碱含量及骨料级配对大坝混凝土碱骨料反应的影响  

Effects of alkali content and aggregate gradation on alkali-aggregate reaction of dam concrete

作　　者：刘晨霞[1] 计涛[1] 陈改新[1] 纪国晋[1] 张扬三 LIU Chenxia;JI Tao;CHEN Gaixin;JI Guojin;ZHANG Yangsan(China Institute of Water Resources and Hydropower Research,Beijing 100038,China;Beijing IWHR-KHL Co.,Ltd,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038 [2]北京科海利工程技术有限公司,北京100038

出　　处：《北京水务》2022年第5期62-65,共4页Beijing Water

基　　金：水利部公益性行业科研项目(200701041):恶劣环境与运行条件下大坝混凝土的耐久性研究及应对措施研究。

摘　　要：选用某工程砂岩骨料,参照砂浆棒快速法,研究不同碱含量条件下砂浆试件的最终膨胀率发展规律,试验结果显示碱含量对砂浆试件最终膨胀率影响较大。采用工程实际混凝土配合比,湿筛相应尺寸骨料后分别成型三级配、二级配和一级配混凝土试件,研究不同骨料粒径对碱骨料反应的影响。试验结果表明,随着养护龄期的增长,骨料粒径对碱骨料反应膨胀率的影响逐步减小。工程中应严格控制混凝土碱含量,不同骨料级配混凝土试件的碱骨料反应膨胀规律为快速准确评价碱骨料反应对工程的危害性提供了理论依据。Final expansion ratio of mortar specimens with different alkali content was studied by selecting sandstone aggregate from a project and referring to the accelerating Mortar-bar Method.The results of the experiment showed that alkali content has great influence on the final expansion ratio of mortar specimen.In addition,the effect of different aggregate sizes on alkali aggregate reaction was studied by using concrete mix proportion and wet-screened aggregate of corresponding sizes.Experimental results showed that with the increase of curing age,the influence of aggregate size on the concrete expansion ratio of alkali aggregate reaction decreases gradually.Therefore,alkali content of concrete should be strictly controlled in engineering,and the alkali aggregate reaction test results of concrete specimens with different aggregate gradation provide a theoretical basis for evaluating the harmfulness of alkali aggregate reaction to engineering.

关 键 词：混凝土 碱-骨料反应 骨料级配 

分 类 号：TV43[水利工程—水工结构工程]