超高性能混凝土与普通混凝土界面抗剪强度计算方法

Calculation method for shear strength of UHPC-NC interface

为提高超高性能混凝土(ultra-high performance concrete,UHPC)和普通混凝土(normal concrete,NC)界面抗剪强度设计计算的精确性与合理性,广泛搜集国内外文献中相关的试验数据,建立了包含521组试验数据的UHPC-NC界面抗剪试验数据库,并在假定界面剪切破坏机构的基础上,通过理论分析与数据拟合提出了UHPC-NC界面抗剪强度的计算方法。通过与现有规范设计方法及经验预测方法对比可知,所提出的计算方法具备更高的计算精度。同时,将所提出的计算方法用以改进界面内聚力单元的损伤起始准则,利用有限元软件ABAQUS的二次开发功能,建立UHPC湿接缝受弯试验的有限元模型。与已有研究中的试验结果对比表明,该有限元分析方法可以较精确地模拟UHPC接缝板的受力性能,可用于UHPC-NC组合构件的工程设计与优化改进。

In order to improve the accuracy and rationality of the calculation of shear strength of the interface between ultra-high performance concrete(UHPC)and normal concrete(NC),the relevant experimental data in domestic and foreign literatures were widely collected to establish a database of UHPC-NC bonding shear tests with total 521 test data.Based on the assumption of an interfacial shear failure mechanism,the calculation method of shear strength of the UHPC-NC interface was proposed through theoretical analysis and data fitting.Compared with the existing code design methods and empirical prediction methods,the proposed calculation method exhibits higher accuracy.In addition,the proposed calculation method was used to improve the damage initiation criterion of interfacial cohesive element using the secondary development of ABAQUS,and the finite element model of UHPC wet joint bending tests was developed.Compared with test results in the existing research,the finite element model is proved to be able to simulate the flexural performance of UHPC joint,which can be used for the engineering design and optimization of UHPC-NC composite members.