To let a placed castable set and gain strength before any heat-up, typically for at least 24 hours at roughly 15 to 30 C, kept from drying out. Below about 10 C the cement sets and gains strength slowly, and hot, windy conditions dry the surface too fast. Cure time and temperature are logged, because a poorly cured lining is prone to cracking and spalling during dry-out.
Tarp it and keep the heaters on, it has to cure 24 hours above 15 C before we fire.
Cold-weather pours need heated enclosures. Castable that freezes before it cures is scrap, even if it looks fine.
Also heard as
- curing
Related terms
Green
Describes refractory that has been formed or placed but not yet fired, dried or heated in service.
Dry-out
Controlled first heat-up of a new monolithic lining to drive off water without cracking or spalling.
Calcium aluminate cement
Hydraulic cement that binds most refractory castables, sold in grades of roughly 40 to 80 percent alumina.
Castable
Dry refractory mix of aggregate, fines and binder that is mixed with water and poured or pumped like concrete.