Aircrete is collapsing



  • @hajjargibran After my hunch on the reason mine had deflated, I found this complicated info that seems like it could explain why :
    "There is a critical salt concentration above which the salt acts as a defoamer."
    "We report unexpectedly strong ion-specific effects of counter-ions on the stability and the rate of drainage of planar foam films from solutions of 0.5 mM sodium dodecyl sulfate (SDS) as a function of concentration of a series of inorganic salts (MCl, M = Li, Na, K). We found that the counter-ions can either stabilize the foam films (up to a critical concentration) or destabilize them beyond it."
    https://www.sciencedirect.com/science/article/pii/S0001868615001487



  • My first test batch did something similar, I lost an inch or two after an hour, before it could set up. I'm using the drexel soap. I weighed it and it was in the proper range. I thought it was my mix at first because I calculated out a 5 gallon bucket test run. But then I noticed the test foam on the ground had deflated too by same amount.
    My thought is the well water is effecting the soap, in my case, our well has a lot of rust from old well pipe removed years ago. Could also be inorganic mineral salts in the water. Glad to hear that cleaner water worked for you, I am by a river and will have to test if that water will keep the soap foam stable better than the well water. One other note, I do have a coarser stainless scrubby in my tube, not sure if that would matter?
    If anyone wants to know if their water is good, just make some test foam and let it sit around for an hour or so and see how stable the foam stays. That will be my next test before another batch.

    After my hunch on the reason mine had deflated, I found this complicated info that seems like it could explain why :
    "There is a critical salt concentration above which the salt acts as a defoamer."
    "We report unexpectedly strong ion-specific effects of counter-ions on the stability and the rate of drainage of planar foam films from solutions of 0.5 mM sodium dodecyl sulfate (SDS) as a function of concentration of a series of inorganic salts (MCl, M = Li, Na, K). We found that the counter-ions can either stabilize the foam films (up to a critical concentration) or destabilize them beyond it."
    https://www.sciencedirect.com/science/article/pii/S0001868615001487



  • Experiments are great. However, it will not be true air-crete and will cost more.



  • @HandyDan hi. Yea I was wondering if I was using the wrong mix. I am using concret mix. 10.5lb bag of quickrete. So it is a mix of cement and aggregate. Wrong stuff I guess. No wonder. I have anothe idea too. I am going to mix in crusaded scoria (lava rock) to add strength and still give good insulative value and light weight. Off to get the correct mix now :). Thanks!!



  • @chuckj sand? Portland cement has no sand. Are you using the correct cement?



  • @FoamAir I followed this recipe with my own foam that weighs 85g / ltr made with reverse osmosis water and 7th gen foam. My slurry seems thinner and runnier than yours but maybe that is the pictures not showing up well. Also, there is sand sitting in the bottom of the mix. The cement mixes but there is sand at the bottom in the slurry and after the foam is added as well. Did you have a bit of sand sitting at the bottom too?

    I have formed it and can hear my foam reacting one in the form, it is gassing off and collapsing. I will go buy a small foamer and try. I have Drexel on the way. This is all with reverse osmosis water, foam and slurry. Thoughts?



  • Water chemistry has a lot to do with concrete! Ignoring your water chemistry when mixing any concrete is an invitation for disaster. Sulfates in your water or aggregates in any portland cement mixture are really bad. Here's a link to more information on concrete and sulfates: https://www.understanding-cement.com/sulfate.html#



  • We have hard well water. If/when we begin using aircrete, we'll let you know if we experience the same.



  • @hajjargibran While Leroy gives no clue to the water composition, but even type V cement will react to high concentrations of sulfur/sulfates in the water



  • @hajjargibran Look into "structuring"- meaning- erasing the memory of the water. Dr. Emoto did research on the quality of the water. He found that all water has a memory to it, so what if structuring it would fix any issues with the water? Or just use a reverse osmosis system. Here are a couple links about structured water.

    https://bengreenfieldfitness.com/2012/08/what-is-structured-water/
    https://naturalactiontechnologies.com/structured-water/

    I personally have a small water structurer. I have found it to work fantastically for me.

    If you "NEED" me to come to Washington in August, seriously, please let me know. ;o). I'm sad there are no more spots for the workshop. :(



  • @FoamAir Thank you so much for posting this! :)


  • Administrators

    Thanks Levi, I didn't realize that water quality is so important. I guess we've been lucky with our city water supply. I wonder what it is about the water that makes a difference? I haven't found it mentioned as an issue in my research. If any one has information about the importance of water quality, please let us know. Thanks!



  • Hi All

    We finally have our Little Dragon supplying beautiful aircrete. Turns out the issue was the water quality. We were using well water which for whatever reason was reacting with the foaming agent (seventh generation soap) and causing a reaction which collapsed the bubbles.

    I went to our co-op and filled up a 5-gallon jug with their reverse osmosis water station and voila! The collapsing weak aircrete we had known from previous testing became an entirely different material altogether, thick, viscous, holding its shape. Beautiful. Just like the videos.

    I would like to mention that I had a hard time finding any information regarding water quality and its effect on aircrete. I think that this should be mentioned on the front page of the little dragon, it took us a few months of testing to overcome this obstacle and it would be nice to save others the trouble!

    Blessings,
    Levi



  • FoamAir,

    Great PDF! Thank you FoamAir for the walkthru. We are equally excited about this material and its potential for long-lasting, economical, and beautiful housing. Seems like we are using the proper ratios based on what you mentioned in the PDF which matches up with what is described through Domegaia's videos and website. I suspect the issue might be with our well water source so we are going to try again using the Seventh Generation dishsoap with Reverse Osmosis filtered water from our food co-op in the little dragon.

    Hajjar,

    Also! In addition to that test, we ordered a bottle of the Drexel Foam Concentrate from RuralKing.com as recommended on Domegaia's Foaming Agents page. We are very exctied to see how this performs as it is highly recommended on Domegaia's Foaming Agents page.

    The volumetric ratio between (Water):(Seventh Generation Soap) is 35:1 as posted on Domegaia.com.
    For the (Water):(Drexel Foam Concentrate) it seems that the ratio might be 160:1?
    What ratio would you recommend for the (Water):(Drexel Foam Concentrate) to make AirCrete?

    Thank you for your support, it is greatly appreciated.
    Levi


  • Administrators

    Thanks, that's a great intro to making AirCrete!



  • Hello Hajjar,

    AirCrete was new to me up until a few months ago. Have searched around to get better educated about this building methodology. Struggled with investing in the equipment to make some test blocks. Think others have similar struggles. Have recently moved through that struggle and wanted to share a simple way for anyone to make test blocks too. Am new at making AirCrete blocks but did have an idea for those who do not have the equipment and wanted to get started right away making sample AirCrete blocks and gain confidence in this great technique you have shared with us.

    Being able to make blocks on a budget to gain a better understanding of how AirCrete mixes up, looks, feels, durability, strength, playing with different fibers, weight of a block wet, weight of a block dry, floats, etc is easy to do once you look at this step by step PDF instruction guide:

    https://drive.google.com/open?id=0B0obq8qQMi2bczE1OHNWa0gxWGs

    Easily making these test blocks has really opened up my understanding of the incredible possibilities we can achieve with this building methodology you have shared with us!

    There is so much more we can express with this and be of assistance to helping many people around the planet build affordable shelters to live and work in that are LOW COST, ECOLOGICAL, FIREPROOF, WATERPROOF, PEST PROOF, SAFE, ELEGANT & EASE OF CONSTRUCTION as you define here:

    http://www.domegaia.com/air-crete.html

    Thanks so much to you and your team, the world is now a much better place!

    FoamAir

    0_1496723354895_AirCrete-Recipe-IMG_3264a.jpg

    0_1496723064371_Aircrete-Block-3-stack-and-stucco-small.jpg


  • Administrators

    @leroy
    Something is obviously not right with your mixture. Without being there it's hard for me to analyze. I suggest making smaller batches until you get a mixture that works.



  • @leroy said in Aircrete is collapsing:

    0_1494125704356_Screen Shot 2017-05-06 at 7.54.05 PM.png

    ARE your plans for a homebuilt "Little Dragon" still available? They were available a few months back but I don't see plans listed on the home page unless I'm looking in the wrong place; only the full blown Dragon.

    Thank you Hajjar,
    Dr. Greg Green
    San Miguel de Allende Mexico

    PS are you having another seminar in San Miguel? 'Missed the last one.



  • Hi Hajjar,

    Thank you for the feedback, I just confirmed the weight of a liter of foam on my kitchen scale to be 92 grams per liter which is in the range you mentioned. Again we are using the seventh generation soap as a foaming agent while running the little dragon at 55 psi. The aircrete is still collapsing, same as before.

    Please advise. Perhaps a new foaming agent is in order? Or perhaps the well water we are using might contain minerals that react with the soap or perhaps the concrete?

    Thank you for your help. Very excited to get our aircrete operation dialed and start building!


  • Administrators

    Make sure the foam density is 80 - 100 gr/lt (3oz/qt) then let us know how it works.


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