筏板基础大体积混凝土温度裂缝控制的模型试验

沈阳市某工程2号塔楼筏板基础最大厚度达11 m,给现场施工带来了严峻的挑战。为避免温度裂缝的产生,通过模型试验确定筏板基础大体积混凝土温度监测和裂缝控制措施。模型试验研究表明:混凝土内部温度发展趋势大致可分为"急剧升温"、"快速降温"和"平稳降温"3个阶段,温控工作中可根据不同的温度发展阶段采取不同的混凝土表面保温措施。局部体量过大导致混凝土温度峰值增大,局部突出部分降温速度加快,对温控工作带来不利影响,容易引发混凝土温度裂缝。模型试验的结果为仿真分析与现场温控工作提供了数据支持。

Model test of temperature field of mass concrete for raft-foundation

An eleven meter thick raft-foundation of a high-rise building will be built in Shenyang,which will bring a huge challenge on site operation.Measures which are to avoid thermal crack of raft-foundation are identified through model text.The model test result shows that the development of temperature field of mass concrete can be approximately divided into three phases as"warming fast","cooling fast" and "cooling steadily".Insulating material should be coated in different ways to adapt to the development of temperature field.Protruding part of raft-foundation will lead to the increase of the cooling speed of the protruding part and the thermal spike of mass concrete.Protruding part will bring the negative impact on the control of temperature field,and trigger thermal crack of mass concrete easily.The results of the model test provide data to the simulation analysis and the control of temperature field.