Old concrete fence posts and shed floor

Having nearly finished replacing the fence I have a large stock of partial and complete old concrete fence posts.
The local tip is very picky about throwing stuff like this away - two small bags of hardcore per day, or it is 'commercial waste' and you have to pay.
Now we are about to build a big shed with a concrete base. It occured to me that we could save all sorts of aggravation if we buried the old fence posts in the concrete base. I would wash them first (power washer) to remove all the dirt and detritus. This would presumably not be as strong as a brand new concrete base, but then again this isn't going to do a massive amount apart from being the floor to the shed. As long as they were an inch below the surface then the surface should be fine.
Any good reasons not to do this? The saving on the bulk of the concrete required for the floor, plus the saving from landfill and repeat trips to the tip all sound good.
Cheers
Dave R
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Sounds like a fairly good idea to me. The metalwork in the posts will rust one day, long in the future.
NT
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David WE Roberts wrote:

Seems fine to me, though I would use a sledge hammer to "crack" them and not lay them as a tin of sardines which could weaken the stability of the base, (I think). Leave some space between them.
Once upon a time, when Noggin nogged in the Bad Lands, at a time of Biblical Drought in England's Green and Pleasant Land as Dennis Howell became Minister of Rain, not far from his constituency, I needed rubble to create the base for a kitchen extension to our first house.
I raided the byways for stones and concrete that the less considerate had disposed of.
As I lifted the tailgate of the Maxi, I wondered whether passers-by realised what I was doing or thought I was indulging in inconsiderate tipping!
Fortunately George Dixon didn't pass by.
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David WE Roberts wrote:

Do you have enough to use them as 'formwork' then just fill in the middle with concrete?
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Dave - The Medway Handyman
www.medwayhandyman.co.uk
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Possibly, but I didn't particularly want them at the surface or at the edge - more hidden in the middle somewhere to bulk out the floor without being obvious.
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On Sat, 12 Sep 2009 18:15:44 +0100, David WE Roberts wrote:

================================================ Immediately before you pour the concrete over the posts mix a few buckets of cement and water and pour liberally over the posts. This will help the new concrete to bond to the posts - it's called 'grouting off'.
Cic.
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