Because of the many types of advanced castables on the market today and
due to the specialized development of many of these materials for specific uses, it
is harder to characterize their strength development.
The refractory manufacturer has less leeway in development of most dense conventional castables since they are viewed more or less as a commodity product (every manufacturer makes similar products) in the marketplace, and price dictates formulation constraints.
This is sometimes true for “low end” (superduty, 50% alumina) advanced
castable types in the low- and ultralow-cement classifications.
However, application and performance criteria can and do call for the development and
use of “premium” castables where the use of expensive formulations and exotic modifiers can modify physical properties and characteristics such as strength in specific temperature ranges that correspond to the anticipated service condition.