# Forum Home Renovation Concreting  Busted edge of suspended slab over patio

## craka

How do I go about fixing this?  The lower edge of the slab edge is busted, it's probably about 300 mm along the edge length.

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## phild01

I would be using a magnesium phosphate non shrink grout and some patient forming it up to pour it into.

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## craka

> I would be using a magnesium phosphate non shrink grout and some patient forming it up to pour it into.

  Sorry I've not use any sort of concrete grout before,  is that a  common thing ?   Is it something you can get from the green shed?.

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## Marc

Craka ... can you tell why this happened? Is there a steel bit you can see rusting inside the cavity?

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## craka

> Craka ... can you tell why this happened? Is there a steel bit you can see rusting inside the cavity?

  There is about a half inch of reo bar I can see.  A few years ago I managed to, but not meaning to, knock the concrete edge with the back of an axe.

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## phild01

> Sorry I've not use any sort of concrete grout before,  is that a  common thing ?   Is it something you can get from the green shed?.

  A product I have used but can no longer find was Blue Circle Rapid Patch Concrete.
I suspect Boral Concrete Rapid Patch is the same product. https://www.bcsands.com.au/index.php...ucts_id=151111 
These products don't seem to be as available as they once were. I would choose the magnesium phosphate products over other epoxy type patching products.

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## craka

Could I use 
 Lanko 5kg 136 Rapid Patching Mortar?

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