摘要
低含沙水流低速冲蚀是水工混凝土结构长期服役面临的普遍而又极易忽略的问题。为研究其磨蚀的关键影响因素与规律,设计了一种低含沙低速射流冲刷试验装置,对6种不同配比的混凝土试样开展了4组共计23次长时间冲蚀试验,并且基于试样质量磨损量的精确测量,分析了射流特征参数及混凝土关键掺量对混凝土磨损的影响。试验结果表明,低含沙水流低速冲蚀混凝土的作用可分为法向冲蚀和切向磨削两种作用,速度、面积相同时法向冲蚀的磨损效果高于切向磨削。随着冲刷时间发展,混凝土小时磨损量逐渐降低后趋于某一稳定值。在试验条件范围内,小时磨损量随着射流冲刷速度和含沙量的提高而有所增大,在大冲刷角度时具有较高的小时磨损量。适当增加硅粉及纤维掺量有助于提高混凝土的抗冲蚀性能。并最终建立了最优配比混凝土的含沙水流冲蚀预测模型,以期为混凝土的使用寿命评估和性能提升提供依据。
Erosion by low⁃velocity and low⁃sand content water flow is a common and highly neglected problem faced by hydraulic concrete structures in long service.In order to study the key influencing factors and laws of its abrasion,a low⁃velocity and low⁃sand content jet scouring experimental setup was designed to carry out four groups of concrete specimens with six different ratios for a total of 23 long⁃time abrasion tests,and based on the accurate measurement of the specimen mass abrasion amount,the effects of the characteristic parameters of the jet and the key admixture of concrete on the abrasion of concrete were analyzed.The results show that:the erosion of concrete by low⁃sand content and low⁃velocity water flow can be divided into two types of actions:normal erosion and tangential grinding;the abrasion effect of normal erosion is higher than that of tangential grinding when the speed and area are the same;as the scouring time progresses,the hourly abrasion of concrete gradually decreases and then stabilizes;within the experimental conditions of this study,the hourly abrasion increases with the rise in jet scouring speed and sand content,and is higher at larger scouring angles;appropriate increase in silica fume content and fiber content helps to improve the erosion resistance of concrete.Finally,a prediction model for sandy water flow erosion of optimally proportioned concrete was established to provide a basis for the service life assessment and performance improvement of concrete.
作者
顾磊
戴福旭
李洪彬
王顺
刘勇
GU Lei;DAI Fuxu;LI Hongbin;WANG Shun;LIU Yong(Engineering Research Center of Dredging Technology,Hohai University,Changzhou 213022,China;College of Mechanical and Electrical Engineering,Hohai University,Changzhou 213022,China)
出处
《振动与冲击》
北大核心
2025年第4期238-243,252,共7页
Journal of Vibration and Shock
基金
国家自然科学基金资助项目(51709094)。
关键词
混凝土
小时磨损量
低含沙射流
低速冲蚀
试验
concrete
hourly abrasion
low⁃sand content jet
low⁃velocity erosion
experiment
作者简介
第一作者:顾磊,男,博士,副教授,1982年生;通信作者:戴福旭,男,硕士生,2001年生,E-mail:1601408582@qq.com。
