Equatorial Bulge



  • @Ignacio-DHOME ,
    Thanks for the vote of confidence :) I have designed a hexagon shaped block with a hole in it for #4 or #5 rebar or Basalt Rebar, to run from top of block into the footer/foundation. If each hex was 12 inches across the flats, 3 blocks (3 feet) would be the top of the pony wall. The equator of a 20 fot dome would sit there, the quadrant arc of top of dome would be at 13 feet high from slab, I am 6 ft tall, 1 level of Gadsen scaffold at 6ft up. I can work that, run a belay rope out top of hole and tie off to a tree, wear a climbing harness. Seems doo-able.

    The Litebuilt kiblock design and concept appeals to me,
    http://www.litebuilt.com/techinfo.html#LW-MB
    but there is no readily obtainable form set for those, but i can easily layout a hexagon form with a greased pvc pipe thru the mould/form and cast a bunch of blocks that interlock.

    I know i can use sand with portland to make a block with enough compressive strength, but wonder if i can simply use the same mix that the Aircrete dome radius would be made with. My first Aircrete project is going to be a large dog house for Two big labs, and their partner in waterhose and posthole handle destruction crimes, a boxer. I am still trying to get my head cleared up on structurals of cement/aircrete/concrete before sitting down with autocad and getting a design worked up. Desperately need a workshop, questions on whys and whats are adding up, and documentation has conflicts/option and videos on the web with details and credibility are sparse. Aircrete is the wild west.

    As a side note, I am surprised at all the renegade pvc pipe foam generators designs on the web, runing compressed air and someone has not managed to blow one up. I am leaning towards the little dragon because of the known and proven design, and the safety of a pump getting the foam into the compressed air wand.



  • Probably need a bond beam on top of the pony wall, then start the dome on top of the bond beam. Run carlon elect. conduit inside of it around the perimeter of the pony wall, stub out for elect. boxes.


  • Workshop Instructor

    @Leonidas FASCINATING WORK LEO! I would lean towards making a solid pour formed pony wall with rebar to have the strength of a bond beam. I love the hexagon idea! I am not crazy about rebar inside aircrete though. Aircrete does have a tendency to crack, which is not such a big deal when there is a poly cement fabric incasing and bonding the bricks together as one structure. Is there something else you could use that wouldn't rust, or for that matter, do you really need this step? Again, the fabric is enough in my eyes and experience. Please send pictures of the hexagon brick! Would love to see how you make one!
    Thanks for your ideas, good cutting edge research happening here!


  • Workshop Instructor

    By the way, I did not really answer your question. NO, domes do not need an equatorial bulge. Straight walls are fine. The benefit of the bulge is aesthetics and possible counter force to a earth berming if you plan to bury it. Straight walls with curved radius are strong retaining walls also.



  • Cylinders are very strong vertical structures. I was thinking for best use of dome space, an equator at waste level or countertop level would be the best., IMHO.
    Thanks for starting this conversation on rebar.
    Can a basalt mesh be used for the interior surface? I was wondering because aircrete is so brittle, having the mesh in the middle of the foam slurry, would the aircrete just break off of the mesh? I was wondering if you put a layer of basalt mesh down, put a coating of sticky mortar down on it, and then pour the aircrete on top of it, making the bricks the width of the roll of basalt mesh. You would still mortar the clothe on the finished interior of course.
    Or would the mesh be better for the exterior surface?


  • Workshop Instructor

    Mesh both inside and out. Not sure I followed the basalt mesh idea? For strength add poly fiber sold anywhere to add to the mix.



  • @Ignacio-DHOME ,
    Thank you for the answers. I am convinced now to do from the equator up, and no bulge. On the pony wall, youve schooled me on the better option which is to pour the whole thing with a ready mix truck. My time and money is what drove the whole hex block or kiblock method of the ponywall. My next step is to do a design, run cost and time analyses on the differences. The mountainous site has no sand, and nearest city with a batch plant is 20 miles downhill in the desert. As it is, i would be hauling portland cement to the site in a pickup truck as time and money permitted.

    Steel Re-Bar = The monsanto roundup of the alternative construction world. I work as a civil drafter/designer for an engineering outfit. In 20 years of driving an autocad mouse for architects, engineers, and surveyors the observation is that Modern american mainstream engineering uses steel rebar, and I am probably somewhat brainwashed in favor of it because i am ignorant of alternatives.

    As I research this dome stuff i have stumbled onto the basalt rebar and mesh sites and I really, would like to not use steel. That Basalt comes freight truck in coils. The idea of doing all this work and leaving a rust hole in my blocks for the generations after me i find repugnant.

    The polyester fabric in and out of the structure is like an epoxy/fiberglass surf board or wooden strip built canoe and im sold on the method, but like @upwinger im wondering about using basalt 10mm squares mesh. I dont want to re-invent the wheel much, and probably not qualified to do so. The goal is to get a dome or two up and add to the site once living there.

    Thank you for the council. Its allowed me to procede.



  • Here is a link to basalt mesh...basalt mesh
    I live in an area that may experience a huge devastating earth quake thats long overdue. I was thinking if the mesh is used on the interior, it would prevent any big chunks from falling in.



  • @upwinger ,

    Here is a latenight kitchen table sketch of the block setup like cedar strip canoe cross section with a cove and bead.

    alt text

    The block concept has a hole in it, 10mm Basalt rebar runs in hole, Mortar in hole.

    I dont know if that basalt would flex enough to follow the radius, And if it did, there would probably need be a centering disk to hold it off the side wall of the hole in the block for mortar to set.

    The so called pony wall is called a ring wall, or at ground level a ring beam .

    http://www.waterwiseliners.co.za/images/ringbeam-1.jpg

    https://www.commtank.com/images/temp/Bostik-Water-Tank-Installation-3.jpg

    I sat up last night and ran Trig calcs on the Planset to get the relaionships of the dome, the equator, the foundation all into cad drawing. Now im puttering around with tape measures, strings, nails looking at what kind of floor space and overhaed space is realistic for living. The wall at equator seems to give the most normal use out of a floor plan. The bulge and return to a smaller radius seems to leave wasted space, but it allows a bit smaller ring beam

    Im starting to find that bulge out and back in to the perimeter beam attractive. Similar to the tumblehome on a canoe hull. More labor in the bulge, more materials and cost in a pony wall.

    Also finding that i dont want domes to intersect. A modular pod system with arch connections is going to mean no shared ring beam or ring wall, or ponywall. Whatever the configuration would be called.



  • I found a Dome Being Bult In Yap, Micronesia, Jon Berger.

    Youtube Video

    "Island Girl Aircrete Dome Home, 6/28/19 update, Yap Micronesia"

    20' diameter dome, Sitting 3 feet on top of a pony wall, Equator on the wall, 13' from slab to top of dome and it is all done with the DomeGaia method of aircrete and construction.

    Ooh Rah!, I can see that it is indeed a realistic way to build. Time to get a foam generator and start a small learner/test project. Will post it when its stitched together.


  • Workshop Instructor

    @Leonidas I like all these ideas. I am feeling that the rebar is a little bit over engineering though. The bricks are brittle and think that maybe applying a rigid material like rebar will: one, make it difficult in applying, and two, create such a rigid structure that the bricks will be compromised tremendously if there is an earthquake. I love the basalt mesh idea. To me, with this, it will be plenty strong along with the structural integrity of the dome shape itself to resist falling and breaking off. Making something to resist the forces of nature I feel is a fallacy in engineering that is changing. Harmonizing with movement and the natural integrity of natures forms is the way to go. My two cents...you ARE the the engineer though and it will be you and your family inside:)



  • @Ignacio-DHOME said in Equatorial Bulge:

    @Leonidas I like all these ideas. I am feeling that the rebar is a little bit over engineering though. The bricks are brittle and think that maybe applying a rigid material like rebar will: one, make it difficult in applying, and two, create such a rigid structure that the bricks will be compromised tremendously if there is an earthquake. I love the basalt mesh idea. To me, with this, it will be plenty strong along with the structural integrity of the dome shape itself to resist falling and breaking off. Making something to resist the forces of nature I feel is a fallacy in engineering that is changing. Harmonizing with movement and the natural integrity of natures forms is the way to go. My two cents...you ARE the the engineer though and it will be you and your family inside:)

    Wise words my friend:)

    I want to say a bottom wall to waste level would be fine just not as much aesthetic appeal, maybe, and more floor area to tile and keep clean. I like the idea if its burmed on the outside, or into a hilltop, but you have to think about rain runoff. I was dreaming of a rain catch where three domes intersect. run it into one of the domes and have an indoor waterfall and green room... fresh filtered rainwater pool


  • Little Dragon Tamer

    @upwinger Except for humidity problems I love the indoor waterfall idea.


  • Workshop Instructor

    @upwinger I have thought of water catchment myself. If you do berm all you need to do maybe is ledge the dome with a trough that runs along the side of the dome at a 1/4 inch per foot fall. The fabric and glue would work to do this. It would probably look best if it was below the berm line and graveled so the water falls into the catchment.



  • Hey Folks - My name is Matthew. I have built 3 air - crete domes:

    1. 8 meter diameter in Turkey in 2013. ( https://www.youtube.com/watch?v=OXePjg6A5Kk )
      2928354_orig.jpg

    2. 4 Meter diameter (Rammed Earth fusion) in Spain in 2014.
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    3.5 diameter (Stone fusion) in Turkey in 2018.

    antayla-dome-sep-2018_1_orig.jpg

    I have a diploma in applied Permaculture design from the British Permaculture Association. Here is my portfolio: http://www.holisticprogressiondesigns.com/portfolio.html

    I am based in Turkey & spend time in Spain, but I am open to building in any country in this part of the world.

    You can contact me via whats app on +34 663 911 066
    Or email me at: holisticprogressiondesigns@gmail.com



  • @Ignacio-DHOME Hey my name is Matthew, I am from England & have built several domes in Spain & Turkey. I made rain water catchment for a rammed earth Aircrete dome I built in Spain, here are a few pics...

    105.JPG

    103.JPG

    102.JPG


  • Workshop Instructor

    @Matt-Prosser Really nice work! clean!



  • Beautiful! Brilliant with the rain catchment. I am curious as to how the aircrete domes are doing in earthquake prone areas so far. It is hard to see the actual inside structure of your buildings so I can't tell if it is the aircrete domegaia type build or different?



  • @ormom8 Hello, Apologies for the delayed response. I have built two domes in Turkey (and I'm currently working on a cluster of three) which is a earth quake prone zone.

    Domes are so strong because there are no corners and the weight of the build is distributed into the foundations.

    I typically don't make my own bricks. I buy prepare one's that are used in mainstream construction, normally Ytong brand. As a professional builder this makes more sense for me.

    Thanks for reaching out and good luck with your project.

    Kindly.

    Matt



  • @Ignacio-DHOME Thanks Ignacio!


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