| Magnesium aluminate hydrate (MAH) which is synthesized as a gelly
like material, retains its combined water over a wide range of temperature
and undergoes a series of changes with the rise of temperature.
A strong bond is maintained between periclase grains and MAH which
does not weaken during the gradual decomposition of the latter. By
analogy with the mechanism postulated in the phosphate bond, formation
of contacts between grains and the bond during hardening of the
binder may involve hydrogen bonds. The strength in the so-called
"weak zone" is maintained by generation of anion and cation vacancies
in the binder, producing a reactive non-stoichiometric spinel,
which interacts in the solid state with periclase grains. |
