In this work, the relationship between permeability and drying parameters was evaluated for high-alumina ultra-low cement refractory castables prepared according to different particle size distributions. Variations in the cumulative and discrete distributions were carried out by changing respectively the Andreasen's coefficient (q) and the maximum grain size (Dmax). The performance of 9 different compositions were related to particle packing parameters, such as the separation distances between the fine matrix particles (IPS) and between the coarse aggregate grains (MPT). Results revealed that the simultaneous increase in IPS and reduction in MPT were the causes of an exponential increase in the permeability constants k1 and k2 of Forchheimer's equation and also of a linear decrease in the drying time. The formulation with higher Andreasen's coefficient (q = 0,31) and the maximum grain size (Dmax) of 4,75 mm were the most permeable and with the lowest drying time.
drying; permeability; refractory castables; particle packing, size distribution
