Making Brick Dust Pozzolan

[Anonymous]

Further to my Water Ingress in cellar thread, it was suggested I use a Hydraluic Lime Mortar rather than a normal lime mortar.

The amount of Pozzolan I'm going to need is about half a bucket load, so rather than pay the £40 odd for a bag of Metastar (including delivery) of which I'll use very little, I wondered if anyone had any advice on making brick dust? It will save me a small fortune!

 

[Anonymous]

If you have a cement mixer throw some broken bricks (small) in with some water leave mix for a while until the water has turned to a like a kind of clay slip..
Empty into a bucket leave.... Drain of the excess water leave the muddy consistency to dry out. Voila!
(I like that last word from Biff...... Voila!)
Or use a club hammer and smash them all to bits........

 

[Anonymous]

Do you need a pozzolan with hydraulic?

 

[Anonymous]

Thanks, jake but there no cement mixer here unfortunately, I'll have go the club hammer route instead!

I presume they have to be old bricks, and how fine do I need to make the particles, sharp sand size?

And lastly, what sort of mix, I was under the impression it was 1 brick dust to 1 lime putty to 4 sharp sand?

Thanks!

 

[Anonymous]

I probably didn't make that clear, I have a tub of normal non-hydraulic lime putty for general repairs already, but I needed to mix some up as hydraulic as I need to 'plug some holes' for the winter!

 

[Anonymous]

There must be some readily available cheap household chemical that will act as a pozzolan... is there? MgSO4 woudlnt be practical when needing half a bucketful.

To crush old soft bricks the easy way, line them up and drive over them.

NT

 

[Anonymous]

Old terracotta flower pots would work and be easier to crush up

 

[Anonymous]

Solid fuel boiler ash if you can get it...

 

[Anonymous]

I can get this from my in-laws Rayburn - but can you elaborate a little (sorry if I am being dumb), is it coal ash, or wood ash and does matter if it is smokeless?

 

[Anonymous]

I'm no scientist - ours is anthracite, from the defuct (sob) Trianco central heating boiler, and it was recommended by a lime specialist for use as a pozzolan!

Worked fine...