基于修正压力场理论的活性粉末混凝土梁抗剪分析

Shear analysis of reactive powder concrete beam based on modified compression field theory

在Vecchio和Collins所提出的修正压力场理论(MCFT)基础上,叠加弯矩作用,并考虑活性粉末混凝土(RPC)材料的特点,修正开裂RPC材料的本构关系以及模型的平衡条件,建立了弯剪复合作用下配筋RPC梁截面分析模型.对12根具有不同剪跨比、配箍率、钢纤维体积率、配筋率以及纵筋强度的高强纵筋RPC试验梁进行了模型分析,并与试验结果进行对比.结果表明:该模型能很好地模拟整个试验加载过程,抗剪极限承载力的计算结果以及变化趋势与实测值吻合较好,计算所得的箍筋平均应变在加载后期能表现出弹塑性变化的趋势,RPC受拉本构关系对模型预测的精准性起主要影响,该模型对以剪压破坏形态为主的构件最为适用.

Based on the modified compression field theory(MCFT)proposed by Vecchio and Collins,a new sectional analytical model for reinforced reactive powder concrete(RPC)beams under the combined action of bending moment and shear is established.Because the characteristics of RPC are considered in the model,the constitutive relation of RPC after cracking and equilibrium condition of model are corrected.Twelve high strength reinforced RPC beams are analyzed by this model.The influences of shear span ratio,stirrup ratio,steel fiber content,reinforcement ratio and reinforcement strength are considered.The results of the model are compared with the experimental results.The results show that the model can simulate the whole test loading process very well.The calculation results and the change tendency of the ultimate shear capacity are in good agreement with the measured values.The calculated average strain of stirrups shows a trend of elastic-plastic change at the later stage of loading.RPC tension constitutive relation plays a major impact on the accuracy of the model prediction.The model is more suitable for the component which occurs shear compression failure.