Temperature variation in concrete samples due to cement hydration
Temperature variation in concrete samples due to cement hydration
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DOI：
10.1016/j.applthermaleng.2016.05.048
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发表时间：
2016-06
影响因子：
6.4
通讯作者：
A. Schackow;C. Effting;I. R. Gomes;Isabeli Z. Patruni;Felipe Vicenzi;Camila Kramel
中科院分区：
文献类型：
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作者：
A. Schackow;C. Effting;I. R. Gomes;Isabeli Z. Patruni;Felipe Vicenzi;Camila Kramel
大体积混凝土的大型结构是一个工程问题，由于裂缝所产生的温度应力。如今，许多建筑使用大量混凝土，如大坝，高层建筑和基础设施解决方案。在大体积混凝土结构中，温度梯度主要是由水泥水化热引起的。混凝土性能也直接影响温度梯度。为了防止混凝土结构的裂缝，可以采取一些技术措施，如选择较冷的原材料或预冷（冰）或管道冷却，或应用表面隔热。裂缝会降低结构的安全性、完整性和耐久性。此外，修补裂缝是非常困难的。本文着重于识别哪些属性影响混凝土温度和原材料如何影响热特性。通过试验研究，分析了预冷技术和水泥类型对降低水泥浆温度梯度的影响。数值模拟有助于理解试样中几个点的温度行为。实验结果与数值模拟结果吻合较好。使用低水化热的水泥、较低高度层的混凝土和使用冰是评估的主要性能，它们都导致温度降低。然而，最大的差异是在较低高度的混凝土层。多层混凝土的使用是降低温度的最佳选择。
Large structures of massive concrete are an engineering problem due to cracking created by thermal stresses. Nowadays, many constructions use large amount of concrete, like dams, tall buildings and infrastructure solutions. In big concrete structures, the temperature gradient is mainly caused by cement hydration heat. Concrete properties also directly affect the temperature gradient. To prevent cracking in concrete structures, some technical approaches can be done, such as choosing cooler raw materials or precooling (ice) or pipe cooling, or applying superficial thermal insulation. Cracks will reduce the safety, integrity and durability of the structure. Besides, repairing a crack is very difficult. This paper focus on identifying which properties influence the concrete temperature and on how raw materials affect the thermal characteristics. Experimental tests have been done to analyze how the precooling technique and cement type reduce the temperature’s gradient. The numerical simulation contributed to the understanding of the temperature behavior in several points in the specimen. There was a reasonable agreement between the experimental results and those obtained by numerical simulation. The use of cement with low hydration heat, the concrete in lower height layers and the use of ice were the main properties evaluated, and they all caused a reduction in temperature. However, the biggest difference was noticed in lower height layers of concrete. The use of concrete in several layers was the best option for decreasing temperature.