Dirt-Crete?

[RichNJ]

Many years ago I read an article in, I think, Mother Earth News Magazine. The guy was saying you could make a concrete-like product by taking dirt at the site, cement, water and mix it all up with a rototiller and make concrete.
Has anyone heard of this?
Does anyone know why this would not work?

 

[uppermich]

It's called soil cement. I remember seeing a gov't bulletin many years ago using it for setting poles for a building. I did a search and came up with a few sites that looked interesting:

http:// [url]http://www.gearsinc.com/prod01.htm [/url]

http:// [url]http://www.ctre.iastate.edu/pcc/education/applied_concrete/01presentations/soilcement/Chee-Soilcement_files/frame.htm [/url]

and:
Ken Kern, in the Rammed Earth chapter of his book The Owner-Built
home, writes:
"As a result of adding 15 percent cement to a very fine, sandy-loam
soil, which is 74 percent sand, the strength of the wall increase from
302 to 1,150 pounds per square inch... [snip] Cement is most economical in
soils containing 50 percent or more sand. With this proportion, about 15
percent cement should be used, whereas, with the more ideal proportion of 70
percent sand, only 8 percent cement is needed to achieve the same result.
With a 60 percent sand mix, about 12 percent cement should be added...
[snip] Cement seems to work best with sandy soils. Lime, either slaked or
unslaked, makes one of the best stabilizers for clay soils."

Pat (Techno-Tractor Mom)

 

[RichNJ]

Thanks,

I think that I have Kern's book. I have alot of books from that "era". Tonight after the kids go to sleep I'll check the bookshelf.
After reading all those books on energy efficiency and solar heating and earth sheltered houses I did something that in 1995 everyone told me was a waste of my money and many sub-contractors (heating/AC, electrical, even carpenters) would not work on the house. They thought that it would ruin their reputations and we would sue them when the whole thing did not work.
We built a solar heated house. It has been very comfortable. I can open a window in the winter and let the cool fresh air in without worrying about the "oil burner" coming on. It looks like a conventional colonial/farmhouse on the outside and open and spacious on the inside.
I only wish that I had bought the Kubota when we were building. It would have made many tasks much easier and saved probably hundreds of hours of manual labor (my labor to be exact).

 

[patrickg]

Down in Baja California Norte, near San Felipe I have a leased property in a solar powered community. Soil cement was the pavement of choice for a Mexican federal road off the paved blacktop highway. It was the most for the least for us gringos. Yeah, we paved the Mexican road, through our community anyway but past that dune buggy or 4wd recommened although I've seen Mexican Navy duce and a half trucks go through easily.

There is more to rammed earth than Earth Ships (old tires filled with rammed earth to make houses) I have seen (don't recall which architecture journal) a house made of local dirt mixed with cement and rammed tightly into forms to produce really thick walls with the thermal characteristics of adobe or better. It was used for both internal and external walls, load bearing and non-load bearing as well as niches and alcoves. This particular example was hand rammed by the owner builder and friends. When the forms were filled they were raised to gain more height and filled again. When thte forms are removed the walls were quite attractive with a nice "marbleing" of colored striations. I don't recall if any sealant was used but the walls were not firred or painted as they had good rustic eye appeal.

As I recall, they did N O T add water to get a conventional pourable concrete consistency, just mixed it and rammed it. Also don't recall how long the stuff required to asymptotically approach its final strength. Regular (not strongly chemically modified) cement mixes attain 90% of their final strength in 28 days. And as a curious fact, never actually stop curing on a scale relevant to a human lifetime, they just get slower and slower aproaching the final strength value.

"Fine Homebuilding" may have been the journal in question, over a year back...

Patrick

 

[patrickg]

So Rich, your the cullprit! I was wondering who was hoarding all the good books that are out of print on those topics. Gonna build soon, nearly got the site nailed down, south facing slope over looking a couple ponds, perk test went OK.

Solar energy... Poured a slab a few days ago to connect back door of mom's new house to the garage (8ft gap)

Slab is about 10x25 for a breezway/sunroom , southern exposure. Was really nippy last night, in 40's. This PM the slab was very nicely warmed. Makes me all tingly to think how the low winter sun will warm that slab and allow being out in the sun room to look at the stars on winter evenings without wearing a parka. Will use glazing to maximize solar gain for winter comfort, good overhang to shade the windows in summer and blinds to make adjustments.

Getting ready to try to figure out the solar gain-mass storage problem of a heavy walled above ground concrete safe room with full eastern and southern exposure. Don't want to build an oven or a deep freeze or rely on mechanical systems for heat or cooling. Gotta get creative... uh next miracle is scheduled for precisely 1130 day after tomorrow.

Patrick

 

[uppermich]

I'm from that "back to the land era" as well. I'm planning to either build a new house or extensively remodel (basically rebuild) my present place in the next few years. I will definitely take advantage of solar and maybe wind as the property slopes South, overlooks the water and gets a fair share of wind. It's a harsh climate, so any heat gains will pay for themselves in no time.

I'm also toying with building a new barn set into the hill. It would have drive-in access and a greenhouse on the upper level and the animals below. Even considering a connection to the house via a tunnel. Don't think it will fit into the budget though. These kinds of future projects are one of the reasons why I got my Kubota and backhoe.


Pat (Techno-Tractor Mom)

 

[Hillbilly]

I checked into some road building one time.I had this info sent to me:
In the UK farmers use many low cost techniques.Depending on your climate they may be suitable for your use.Cement (component of concrete) is often used to first stabilize the soil-laid over the surface by hand and scarified in to about 5 to 10 inches using a mechanical hoe(amount and depth dependent on weight of vehicles using the road).This is then compacted using a roller.This makes a cement bound road base providing structural strength.Then a cheap method of sealing the road against water ingress is to use a bitumen emulsion sprayed by hand and aggregate chippings applied depending on traffic but nominal 1/4 inch is normally used.This should be repeated to form a double dressing (double chipseal).This should provide a low cost road and re-treatments of the chipseal will keep it serviceable.There are many sites with specification details-one is www.rea.org.uk (UK road emulsion association-independent organization) look under surface dressing,retread (harrowing technique) and small machines (application equipment)
Best of luck
Martin
The Bitumen Man !

Bitumin@btinternet.com

 

[Hillbilly]

Also check out: polypavement.com

 

[RichNJ]

Thanks for your input. I am looking to put a floor in my new pole barn. Pre-mixed concrete from a truck would be a luxury and at about $1600 it is not that costly. However I was looking for something cheaper because I don't need a perfectly floated concrete floor. Just something to put equipment on. I have checked out the websites from your posts and did a rough comparison on price on the products and figured that it's probably the best bang for the buck to mix my own concrete and pour it in small batches when I have time.