Hawaiʻi's Technology Community

Hey Folks,


I want to make a concrete water tank for my property on the Big Island.  I wanted to try to use a geopolymer cement to do it in a green way *and* to improve resistance to acidity.  Then I got to thinking more!  It would be great to use local materials and not buy imported fly ash or kaolin clay.


Is there anyone out there who has experimented with local material?  I think ocean sand is a sodium carbonate (limestone like material).  But, I don't really consider that an abundant local material.  I'm not sure mining it from the ocean floor is a such a great idea.  Anyone know the make up of crushed black lava rock?


If you don't know what I'm talking about here is a short video trying to make pyramid stone:


The theatrics is a bit silly but the result is very cool.



Views: 423

Reply to This

Replies to This Discussion

Poly tanks are probably more environmentally friendly, unless you have materials nearby that are appropriate for the task.


Maybe, but, I absolutely don't want my drinking water siting around in plastic, even the approved stuff, for long periods of time.  It's not really about the water tank.  The point is more of an experiment to see if the geopolymer thing can be done with local minerals.  Hawaii should minimize importation of food, fuel, and building materials.  The basics of life.  Food is easy to accomplish.  People are working hard on the energy thing.  I haven't really seen people focus on building material.  If a local cement could be found that would be a big step.  I don't know, maybe someone has already done it.  But, geopolymers are starting to be big.  Check out:


They are calling it a carbon negative cement.  I think Grancrete is in the magnesium phosphate family of cements.

Brian said:

Poly tanks are probably more environmentally friendly, unless you have materials nearby that are appropriate for the task.


I just found out that there is a large deposit of volcanic ash in the Ka'u desert on the leeward side of Kilauea.  Does anyone know if this ash is Pozzolanic?  Pozzolana is what the Romans used to create cement, still standing more than 2000 years old, and it can set submerged in water.  It is a low temperature cement.  Class F fly ash is also Pozzolanic.

It's been a million years since you made this post, and I was wondering if you were successful with your project, and if you discovered a source for pozzolan on the Island? You could probably make lime from seashells. If true, I have a project uniquely suited to the Islands.

Reply to Discussion



web design, web development, localization

© 2024   Created by Daniel Leuck.   Powered by

Badges  |  Report an Issue  |  Terms of Service