Permeability is an important tool to evaluate and optimize the drying schedules and the durability of refractory castables. In this paper, permeability constants, obtained by Forchheimer's equation, were correlated with flexural strength of self-flow cement-free refractory castables containing Alphabond as hydratable phase. Samples were submitted to heat treatment up to 1650 ºC in order to evaluate the influence of microstructural changes on permeability and mechanical strength. Results previously obtained for ultra-low high-alumina castables, with and without the addition of microsilica were used for analysis and comparison of properties.
permeability; refractory castables; drying; mechanical strength
