混凝土早期热-力学模型及工程应用

考虑混凝土早期强度的本构关系,结合化学反应速率描述温度对混凝土绝热温升方程的影响,对大体积混凝土结构早期的温度场和应力场进行研究。温度场的求解基于等效时间的非线性热传导方程,应力场求解考虑混凝土初期徐变影响。结合苏州轨道交通地下车站工程实例,对大体积混凝土施工期和运行期温度场和应力场进行仿真计算。结果表明,夏季开始浇筑的车站主体结构必须采取适当的温控措施,以保证大体积混凝土不产生温度裂缝。

Thermo-mechanical model of concrete at early age and its engineering application

Considering the constitutive law of concrete at early age and the effect of temperature on the adiabatic temperature rise equation based on chemical reaction rate,the temperature and stress fields of massive concrete structures at early age were studied.The temperature field was solved by equivalent time-based non-linear heat conduction equation.The creep of concrete at early age was taken into account for solving the stress field.According to a construction case of substation in Suzhou,3D numerical simulation of temperature and stress fields of massive concrete during the construction and operation stages is performed.The study shows that in order to avoid the cracks of massive concrete caused by temperature,temperature control measures should be taken for the main structures of the substation constructed during summer time.