[Greenbuilding] geopolymer or alkali activated cements

[Ocean Swells]

hello all.

i was wondering if anyone here has experimented with geopolymers
(coined by joseph davidovits) or the broader alkali-activated cements?
 i watched the video where davidovits tried, and seemed to succeed, in
reproducing how the egyptians may have poured synthetic limestone
using materials available to the egyptians.
(http://www.youtube.com/watch?v=4FuJAbTmaLI) the video used:

===
lime (hydrated) 8 parts
sodium carbonate (washing soda) 6 parts
kaolin clay 16 parts
water
mixed in aggregate: 450 parts loose limestone (sans clay)  (???calcium
carbonate???)
===

i'm here on the big island of hawaii.  i want to try to reproduce
something similar.  i have given myself the project of building a
concrete water tank to hold rainwater.  i want to do it without
portland to see if it can be done here with mostly local materials (i
include neighboring islands).  i am allowing myself to import hydrated
lime and washing soda.  i really don't know what i'm doing.  i don't
know about cements.  i don't know about soils, rocks, and minerals.
but i'm trying to learn.  obviously i'm going to try very small
batches to see what works.  but, i would like other, more educated
guesses.  maybe i'm taking on an impossible task?

Here are what I see as local materials:
"Red Dirt" - oxisols - iron oxide, aluminum oxide, kaolin clay (comes
from neighbor islands)
"Lava Rock" - basalt - i don't mind using processed into basalt sand.
(this is the most local)
"Ocean Sand" - *not* silicate, i think ocean sand is a calcium
carbonate, from coral, ???like limestone???  (hard to get on big
island but on ocean floor)

i was thinking that the following might be a start:

lime, washing soda, red dirt, aggregate: either ocean sand, basalt
sand, or both, plus larger basalt aggregates.

does anyone have any comments and or leads?  do i need to add more red
dirt because it is not pure kaolin?  will it work with the iron oxide?
 does anyone know of other materials on the island that may be useful?
 could basalt work without the kaolin?

i appreciate any leads,

thanks,
jason