进行了数值模拟。有限元模型考虑了火灾作用后混凝土和钢筋的材料损伤,分析了火灾时间、剪跨比、混凝土强度、箍筋直径和箍筋间距对钢筋混凝土梁抗剪承载力和刚度的影响程度。结果表明,随着火灾时间的增加、剪跨比的增大或混凝土强度的下降,火灾后钢筋混凝土梁的抗剪承载力和刚度均明显下降。随着箍筋直径的下降或箍筋间距的增大,火灾后钢筋混凝土梁的抗剪承载力下降,而刚度变化较小。

Shear capacity of fire-damaged reinforced concrete beams

In order to research the shear capacity of fire-damaged reinforced concrete(RC) beams,the nonlinear finite element model was developed.Considering mechanical properties descending of concrete and steel reinforcing bar,the parameters of fire-damaged RC beam,including fire time,shear span to depth ratios,concrete strength,stirrup diameters and stirrup spacing,were analyzed.Based on numerical analysis,the change of shear capacity and rigidity of fire-damaged RC beam were identified.The results showed that with fire time increase or shear span to depth ratio increase or concrete strength decrease,shear capacity and rigidity of fire-damaged RC beam declined obviously.With stirrup diameters decrease or stirrup spacing increase,shear capacity of fire-damaged RC beam declined,but rigidity of fire-damaged RC beam had little change.