大体积混凝土温度及温度应力影响因素研究

Influential Factors of Mass Concrete Temperature and Temperature Stress

以沙特海尔港码头胸墙结构为模型,利用有限元分析软件Midas分别模拟了不同浇筑温度、比热、导热系数、长宽比下混凝土最高温度及温度应力在各龄期下的发展规律,并对各影响因素的影响作用进行了对比,结果表明:随着浇筑温度的增大、导热系数的减小、比热的减小、长宽比的增大,混凝土内最高温度增大,温度应力增大;浇筑温度、长宽比对混凝土温度及应力的影响作用较大;混凝土温度早期增长快,温峰过后不断降低,温度应力出现"快速增长-减小-再增长"的趋势,早期拉应力存在混凝土表面,后期存在于混凝土内部。以上结果可为实际施工中混凝土的防裂提供理论依据,并取得较好效果。

As the Saudi Ras A1 Khair Port breast wall for a model, the finite element analysis software Midas was used to simulate the development law at different age of concrete maximum temperature and temperature stress under different pouring temperature, heat capacity, heat conductivity and length-width ratio. The results show that with the increase of pouring temperature and length-width ratio, decrease of heat capacity and heat conductivity, the maximum temperature and temperature stress of concrete increase, and the effect of pouring temperature and lengthwidth ratio on concrete temperature and temperature stress is relatively larger. The concrete temperature increases rapidly at early age,however, decreases continually after temperature peak, and the temperature stress presents a trend of rapid growth-reduce-growth. Moreover, the tensile stresses at early age exist on the surface of concrete , while inside the concrete at late age. All above provides a theoretical basis for concrete crack prevention in actual construction.