Vibrocasting of Silicon Carbide Based Concrete Materials

In order to reduce the water demand of silicon carbide vibratory casting masses with high-alumina cement additives, the impact of various deflocculant of different natures to silicon carbide vibratory casting masses was investigated. The deflocculants used included polycarboxylate ether-based, sodium polyacrylate, high-molecular-weight poly-N-vinylpyrrolidone, and sodium salts of polymethylene-β-naphthalenesulfoxylic acid. Multifractional compositions of silicon carbide (2-3 mm, 1-2 mm, 0,5-1 mm, 0,2-0,5 mm, 0,063-0,12 mm fractions) with high-alumina cement and silicon additives, as well as with deflocculants, were studied. The firing of the materials was conducted in an oxygen atmosphere at temperatures between 1000 and 1400˚С. The adverse effect was demonstrated for deflocculant based on sodium polyacrylate and high-molecular-weight poly-N-vinylpyrrolidone, as the usage of these additives increases the water demand of the mix. A smaller amount of water used for the mass production allows the processing of more dense materials with reduced open and closed porosity. Using deflocculants, the moisture content of the material is reduced to 6.5%.