Limestone chip instead of gravel in concrete

knockavullig

Caution - stupid question coming up!

Our back garden is currently covered with chipped limestone (approx 1-2cm mix) on a geotextile base with various trees etc popping up. We're looking to raise the level of the garden and cover the lot with grass and shrubs. This has me needing to find a use for approx 12 tonnes of the chipped limestone.

I'm planning on putting a raft foundation for a shed/office and also a foundation for retaining wall to raise the garden by about 75cm. Can I wash the chips and use them instead of gravel for the concrete foundations? Or should I just stick to using them as sub-base material? Or should I just dig a massive hole?

Thanks in advance!

Peter

Boiled-egg

There probably a bit too clean to go into conc on their own, you would need to add sand. If I was you I'd use it inside your raft l.e. for banking up from the edge beams.

knockavullig

Thanks for that. Was going to add sand alright. Had been thinking about 1:1:2 cement, sand, stone for an M25 mix. I think if I use it at all for concrete I'll probably end up using it in not as critical areas such as concrete infill for the cavity block element of the retaining wall.