On 2/18/2012 10:59 AM, rangerssuck wrote:
I was watching a concrete delivery yesterday and got to wondering -
what happens with the concrete that is left over in the truck? I
suppose they keep the truck turning with some extra water so it
doesn't solidify into a solid block, but then what? Does it get used
for something, or do they just have to find a place to dump it?


Boy, there sure is a lot of misinformation available here.

There are many variables in the concrete business. It is not unusual to
have a cubic yard or more of leftover concrete in the truck after the
pour. The driver has a huge obligation to clean all chutes, hopper, and
any splatter on the rear of the truck before he goes back on the street
- this has more to do with broken windshields and law suits. He dumps
whatever water he has left into the drum with the left over concrete if
there is any chance of it setting up before he gets back to the yard.
If it happens to be a yard that casts the big blocks, they will use up
the concrete making them if there is time. These blocks are 2' x 2' x
4' with tongue and groove surfaces so they can be stacked with a piece
of heavy wire rope cast in the top for a lifting eye. These blocks take
16 CF (about .6 of CY) and weigh between 2000 and 2500 #. When a yard
is really busy there is often not time to deal with these and not all
yards even make them. The driver empties the truck in a designated area
of their yard. The EPA requires that they hold the runoff water. The
left overs are junk that is not usable for anything in the concrete
business. It is usually referred to as "wash out". If you have a
parking lot or some other use for the material, they will usually sell
it far cheaper than you can even buy #57 stone. You will need your own
dump truck and make an arrangement with the yard to load.

We have sometimes received concrete so fresh we could have finished it.
There is no or very little picking and choosing. Whatever the loader
scoops up is what you get. It may have hardened lumps, etc. It is all
material that breaks fairly easy under track equipment, usually even a
backhoe. It makes a fantastic fill material and even finish road or
parking surface. Even though the cement has turned hard, it will sort
of re powder under the machines and the stuff gets really hard after
some rain and grading. It is not homogenous concrete, but it is a dense
and solid surface.

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Keep the whole world singing . . .
Dan G
remove the seven