Concrete pillar top cast cap mix

[ellal]

I want to make a shaped cast concrete cap for a brick pillar.
Overall approx size is 50cmx50cmx20cm.

What is the best mix (sand types) and what additives should I use?

 

[jj4091]

Wouldn't it be easier to just buy a ready made one. The materials will probably be just as expensive

 

[noseall]

I want to make a shaped cast concrete cap for a brick pillar.
Overall approx size is 50cmx50cmx20cm.

What is the best mix (sand types) and what additives should I use?

Pea gravel. Screed sand (sharp sand). Cement. Release agent for the shutter box surface. Not sure I'd use any additives.
Four parts pea gravel - two parts screed sand - 1.5 parts cement - mixed well.

Probably.

 

[ellal]

Thanks for the replies.

Can't find a suitable cap to buy, so will have to give it a go.

 

[cdbe]

My dad cast these about 40 years ago, normal concrete with a bit of extra sharp sand in a wooden mould. They're the shape they are to stop the local teenagers from sitting on the wall when that was a thing. A mate of mine used to make concrete stuff - slabs, gravel boards etc and used a vibrating table - so if you could replicate that somehow? Maybe a hammer drill with a big bolt in against the sides of the mould.

 

[Deluks]

A mate of mine used to make concrete stuff - slabs, gravel boards etc and used a vibrating table - so if you could replicate that somehow? Maybe a hammer drill with a big bolt in against the sides of the mould.

Or borrow the wife's 'other' husband

 

[ellal]

Made a box mold and sculpted the top by hand.
Used sharp sand/cement mix and vaseline on the inside of the mold which worked well.

Thanks for the tip about the drill/bolt.
Not too many air bubbles, and as it will be painted can use a bit of 'rock solid' filler.

Now just got to get it on top of the pillar.
Given the weight, thinking it might have been wise to cast in place!