某黄河大桥承台大体积混凝土的水化热分析

Hydration Heat Analysis of Mass Concrete for Pile Cap of a Yellow River Bridge

为解决大体积混凝土的水化热问题,结合某黄河大桥工程,在其44号承台内部预埋设冷却管并利用有限元软件midas Civil进行水化热数值分析。结果表明:模型内各层各测点温度的变化趋势曲线基本符合混凝土水化热温度变化规律。对有无冷却管模型的温度场结果进行对比分析发现最大内外温差在水管冷却作用下下降了17.18℃,冷却效果显著;同时混凝土各龄期的温度应力值均小于其对应的容许抗拉强度,有效抑制了温度裂缝的产生,提升了大体积混凝土的抗裂性能。预埋冷却管能有效降低大体积混凝土在浇筑过程及浇筑完成后所产生的水化热。

In order to solve the problem of hydration heat of mass concrete,combined with a Yellow River Bridge project,the cooling pipe is pre-embedded inside its No.44 supporting platform and the finite element software midas Civil were used for the numerical analysis of hydration heat.The results indicate that pre-embedded cooling pipes can effectively reduce the hydration heat produced by the mass concrete during and after the pouring process,compared with the temperature field results of the model without cooling pipe,it is found that the cooling effect of the water pipe makes the maximum temperature difference between inside and outside of the model decrease by 17.18℃,which has a significant cooling effect;meanwhile,the value of temperature stress in concrete at all ages is less than its corresponding allowable tensile strength,which effectively inhibits the generation of temperature cracks and improves the crack resistance of mass concrete.