低热水泥全级配混凝土断裂试验及尺寸效应分析  

FRACTURE TEST AND SIZE EFFECT ANALYSIS OF LOW-HEAT CEMENT FULLY-GRADED CONCRETE

作　　者：高小峰 胡昱[2] 杨宁 邬昆 李庆斌[2] GAO Xiao-feng;HU Yu;YANG Ning;WU Kun;LI Qing-bin(College of Civil Engineering,Zhejiang University of Technology,Hangzhou,Zhejiang 310023,China;State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084,China;China Three Gorges Projects Development Co.,Ltd,Chengdu,Sichuan 610041,China)

机构地区：[1]浙江工业大学土木工程学院,浙江杭州310023 [2]清华大学水沙科学与水利水电工程国家重点实验室,北京100084 [3]中国三峡建设管理有限公司,四川成都610041

出　　处：《工程力学》2022年第7期183-193,共11页Engineering Mechanics

基　　金：国家自然科学基金项目(51839007,52009123);中国长江三峡集团有限公司科研项目(WDD/0427,BHT/0806);清华大学水沙科学与水利水电工程国家重点实验室开放基金项目(sklhse-2020-C-04)。

摘　　要：该文分析了低热水泥全级配混凝土断裂性能的尺寸效应规律。通过在大坝工程施工现场浇筑成型试件有效高度为0.75 m、1.5 m和2.25 m的楔入劈拉试件并开展试验,获得低热水泥全级配混凝土稳定的双K断裂参数。基于试验结果,采用理论方法推求全级配混凝土无尺寸效应的失稳和起裂韧度,预测任意尺寸试件的最大和起裂水平荷载。研究发现,当韧带高度与骨料最大粒径比值大于等于6.0后,双K断裂参数趋于稳定。尺寸效应模型及其演化形式可用于确定全级配混凝土无尺寸效应的起裂和失稳断裂韧度,定量分析强度与韧度对裂缝扩展的影响,并可通过引入等效几何参数,分别建立任意尺寸试件最大和起裂水平荷载的预测方程。This paper analyzes the size effect of the fracture parameters of low-heat cement fully-graded concrete. Wedge-splitting specimens with effective heights of 0.75 m, 1.5 m, and 2.25 m were cast on the construction site of a dam project, and tests were carried out to obtain the stable double-K fracture parameters of low-heat cement fully-graded concrete. Based on the test results, theoretical methods were used to derive the size independent unstable and initiation toughness of fully-graded concrete, and to predict the maximum and initiation horizontal loads of a specimen with an arbitrary dimension. The study found that when the ratio of ligament height to the maximum aggregate dimension is greater than or equal to 6.0, the double-K fracture parameters tend to be stable. The size effect model and its evolution forms can be used to determine the size independent unstable and initiation toughness of fully-graded concrete, quantitatively to analyze the influence of strength and toughness on crack propagation, and by introducing an equivalent geometric parameter, the prediction equations for the maximum load and crack initiation horizontal load of arbitrary size specimens can be established respectively.

关 键 词：水工结构 断裂参数 低热水泥 全级配混凝土 尺寸效应 

分 类 号：TU528[建筑科学—建筑技术科学] TU501