摘要
基于边界效应模型(BEM)确定了无尺寸效应砂浆梁试件的抗拉强度和断裂韧度,通过三点弯曲切口梁断裂试验验证了不同梁高、缝高比、跨高比的粗砂、细砂砂浆梁试件的无尺寸效应,并引入了微观特征参数C_(ch)和离散系数β、C来表示材料的不均匀性和不连续性。此外,还将基于BEM结果与基于传统弹性力学理论试验结果进行了比较。结果表明:基于BEM,只需测得试件的极限荷载,就可以得到无尺寸效应的抗拉强度和断裂韧度;C_(ch)分别取粗砂砂浆的平均骨料粒径和细砂砂浆的平均孔径;基于正态分布分析,得到可靠度为95%的抗拉强度和断裂韧度的上下限;基于BEM所得的断裂参数较基于传统弹性力学理论得到的结果更准确,BEM可以有效解决断裂参数中存在的尺寸效应问题。
The tensile strength and fracture toughness of no size effect mortar beam specimens were determined based on the boundary effect model(BEM).Three point bending incision beam fracture tests were conducted to verify the no size effect of coarse sand and fine sand mortar beam specimens with different beam heights,joint height ratios,and span heights.Microscopic characteristic parameters C_(ch) and dispersion coefficientsβand C were introduced to represent the inhomogeneity and discontinuity of materials.In addition,the BEM results were compared with the experimental results based on traditional elastomechanics theory.The results show that based on the BEM,the tensile strength and fracture toughness without size effect can be obtained by only measuring the ultimate load of the specimen.C_(ch) is taken as the average aggregate particle size of coarse sand mortar and the average pore size of fine sand mortar,respectively.Based on the analysis of normal distribution,the upper and lower limits of the tensile strength and fracture toughness with the reliability of 95%are obtained.The fracture parameters based on the BEM are more accurate than the results based on the traditional elastomechanics theory,and BEM can effectively solve the problem of size effect in the fracture parameters.
作者
陈厚彬
杨树桐
虞烜
CHEN Houbin;YANG Shutong;YU Xuan(College of Engineering,Ocean University of China,Qingdao 266000,China)
出处
《混凝土与水泥制品》
2025年第10期15-20,26,共7页
China Concrete and Cement Products
基金
国家自然科学基金面上项目(52178259)
山东省自然科学基金项目(ZR2020KA001)。
关键词
水泥砂浆
抗拉强度
断裂韧度
边界效应模型(BEM)
粗砂
细砂
Cement mortar
Tensile strength
Fracture toughness
Boundary effect model(BEM)
Coarse sand
Fine sand
作者简介
第一作者:陈厚彬(1998-),男,硕士。E-mail:2857018047@qq.com;通信作者:杨树桐(1979-),男,教授,博士生导师。E-mail:shutongyang2013@163.com。
