弯剪共同作用下活性粉末混凝土梁截面分析程序探讨

Discuss the Sectional Analysis Program of RPC Beams Under the Compound Action of the Bending and Shearing

为了研究配箍率对高强箍筋活性粉末混凝土(RPC)梁抗剪性能的影响,开展6根配置HRB400级箍筋RPC梁的抗剪试验。考虑RPC的材料特征参数与钢纤维对斜截面承载力的影响,分析有腹筋与无腹筋梁在剪力传递机理及裂缝控制方面的差异。基于修正压力场理论,对开裂后的混凝土在拉、压应力下的本构关系及裂缝处的应力平衡条件进行适当修正;将弯矩效应叠加至纯剪作用下的截面分析中建立RPC梁在弯剪复合作用下的分析模型,并采用MATLAB软件编制RPC梁斜截面抗剪强度分析计算程序;对RPC简支梁的试验结果与计算结果进行对比分析。研究结果表明该计算程序能够较好地预测高强钢筋RPC梁的受剪承载力,具有一定的参考和实用价值。

In order to explore the influence of shear span ratio on shear behavior of RPC beams with highstrength stirrups, six RPC beams with HRB400 Stirrups were tested. Considering the characteristic parameters of RPC and steel fiber influence on the bearing capacity of inclined section, the section analysis model of RPC beam under the action of bending shear was constructed according to the difference between the RPC beams with and without stirrups in the shear force transfer mechanism and the crack control of the beam. A appropriate revision of constitutive relation of cracking concrete under tension and compression stress and stress equilibrium condition of cracks based on the modified compression field theory was made of. The pure shear was overlaid with bending mo- ment. An analysis model of RPC beams was established under the compound action of the bending and shearing and used MATLAB software to write a calculation and analysis procedure for shear strength on inclined section of RPC beams around it. The accuracy of the calculation method was analyzed by the ratio of the test results and the calcu- lated results. The results show that the method can well predict the shear capacity of RPC beams, and it has a certain reliability and practicability.