摘要
针对粗骨料体积占比对水工混凝土湿胀特性影响规律尚不明确的问题,本文基于典型大坝工程湿筛二级配混凝土配合比,设计并开展了不同粗骨料体积占比(42%、47%、52%和57%)下水工混凝土湿胀试验,测试获得了不同浸水时间下水工混凝土的湿胀应变,进而采用称重法测试获得不同粗骨料体积占比下水工混凝土的湿胀系数,最后建立了考虑粗骨料体积占比因素的水工混凝土湿胀应变模型。研究结果表明,随着粗骨料体积占比的增加,混凝土湿胀系数增加,由于相应的吸水速率减小,而且其减小幅度大于湿胀系数增长幅度,进而导致湿胀应变减小;相对三次函数、对数函数和组合指数函数来说,基于双曲线函数建立的湿胀应变模型能更好地反映不同粗骨料体积占比对水工混凝土湿胀变形的影响。
To address the poor understanding in previous experimental research of hydraulic concrete wet expansion on the influence of coarse aggregate volume fraction,this study adopts a representative concrete mix design often used in typical dam engineering practice,featuring a wet-screened two-stage aggregate gradation.Specimens with coarse aggregate volume fractions of 42%,47%,52%,and 57%are designed and tested in our wet expansion experiment,and their wet expansion strain is measured under the condition of different immersion durations.Then,the wet expansion coefficient for each of the volume fractions is determined using the gravimetric method;A new predictive model for wet expansion strain is developed that incorporates the factor of volume fractions explicitly.Results indicate that with an increasing coarse aggregate volume fraction,the wet expansion coefficient increases,but the wet expansion strain is reduced because the rate of reduction in the water absorption rate has a greater effect.Compared to those equipped with a cubic,logarithmic,or combined exponential functions,our new wet expansion strain model based on the hyperbolic function captures more effectively the influence of varying coarse aggregate volume fractions on the wet expansion behaviors of hydraulic concrete.
作者
黄耀英
周彧婕
崔卫天
李泽鹏
包腾飞
HUANG Yaoying;ZHOU Yujie;CUI Weitian;LI Zepeng;BAO Tengfei(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China;College of Water Conservancy and Hydropower Engineering,Hohai University,Nanjing 210024,China)
出处
《水力发电学报》
北大核心
2025年第12期113-124,共12页
Journal of Hydroelectric Engineering
基金
国家自然科学基金(52179135,52239009)。
关键词
水工混凝土
粗骨料体积占比
湿胀应变
湿胀系数
湿胀应变模型
hydraulic concrete
coarse aggregate volume fraction
wet expansion strain
wet expansion coefficient
wet expansion strain model
