【摘要】 混凝土结构的修补加固已经成为一个重要的工程领域，为考察切槽下黏结锁固的新旧混凝土抗剪强度曲线与裂纹演化规律，进行了新旧混凝土进行力学参数的提取，提供了1种建立精细化混凝土模型的方法。结合数值模拟的方法进一步研究了距加载面为3.5 cm、5.5 cm、7.5 cm、9.5 cm、11.5 cm的不同距离的单切槽与0°、16°、30°、41°、49°的不同法向角的独立及连续切槽下的新旧混凝土叠合体剪切峰值应力与破坏形态。结果表明：三角形锯齿切槽下新旧混凝土叠合体剪应力-剪切变形曲线由弹性阶段、第一弹塑性阶段、第二弹塑性阶段、脆性断裂阶段、残余强度阶段5个部分组成。微观裂隙在新旧混凝结合面以剪坏为主，在锯齿以拉坏为主。切槽位置的变化及三角形切槽角度的变化都会对峰值应力有影响，随着切槽位置远离受力面，新旧混凝土结合面的抗剪强度会降低。在独立及连续锯齿切槽下试块的抗剪强度都随着切槽法向角的增大而增大，且当法向角在40°～50°时有着显著提升。微观裂隙更加分散，独立裂隙增多，宏观裂纹有向混凝土结合面向内部的发展趋势。更多还原

【Abstract】 The repair and reinforcement of concrete structure has become an important engineering field.In order to investigate the shear strength curve and crack evolution law of new and old concrete bonded and locked under the notch,the mechanical parameters of new and old concrete were extracted,providing a method to establish a refined concrete model.Combined with the numerical simulation method,the shear peak stress and failure mode of new and old concrete composite under the notch with different normal angles of 0°,16°,30°,41°,49° and notche under different positions of 3.5 cm,5.5 cm,7.5 cm,9.5 cm,11.5 cm the old concrete from the loading surface were further studied.The results show that the shear stress-shear deformation curve of new and old concrete composite under the triangular sawtooth notch is composed of five parts:elastic stage,the first elastic-plastic stage,the second elastic-plastic stage,brittle fracture stage and residual strength stage.The microcracks are mainly shear failure in the new and old concrete binding surface,and mainly pull failure in the sawtooth.The change of notch position and the change of triangular notch angle will affect the peak stress.With the notch position far away from the force surface,the shear strength of the new and old concrete binding surface will decrease.The shear strength of the test block under the independent and continuous sawtooth notch increases with the increase of the normal angle of the notch,and when the normal angle is drom 40 degrees to 50 degrees,there is a significant increase.The micro-cracks are more dispersed,the independent cracks increase,and the macro-cracks have a tendency to develop into the concrete.更多还原