荆岳长江公路大桥南塔承台大体积混凝土温度裂缝控制

通过优化配合比,有限元仿真模拟荆岳长江公路大桥南塔上游承台混凝土结构温度、应力场的分布及发展过程,提出温控标准,并采取控制水泥的进场温度,骨料,泵管遮盖保温,混凝土内部通冷却水冷却,保温养护等措施,控制冬期施工的大体积混凝土温度.现场布设测温元件,实时监测结构物的温度变化,从监测结果和拆模后的情况来看,实测温度和仿真模拟结果吻合,承台混凝土表面未出现温度裂缝,温控效果良好.

Thermal Crack Control Technology of Mass Concrete in Pile Cap in Jing Yue Yangtze River Bridge

The temperature,thermal stresses distribution and development of pile cap concrete structure are simulated by finite element in up-stream of south tower of Jing Yue Yangtze River Bridge.According to these simulating data,the principle of temperature control is proposed.Some measures are taken to control the mass concrete temperature in winter construction such as optimizing mix ratio,controlling the used cement temperature,warming aggregates and pump pipes,cycling the cool water,warmed cured and so on.The temperature sensors are embedded in concrete to monitor the temperature of concrete in time and the results show that the real temperature inner concrete are correlative to the simulated, and there is no thermal cracks after taking off the forms.The effect of temperature control is satisfactory.