View Full Version : Crushed concrete floor question


JBAUTO
06-17-2010, 11:13 AM
So I'm taking out my floor and the local dump wants $1000.00 yes a grand to get rid of 6cu yards of concrete.

The concrete is broken up to pieces no bigger then 3x3".

Question is if I dig floor under garage 12" can I used the crushed concrete as a base and pack it down with a compactor then do a layer of 6" sandfill??

Or am I asking for trouble??


Josh

Will S.
06-17-2010, 11:22 AM
Don't take it to the local dump; find a company who owns a dirt pit, crushed concrete and gravel supplier, etc. They will gladly take it for free. They grind it up, and sell it.

Can't answer your question on whether you should re-use it under the new floor. I would not, but if you have enough property to dig a pit, bury it and back-fill with dirt, that may be an option.

JBAUTO
06-17-2010, 11:26 AM
The only local dump within 100km wants $100.00 per ton plus tax 13% so I'm looking at like 18,000lb on concrete

or I want to extend my drive way if I dig down a foot there and put this as fill and put some crushed stone then get it paved. If that would work???

JBAUTO
06-17-2010, 11:27 AM
Oh local dirt stone pit good idea I'll look today thanks

willymakeit
06-17-2010, 02:38 PM
Drive around. There is always someone wanting free fill.

Jack Olsen
06-17-2010, 03:39 PM
You can sell concrete that's rebar free -- not pay to have it taken away.

Red05GT
06-17-2010, 05:20 PM
We built a house a few years ago on a lot where there had been a previous foundation.
We busted up the foundation and slab into smaller pieces than you're talking and put
in in the new garage for base, one layer thick and then used pea gravel for balance of
fill and then poured the slab. There was over a foot of fill over the concrete and the pea
gravel worked good for filling the voids between the chunks of concrete fill. Never seen any sign of any settling or movement. I would check with the demolition or recycling
guys first though. If you dig out extra dirt, then you have to deal with that material
plus renting the compactor,extra time handling the busted up concrete a second time
etc.

JBAUTO
06-17-2010, 06:09 PM
Thanks guys for the advice. I found a place hour away that wants like 40 bucks to get rid of it. But i was thinking. I want to extend my driveway and i was thinking of breaking up the concrete smaller and use this say 2-4" of crushed concrete then some gravel then get the driveway paved?

Would this work ?

walrus
06-17-2010, 07:30 PM
Thanks guys for the advice. I found a place hour away that wants like 40 bucks to get rid of it. But i was thinking. I want to extend my driveway and i was thinking of breaking up the concrete smaller and use this say 2-4" of crushed concrete then some gravel then get the driveway paved?

Would this work ?
Yes it will work, with the caveat that the big chunks even when compacted might have voids. The voids might fill in over time with the fines in the gravel over the top of it. A thin layer of broken concrete won't have the voids a thick layer would. You could also cover it with filter fabric if really concerned

Zeke
06-17-2010, 08:22 PM
I would break it down as much as you can and then blend it with smaller stone and course sand. That will be an excellent base if compacted.

bczygan
06-17-2010, 08:57 PM
Some more things to think of:

Good concrete is more a matter of tending to all the factors, rather than any one being the secret. Crushed concrete doesn't work well as a base because it doesn't lock together creating a monolithic surface. While crushed conc. isn't the best base, it can be done well.

Crushed conc. works best when used as fill, with a good base over it. But unless you need the fill, removing existing usable material to replace it with crushed concrete is a waste. If you use crushed conc. as fill, the larger the concrete, the larger the equipment needed to compact it. A good base and drainage are very important. What is your sub base material? Compacting the base is important. Do it in small lifts (thin layers). Compacting works best if there is a range of sized of material. Smaller sized material fills the voids. Do NOT use sand in any way. It doesn't compact as well as stone fines. Everything locks together and creates an almost concrete hard surface with stone. This works best with a limestone mix with fines in it.

Prep is important. You might want to use a landscape fabric under the base to keep the fines from sinking further and the large pieces from migrating. Grading and drainage is very important. Grading allows water to flow off and from under a slab. If there is drainage side to side you may need drain pipes from one side of the slab to the other to prevent water ponding and seeping under the slab. Perimeter drain pipe keeps water from under the slab. Water freezes and expands and cracks concrete by lifting and then dropping the slab. Use drainage pipe with sleeves (Socks)to keep out fine material. Set drainage pipe in pea gravel beds. Slope to daylight or into a french drain.

Use fiberglass reinforcing AND steel reinforcing. Use expansion AND sawed control joints. Use good quality expansion joint material, filler rods and sealant in expansion joints. Use properly spaced expansion and control joints. Expansion joints let the slab expand and contract without cracking from being constrained. Control joints make any cracking happen in the joint rather than randomly. Fiberglass helps with small surface cracking.


Get a good concrete crew who know how to properly lay and finish concrete. Proper finishing actually creates more density and partially waterproofs concrete. Do the job in the right weather (Not too hot or cold).

Bill

6768rogues
06-17-2010, 09:54 PM
Haul it to my house and I will only charge you $500 to take it off your hands.
I would break it up smaller and use it as base, mixed with gravel.

70redbee
06-17-2010, 10:09 PM
Do you have a low spot anywhere on your property? If you do or if you have a place that could just be built up,then break up the concrete in as small of pieces as possible,dig a hole deep as you can to contain the concrete and cover it with the soil that came out of the hole. This could be in several places around your property.Could even use some for landscaping purposes...rock gardens with flowers and bushes. Just don't pay to have it hauled away.

Bib Overalls
06-17-2010, 10:12 PM
You may be able to rent something like this. Or someone in your area may offer an on site crushing service.

http://www.youtube.com/watch?v=7F5yCZJKcdE

DIC
06-17-2010, 10:49 PM
You may be able to rent something like this. Or someone in your area may offer an on site crushing service.

http://www.youtube.com/watch?v=7F5yCZJKcdE




That looks like the ticket.............:thumbup:

Deltarat
06-17-2010, 11:07 PM
My son just bought a load of crushed concrete that the highway dept. picked up from the highway for $300 for 20 tons.It made a great drive. I wish I had seen it before I spent $800 for a load of gray rock for the drive to my shop.

jabberwoki
06-17-2010, 11:24 PM
yep may want to add coarse sand on top to fill in the voids make sure the concrete is well broken up and compacted wash the sand in then cover with 6mil plastic in a couple of layers as a vapor barrier

bgott
06-18-2010, 12:29 AM
Crushed concrete is really popular here in Houston, TX. for private roads and driveways.

Red05GT
06-18-2010, 07:16 AM
There's a big difference between concrete that has been crushed by a processing
machine and irregular chunks in various shapes and sizies.

mrpowderkeg
06-18-2010, 10:35 AM
Crushed concrete that comes from a commercial processing place is wonderful as a base. First, it locks together, the jagged edges bit into each other, and second, when crushed, it comes out as small bits about 1 inch in diameter, along with "powder" that fills in any voids. The concrete isn't just concrete when processed, it has sand, dirt and other stuff that when crushed it mixes in and fills the voids. We use it under streets in areas with high groundwater. One compacted, it's a bitch to screed or dig in with a shovel We usually use the crushed as a base and sand as a final base because the crushed sucks to screed.

I don't know where you are at, but any place around here that sells concrete or aggregate will take your old concrete for free.