what the best type of cut for concrete?

hi all,

deciding to explore a polished concrete floor for my outdoor area further.

area is approx 5mts wide by 8mts long and although its main use will be for entertaining it will occasionally hold 2 cars on it. concrete will be 130mm, f82, 32mpa with plastic on base.

i have been advised to my disappointment that i MUST have a cut in any length greater that 5mts. question is what is the best and most discreet type of cut for this applicatio (dont want to distract from one piece polished effect). a few types were mentioned but the only 2 that i can remember are the expansion joint (aluminium with rubber on either side) or a saw cut filled with either silicone or matching cement in hole.

cheers

b

Alpsy

Perhaps this is what you are looking for.

http://www.connollykeyjoint.com/

From an article I saw (it was on the site of one of the places that supplies sealers for polished concrete floors) - they recommended getting it saw-cut something like the day after the slab is poured so that you don't get too much shrinkage cracking while it dries. I think they filled the cuts with an epoxy before polishing.

Strictly speaking, you don't have to get it cut; its just that if you don't, when you get shrinkage cracking you might not like where the cracks appear. Its outside so I reckon you could get away with cracks unless you are after a totally perfect finish.

But if you get your pour done on the hottest, driest, windiest day in summer, and it ends up with shrinkage cracks that your cat could fall down, don't blame me!

Nothing worse than cracked concrete, maybe make the joints a feature and put more than less.

Just a thought! (Although your specs look very good)

Alan M