Studies on foamed concrete micropores and their effects on stress distribution and heat conduction

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.