ECC与既有混凝土结合面的抗剪性能

Shear Resistance Property of ECC Existing Concrete Interface

摘要:

为研究高延性水泥基复合材料(ECC)与既有混凝土结合面的抗剪性能及抗剪荷载的作用机理,设计并加载了3组带结合面的Z形剪切试件和1组混凝土整浇对比试件,分析配筋率和结合面处理方式对试件抗剪承载力、荷载滑移曲线、钢筋应变及结合面抗剪承载力组成等因素的影响,得到适用于ECC与既有混凝土结合面抗剪承载力的计算方法,在此基础上研究了抗剪承载力的组成及全过程变化规律,同时给出了剪切承载力各组成在动态过程中的计算方法.结果表明：ECC与既有混凝土结合面的抗剪性能强于普通混凝土;采用键槽连接处理的试件,其抗剪承载力高于凿毛粗糙面试件.本文提出的计算方法可以较好地计算试件的抗剪承载力,能够反映其各组成随滑移的变化规律.

Abstract:

In order to study the shear behavior of bonding interface between engineering cementitious composites（ECC） material and existing concrete as well as the action mechanism of shear load, three groups of Z shape direct shear specimens with joints and one group of whole cast in place contrast specimens were designed and tested. The effects of different reinforcement ratios and treatment methods of joints on shear strength, load slip curve, steel strain and shear strength of joints were investigated and compared. The results show that the shear bearing capacity of ECC concrete interface is stronger than that of ordinary concrete under shear load, the shear bearing capacity of specimens treated with keyway is higher than that of rough surface. The shear bearing capacity of specimens is determined by the interfacial bonding force and boundary. The higher the reinforcement ratio is, the smaller the proportion of interfacial bonding force is. The calculation method proposed can calculate the shear capacity and reflect the variation of its components with slip.