Thanks! We wanted to share what were learning as we were figuring it out. If you keep watching our next videos, you will see that we started having issues. We think it was likely from the icy cold well water and colder outdoor temperatures. Drexel does not work well if it's too cold. A possible solution is adding some warm water to the soap solution. Best wishes! 😊
Terrific summary Sir. Your methods are terrific and database is well organized. Enjoyed the coming attractions at the end. The lizards were quite startling. Wishing you both another great week. Cheers
Thanks so much! Yes, the small lizards really love the garden wall. 😅 I figured if I quickly knocked the board off there would be some lizards under there, and I wasn't disappointed. 😊
awesome work, we appreciate the information! Ive been toying with the idea of making aircrete structural insulated panels, seems like it could be pretty interesting for diy builds.
We are really impressed with aircrete. It is definitely a bit tricky to get it right, but now that we mostly have the hang of it, it's pretty fun to make, and I think it will make a great house, and many other great projects. 😊
I would recommend basalt rebar and mesh materials a dual mixer with up mixing action from northern tools. me thinks air Crete harry has links. polystyrene balls. Broken up polystyrene material inverted electric motor blended with a 50 gallon drum a side shute with 1\2" mesh low down n a duct to a collecting bag with a cloth top to llet air out also Drexel 1-25 or some such (farm supply houses ) foam holds really well designed to hold bubbles while farmer sprays a field and marks where he has been. U can use some admixture that reduces water and makes mix weter. also I am looking to see what a pvc glue that sets fast would do. Something I think a concrete bonder or admix Adding basalt rebar. Mesh. fiber. May be better n longer lasting. having steel / rebar close to the location of where bending is going to happen most concrete products are very week in tension but are good in compression the problem with steel is that when it starts to rust it expands breaks the concrete away and the rusted metal looses strength as well. Its possible that the basalt rebar will not suffer from that but it is not as strong as steel in sudden impact situations. It gets hit with a fast kinetic impact
Thank you for your efforts . I suggest you to add three ingredients to the mixture *super plasticizer - Eter polycarboxylate (300 ml per 100 kg cement) ** 12 mm polypropylene fibers (50 grams PP per 100 kg cement)*** microsilica (10kg ms/100kg C )or fly ash (I don't know how much because it is not produced in our country)
I wonder if using the strong standard mix for the roof is a good idea... I would want the heavy wire in there for fall protection in the event of catastrophic failure.... a further test of side by side, With/Without wire using the same barrel mix, not one then another so you have the exact same mix/mixing solution in the mould
Very impressive R+D, thanks for sharing that! Boric acid would explain the soft samples. But those won't get termites! An insulating extender is fly ash, which is small hollow spheres, if your local ready mix plant has it (in bulk), then a lot cheaper than bagged sand, and very nice to work with. It helps flow into forms, but the carbon content (from burning coal) may reduce foaming? edit: But if your foam-only mix is strong enough, you can't beat the price of air!
Thanks! Fortunately regular aircrete doesn't get termites either. Yes, an attic filled with paper, would need something in it to make it less flammable and resistant to termites. So an untreated paper product would probably perform differently. We tried pretty hard to find a place to get fly ash, it sounds like good stuff. No one anywhere around here seem to sell it. They use it in their mixes but do not sell it. One guy said it's so fine, that it's practically a liquid and they don't have any way to load it for distribution.
Check out Kirsten Dirksen's most recent vid of the cork sided home. Turns out, it is built with aircrete blocks w/ fine sand & limestone? They didn't seem to know what to call it? A great vid & home design altogether!
Wow, lots of testing to determine that aircrete shouldn't be used as a header. It's great that you understand your limitations in construction. BTW, classes for proper aircrete methods are not so expensive in relation to the cost of traditional construction materials.
Our tests were to practice making aircrete and to compare the different methods of making it, to determine it's characters, process of making, and which recipe we wanted to use. I surmise that not many who take classes decide to use aircrete either. We can't find anyone actually living in an aircrete house, and certainly not many people. Aircrete shrinks, and if not made perfectly, it is brittle, so I wouldn't recommend building a house out of traditional homemade aircrete. We did a cost comparison, and aircrete isn't cheap, but now that the prices of lumber have doubled again, it may be some less than traditional construction.
Thanks for honestly sharing also things that doesn't work !! : ) The inbeatable way of building a cheap to build, ecological and cheap erergy consumptions worth, is... Load bearing strawbale house ! I know peoples doing their "straw yurt" for arond 5000€ / 6m diameter ones (cost without land, without networks and inside stuffs..)
Yes, we are so glad we didn't try to build with aircrete. Straw bale is definitely a much better option than aircrete! Not that it can't be done here, but we decided against straw bale because of the torrential monsoon rain storms we get in the summer. 🌞🏜️
Thanks a lot for the testing!! Please show us as much as you can when you build your house too, this is very valuable information for us watchers who are thinking about doing similar builds.
Very cool destructive testing. I used to do geotechnical testing for a consulting firm in phoenix a few years ago. Used to do shear testing for mining rock cores for shear strength analysis.
@@RedandAprilOff-Grid oh that’s a bummer! I wonder if the extreme temperature swings of the desert might factor into that as well? I know we had an issue with mortar on a rock wall we had in Phoenix that kept cracking from the hot/cold variances. Either way cool concept!
I should mention now, I’ve discovered your latter videos that concluded not to use the material. I very much appreciate your research and conclusions. I realize there are many variables and this is a complex matter. It appears you have enough resources to have options, which is great. For me; I’ve seen others do this adequately (mostly in tropical climates which may be a factor) We will be serving in a third world country, with fewer options, and less expensive labor cost. So, we are willing to use the material. Also, the dome form is also acceptable to us. I wish you all the best.
My best guess is that the colder temperatures were the main issue. We tried to set the Drexel out in the sun to warm, but it was still pretty cold. With each new batch, we thought we had it figured out, but they just kept turning out worse. We noticed the foam was becoming more dense and he tried to adjust for it. The foam was under 100 grams per quart, so it should have been ok. We would have had to wait until spring to do any further testing, so we don't know for sure. Not much is known about the long term durability of aircrete, so it was starting to seem pretty risky to build a house with it. If we were able to make good and consistent batches, we would have went with it, but our later batches were really brittle. Here is an impressive dome that was built on an island. The guy said it started cracking and couldn't be repaired because the aircrete is too powdery. th-cam.com/video/UJmAF0SuvkA/w-d-xo.html It is a big dome and the bricks were pretty thin. He also said he had a lot of issues with getting consistent batches. Best wishes! Aircrete is pretty finicky stuff, but with more time, we might have been able to figure it out. Best wishes!
@@RedandAprilOff-Grid Follow up on Micronesia Dome. I’m thinking 6 to 8” minimum, with “abaca cloth” (Philippine Hemp) interior and exterior. Honestly, building with standard hollow blocks and metal trusses (with extra tie downs) would probably suffice and be more practical. I’ve seen homes in our range built for about $20 to 35k US minus the land and appliances, extra water tower or solar. We want to provide homes for the poor that can withstand typhoons. It’s a shame we couldn’t utilize the air forms and blown cement, as that would appear to be a perfect solution. All the best, Kevin
We could only do the break test one time, but did the drop test on both sides. We later tested the bricks dry, and did the break test with the remaining long bricks that were still intact.
I have worked at a pre cast place and I am not 100% sure on this as we don't mix like you do , however if you mix at a slower speed that might make a difference to strength and consistency, even at a professional place it is still an unknown art, I found for our small form Items that my team made the best concrete was slowly mixed over an extended time, 15 min plus 15 to 20. Anyway to be brief try slowing your mixing speed
I absolutely love all this testing data! Thanks so much for sharing all your hard work with us. What attracts people to DIY aircrete is the idea of an insulating structural material; but nobody knows how strong it is, or what the R value is! You've made a huge contribution to the first knowledge gap and I think your subscriber count is going to explode over the course of this house build for putting out awesome content like this. The issue of insulation value is still completely unknown though. Everybody blindly parrots "an R value of 2" because that's what autoclaved aircrete is. Nobody is capable of DIY autoclaved aircrete, so it's not a relevant number! Depending on the DIY aircrete mix, it probably ranges between an R value of 1.25 and an R value of 3.5. It's actually possible to get a relatively simple measurement of R value though (or perhaps more accurately "comparative thermal conductivity". Although you're probably sick to death of testing, Mathias Wandel put out a video of a simple methodology for measuring R-value with a $40 infrared thermometer. He put out a little spreadsheet that handles the math. He did it for a wall in his home, but it wouldn't be hard to adapt to a small aircrete box with a $10 electric coffee warmer inside. Just a thought. The video title is "Measuring house wall R-values using an infared thermometer". Here is a link to his video: th-cam.com/video/6FGfn27Qj54/w-d-xo.html
Thanks so much! The R value is something that would be very interesting to know, and to see how it changes with heavier and lighter mixes. We haven't got around to researching how to do it all. We'll check out the video. Thanks! 😊
We just watched the video, and Red wants to try it! We already have a tiny heater with a thermostat, and an infrared thermometer. He just ordered a temperature probe to make sure the inside of the box stays a consistent temperature. Thanks for the information! 😊
@@RedandAprilOff-Grid Very cool! I'm excited to see the results. I recently saw an interesting R value approximation/test for aircrete done by Stephen Williams. His channel is all about EPS foam aircrete and he's got some fascinating content. His methodology was to construct 12"x12" boxes with 2" thick walls, and then he put a frozen bottle of water inside. I think he measured the time it took to melt the ice. He used a identically constructed, pure EPS styrofoam box as a benchmark. I'm not really sure how he accounts for thermal mass differences between materials though. For example, if a pure concrete box was left outside and frozen, it might seem to outperform a lightweight aircrete box in keeping a frozen bottle cold. Another consideration is ensuring that each box is comparably well-sealed to minimize differences owing to air leaks. Still, it's a very simple and useful way to compare your sample's performance against a known benchmark (styrofoam) and other samples. Stephen seems like a really sharp guy, and he's clearly passionate about aircrete. He would be a really great person for you guys to chat with about R-value, and your plans generally. The title of video is "Aircrete on Steroids, Aircrete Styrofoam. Build Cheap". The relevant portion starts a 9:15 in the vid. Here is a link: th-cam.com/video/27v7Oq-q9xs/w-d-xo.html
He has lots of interesting ideas, but I'm not sure where he's going with it. I have a hard time believing that a 5 inch styrofoam wall that can easily be pushed over, will support a 2 story structure with just the addition of fabric and a coat of plaster. If he put one of his blocks in a fire pit, it would melt and burn. He moved the torch away every time it started to melt or catch fire. Aircrete definitely does not burn, melt, or catch fire. His way of building looks very time consuming, you would need a lot of space, and time, to gather and shred that much styrofoam. We can make 4 full batches of aircrete in less than 2 hours including cleanup, and it makes around 20 cubic feet of usable material. Measuring R value in that way would give some comparison information, but I would wonder how accurate it is.
@@RedandAprilOff-Grid We're on the same page for pretty much all of the above. I see EPS-crete as an intriguing insulation material, but I'm very leery of it as a structural material. I definitely wouldn't build a house out of it. I only mentioned the video because it was an interesting first stab at comparing thermal conductivity of different aircrete mixes by timing how long it takes for them to melt. His test fails to account for the effect of different thermal masses and air leakages among samples though. I'm not clever enough to think of a better idea, but sometimes it helps to see what other people have done in the past, try to identify weakness and improve on them. :)
have you seen the Styrofoam-crete some people are experimenting with? seems a bit less strength but greater r value and lower weight may not be appropriate in your application. just curious on your thoughts
Yes we have. It is an interesting idea, but we really aren't interested in trying to gather, shred, and store, the tremendous amount of styrofoam we would need to build our house. Assuming we could find styrofoam for free, it would still require a lot of trips into town, which aren't free. The equipment needed, the mess, and the effort required to pack the mixture into the forms is another issue, and there plenty of other issues I haven't mentioned. The foaming solution used to make aircrete insulative takes up much less space and is a much faster and easier process. Also aircrete absolutely won't burn or melt no matter how long you hold a torch to it. Making aircrete is a challenge, and there are many things that can go wrong. We think we may have finally made all of the possible mistakes, and hopefully we have it figured out. We'll keep sharing as we keep learning.
Our latest videos, show some of our more recent not so great batches. It could be because the Drexel and well water were too cold? Aircrete is tricky stuff, and we don't have time to keep experimenting with it, so we have moved on to using other materials. Best wishes on your projects!
what type of portland cement were you using? Some cements are formulated to cure faster although more expensive it may help with the sinking problem and so allow a sand cement mix.
You have to keep in mind aircrete is supposed to be week and full of air... the straight comes from the reinforcement fabric the shape and the monolithic outer layer.
Yes, these samples were only cured for 7 days, so they didn't have their full strength yet. The testing was so we could practice making aircrete, make sure it's a material we are comfortable in using to build our house, and to compare the different mixes to each other.
@@RedandAprilOff-Grid of course, and your bricks look good even some of the failures. I did a lot of testing and foam machine building... I found issues throughout, when you think you got everything right and start mass production.... it still fails randomly.
There definitely seem to be a lot of different things that can go wrong. We have had some issues with our last few batches not turning out quite as well. After testing all of the other variables, we think it is from not mixing the Drexel around in the jug before every use. The last 1/3 of the bottle doesn't seem to be working as well, and it is darker in color. We'll know more after we make some more batches using a new jug.
@@RedandAprilOff-Grid I've seen that too first couple batches are really good... but then most bad... then you check everything but can't figure it out. Try adding a little glisten... it tends to settle at the top and you use it first.
We thought about it, but we already know that a brick that size of would not dent or crack, and it would take a tremendous amount of weight to break the long brick.
Aircrete's fun compared to normal concrete, at least for walls. But they've been making aerated bricks for a long time, and it's got a better R value than any aircrete batch. And then, styrofoam is a much better insulation. Did you try sawdust?
We prefer working with concrete. It doesn't leak out of the forms, and it always turns out good and strong. We didn't try sawdust because we wanted to use materials that were easily available to us, and that we could get enough of to build a whole house.
The batches are all different, some had fine sand, paper, fibers and different amounts of foam. As the temperatures started getting cooler, the samples started turning out worse.
@@kalervomakinen2076 As hot as we get, I don't think summer would have worked either. Aircrete would have been a nightmare in so many ways. Trying to make the forms watertight, keeping the walls wet until they cure, dealing with failed batches and cracks and powdering. Aircrete is not inexpensive, long lasting, or easy to work with. We are so glad we didn't try to use it to build our house. In my opinion, there are much better options out there.
Yeah but...did you create all the samples on the same day? If one sample per day at the same time, then you should test that sample seven days out from time of pour at the same time to be accurate in the seven day cure time, right? Thanks for sharing
It would be nice to know, but we haven't looked into how hard it would be to figure it out. I'm assuming it's not easy. I'm sure our stronger mixes are not as insulative but we aren't too worried about the exact number. I think with our 8.5 inch walls, south facing windows with the proper overhang for the summer, and the amount of thermal mass, the house will require very little heating or cooling. It will be interesting to see how it does.
I was wandering what kind of steel wool you used, and how many?... last I had corse and fine stainless steel wool alternating. I don't think more than 8 pads.
Here is the video of Red putting together the foam generator. The kit had a large coarse piece of steel scrubber pad stretched out then stuffed in the wand. th-cam.com/video/n_zsgV4t1fY/w-d-xo.html
@@RedandAprilOff-Gridwhat, I didn't have good results with corce steel wool, and only one pad... it makes big bubbles if you're near the coast or use Amazon fine stainless steel makes smaller bubbles, look for boating supply. Had good results first use with standard steel wool pads. After they start to rust they are no good... same with brass wool, though brass lasted at least 3x longer... had a suspension I was building too much pressure behind the stack of pads...
Really like to see a glass or basalt fiber mix test. Maybe a lite mix and a heavier mix like you did the cellulose fiber. I've thought you don't want long fibers because they then to knot and clump up but short fibers (like 1/4") do quite well for crack resistance in conventional concrete too.
We have seriously considered it, but it would add a lot of cost to the build so have decided against it. Red called around but can't find anyone local that sells it for a reasonable price, and it's not cheap online either.
@@RedandAprilOff-Grid considering the total investment we make in our houses and the supposed added crack resistance down through the years I think the cost is actually comparatively cheap. We're not talking thousands of pounds of fiber, I believe I've read it's about 10 oz of fiber per cubic yard (although that might have been the plastic fiber I'm confusing it with, still it's probably only 30 or so pounds of fiber. I've bought chopped fiberglass for composite mold making and paid less than $8 a pound.
We were looking into 1/2 inch and can't find it for less than $15 a pound. One place was $10 but they were charging $26 shipping! We also need the type that is alkaline resistant to go in concrete. One local place has some kind of fiberglass fibers, but the lady didn't know anything about it, she said it's in a very small bag for $6, but maybe we'll go check it out next time we are in town. Tomorrow we are planning to make a batch with nylon fibers, we have some we can use and if works well, I think we could figure out a way to get it pretty cheap. With our design, the aircrete does not need to be structural, and right now, we are planning to use the wire mesh and rebar on the inside and, it's expensive, but probably fiberglass netting on the outside. We'll have some time to think about it.
Update: We found a more reasonable place to order the fibers and will be tested basalt fibers and fiberglass fibers! It will take some time, but hopefully within the next month, we'll have those results. If the fibers work well, we shouldn't need to add the wire mesh, just rebar to connect it to the frame. We are also looking into a way to test the R value, that would be awesome to know. Thanks for your persistence!
We haven't, but it would be interesting to see what it would do. We considered adding straw to a batch of aircrete, but couldn't think of a good way evenly chop it. We figured it would be too much trouble. We also aren't sure long term how it would hold up in the cement.
We calculated the cost in another video. We learned that building with aircrete is not less expensive, and it's a lot more work. Our stick built house with a layer of exterior insulation is way more efficient, and was much easier to build. Aircrete is very temperature sensitive and finicky to make. Similar materials like autoclave only have a 20 to 30 year lifespan.
We wondered how that would work too. The dry testing on the paper fiber samples was pretty interesting, the results from that is in our most recent video.
I hear mortar mixers probably work for aircrete, but I think a cement mixer is not ideal. Mortar mixers are quite expensive. Mixing is way more tricky than we were expecting, but I think we about got it figured out. The batches are not bad at all to make, everything is so much lighter than regular concrete. We did 4 batches in less than 2 hours including clean up. So once we start pouring the house, it should go pretty fast, and it's not too strenuous with 2 people.
@@RedandAprilOff-Grid $140 for 4 oz, surface area of 1000 sq m, I may get some and test a batch, after Christmas. It seems it would increase surface tension by increasing the area which may help enhance the mechanical properties.
We were planning to build a metal structure and use aircrete for the insulation and put fiberglass mesh on the inside and outside, then stucco it, but we decided making our own aircrete wasn't going to work well in our situation. 🌞🏜️
Red you have some really good aircrete! It is frustrating when it becomes inconsistent. I'm switching over to styrofoam with some foamed binder and this is part of the reason why. I'm also testing tons of admixtures for additional binders. I'm trying to formulate something similar to the SIXBAU blocks - th-cam.com/video/r2vcHKzDYnc/w-d-xo.html . I think I am getting close, but now trying to find cheaper ingredients. Cement testing takes so long when you have to wait days between test. You are getting a good cure and I think that is a problem other have is they don't wet cure their blocks and they become really weak. Are you thinking of doing a mono-pour or blocks? I personally would not feel comfortable with aircrete other then infill or dome shape, but that does not mean it can be done. If you can put up a light roof and get the shear strentgh needed for your structures weight you can make it work. I've done shear wall retrofitting, anything is possible. Problem is, there are no numbers for shear strength of textile reinforced aircrete walls so you have to get the outside/inside skin done well. DO NOT USE THE POLYESTER ROOFING FABRIC. You could also do an infill setup with steel to the roof or design a shear wall system using inside walls that attach to the roof then to the outside aircrete walls. You would need a correct size footing for the inside shear wall to keep it down tight, slightest uplift and shears walls fail to work.
It has been a challenge, but we feel like we are getting a pretty good handle on what not to do, and are getting the mixing figured out. Filling in the garden wall has been great practice and something we want done anyway. We are planning to do poured walls with support every 8 feet. We'll be sharing more details on that soon. Best wishes on your projects, that sounds cool. I shared your comment with Red, but I answer the comments and questions. Thanks for the input and best wishes on your projects! - April 😊
We considered building with rammed earth or poured concrete, but we wanted good insulation. In the end, we are very glad we didn't try to build with aircrete, our house turned out great. 🏡🏜️
I think that you should keep the aircrete - to outside projects & patio roof trusses. I don't think that trusting it for you House walls and foundations is a good idea.
Patio roof trusses are an interesting use for aircrete. My Little Homestead made it work, but it didn't look easy, and I'm pretty sure it wasn't cheap. Our foundation is concrete, we were considering trying to use a more dense aircrete for the floor.
I just watched Aircrete Harry's vid, talking about his thickening solution. Is that the same/ similiar to the glycol do u know? Also, how much glycol are you adding per batch? Ok, watching ur vid now 🤗
No, the glycerin is just something we decided to add just in case our Drexel wasn't mixed well. The tiny house aircrete guy was saying the glycerin can come to the top of the Drexel making your first batches turn out better than the later batches. Glycerin is pretty cheap, so we are adding a little as an extra insurance. From what I understand, Harry's thickening agent is only available for sale commercially or in large amounts, so he bought some and selling it in one gallon jugs. We have some, but the trial batch we used it in was probably under mixed and it leaked out some which causes big air pockets. Our most recent batches seem to be showing that under mixing produces a much worse product than over mixing. You have made a lot of aircrete! The thickness and texture of your batches look really good. Best wishes with your house!😊
@@RedandAprilOff-Grid I mix the Portland& water in a cement mixer first, and then try to limit the mixing duration in the barrel w/ the foam w/ the hand mixer to a minimum- just enough to mix the foam +slurry consistently. Originally, I was thinking low water would result in a stronger result, but your vids have dispelled that illusion!
5 gallons of water is somewhat of a low water mix already. Many use 6 or even 7 gallons of water, which does seem to produce a weaker mix. 4 should hypothetically work, but it hard to mix and hard to whip the foam into.
@@RedandAprilOff-Grid and you can have particals settings with no where for the water to go. The problem quickly cascades as more bubbles pop, more separation, more air out.. I make sure to put holes in my plastic now. I AM NOW LOOKING INTO HEATING THE MOLD TO DECREASE SET TIME
True, that could make a difference. We got the sand off out of our seasonal pond and it was sifted through a number 40 screen. He held it up high so as much dirt would blow off as possible, but I'm sure it still had some dirt. This was also one of our moussey mixes, so that probably effected the strength some too.
If you have not seen this guy's video on aircrete wall issues, more relevant (more shrinkage) if you pour-in-place: th-cam.com/video/TCAIZiQu3W4/w-d-xo.html
concrete don't hold tensile force, so stop doing it. It is better to test the sample with different bar sizes and see how much tensile load it can hod up. Thank you
Yes, we were planning to add multiple reinforcements. We were just testing the aircrete on its own as well as our ability to make good and consistent batches.
A few comments: What features of aircrete are you persuing? You talk about insulation but do not test that parameter. Your DOE results are hard to interpret based on the test parameters. The choice of test method is curious. Concrete is not good in tention. It works in compression. But it is a test parameter. Impact resistance did not make sence until you mentioned you were going to use it for a flooring material. Brief search show an optimum aircrete R-value of 3.7 per inch, so you might get an ~R30 in an 8 inch wall of very cured & sealed material. But the parameter is not tested. Reviewing your videos because I must have missed the objective.
We would love to test insulation value and compression but those are hard to measure and difficult to test without the proper equipment. We know enough about aircrete to know it is reasonably insulative, and possibly very insulative. It can be reasonably strong, but more often people are getting batches that are weak and crumbly. We have also seen a few successful builds and know it can be a great material with many benefits. We are testing to see if we can make good, consistent batches that we feel will be suitable to build our house. Also to see which recipes yield the best results in the areas we are able to test. The aircrete will not be load bearing, so that doesn't matter too much. We wanted a material that is insulative but also has a lot of thermal mass. The issue with straight concrete and blocks is they have almost no insulation value. We strongly considered, rammed earth, but again it has very little insulative value and is very labor intensive. We expect this to be a fairly fast and cost effective way to build a house. I can't guarantee that it will work, but we are pretty excited about it and think it will make a pretty awesome house, but only time will tell.
Yes we have th-cam.com/video/Ogf2hIboyFI/w-d-xo.html but we thought aircrete was worth a try, it is more insulative and faster to build than rammed earth. We got a garden wall out if it anyway, and while we were making aircrete the price if lumber has gone down. 😏🏠
The amount of information contained in your videos ... and your testing methods ... are incredible. THANK YOU!
Thanks! We wanted to share what were learning as we were figuring it out. If you keep watching our next videos, you will see that we started having issues. We think it was likely from the icy cold well water and colder outdoor temperatures. Drexel does not work well if it's too cold. A possible solution is adding some warm water to the soap solution. Best wishes! 😊
but he left out the most important,,, weight per cubic ft and cost per cubic ft
Try with the rice straws and banana fiber both are given best results for us
😎👍
Terrific summary Sir. Your methods are terrific and database is well organized. Enjoyed the coming attractions at the end. The lizards were quite startling. Wishing you both another great week. Cheers
Thanks so much! Yes, the small lizards really love the garden wall. 😅 I figured if I quickly knocked the board off there would be some lizards under there, and I wasn't disappointed. 😊
awesome work, we appreciate the information!
Ive been toying with the idea of making aircrete structural insulated panels, seems like it could be pretty interesting for diy builds.
We are really impressed with aircrete. It is definitely a bit tricky to get it right, but now that we mostly have the hang of it, it's pretty fun to make, and I think it will make a great house, and many other great projects. 😊
I would recommend basalt rebar and mesh materials a dual mixer with up mixing action from northern tools. me thinks air Crete harry has links. polystyrene balls. Broken up polystyrene material inverted electric motor blended with a 50 gallon drum a side shute with 1\2" mesh low down n a duct to a collecting bag with a cloth top to llet air out
also Drexel 1-25 or some such (farm supply houses ) foam holds really well designed to hold bubbles while farmer sprays a field and marks where he has been.
U can use some admixture that reduces water and makes mix weter.
also I am looking to see what a pvc glue that sets fast would do. Something I think a concrete bonder or admix
Adding basalt rebar. Mesh. fiber. May be better n longer lasting.
having steel / rebar close to the location of where bending is going to happen most concrete products are very week in tension but are good in compression the problem with steel is that when it starts to rust it expands breaks the concrete away and the rusted metal looses strength as well.
Its possible that the basalt rebar will not suffer from that but it is not as strong as steel in sudden impact situations. It gets hit with a fast kinetic impact
Thank you for your efforts . I suggest you to add three ingredients to the mixture *super plasticizer - Eter polycarboxylate (300 ml per 100 kg cement) ** 12 mm polypropylene fibers (50 grams PP per 100 kg cement)*** microsilica (10kg ms/100kg C )or fly ash (I don't know how much because it is not produced in our country)
Thanks, we are done with aircrete, but maybe someone else will try it. We tried to get fly ash, but couldn't find anyone that sells it. 🌞
I wonder if using the strong standard mix for the roof is a good idea... I would want the heavy wire in there for fall protection in the event of catastrophic failure....
a further test of side by side, With/Without wire using the same barrel mix, not one then another so you have the exact same mix/mixing solution in the mould
Very impressive R+D, thanks for sharing that! Boric acid would explain the soft samples. But those won't get termites! An insulating extender is fly ash, which is small hollow spheres, if your local ready mix plant has it (in bulk), then a lot cheaper than bagged sand, and very nice to work with. It helps flow into forms, but the carbon content (from burning coal) may reduce foaming? edit: But if your foam-only mix is strong enough, you can't beat the price of air!
Thanks! Fortunately regular aircrete doesn't get termites either. Yes, an attic filled with paper, would need something in it to make it less flammable and resistant to termites. So an untreated paper product would probably perform differently.
We tried pretty hard to find a place to get fly ash, it sounds like good stuff. No one anywhere around here seem to sell it. They use it in their mixes but do not sell it. One guy said it's so fine, that it's practically a liquid and they don't have any way to load it for distribution.
Check out Kirsten Dirksen's most recent vid of the cork sided home. Turns out, it is built with aircrete blocks w/ fine sand & limestone? They didn't seem to know what to call it? A great vid & home design altogether!
@@ogfoundation Very cool video. I think those may be Aircrete EU, who just opened their biggest plant in Mexico to serve US markets.
Wow, lots of testing to determine that aircrete shouldn't be used as a header. It's great that you understand your limitations in construction. BTW, classes for proper aircrete methods are not so expensive in relation to the cost of traditional construction materials.
Our tests were to practice making aircrete and to compare the different methods of making it, to determine it's characters, process of making, and which recipe we wanted to use. I surmise that not many who take classes decide to use aircrete either. We can't find anyone actually living in an aircrete house, and certainly not many people. Aircrete shrinks, and if not made perfectly, it is brittle, so I wouldn't recommend building a house out of traditional homemade aircrete. We did a cost comparison, and aircrete isn't cheap, but now that the prices of lumber have doubled again, it may be some less than traditional construction.
Thanks for honestly sharing also things that doesn't work !! : )
The inbeatable way of building a cheap to build, ecological and cheap erergy consumptions worth, is... Load bearing strawbale house !
I know peoples doing their "straw yurt" for arond 5000€ / 6m diameter ones (cost without land, without networks and inside stuffs..)
Yes, we are so glad we didn't try to build with aircrete. Straw bale is definitely a much better option than aircrete! Not that it can't be done here, but we decided against straw bale because of the torrential monsoon rain storms we get in the summer. 🌞🏜️
Thanks a lot for the testing!! Please show us as much as you can when you build your house too, this is very valuable information for us watchers who are thinking about doing similar builds.
Thanks for watching! We are continuing to learn more all the time. 😊
🎉
Very cool destructive testing. I used to do geotechnical testing for a consulting firm in phoenix a few years ago. Used to do shear testing for mining rock cores for shear strength analysis.
Thanks! 😎 We are so glad we didn't build with aircrete! The aircrete garden wall we made is really cracking and shrinking.
@@RedandAprilOff-Grid oh that’s a bummer! I wonder if the extreme temperature swings of the desert might factor into that as well? I know we had an issue with mortar on a rock wall we had in Phoenix that kept cracking from the hot/cold variances. Either way cool concept!
I should mention now, I’ve discovered your latter videos that concluded not to use the material. I very much appreciate your research and conclusions. I realize there are many variables and this is a complex matter. It appears you have enough resources to have options, which is great.
For me; I’ve seen others do this adequately (mostly in tropical climates which may be a factor) We will be serving in a third world country, with fewer options, and less expensive labor cost. So, we are willing to use the material. Also, the dome form is also acceptable to us.
I wish you all the best.
My best guess is that the colder temperatures were the main issue. We tried to set the Drexel out in the sun to warm, but it was still pretty cold. With each new batch, we thought we had it figured out, but they just kept turning out worse. We noticed the foam was becoming more dense and he tried to adjust for it. The foam was under 100 grams per quart, so it should have been ok. We would have had to wait until spring to do any further testing, so we don't know for sure.
Not much is known about the long term durability of aircrete, so it was starting to seem pretty risky to build a house with it. If we were able to make good and consistent batches, we would have went with it, but our later batches were really brittle.
Here is an impressive dome that was built on an island. The guy said it started cracking and couldn't be repaired because the aircrete is too powdery. th-cam.com/video/UJmAF0SuvkA/w-d-xo.html
It is a big dome and the bricks were pretty thin. He also said he had a lot of issues with getting consistent batches. Best wishes! Aircrete is pretty finicky stuff, but with more time, we might have been able to figure it out. Best wishes!
@@RedandAprilOff-Grid Thank you again for sharing so much on this platform, so succinctly. Cheers
@@RedandAprilOff-Grid Follow up on Micronesia Dome. I’m thinking 6 to 8” minimum, with “abaca cloth” (Philippine Hemp) interior and exterior. Honestly, building with standard hollow blocks and metal trusses (with extra tie downs) would probably suffice and be more practical. I’ve seen homes in our range built for about $20 to 35k US minus the land and appliances, extra water tower or solar. We want to provide homes for the poor that can withstand typhoons. It’s a shame we couldn’t utilize the air forms and blown cement, as that would appear to be a perfect solution. All the best, Kevin
I really love the way you show your results. This will be very helpful for others building with aircrete. 😃👍
Thanks so much! 😊
Outstanding work sir.Got plenty of info.Now I’m waiting for your next magic.Keep going 👍
Thanks, and thanks for watching! 🙂
Would like to see testing on other side of block to determine if density changes compared to gravity.
We could only do the break test one time, but did the drop test on both sides. We later tested the bricks dry, and did the break test with the remaining long bricks that were still intact.
@@RedandAprilOff-Grid Excellent. Sound testing. I like it!!
I have worked at a pre cast place and I am not 100% sure on this as we don't mix like you do , however if you mix at a slower speed that might make a difference to strength and consistency, even at a professional place it is still an unknown art, I found for our small form Items that my team made the best concrete was slowly mixed over an extended time, 15 min plus 15 to 20. Anyway to be brief try slowing your mixing speed
Thanks! Yes, longer, slower mixing probably would have helped.
I absolutely love all this testing data! Thanks so much for sharing all your hard work with us. What attracts people to DIY aircrete is the idea of an insulating structural material; but nobody knows how strong it is, or what the R value is! You've made a huge contribution to the first knowledge gap and I think your subscriber count is going to explode over the course of this house build for putting out awesome content like this. The issue of insulation value is still completely unknown though. Everybody blindly parrots "an R value of 2" because that's what autoclaved aircrete is. Nobody is capable of DIY autoclaved aircrete, so it's not a relevant number! Depending on the DIY aircrete mix, it probably ranges between an R value of 1.25 and an R value of 3.5. It's actually possible to get a relatively simple measurement of R value though (or perhaps more accurately "comparative thermal conductivity".
Although you're probably sick to death of testing, Mathias Wandel put out a video of a simple methodology for measuring R-value with a $40 infrared thermometer. He put out a little spreadsheet that handles the math. He did it for a wall in his home, but it wouldn't be hard to adapt to a small aircrete box with a $10 electric coffee warmer inside. Just a thought. The video title is "Measuring house wall R-values using an infared thermometer". Here is a link to his video:
th-cam.com/video/6FGfn27Qj54/w-d-xo.html
Thanks so much! The R value is something that would be very interesting to know, and to see how it changes with heavier and lighter mixes. We haven't got around to researching how to do it all. We'll check out the video. Thanks! 😊
We just watched the video, and Red wants to try it! We already have a tiny heater with a thermostat, and an infrared thermometer. He just ordered a temperature probe to make sure the inside of the box stays a consistent temperature. Thanks for the information! 😊
@@RedandAprilOff-Grid Very cool! I'm excited to see the results.
I recently saw an interesting R value approximation/test for aircrete done by Stephen Williams. His channel is all about EPS foam aircrete and he's got some fascinating content. His methodology was to construct 12"x12" boxes with 2" thick walls, and then he put a frozen bottle of water inside. I think he measured the time it took to melt the ice. He used a identically constructed, pure EPS styrofoam box as a benchmark.
I'm not really sure how he accounts for thermal mass differences between materials though. For example, if a pure concrete box was left outside and frozen, it might seem to outperform a lightweight aircrete box in keeping a frozen bottle cold. Another consideration is ensuring that each box is comparably well-sealed to minimize differences owing to air leaks. Still, it's a very simple and useful way to compare your sample's performance against a known benchmark (styrofoam) and other samples.
Stephen seems like a really sharp guy, and he's clearly passionate about aircrete. He would be a really great person for you guys to chat with about R-value, and your plans generally. The title of video is "Aircrete on Steroids, Aircrete Styrofoam. Build Cheap". The relevant portion starts a 9:15 in the vid. Here is a link:
th-cam.com/video/27v7Oq-q9xs/w-d-xo.html
He has lots of interesting ideas, but I'm not sure where he's going with it.
I have a hard time believing that a 5 inch styrofoam wall that can easily be pushed over, will support a 2 story structure with just the addition of fabric and a coat of plaster.
If he put one of his blocks in a fire pit, it would melt and burn. He moved the torch away every time it started to melt or catch fire. Aircrete definitely does not burn, melt, or catch fire.
His way of building looks very time consuming, you would need a lot of space, and time, to gather and shred that much styrofoam. We can make 4 full batches of aircrete in less than 2 hours including cleanup, and it makes around 20 cubic feet of usable material.
Measuring R value in that way would give some comparison information, but I would wonder how accurate it is.
@@RedandAprilOff-Grid We're on the same page for pretty much all of the above. I see EPS-crete as an intriguing insulation material, but I'm very leery of it as a structural material. I definitely wouldn't build a house out of it. I only mentioned the video because it was an interesting first stab at comparing thermal conductivity of different aircrete mixes by timing how long it takes for them to melt. His test fails to account for the effect of different thermal masses and air leakages among samples though. I'm not clever enough to think of a better idea, but sometimes it helps to see what other people have done in the past, try to identify weakness and improve on them. :)
it will work great for wall cavity / instead of fiber glass R13
Fiberglass insulation is cheaper and much easier.
have you seen the Styrofoam-crete some people are experimenting with? seems a bit less strength but greater r value and lower weight may not be appropriate in your application. just curious on your thoughts
Yes we have. It is an interesting idea, but we really aren't interested in trying to gather, shred, and store, the tremendous amount of styrofoam we would need to build our house. Assuming we could find styrofoam for free, it would still require a lot of trips into town, which aren't free. The equipment needed, the mess, and the effort required to pack the mixture into the forms is another issue, and there plenty of other issues I haven't mentioned.
The foaming solution used to make aircrete insulative takes up much less space and is a much faster and easier process. Also aircrete absolutely won't burn or melt no matter how long you hold a torch to it.
Making aircrete is a challenge, and there are many things that can go wrong. We think we may have finally made all of the possible mistakes, and hopefully we have it figured out. We'll keep sharing as we keep learning.
Thanks for the vidoe man .. keep it up
Fantastic! Thanks!
Thanks. I’m looking for insulation material. It’s between aircrete & hempcrete,
Our latest videos, show some of our more recent not so great batches. It could be because the Drexel and well water were too cold? Aircrete is tricky stuff, and we don't have time to keep experimenting with it, so we have moved on to using other materials. Best wishes on your projects!
Well, April couldn't sleep so turned the puter on and there you were, more results. Intensive indeed
Thanks for watching! 😊
what type of portland cement were you using? Some cements are formulated to cure faster although more expensive it may help with the sinking problem and so allow a sand cement mix.
We mostly used type I/II, but also tried some III/IV, when there were shortages of I/II.
You have to keep in mind aircrete is supposed to be week and full of air... the straight comes from the reinforcement fabric the shape and the monolithic outer layer.
Yes, these samples were only cured for 7 days, so they didn't have their full strength yet. The testing was so we could practice making aircrete, make sure it's a material we are comfortable in using to build our house, and to compare the different mixes to each other.
@@RedandAprilOff-Grid of course, and your bricks look good even some of the failures. I did a lot of testing and foam machine building... I found issues throughout, when you think you got everything right and start mass production.... it still fails randomly.
There definitely seem to be a lot of different things that can go wrong. We have had some issues with our last few batches not turning out quite as well. After testing all of the other variables, we think it is from not mixing the Drexel around in the jug before every use. The last 1/3 of the bottle doesn't seem to be working as well, and it is darker in color. We'll know more after we make some more batches using a new jug.
@@RedandAprilOff-Grid I've seen that too first couple batches are really good... but then most bad... then you check everything but can't figure it out. Try adding a little glisten... it tends to settle at the top and you use it first.
Please include a test on a regular concrete block 9 x 4 inch. For comparison.
We thought about it, but we already know that a brick that size of would not dent or crack, and it would take a tremendous amount of weight to break the long brick.
Aircrete's fun compared to normal concrete, at least for walls. But they've been making aerated bricks for a long time, and it's got a better R value than any aircrete batch. And then, styrofoam is a much better insulation. Did you try sawdust?
We prefer working with concrete. It doesn't leak out of the forms, and it always turns out good and strong. We didn't try sawdust because we wanted to use materials that were easily available to us, and that we could get enough of to build a whole house.
Was there any isolation as to what the variable(s) were at play in understanding why such a mixed bag of results were obtained ?
The batches are all different, some had fine sand, paper, fibers and different amounts of foam. As the temperatures started getting cooler, the samples started turning out worse.
@@RedandAprilOff-Grid So better results may have been had in the summer ? and you may have had gone with it instead ad it been summer ?
@@kalervomakinen2076 As hot as we get, I don't think summer would have worked either. Aircrete would have been a nightmare in so many ways. Trying to make the forms watertight, keeping the walls wet until they cure, dealing with failed batches and cracks and powdering. Aircrete is not inexpensive, long lasting, or easy to work with. We are so glad we didn't try to use it to build our house. In my opinion, there are much better options out there.
Am considering using it to make insulation for a cabin build @@RedandAprilOff-Grid
@@kalervomakinen2076 Rockwool is a much easier and likely cheaper insulation option, but good luck if you decide to try aircrete. 🙂
Those softer ones might make good road barriers...
They do look somewhat like them. 😄
Well i recon you tested the hell out of this ;) good info.
Thanks, we are pretty impressed with aircrete's performance! 😊
Yeah but...did you create all the samples on the same day? If one sample per day at the same time, then you should test that sample seven days out from time of pour at the same time to be accurate in the seven day cure time, right? Thanks for sharing
We made 2 samples a day, and tested everything on the 8th day depending on when it was poured.
Do you have any plans to do insulative tests on the different mixes?
It would be nice to know, but we haven't looked into how hard it would be to figure it out. I'm assuming it's not easy. I'm sure our stronger mixes are not as insulative but we aren't too worried about the exact number. I think with our 8.5 inch walls, south facing windows with the proper overhang for the summer, and the amount of thermal mass, the house will require very little heating or cooling. It will be interesting to see how it does.
@@RedandAprilOff-Grid Yeah, when I get to it I am hoping to cool with an ice cube and heat with a hair dryer. One can dream
have you tried making longer posts ???
did you build a water softener ???
These were just test samples, we were planning to do poured in place walls for the house. We used an RV water softener.
I was wandering what kind of steel wool you used, and how many?... last I had corse and fine stainless steel wool alternating. I don't think more than 8 pads.
Here is the video of Red putting together the foam generator. The kit had a large coarse piece of steel scrubber pad stretched out then stuffed in the wand. th-cam.com/video/n_zsgV4t1fY/w-d-xo.html
@@RedandAprilOff-Gridwhat, I didn't have good results with corce steel wool, and only one pad... it makes big bubbles if you're near the coast or use Amazon fine stainless steel makes smaller bubbles, look for boating supply. Had good results first use with standard steel wool pads. After they start to rust they are no good... same with brass wool, though brass lasted at least 3x longer... had a suspension I was building too much pressure behind the stack of pads...
All concrete should be tested for compression eg psi, tensile strength is very limited without rebar.
We were planning to add reinforcement, but were testing the material itself, as well as our ability to make consistent good batches.
Really like to see a glass or basalt fiber mix test. Maybe a lite mix and a heavier mix like you did the cellulose fiber. I've thought you don't want long fibers because they then to knot and clump up but short fibers (like 1/4") do quite well for crack resistance in conventional concrete too.
We have seriously considered it, but it would add a lot of cost to the build so have decided against it. Red called around but can't find anyone local that sells it for a reasonable price, and it's not cheap online either.
@@RedandAprilOff-Grid considering the total investment we make in our houses and the supposed added crack resistance down through the years I think the cost is actually comparatively cheap. We're not talking thousands of pounds of fiber, I believe I've read it's about 10 oz of fiber per cubic yard (although that might have been the plastic fiber I'm confusing it with, still it's probably only 30 or so pounds of fiber. I've bought chopped fiberglass for composite mold making and paid less than $8 a pound.
We were looking into 1/2 inch and can't find it for less than $15 a pound. One place was $10 but they were charging $26 shipping! We also need the type that is alkaline resistant to go in concrete. One local place has some kind of fiberglass fibers, but the lady didn't know anything about it, she said it's in a very small bag for $6, but maybe we'll go check it out next time we are in town.
Tomorrow we are planning to make a batch with nylon fibers, we have some we can use and if works well, I think we could figure out a way to get it pretty cheap.
With our design, the aircrete does not need to be structural, and right now, we are planning to use the wire mesh and rebar on the inside and, it's expensive, but probably fiberglass netting on the outside. We'll have some time to think about it.
Update: We found a more reasonable place to order the fibers and will be tested basalt fibers and fiberglass fibers! It will take some time, but hopefully within the next month, we'll have those results. If the fibers work well, we shouldn't need to add the wire mesh, just rebar to connect it to the frame. We are also looking into a way to test the R value, that would be awesome to know. Thanks for your persistence!
@@RedandAprilOff-Grid smiley face )
Have you tried baking soda, sugar, vinegar mix, with straw/hay as reinforcement?
We haven't, but it would be interesting to see what it would do. We considered adding straw to a batch of aircrete, but couldn't think of a good way evenly chop it. We figured it would be too much trouble. We also aren't sure long term how it would hold up in the cement.
@@RedandAprilOff-Grid maybe a lawn mulcher.
@@RedandAprilOff-Grid th-cam.com/video/eqLXXjvQXgI/w-d-xo.html
Yes, but it's also very cheap and easy for the average person to manufacture and use.
We calculated the cost in another video. We learned that building with aircrete is not less expensive, and it's a lot more work. Our stick built house with a layer of exterior insulation is way more efficient, and was much easier to build. Aircrete is very temperature sensitive and finicky to make. Similar materials like autoclave only have a 20 to 30 year lifespan.
I got the same crappy results with saw dust mix as your cellulose mix did.
We wondered how that would work too. The dry testing on the paper fiber samples was pretty interesting, the results from that is in our most recent video.
Is there a point when it makes sense to invest in a cement mixer? I would think the investment would be worth it.
I hear mortar mixers probably work for aircrete, but I think a cement mixer is not ideal. Mortar mixers are quite expensive. Mixing is way more tricky than we were expecting, but I think we about got it figured out. The batches are not bad at all to make, everything is so much lighter than regular concrete. We did 4 batches in less than 2 hours including clean up. So once we start pouring the house, it should go pretty fast, and it's not too strenuous with 2 people.
carbon nanotubes in the portland mix? 300 um..
Not sure if you can buy it anywhere for a reasonable price, but it looks awesome. 😎
@@RedandAprilOff-Grid $140 for 4 oz, surface area of 1000 sq m, I may get some and test a batch, after Christmas. It seems it would increase surface tension by increasing the area which may help enhance the mechanical properties.
I've been told that if you mix sugar into cement, it won't set properly. I don't know why I needed to share this.
Thanks for the tip. 😂
how long did you let it dry before testing?
They were tested wet. We watered them in the morning, covered back up, and tested in the afternoon.
how to make it load bearing
We were planning to build a metal structure and use aircrete for the insulation and put fiberglass mesh on the inside and outside, then stucco it, but we decided making our own aircrete wasn't going to work well in our situation. 🌞🏜️
Red you have some really good aircrete! It is frustrating when it becomes inconsistent. I'm switching over to styrofoam with some foamed binder and this is part of the reason why. I'm also testing tons of admixtures for additional binders. I'm trying to formulate something similar to the SIXBAU blocks - th-cam.com/video/r2vcHKzDYnc/w-d-xo.html . I think I am getting close, but now trying to find cheaper ingredients. Cement testing takes so long when you have to wait days between test.
You are getting a good cure and I think that is a problem other have is they don't wet cure their blocks and they become really weak. Are you thinking of doing a mono-pour or blocks? I personally would not feel comfortable with aircrete other then infill or dome shape, but that does not mean it can be done. If you can put up a light roof and get the shear strentgh needed for your structures weight you can make it work. I've done shear wall retrofitting, anything is possible. Problem is, there are no numbers for shear strength of textile reinforced aircrete walls so you have to get the outside/inside skin done well. DO NOT USE THE POLYESTER ROOFING FABRIC. You could also do an infill setup with steel to the roof or design a shear wall system using inside walls that attach to the roof then to the outside aircrete walls. You would need a correct size footing for the inside shear wall to keep it down tight, slightest uplift and shears walls fail to work.
It has been a challenge, but we feel like we are getting a pretty good handle on what not to do, and are getting the mixing figured out. Filling in the garden wall has been great practice and something we want done anyway. We are planning to do poured walls with support every 8 feet. We'll be sharing more details on that soon. Best wishes on your projects, that sounds cool. I shared your comment with Red, but I answer the comments and questions. Thanks for the input and best wishes on your projects! - April 😊
Can we not just make a concrete block and move on?
We considered building with rammed earth or poured concrete, but we wanted good insulation. In the end, we are very glad we didn't try to build with aircrete, our house turned out great. 🏡🏜️
I think that you should keep the aircrete - to outside projects & patio roof trusses. I don't think that trusting it for you House walls and foundations is a good idea.
Patio roof trusses are an interesting use for aircrete. My Little Homestead made it work, but it didn't look easy, and I'm pretty sure it wasn't cheap. Our foundation is concrete, we were considering trying to use a more dense aircrete for the floor.
I just watched Aircrete Harry's vid, talking about his thickening solution. Is that the same/ similiar to the glycol do u know? Also, how much glycol are you adding per batch?
Ok, watching ur vid now 🤗
No, the glycerin is just something we decided to add just in case our Drexel wasn't mixed well. The tiny house aircrete guy was saying the glycerin can come to the top of the Drexel making your first batches turn out better than the later batches. Glycerin is pretty cheap, so we are adding a little as an extra insurance. From what I understand, Harry's thickening agent is only available for sale commercially or in large amounts, so he bought some and selling it in one gallon jugs. We have some, but the trial batch we used it in was probably under mixed and it leaked out some which causes big air pockets. Our most recent batches seem to be showing that under mixing produces a much worse product than over mixing. You have made a lot of aircrete! The thickness and texture of your batches look really good. Best wishes with your house!😊
@@RedandAprilOff-Grid I mix the Portland& water in a cement mixer first, and then try to limit the mixing duration in the barrel w/ the foam w/ the hand mixer to a minimum- just enough to mix the foam +slurry consistently. Originally, I was thinking low water would result in a stronger result, but your vids have dispelled that illusion!
5 gallons of water is somewhat of a low water mix already. Many use 6 or even 7 gallons of water, which does seem to produce a weaker mix. 4 should hypothetically work, but it hard to mix and hard to whip the foam into.
@@RedandAprilOff-Grid and you can have particals settings with no where for the water to go. The problem quickly cascades as more bubbles pop, more separation, more air out.. I make sure to put holes in my plastic now.
I AM NOW LOOKING INTO HEATING THE MOLD TO DECREASE SET TIME
Air raid shelters should use aircrete blocks
😂
I think it's possible your sand was so weak because it wasn't "washed" I could be wrong
True, that could make a difference. We got the sand off out of our seasonal pond and it was sifted through a number 40 screen. He held it up high so as much dirt would blow off as possible, but I'm sure it still had some dirt. This was also one of our moussey mixes, so that probably effected the strength some too.
If you have not seen this guy's video on aircrete wall issues, more relevant (more shrinkage) if you pour-in-place: th-cam.com/video/TCAIZiQu3W4/w-d-xo.html
Hello how are you doing
Hi! We are doing well. 🙂
Nice to hearing from you
concrete don't hold tensile force, so stop doing it. It is better to test the sample with different bar sizes and see how much tensile load it can hod up. Thank you
Yes, we were planning to add multiple reinforcements. We were just testing the aircrete on its own as well as our ability to make good and consistent batches.
A few comments: What features of aircrete are you persuing? You talk about insulation but do not test that parameter. Your DOE results are hard to interpret based on the test parameters.
The choice of test method is curious. Concrete is not good in tention. It works in compression. But it is a test parameter. Impact resistance did not make sence until you mentioned you were going to use it for a flooring material.
Brief search show an optimum aircrete R-value of 3.7 per inch, so you might get an ~R30 in an 8 inch wall of very cured & sealed material. But the parameter is not tested.
Reviewing your videos because I must have missed the objective.
We would love to test insulation value and compression but those are hard to measure and difficult to test without the proper equipment. We know enough about aircrete to know it is reasonably insulative, and possibly very insulative. It can be reasonably strong, but more often people are getting batches that are weak and crumbly. We have also seen a few successful builds and know it can be a great material with many benefits. We are testing to see if we can make good, consistent batches that we feel will be suitable to build our house. Also to see which recipes yield the best results in the areas we are able to test. The aircrete will not be load bearing, so that doesn't matter too much. We wanted a material that is insulative but also has a lot of thermal mass. The issue with straight concrete and blocks is they have almost no insulation value. We strongly considered, rammed earth, but again it has very little insulative value and is very labor intensive. We expect this to be a fairly fast and cost effective way to build a house. I can't guarantee that it will work, but we are pretty excited about it and think it will make a pretty awesome house, but only time will tell.
@@RedandAprilOff-Grid ok.
My mistake.
They were good questions and I'm sure there are others who are wondering the same thing. 😏🙂
☺
Someone sent a link on how to test and calculate R value. It looks doable, and we already have most of what we need. Hopefully it will work!
You are doing it wrong. There should be no visible bubble at all while pouring.
th-cam.com/video/TweER67O0e8/w-d-xo.html
What a waste of time and money...
Have you heard of rammed earth?
Yes we have th-cam.com/video/Ogf2hIboyFI/w-d-xo.html
but we thought aircrete was worth a try, it is more insulative and faster to build than rammed earth. We got a garden wall out if it anyway, and while we were making aircrete the price if lumber has gone down. 😏🏠