paul wrote:
wrote in message
oups.com...
paul wrote:

I am trying to mix the right quantities of sand, cement and lime to
produce
a 5:1:1 mix. I have 25kg bags of cement and lime. The lime (hydrated)
bags
are slightly bigger than the cement bags and I am having difficulties
getting the right quantities to mix.
Using a half bag of cement is approx 3-4 shovel loads and using a half
bag
of lime I get approx 4-5 shovels but I expect will be lighter than the
cement since it is denser.
Ideally I would like to do this by the half bag to make the mix accurate.
How many shovels of the sand should I be using? Someone recommended 10
shovels to 1/2 bag of cement & 1/2 bag of lime but in volume (i.e. not
weight) this doesn't seem right to get a 5:1:1 mix.
Incidently I'm using a 100ltr electric mixer to mix it all up.
Thanks
Paul
1:1:6 by volume is the standard mix. The other well known non-equal
lime:cement mixes fail prematurely. To convert to weight ratios I guess
you'd just need to measure the densities and work it out.

I'm wondering what youre using 1:1:5 for though, its not a mix I know
of any application for.

The mix I'm using is for a Bulwell stone wall which is also a retaining
wall, i.e has earth behind it all the way to the top of the wall which is
approx 2.5m high. It was recommended by a builder I had round, having said
that the next guy I had round recommended a lime:sharp sand mix without
cement.
Paul


I used a mix in my wall varying from about 1:1:5 cement/lime/sand to
1:1:8 when I got a bit low on sand and cement to 3:1:15 when I nearly
ran out of cement.

The more cement the harder and the faster it sets. The more sand the
more porous and crumbly it is when it sets.

But really, none of it is THAT critical. What is more critical is tying
the whole thing together when you use any cement, to make sure it
doesn't crack.