沿海地区桥梁超大零号块裂缝控制技术

Cracks Controlling Technology of Ultra Large Zero Block for Bridge in Coastal Area

某大桥主墩零号块结构尺寸大,采用C55混凝土,收缩大,施工过程中处理不当极易出现裂缝,在混凝土配合比优化设计的基础上,依据温度场及温度应力场仿真计算结果制定了相应的温控标准,并通过原材料温度控制、混凝土掺加碎冰拌和、液氮预冷混凝土、埋设冷却水管通水冷却等措施,使该零号块箱梁未出现有害温度裂缝,达到了预期的温度控制效果。

Due to the large structure size of zero block of some river bridge, the concrete is easy to crack in construction when using C55, based on the optimization of concrete mix proportion, the standard of temperature controlling was made according to the result of temperature and thermal stresses distribution of mass concrete. By controlling materials temperature, mixing concrete with ice, cooling concrete with liquefied nitrogen and applying recycling cool water, harmful cracks was not appeared in mass concrete of ultra large zero block of the river bridge and anticipated temperature control requirements was achieved.