The geopolymer has been prepared from fly ash, metakaolin and Quartz sand, by using the liquid sodium silicate as structural template and sodium hydroxide solution as activator. The effect of glass fiber on the properties of the geopolymer has been studied.
Source: Scientific.Net
Might be the right place to post this: a GP formula similar to the one described above. This is from Elliot Hallmark at … I’ve edited the recipe a lot for readability and “humor”, so I have certainly introduced some mistakes…blame me not Elliot.
== Elliot’s GP “stuff” ==
STEP (A) … alkali silicate solution
Need:
- 500g SS40 [water glass, commercial sodium silicate formulation]
- 136g sodium hydroxide (NaOH) [lye, caustic soda, drain cleaner]
- pyrex/plastic rated for boiling water
- sealable glass jar
- crock pot
# In pyrex, add SS40, then pour in NaOH pellets.
# Gets very hot.
# Stir to yield lump-less cloudy white solution.
# Relax a few minutes.
# Transfer to glass jar with a lid.
# Cook (boil?) in crock pot several hours until solution is clear.
# Make sure crockpot doesn’t run dry!
# That’s it!
Note: Reheating and stirring will redissolve precipitate that may form if solution sits around for days.
STEP (B) … GP binder
Need:
- 600g alkali silicate solution from “A”
- 505g metakaolin (calcined kaolin)
- 128g water, you hoseheads
- nonreactive mixing vessel
# Mix really well, with mixer, 5-10 minutes.
# Let sit for 2 hours… it’s “dissolving”/”depolymerizing” or something.
STEP (C) … Mix in aggregate
Need:
- 320g silica flour (“micronized α-quartz”)
- 640g fine sand
- 640g mason’s sand
# Mix these aggregates together.
# Aggregates not key — use whatever sandy/limestoney stuff you got.
# Mix in GP binder.
# Ta-daa!
# Cures 60*F – 100*F.
# Keep moist / cover with plastic.
# Set indoors without any further action.
# Takes a few weeks to be sure it’s durable stuff.
FINAL RUNDOWN … overall ratios
1:2:2 — powder aggregate : fine aggregate : coarse aggregate
4:5 — GP binder : aggregate
2:1.5:.5:1:2:2 — sil-sol:metakaolin:water:powder:fine:coarse
Note: Metakaolin is a pozzalon. Any aluminosilicate pozzolan could
potentially work. Slag powder ~= volcanic ash ~= 750*C calcined kaolin
~= PowerPozz ~= grog from failed bisqueware.
Advice: Aluminosilicate species dictates ratio of “alkali silicate solution” to pozzolan. Kaolin != metakaolin != mullite != clay from my yard. Wikipedia those terms. Wear hand/eye/skin protection.
Head’s Up: Sure, this is an incomplete recipe… like, what are the “open”, “tack”, and “set” times of the concrete? Results of kneading/overmixing? Try adding more aggregate, vibrating, tamping? Add secret magnesium or calcium salt to speed set-time at room temps? Oh, the questions you could answer!
:r]
Hi,
AJ edited and posted this personal communication with my understanding that he would link to my blog (where he found me to contact me). Specifically, on the subject of calcium or magnesium (hydroxide, sulfate, chloride, silicate) I posted this:
permafacture.org/articles/2011/03/16/intro-to-calcium-geopolymer
pardon the dust.