Can decomposed granite be mixed with cement for use as structural concrete?

We have a mountainous property with no sand and very little rock other than granite. Can I use decomposed granite (as fine as sand and small pebbles) as aggregate, instead of river gravel and or sand?

sort by: active | newest | oldest
rickharris1 year ago

Looks like the chips will be OK. BUT like everything size matters.

MikeT107 (author) 1 year ago

Thanks for the responses. I guess there is a reason you only see deco on tennis courts, driveways and paths. Looks like I'll be hauling rock. Nice pun Joe.

I think the proof is going to be in the finished product.

What I am suggesting is: You mix up some sample blocks. Then let them cure. Then test the strength of the finished blocks.

I do not know where, to whom, you'd go for professional help for this sort of thing.

This site:

came up near the top in a Google(r) search for "concrete testing"

IIRC Frank Lloyd-Wright used decomposed granite concrete for the blocks of the Gehry house in LA, and some blocks at Southern Florida didn't go well.

So I guess that rock is OK aggregate, but you really don't want to take it for granite.

Heh... Take it for granite. It's a pun. ;-P

+1 His River House had to be saved with support posts

One might say he overextended his reach :)

Someone with Guts or a Huge Ego had to try these ideas, after all, we learn more from our failures then from success... That's why we push working designs harder and harder, to find a failure to learn from....


Brilliant architect, crap structural engineer. He was warned by his student, and by the rebar company the design wasn't stable.

The West Pennsylvania Conservancy's engineers did an amazing job fixing it some years ago. Its now been fixed with post tensioned concrete IIRC.

It is OK for walk ways and drive ways only.

Use it for things like a bridge wall or a foundation and it will not last.

Does not matter really what use as an aggregate as long as it is strong enough - and I guess granity qualifies for strong ;)
People use paper, saw dust, sand, polystyrene and more, so using what you have at ahnd just seems like logic to me.