张花高速澧水大桥索塔基础大体积混凝土温控

 结合张花高速澧水大桥索塔基础大体积混凝土施工,根据热传导和有限元基本原理,应用MIDAS软件建立了澧水大桥索塔基础大体积混凝土温控计算模型.根据计算结果确定了温控方案,对大体积混凝土施工全过程进行实时温度监测,实现了大体积混凝土温度控制的信息化施工,为混凝土冷却水通水和保温保湿养护等温控措施提供了依据.大体积混凝土浇注完成后,索塔基础未出现温度裂缝,达到了预期目标.工程实践表明本文采用的大体积混凝土温度控制方法和流程有效,可供桥梁索塔基础等大体积混凝土施工借鉴.

Mass Concrete Temperature Control of Lishui Bridge Tower Foundation in Zhanghua Highway

According to the basic principle of heat conduction and FEM, mass concrete FEM model of Lishui Bridge tower foundation is established by using software MIDAS. Temperature controlling scheme is determined based on the calculation results. Temperature of Lishui Bridge tower foundation is monitored in order to provide evidence for temperature controlling measures including water cooling, heat preservation and moisture retention, etc. Information construction for mass concrete temperature control is implanted. Low thermal cement should be used in mix design of concrete. Adding a certain amount of fly ash into concrete is helpful to control temperature of mass concrete. Cooling water should run through cooling pipe after mass concrete poured, and stop when cooling rate is close to or even greater than 2.0℃/d. If temperature of mass concrete is going up after stopping cooling water, cooling water should run through again. Heat preservation should be done when the inner-surface temperature difference is close to or even greater than 25℃. The temperature controlling scheme is repeated until temperature of mass concrete is stable. Analysis results are introduced. There have been not temperature crack on the surface of tower foundation after mass concrete was poured. Therefore expected target is realized. Engineering practice indicates temperature controlling method and technological process that are introduced in the article are reasonable and effective, and can be used as references for mass concrete construction of bridge tower foundation.