The Brew Cabin

Posted: **Thu May 19, 2005 8:18 am**

Can anyone give me advice on the best way to calculate the proportions of Cement/Ballast for the above size mixer for a full load (90L).

I have the Cement and Ballast in 25Kg bags and will be using a mix ratio of something like 1:5.

I know measuring out in Buckets will work,( 1 Bucket or Shovel of cement to 5 Buckets or Shovels of Ballast). I just need to know the quickest way of getting a full load in the cement mixer so that I can get the right mix and maximise my time.

Thanks

Posted: **Sun May 29, 2005 1:42 pm**

Ballast is a fairly ad-hoc mix of fine and coarse aggregates. I really wouldn't be happy using it for anything other than a lean mix concrete to be used as a fill material.

Using a 90 litre mix, I'd chuck in half-a-bucket of water, one bag of ballast, half a bag of cement, then add the second bag of ballast. Once that's turning over, add a further halfd-bag of ballast and more water as necessary to achieve the desired slump.

Putting all the agg in first and then adding cement and water never creates a good batch of concrete in those little mixers: you need to add the ingredients a bit at a time.

The Brew Cabin

Calculating quantaties of materials for 130l cemen