Thermal properties and stability of reactive magnesia cement

The unique ability of reactive magnesium oxide cement (RMC) to permanently sequester environmental carbon dioxide (CO2), followed by sufficient strength gain, makes it an attractive material for greener construction. The potential of RMC and its combination with various supplementary materials have been demonstrated for construction by several researchers. In this study, the thermal properties of the RMC-based paste, along with its thermal stability after prolonged and cyclic high-temperature exposure, are reported. The results reveal that, in general, the RMC-based paste samples cured under an ambient environment as well as the ones cured under accelerated carbonation undergo strength gain after cyclic exposure to temperature as high as 300 degrees C. In terms of thermal properties, the general trend was found to be an increase in the specific heat and a decrease in the thermal conductivity and the thermal diffusivity with increasing temperature for both types of RMC-based paste samples. These results reveal a remarkable ability of the RMC to sustain high temperatures with excellent strength retention making it suitable for high temperature and energy storage applications.

Automated summary

The research demonstrates that RMC-based paste samples gain strength after exposure to temperatures as high as 300 degrees C, regardless of whether they were cured in ambient conditions or under accelerated carbonation. The specific heat of the samples increases while thermal conductivity and thermal diffusivity decrease with increasing temperature, indicating that RMC has excellent strength retention at high temperatures.