The Influence of High Temperature on the Properties of Modified Cement Stone

The influence of highly dispersed tungsten-containing powders (WC, WO3, a mixture of WC, TiC) obtained as a result of recycling of carbide products on change in the structural and physico-mechanical properties of cement materials at elevated temperatures has been studied. Powders of tungsten carbide WC, tungsten oxide WO3, mixtures of tungsten and titanium carbides WC, TiC (average particle size 20–150 nm, agglomerates 300 nm – 1.5 microns) were added to the cement mortar, by partial replacement of the binder, in various concentrations (1–5 wt. %). The effect of additives on the thermal stability of cement samples was assessed by weight loss, residual compressive strength, exposed to temperatures at 300, 600 and 800оC for 2 hours. The microstructural analysis was performed using scanning electron microscopy (SEM) with an integrated energy dispersion analysis system. It was established that in the entire temperature range under consideration (20–800оC), the modified samples demonstrate a denser microstructure, have less mass loss and have increased residual compressive strength compared with the control composition. The obtained research results are of considerable value for understanding the mechanisms of influence of highly dispersed tungsten-containing particles on the characteristics of cement materials under high-temperature exposure.