On Thu, 9 Jun 2016 09:55:14 +0100, John Rumm wrote:

On 09/06/2016 09:47, The Natural Philosopher wrote:
On 08/06/16 23:44, Turboweasel wrote:
replying to Set Square, Turboweasel wrote:
Just carried 9 in the back of my volvo, with spring assisters lol. wasnt
bad!

IIRC around 20kg

It does rather depend on the size. The last batch of 600x600x40mm slabs
I bought were 33kg each.

I've always worked on a relative density of 2.4 - for slabs in the real
world this woul be 2.4kg/li.
So, 900x600x50:
9x6x0.5=27li, times 2.4=64.8(kg).
The Paving Expert gives 64kg
http://pavingexpert.com/pccflag1.htm
about 80% of the way down the page.
--
Peter.
The gods will stay away
whilst religions hold sway