Pozzolan concrete?

[mazoli]

Hi there,
Recently I did a lot of reading regarding pozzolanic reactions and pozzolan concrete. Just wondering if there is anybody who successfully made artificial rock using fly ash and lime (and/or any other additives). Found out that some old roman pozzolanic concrete that are underwater in the sea are still standing today. Any recipee or idea regarding this could be helpful. To create artificial "live" rock, so far I only found recipees using portland cement.
Cheers,
Zoli

 

[cowboy]

I dont know if this will help you but it gives the basic chemical makeup of the different types of pozz along with the different classes of cement, I also have a mill run cert on both cement and pozz that I'm currently looking for.

 

[mazoli]

Thank you for the info and attachment. I also found several research papers regarding this topic, but would be interested if anyone has a hands on experience (recipee that works) creating artificial rock using this approach. It is most likely a technological question: how much ingredients and in which order to mix to get a strong enough mixture that also has some porosity.

 

[cowboy]

Designing cement is definitely something I can help you with the only thing is the permeability of the cement mixture.
A good blend to try
50cem/50pozz 6%bentonite
The bentonite will help with your particul suspension, and keep your slurry homogenous.
As the cement starts to get the consistency honey u can pump CO2 through the cement and it will help create your porosity.
This blend can be mixed at 12.4 lbs/gal.
If you would like I can give you the true weights of that.

 

[mazoli]

Hi, I'm not too familiar with terms, so please be patient with me :)
So bentonite is a clay (montmorillonite), right? This is what I found on the net. Not sure where can I buy it, but will look it up.
Not sure what you mean by 50cem/50pozz.

12.4 lbs/gal means that for 12.4 lbs of solid powder I should add 1 gallon water? thanks

 

[cowboy]

Sorry I get a little carried away sometimes. But yes bentonite is essentially clay check your sheet rock muds I believe that's what they are made of. 50% cement and 50% pozz 6% by weight of cement bentonite.
So water is 8.34lbs/gal what your going to do is mix the cement to 12.4lbs/gal I will calculate that for you shortly and get you everything in grams.

 

[cowboy]

12.4 lbs/gal 50/50 Cement
Cement 407.12 g
Pozz 320.50 g
Bentonite 43.66 g
Water 714.57 g
this cement will run about 700-900 PSI in 72hrs at 91Degf. it will continue to cure for awhile there after approx 45 days.
this should give you a 1000 ml sample for testing purpose.
you can also add 2% by weight of cement CACL2 to help with the early set of the cement insure that the concentration is 94-99% or else it will slightly slow the set of the cement

 

[mazoli]

Sorry, I have more questions.
What is the Cement 407.12 g (is this white portland cement?) and what is
Pozz 320.50 g?

 

[cowboy]

It's no problem and it's going to be Portland cement weighed at 407.12 grams and pozz is just short for pozzolan I calculated the weight from raw pozzolan no extra additives

 

[mazoli]

Thanks. Mixing the powders together then add the water or is there any special order to mix them?

 

[cowboy]

Just make sure the powders are well blended before mixing with water. And mix vigorously until the liquid is homogenous

 

[mazoli]

Interesting article about geopolimers: http://www.instructables.com/id/Roman-Geopolymer-Concrete-Recipe/?ALLSTEPS
This is what I was looking for, creating rock/concrete without PC.

 

[cowboy]

Ok reading the article it resembles a class c well cement mixed with a type C pozzolan. Now in Hungary if you have access to the oil field products you can use class A or class G as a substitute for class C.