Ferroconcrete?

Joseph Shaul

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206
Location
Madison, WI
Is anyone here familiar with ferroconcrete construction? I've got a few projects that might make use of it, but I'm a bit confused as to where to start.
 
Joseph do a Google search for ferro concrete construction you might do a search on youtube also. I have seen some videos of it being done I think on there. They talk about it on the Barrelponic forum I go too and also the aquaponics folks use it sometime too.

Jay
 
Liberty Ships were made of Ferro-Cement in WWII.

It's basically what it sounds like, Reinforced concrete molded into shapes. Some of those shapes make boats.

There are even contests for College engineering teams where they race small boats made out of ferro cement. Using various materials, they are able to make some pretty fast, light boats out of 'concrete'. I'd bet Jeff would have some more info on how fast they are, but I doubt they could compete with his kayaks...
 
No experience with the type used for boats and such. When I saw ferroconcrete in the thread title, I was thinking along these lines:

http://starwars.wikia.com/wiki/Ferroconcrete

Although that particular example is a Star Wars reference, I've worked with a similar material years ago when I was working in the testing lab. Sandia National Lab in Albuquerque was looking for a material to use for radiation shielding, and we tested a mix design that used magnetite for the aggregate instead of regular sand and gravel. It made some extremely dense and strong concrete. While the average concrete test sample (a 6" diameter cylinder that's 12" long) weigh around 30 to 35 pounds, the magnetite mix samples weighed about 70 pounds. It was also very exciting to run through compressive tests. Typical compressive testing involves putting a test cylinder in a hydraulic press and squishing it to the point of failure. Usually, the sides of the cylinder start to crumble, the needle on the gauge starts to drop (about 2/3 of the way up the dial), and you shut the machine down. Nothing too exciting. I don't recall the specific numbers, but the strongest mixes we typically tested would maybe go 3/4 of the way up the dial before the sample would fail. With the magnetite concrete, it wasn't unusual to peg the needle on the machine while the sample remained intact. And in the cases where the sample did fail, it was generally very explosive, shooting chunks of the sample to the far side of the lab. We did have a safety cage made of expanded metal to contain the bigger chunks, but I broke lab glassware 40' away with the pieces that shot through the mesh. Good times. :D
 
Joseph do a Google search for ferro concrete construction you might do a search on youtube also. I have seen some videos of it being done I think on there. They talk about it on the Barrelponic forum I go too and also the aquaponics folks use it sometime too.

Jay

I've had some difficulty getting solid answers, and was hoping to get some information from people with lots of experience actually building things. Lots of the folks on here seem to be carpenters, contractors, or just hardcore DIYers.
 
You know, I can't actually find anything that says liberty ships were ferro-cement. I've heard that before, but right now I can't find anything that corroborates that. So I retract that statement. :huh:

But here is a link that talks about concrete ships...

http://en.wikipedia.org/wiki/Concrete_ship

Yep. I wondered about that statement. I once saw a documentary on the building of the Liberty ships. They were standard iron and steel construction. Albiet, the construction was quicky and pretty flimsy. That is why few, if any, still survive.
 
I don't know about Liberty ships... we had one in our flotilla when I was stationed on Treasure Island... it had been converted to a Radar Picket ship and it was made of steel....

First I ever heard about the ferro cement boats, about 20 or 25 years back one of the racing yachts that ran in the cup races was supposedly made from ferro cement.... they made a light weight mesh frame, then use a relatively liquid type of cement and blew it into the mesh to creat the hull.... also think they do that with swimming pools too.
 
Yeah, I'm not even sure where I came up with that now. Did more research on Liberty ships and it's even more impressive... Welded versus Riveted. Pretty cool stuff.

Anyhow,

Here's about the only link I can find on FerroCement building. Not much in the way of small scale molding.

FerroCement Building Links

Joeseph, I suspect you'd be breaking new ground with your round hollow concrete spheres :thumb:
 
As far as I know it is wire mesh shaped in whatever form you want to achieve and covered with cement.

It was quite on trend on the 70's to build futuristic houses and geodesic domes.

Some years ago I was interested in geodesic domes and I found quite impressive pics of houses built with it.
 
Let us know what specific questions you've got, and if we can, we'll try to answer. What types of things are you considering building?

I'm trying to build a small hollow sphere, roughly 10" in diameter. The problem is that there needs to be a fairly precise recessed ring around a hole, and managing this with a standard layup construction would be quite difficult. I'm wondering if it's advisable to put the metal armature in a mold and pour cement around it, or to coat the armature in the manner of a layup before placing it the mold.
 
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