hi,

I am forming up a large slab of concrete which will be used as a
mantle. I will then cement sandstone as the finished product. I wanted
to find out whether there is any additive that I can add to the
concrete so that it is not affected by the heat. I want to avoid
cracking !

thanks !

"avp27" wrote in message
oups.com...
hi,

I am forming up a large slab of concrete which will be used as a
mantle. I will then cement sandstone as the finished product. I wanted
to find out whether there is any additive that I can add to the
concrete so that it is not affected by the heat. I want to avoid
cracking !

You can use fired aggregate.

--
Mike W

"avp27" wrote


I am forming up a large slab of concrete which will be used as a
mantle. I will then cement sandstone as the finished product. I wanted
to find out whether there is any additive that I can add to the
concrete so that it is not affected by the heat. I want to avoid
cracking !

Sounds dodgy to me!
With all that heat I would expect it to go with a bang.
Any rebar going in there?

Phil

On Apr 20, 9:06 pm, "TheScullster" wrote:
"avp27" wrote



I am forming up a large slab ofconcretewhich will be used as a
mantle. I will then cement sandstone as the finished product. I wanted
to find out whether there is any additive that I can add to the
concreteso that it is not affected by the heat. I want to avoid
cracking !

Sounds dodgy to me!
With all that heat I would expect it to go with a bang.
Any rebar going in there?

Phil

Yep. 13mm rebar. Its a bit over the top but its all I had in the
shed... Still sounds dodgy ?