2016 Volume 72 Issue 4 Pages 400-410
Geopolymer using fine powder of melt-solidified slag made from municipal waste as an active filler occasionally loses rapidly fluidity after mixing. The possibility of improving the fluidity were investigated for two methods, one is to use the stored fine powder of the slag and the other is to use fine powder of the stored slag. Influence of storage method and storage period on chemical ingredients was investigated using several chemical analyses. Influence of storage method and storage period on fluidity and compressive strength of the geopolymer were also investigated.
It is revealed from the chemical analyses that hydrate and calcium carbonate are generated during storage when the slag is stored after grinding and that hydrate is generated during storage when the slag is stored before grinding. The experiments showed that the fluidity of the geopolymer mortar which use the slag powder as an active filler was improved. Compressive strength of air cured geopolymer mortar is decreased with the increase of storage period as generation amount of hydrate or calcium carbonate increases in the slag. It is confirmed that improvement of fluidity and reduction of compressive strength are caused to the change in the slag by storage. Meanwhile compressive strength of steam cured geopolymer mortar is not influenced by the change in the slag by storage. It is conceivable that this is caused to the restraint of reaction based on latent hydraulicity as condensation polymerization dominates under high temperature.
