Integration of thermal performance of cement-based composite modified with ZrB2 nanoparticles.

The degradation of cement products at high temperature with different amounts of zirconium diboride nanoparticles (0, 0.5, 1, 3, and 5 mass%) with the nano-filling effect was investigated in the experimental program. The ZrB2 nanoparticle incorporation in the cement matrix showed a remarkable influence on the thermal protection of the composite at high temperature, whose mass loss was 6 mass% after 30 min at 1000 ℃. ZrB2 is converted to zirconia (ZrO2) and boron trioxide (B2O3) when the temperature rises and oxidative conditions are created in the environment to protect the surface from oxygen by cutting off the penetration of channels. The mechanical test results indicated that cement compressive strengths were improved with the increase of ZrB2 nanoparticle concentrations by as much as 45% for 5 mass% nanoparticles, compared to only a 4% increase with the addition of 0.5 mass% ZrB2 nanoparticles to the cement sample after 28 days. On the other hand, the samples modified with 5 mass% ZrB2 nanoparticles do not show the effect of spalling, as a result of the effect of filling the apparent pores and increasing the particle packing in the nanocomposite. [ABSTRACT FROM AUTHOR]