全级配混凝土抗拉性能的随机特性及数值分析

Study of Stochastic Behavior of Tensile Properties of Full-Grade Concrete by Numerical Analysis

以大型水利水电工程中广泛运用的全级配混凝土为对象,研究了骨料的几何随机性和砂浆、界面(骨料/砂浆界面)的力学随机性对全级配混凝土抗拉性能的综合影响.基于非线性损伤理论以及有限单元法,采用FORTRAN自编程序,通过50组随机试件的单轴拉伸数值试验,研究了骨料、砂浆及界面的随机特性对弹性模量、峰值应变以及极限抗拉强度的影响,对比了各自的影响程度,探讨了数值分析中同时考虑骨料、砂浆及界面随机性的必要性.

Full-grade concrete is widely used in large-scale hydraulic and hydropower projects. The tensile properties of full-grade concrete are studied with the geometric randomness of aggregates as well as the mechanical randomness of mortars and interfaces(i.e. aggregate/mortar interfaces). Based on nonlinear damage theory and finite element method, and using the program coded by authors with FORTRAN, a series of uniaxial tensile numerical tests with 50 random specimens are conducted. According to the test results, the discrete property of elastic modulus, peak strain and ultimate tensile strength is studied under the effects of randomnesses of aggregates, mortars and interfaces. Finally, the necessity of at the same time considering the randomnesses of aggregates, mortars and interfaces is discussed.