Cement-Free Refractory Concretes for Stress-Reduced Structures

Refractory concretes have significantly increased their importance for the production of steel,
aluminium, cement, lime and the like. Thus, more and more their properties have come into focus,
so not only the installation behaviour is important, but drying-out and heating-up procedure and
performance regarding thermomechanical and thermochemical behaviour as well.
The thermochemical behaviour is mostly characterized by the chemical/mineralogical
composition, while the drying-out and heating up behaviour and the performance are also based
on microstructural param-eters. Here, cement-free concretes of the sol-gel- and geopolymerbonded
types are the latest state of the art. Their heating-up behaviour can be described as easy
to dry, spalling due to steam explosions are largely avoided by reduced contents of crystallinebonded
hydrate water. Faster heating rates save money, time, and energy and are thus
ecologically and economically advantageous. Furthermore their perfor-mance during use is
characterized by less thermomechanical tensions in the monolithic lining, resulting in an improved
performance and longer lifetime.