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混凝土与制品
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基于等效龄期的机制砂高性能混凝土强度快速评价方法与工程应用

作者:张兴志1,杨海成2,于方2

关键字:基于,等效,龄期,的,机制,砂,高性能,混凝土,

 
(1.浙江舟山北向大通道有限公司,浙江 舟山  316000;
2.中交四航工程研究院有限公司,水工构造物耐久性技术交通行业重点实验室,广东 广州  510230)
    摘要:大体积混凝土结构受水化温升的影响,结构内部温度显著高于环境温度,结构内部混凝土的强度发展规律与同条件养护试件存在一定差异。针对C40~C60三种强度等级机制砂高性能混凝土,研究了20~80 ℃养护温度对机制砂混凝土抗压强度的影响规律,结果表明:高温养护加快了机制砂高性能混凝土早龄期抗压强度的发展,但对于80 ℃养护温度,高温养护对混凝土后期的抗压强度有不利影响;建立了等效龄期与机制砂高性能混凝土抗压强度、抗拉强度之间的函数模型,大体积混凝土实测结果与计算值较为吻合,在大体积混凝土结构开裂风险分析时,应考虑结构内部温升的影响。
    关键词:等效龄期;机制砂高性能混凝土;抗压强度;养护温度;预测模型
    中图分类号:TU528.01        文献标识码:A        文章编号:1001-702X(2020)09-0135-04
 
Rapid strength evaluation method and engineering application of machined sand high performance concrete based on equivalent age
ZHANG Xingzhi1,YANG Haicheng2,YU Fang2
(1.Zhejiang Zhoushan North Channel Co. Ltd.,Zhoushan 316000,China;2.Key Laboratory of Harbor & Marine Structure Durability Technology of the Ministry of Communications,CCCC Fourth Harbor Engineering Institute Co. Ltd.,Guangzhou 510230,China)
    Abstract:Internal temperature of mass concrete structure is significantly higher than the ambient temperature due to hydration caused temperature rise. There are some differences between strength development law of concrete inside mass structure and curing specimen under site maintenance. Effects of curing temperatures at 20~80 ℃ on compressive strength of concrete were studied for C40~C60 three strength grade high performance concrete. Result show that high temperature curing accelerates development of early age compressive strength. However,high temperature curing had adverse negative influence on the later period compressive strength for curing temperature of 80 ℃. Function model between equivalent age and compressive strength,tensile strength of high performance concrete were established. Measured results of mass concrete agree well with the calculated values. Influence of internal temperature rise should be considered at analysis of cracking risk of mass concrete structure.
    Key words:equivalent age,high performance concrete with machined sand,compressive strength,curing temperature,precast model