拱座大体积混凝土施工温控技术研究

Research on Temperature Control Technology of Mass Concrete Construction in Abutment

温度裂缝是大体积混凝土裂缝的主要形式,大体积混凝土裂缝对其使用寿命有很大的危害。以找龙坝河特大桥工程为工程背景,介绍了钢管混凝土拱桥大体积混凝土拱座施工过程中混凝土温度控制的原则和标准。通过制定的温控方案采取了一系列温控措施并进行有效监控,充分说明采用混凝土浇筑顺序的调整、混凝土的配合比的优化、骨料遮阳、加冰作业、监控过程中调整冷却水流量的综合方案能够控制混凝土内部温度和内表温差。工程方案实施后取得了良好的效果,未出现明显可见的危害性裂缝,达到了预期的温控目标。

Temperature crack is the main form of mass concrete crack, mass concrete cracks have a great hazard to structure service life. Taking the Zhaolongba bridge as the engineering background, the principle and standard of concrete temperature control during the construction of large-volume concrete abutment of CFST arch bridge are introduced. Take a series of temperature control measures and effectively monitored by the developed temperature control plan, it shows clearly that comprehensive plan of adjustment of concrete pouring sequence, concrete mix ratio optimization, aggregate shading, ice-adding operation, and during monitoring adjust cooling water flow can control the internal temperature and the table difference in temperature of the concrete. The implementation of the project scheme achieves good results and there are no obvious harmful cracks, complying with the expected temperature control target.