It seems you have been seeking an answer to this BIG Question , for sometime.
While were not as well known as the “company name“, that this posting is in, Maybe I can help ~ a little. Yes, we at Georgia Adobe Ecoitecture, have certainly designed & built many retaining walls, with some clay used over the years.
99% of Our Georgia Adobe Homes, are built with ingredients such as Used Tires and Rammed Earth, and are also built above ground & then back filled, on 3 sides to add additional heat sync and stability to the project, thus the walls are forming what one might term " retaining walls ".
Additionally & sometimes a separate or much more conventional "retaining wall" is also needed, perhaps in the landscape and we may design and build such a wall from Rammed Earth “clay” mixes. While this fill mixture includes Clay soils, It Is Never in either example, simply a Clay wall, as that sand makes up the largest portion ( 70% ) of “Traditional” Rammed Earth mixtures. Often Portland cement is added too.
As that “retaining walls” can take upon many sizes, heights and engineering requirements, the solution to your projects needs & your question, are most likely hidden the details.
Clearly, we can't engineer walls for free or in a posting board but, perhaps could you elaborate a bit more, about you situation & I ( & others too ) might could attempt to offer additional suggestions .
Oh , by the way, if you or others are interested in alternative & inexpensive construction processes , we are registering students now, for our fall classes in Georgia Adobe Ecoitecture's style of carbon –0– self sustainable construction. This is held at at our "new" Georgia Adobe Home Building Academy facility & The details are posted at our web page.
I want to tag onto this post to hopefully get some advice as well. I have a big pile of clay that came from digging a small pond. It is grey and near 100%pure(like pottery stuff). I am working on a small lot and want to reuse it and turn it into something else. I've looked at many of these cool earthen building techniques and it seems that most require sand for structural integrity. So that's why I'm here thinking about rammed tires and "earthships". I would prefer to bring in as little sand or outside material as possible, so the big question is what can I get away with. Or what is another building suggestion. I just want to build a small single room hut like 12'dia and use as much of that clay up as possible.
Thanks for the help.
posted 5 years ago
Not sure if that was to me or not, but here goes about 2 cents worth of " free advice":
I.M.H.O., Much like my "Georgia Adobe's" (TM) , "Earthship's" (TM) are just a "marketing trademark"
of a particular company, that describes their quality of work or products & perhaps appearance too, but not a particular building or materials use only.
Tires are just "free forms" and not for clay holding.
Clay is a free base material, that comes with many pieces of land, and just like Portland cement is, It's a binder, but not the single building material you will need.
Let's mentally Experiment a bit here , that would be the first methodology to most learning.
LOOK AT CLAY AND THEN AT PORTLAND CEMENT, UNDER YOUR OFFICE MICROSCOPE AND ONE WOULD SEE PLATELETS ! To me it always looks like the stack of dishes, that I once dropped into our kitchen floor - all broken up, but still flat or disk looking, yet all inter-tangled ,one upon the other, in places though .
Imagine making a brick, with just Portland cement (or go try to) it won't hold , as when it becomes dry it's brittle. Now add the 70% sand and mix well with water and you get a water stable brick.
Now, try that with clay, straw & sand & you have a brick, that's stable when dry, yet not water resistant. Even inside a free forming device like a tire, its just soft clay & not a complete building material with the structural ability required to build with. Now some will say ~ as you alluded to, "what about potters clay" ? While a fine product for many things, Its another device, with other properties than load bearing construction in mind. And, yet strong, it's not a complete building material, until vitrified ( burning & baking together those silica sands & clay into a pot or vase) , and even that sometimes breaks into many pieces , if not done correctly. If one were to bake a brick with this mix, the straw will allow a chimney effect, during firing and there are many tutorials on that subject.
At the end of my personal experiments, I find that ( like the old saying goes "parts is parts" ) I like to use the right stuff, so as get the best results.
I hope some of that was useful to you and ~ Y'all be safe building out there !.
We live in West Plains, MO and are building a EarthShip. When we excavated the area to build our home we found the dirt to be clay and rock. This is perfect building material for a EarthShip. You use the material of the area of where you are building. We are on our 3rd row of tires. When the compacted tires sit for a day they become hard as a rock. Nothing wrong with using the natural clay from the earth for making a EarthShip of any kind. We like to use lots of rocks as well. Helps to hold in the clay, sand, or any kind of soil that you would have on site. You have to remember you are compacting the tire. Putting in 3 to 4 wheel barrow loads of dirt into one tire. Nothing wrong with using the natural clay from the ground. When using it though make sure it is dry. Otherwise the clay sticks to you sledge hammer. Have fun. We do have a website and facebook page that you can go to for more information. www.severinearthship.weebly.com or severin earthship in the ozarks for Facebook.
We packed our tires with black clay when we began our earthship 8 years ago. We went about a dozen rows up...still standing today.
I would agree to use dry clay. Clay, depending on variety, can swell up to 500 times its dry size. If you pack when it is wet, it will shrink as it dries, and wont be packed as tightly. Also be sure to keep it dry (under a tarp or plastic) until it is weather sealed.
To anyone wanting to build an earthship:
1. My first and best advice is to build one small circle room about 10ft. in diameter and close it in, roof, door, maybe even a small window, and solar panel light... Practice makes perfect, and you will be much better at it, the second time around.
2. Long straight walls are harder than curves unless you are building a sloped retaining wall into the side of a hill. The longer and straighter it is, the greater chance for leaning... I cannot stress how important it is to make sure each tire is level as you go up. Curves are more forgiving. Circles are the easiest.
3. Build one room or two at best, completely finish them, and MOVE IN. Plan it like an efficiency apartment with everything you need and nothing extra. Plan it in such a way that you can add on later...We called ours Phase 1, phase 2 phase 3 etc. After you are moved in and your biohome is up and running, then add on one room at a time as you need it, and finish it before moving to the next one. Let it grow with your family. We didn't do this....eight years later, we are still working....the end is in sight, but it took longer than we anticipated. Sometimes the issue is not enough money...sometimes the issue is not enough time. You will be surprised how your opinion of what you need/want will change over time.
4. Keep it SIMPLE
That is my wisdom, for what it is worth. Happy building.