The effect of nanoparticles on the properties of calcium aluminate cement pastes at high temperatures

Heated cementitious pastes could be used as thermal energy storage materials. The effects of nano-silica, nano-magnesia and nano-zirconia on the evolution of the mechanical and thermal properties of calcium aluminate cement (CAC) pastes at three temperatures (105, 350 and 900°C) were investigated. At 105°C, the addition of nano-zirconia resulted in better residual compressive strength than those of the pastes with the other nanoparticles. The improvement in thermal properties of the pastes with added nanoparticles was mainly at temperatures of 350°C and 900°C. The main reason for the difference of properties is that the incorporation of nanoparticles accelerates the forming process of the solid phase according to calorimetric analysis. The microstructure of the pastes was also found to be affected by the nanoparticles. X-ray diffraction and thermogravimetry analyses were conducted to investigate the phases and the mass changes, respectively. The experimental results show such nanoparticle optimisation would enable the development of novel forms of functional CAC materials for use at high temperature.