【摘要】 早龄期混凝土表面开裂是工程中普遍存在的问题。模拟了某拱坝17号坝段混凝土在短历时暴雨袭击下的温度变化,分析了336.5 m高程裂缝产生的主要原因,并且讨论了其在有无保温养护条件下混凝土的温度变化和温度应力情况。计算结果表明,短历时暴雨引起的气温骤降和混凝土表面放热系数增大,是该表面裂缝产生的主要原因;做好表面保温养护工作可有效防止混凝土开裂,对后期大坝安全运行具有重要意义。更多还原

【Abstract】 Surface cracking of early-age concrete is a common problem in hydroelectric projects.The concrete temperature variation of monolith 17 of an arch dam during a short-duration storm was simulated and the main cause of concrete crack at height of 336.5 was analyzed;the concrete surface temperature and thermal stress changes with and without heat insulation measures were discussed.The results show that: a sudden temperature drop and the increment of concrete surface heat release coefficient caused by the short-duration rainstorm are the main causes of the crack;reasonable surface protection and heat insulation efforts could prevent the concrete cracking,and make a great significance to the safe operation of the dam.更多还原