An investigation of the characteristics of high alumina refractory castables

Refractory castables or concretes, a comparatively new member of the refractories family, are an admixture of highly aluminous cements and graded refractory aggregates, blended in predetermined proportions very much like structural concrete. The refractory aggregates must contain a large amount of fines contrary to the requirements of ordinary concrete. Unlike the Portland cements, which are mainly combinations of calcium silicates, the highly aluminous cements are predominantly calcium aluminates. They are comparatively of a refractory natures, having the hydraulic setting property combined also with high early strength. The discovery of the fact that these refractory concretes could be cast, in situ, into various structures, shapes and sizes, made a great advance in the application of such castables in a wide variety of installations in metallurgical, ceramic, gas and other industrial furnaces. Present day castables are also available in forms suitable for gun emplacement, for hot patching or for coating work. With the growing need for better and more economical refractories, the investigation into various properties of such castables, opens day-by-day, new and interesting fields of application --Chapter I. The Problem, page 1