Ceramics-Silikáty 53 (4) 276-282 (2009)

ALUMINOSILICATE POLYMERS - INFLUENCE OF ELEVATED TEMPERATURES, EFFLORESCENCE

F. Škvára, L. Kopecký, L. Myšková, V. Šmilauer, L. Alberovská, L. Vinšová

Sodium is obviously bonded in the aluminosilicate polymer structure as Na(H₂O)_n⁺ and not as Na⁺. The Na bond in the aluminosilicate polymer structure is weak and this fact explains the tendency of aluminosilicate polymer material to the formation of efflorescence in a humid environment. The strength values of the aluminosilicate polymer fired at temperatures in the range of 200 – 1000°C attain their maximum at 200°C; they decline gradually afterwards. The aluminosilicate polymer strength after firing is substantially higher than the residual strength of Portland cement.. The Na bond in the structure suffers a fundamental change and, starting from 600°C, the character of the Na bond is the same as that in vitreous materials. The Na leaching declines in a very significant way after firing at temperatures above 600°C and the tendency to the formation of efflorescence disappears. Aluminosilicate polymer materials exhibit excellent material properties. Nevertheless, there are also some drawbacks associated with their application. They are, first of all, an easy leaching of alkaline components and the formation of efflorescence.

Keywords: Aluminosilicate polymer, Geopolymer, Efflorescence, Temperature