Refractory castables present a broad variety of placing methods, defined mainly by the desired application and by the material microstructural characteristics. Among the most important, it can be mentioned the self-flowing, which are cast without external shearing; the pumpable, conveyed through metallic pipes, and the vibrated. These classes of castables present a great range of properties as permeability, hot modulus of rupture and creep resistance. As they also present particularities in their drying behavior, it is reasonable to consider that they would also have different needs of drying additives. In order to verify this hypothesis, three castables compositions were designed by the Andreasen particles packing model: self-flowing (q = 0.21), pumpable (q = 0.26) and vibrated (q = 03.1). Polymeric fibers of several geometries were added to these compositions and their effect as drying additives were evaluated. It was found out that the fiber addition brought benefits in all the formulations, increasing their drying rates.
refractory castables; self-flowing; pumpable; vibrated; drying polymeric fibers
