Klemczak Barbara
Faculty of Civil Engineering, Silesian University of Technology, Akademicka 5, 44-100 Gliwice, Poland.
Materials (Basel). 2019 Nov 8;12(22):3689. doi: 10.3390/ma12223689.
Prediction of hydration temperature and induced stresses in mass foundation slabs, due to the hydration effects is a difficult task. The complexity of this issue is compounded by transient and non-linear thermo-mechanical phenomena as well by a significant number of contributing technological and material factors that affect the early-age volume changes. This is a probable reason for the limited number of simple analytical methods allowing for the estimation of these effects. This work presents a new proposal in the discussed field. The submitted analytical method for determining the hydration temperature rise, its differentials at a cross-section and induced thermal stresses in mass concrete foundation slabs considers the majority of important technological and material factors, such as the initial temperature of the concrete, the ambient temperature, the thermal properties of the concrete and the heat exchange conditions on the slab surfaces. In stress analysis, both self-balanced and restraint stresses are calculated. Finally, the method is validated in FE analysis conducted for the slabs with various heights and made of different types of cements, as well as by the thermal measurements from the construction site. Due to the limited number of methods allowing for the analytical estimation of the early age thermo-mechanical effects in slabs, this new proposal can be useful in the assessment of these effects.
预测大体积基础板因水化作用产生的水化温度和诱导应力是一项艰巨的任务。瞬态和非线性热机械现象以及大量影响早期体积变化的技术和材料因素使这个问题变得更加复杂。这可能是用于估算这些效应的简单分析方法数量有限的一个原因。本文提出了该领域的一项新建议。所提交的用于确定大体积混凝土基础板水化温度升高、其截面温差和诱导热应力的分析方法考虑了大多数重要的技术和材料因素，如混凝土的初始温度、环境温度、混凝土的热性能以及板表面的热交换条件。在应力分析中，计算了自平衡应力和约束应力。最后，通过对不同高度和不同类型水泥制成的板进行有限元分析以及施工现场的热测量，对该方法进行了验证。由于能够对板早期热机械效应进行分析估算的方法数量有限，这项新建议在评估这些效应方面可能会有所帮助。
