What is geopolymerisation? refer http://geopolymer.org
Si / Al =2/1 for cements and concretes
Avoid making very surface hard sample that is nothing more than soluble silicates that have migrated from inside the sample after de-moulding and air curing. (will not pass a water test). Moist curing essential.
Geopolymer mineral chemical compound or mixture of compounds.
eg silico-aluminate (-Si-O-Al-O-)
created by a process of geopolymerisation.
- micro structures of geopolymers temperature dependent.
- X-ray shows amorphous at room temperature
- evolves to crystalline matrix at > 500 deg C
Geopolymerisation two synthesis routes
- alkaline medium
- acid medium
Is a process of combining many small molecules known as oligomers into covalently bonded network.
The geo-chemical synthesis are carries out through oligomers that provide the unit structures of the 3D macro molecule edifice.
Alumino-Silicate geopolymers Si:Al=2 -Si-O-Al-O-Si-O- silate-siloxo (poly(silate-siloxo))
- slow siloxo ( -Si-O-Si-O-)
- very fast oligo-silate (-Si-O-Al-O-)
How do we get silate and siloxo?
for example de-polymerisation (alkalination ) of alumino-silicate compounds
A geopolymetric micel
Chemically bonded water – a little shrinkage