Further research on the pore structure of foamed concrete contribute to expand the application of energy-efficient buildings. In this paper, the micropore structure features of foamed concrete were characterized by nuclear magnetic resonance. It is found that the pore size of foamed concrete ranged from 1 nm to 74.84 μm. In order to understand the effect of micropores on the performance of foamed concrete, the models with (Model I) and without micropores (Model II) were established. Besides, the heat conduction and stress distribution of foamed concrete were simulated numerically. Meanwhile, the thermal conductivity and compressive strength were tested as the reference for numerical simulations. The results show that the heat conduction flux and temperature gradient of Model I were increased by 12%–13% and the thermal conductivity was increased by 2.63% compared to Model II. Thermal conductivity of Model I was closer to the experimental results. The stress of Model I was increased by 1.32%–54.66% compared to that of Model II. This indicates that the micropores can significantly increase the stress concentration in the foamed concrete.

中文翻译：

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泡沫混凝土微孔及其对应力分布和热传导的影响研究

对泡沫混凝土孔隙结构的进一步研究有助于扩大节能建筑的应用。本文利用核磁共振技术对泡沫混凝土的微孔结构特征进行了表征。结果发现，泡沫混凝土的孔径范围为1 nm~74.84 μm。为了了解微孔对泡沫混凝土性能的影响，建立了有微孔（模型一）和无微孔（模型二）的模型。此外，还对泡沫混凝土的热传导和应力分布进行了数值模拟。同时测试了导热系数和抗压强度，作为数值模拟的参考。结果表明，与模型II相比，模型I的热传导通量和温度梯度增加了12%~13%，导热系数增加了2.63%。模型I的导热系数更接近实验结果。模型I的应力较模型II增加了1.32%~54.66%。这表明微孔可以显着增加泡沫混凝土中的应力集中。