挡潮闸闸墩高性能大体积混凝土温度效应与控制

为了解决某挡潮闸枢纽工程中高性能大体积混凝土结构浇筑时的温度控制问题,避免因混凝土干缩、自体积变形、外部约束和温度效应等因素引起混凝土开裂,取闸室底板和中墩进行三维有限元建模,对闸墩采取不同的温控措施,进行闸墩温度场和温度应力场的仿真分析,研究闸墩冷却水管布置方案的温控效果并提出科学合理的温度控制措施,为现场科学施工提供理论指导。仿真结果表明:通水冷却效果良好,闸墩均未出现裂缝;在混凝土浇筑初期采取降低入仓温度和通水冷却等降温措施来减小由于混凝土水化热引起的最大温升,可以有效减小混凝土温降阶段的降温幅度;控制最大温升、内外温差及温降速率是大体积混凝土闸墩温控防裂的关键。

Temperature effect and control analysis of high-performance mass concrete for pier of tidal gate

To avoid concrete cracking due to concrete shrinkage,autogenous deformation,external constraints,and temperature effects,it is necessary to solve the temperature control problem of high-performance mass concrete structures during the pouring process.With different temperature control measures for piers,simulation analysis of the temperature field and temperature stress field was conducted.Then,the temperature control effect of the cooling water pipe layout scheme was analyzed,and reasonable temperature control measures are proposed to guide field construction.The simulation analysis results show that there are no cracks on the pier because of good water cooling effects;pipe cooling and decrease of the placing temperature can be used to decrease the maximum temperature rise caused by hydration heat of concrete during the initial concrete pouring,and to decrease the range of the temperature decline;and control of the maximum temperature rise,temperature difference,and freezing rates is critical for crack control of the mass concrete pier.