Type 1 or recycled crushed for ground bearing slab?

[flanagaj]

Just a general question for those who have been there and done that.  I need to order 30m2 of type 1 or crushed concrete for the ground bearing slab.  That equates to 72 ton and type 1 is £33.50/ton

Recycled crushed will probably save me half that amount, but I wanted to ask what people's thoughts are on type 1 vs recycled.  The ground below is flinty as anything and then it goes to chalk, so I don't think there are any concerns about settlement.

[Nickfromwales]

15 minutes ago, flanagaj said:

Just a general question for those who have been there and done that.  I need to order 30m2 of type 1 or crushed concrete for the ground bearing slab.  That equates to 72 ton and type 1 is £33.50/ton

Recycled crushed will probably save me half that amount, but I wanted to ask what people's thoughts are on type 1 vs recycled.  The ground below is flinty as anything and then it goes to chalk, so I don't think there are any concerns about settlement.

Check with the SE, they will have specified?

[flanagaj]

21 minutes ago, Nickfromwales said:

Check with the SE, they will have specified?

Just checked and their spec just states hardcore (looks like a lifted and shifted spec) 

[Nickfromwales]

1 minute ago, flanagaj said:

Just checked and their spec just states hardcore (looks like a lifted and shifted spec) 

In that case you just need to choose for yourself, and ensure any details for layering / compaction are observed.

 

Have this chat BEFORE anyone starts work, not after............... 

[flanagaj]

9 minutes ago, Nickfromwales said:

In that case you just need to choose for yourself, and ensure any details for layering / compaction are observed.

 

Have this chat BEFORE anyone starts work, not after............... 

I'm going to do this job myself.  

[Nickfromwales]

Just now, flanagaj said:

I'm going to do this job myself.  

Use your rage to punch-compact the bastard  

[Mr Punter]

Crushed concrete / brick will be OK but not any old crap with plaster, wood, rubbish mixed in.

[saveasteading]

Crushed is fine if clean but there is a middle ground if a supplier will sell it graded a type 1.

 

 

BUT

30m2 x say 0.2 is 6m3.

X 2.4t/m3 is 14.4tonnes.

 

Think of it another way. Does this look big enough for 3 lorry loads, or more like one?

Edited 13 hours ago by saveasteading

[mjc55]

I wouldn't use crushed concrete again after our last lot!  Full of rubbish really and didn't compact that well.

 

Local groundworker suggested 75mm crush and run and that was much better.  Much cleaner and compacted really well.

 

Also pretty cheap at £21 a ton!

[FarmerN]

Crushed recycled varies a lot between suppliers, in my experence.

Had some really good some awful , get a sample and check first load when delivered

Edited 11 hours ago by FarmerN

[sgt_woulds]

Geocell recycled foamed glass agregate.  That way you get insulation and hardcore in one product. 

250mm depth = building regs slab insulation.  Also does not need a membrane unless you are in a radon area as it does not wick moisture

Not so cheap though.

[saveasteading]

4 hours ago, mjc55 said:

75mm crush and run 

Excuse me grinning at this. 

Crush and run sounds like the worst of recycled aggregate.

From a quick Google I see,though, that it is a fairly commonly used term, presumably from mishearing and repetition. I just had never heard it said this way.

 

The tech term is crusher run. I have always understood it to mean "as it comes" . Thus it is great for haul roads and heavy duty parking, but not for precision as there isn't a graded mix.

 

75mm crusher run will be everything that went through a 75mm grille. That would feasibly include long lumps, and will vary according to the original material.

So @mjc55 you were lucky or the guy had seen it.

[mjc55]

Hmmm.  I can only go from my own experience, maybe we were just lucky!

 

 

[BotusBuild]

We had 75mm crusher run for our temporary access (still there 😀).

 

We've had upto 32 ton lorries over it and its stood up well. I would use it for a slab foundation - probably will use it for the garage, with a 50 - 75mm sand layer and DPM before slab is poured

Edited 1 hour ago by BotusBuild