Planning to lay a circular slab 4.2m diameter, maybe 100-125mm thick. The ground below is glacial till, no soil, and IMO doesn't even need a sub base. I built a 1m high circular drystone retaining wall 3-4 yrs ago and it hasn't budged an inch.
The slab will be a recreational area within the walled area, which allows 300mm to the wall around the circumference for a suitable gravel and therefore drainage.
Problem is the concrete finish....I really don't want a floated smooth look- ideally a glass aggregate finish would be perfect but a lot of hassle and effort from what I've seen....a lot to go wrong!
Other option would be to:
A- lay it and expose the aggregate as it goes off with a sponge and hose, or
B- let it go off and then hire a diamond floor polisher/grinder later? Any ideas how the finish would look doing it with one of these- a smooth finish would be good though...
Our local quarry does ballast but it's in pink granite, not the finish either of us want, so maybe I'll do the bulk of the slab(70-80mm) in that in one day and do the finish layer(grey) the next morning, maybe 20-30mm thick. Any advice on doing this is appreciated, especially on keeping the thing as monolithic as possible- maybe coat the first slab in a cement slurry before laying the surface layer, use a retarder?
It's my first attempt at a fairly large area, got it planned out ok and I'll probably be doing the mixing and laying unless I can find a mate to labour with consistent enough mixing skills!
The slab will be a recreational area within the walled area, which allows 300mm to the wall around the circumference for a suitable gravel and therefore drainage.
Problem is the concrete finish....I really don't want a floated smooth look- ideally a glass aggregate finish would be perfect but a lot of hassle and effort from what I've seen....a lot to go wrong!
Other option would be to:
A- lay it and expose the aggregate as it goes off with a sponge and hose, or
B- let it go off and then hire a diamond floor polisher/grinder later? Any ideas how the finish would look doing it with one of these- a smooth finish would be good though...
Our local quarry does ballast but it's in pink granite, not the finish either of us want, so maybe I'll do the bulk of the slab(70-80mm) in that in one day and do the finish layer(grey) the next morning, maybe 20-30mm thick. Any advice on doing this is appreciated, especially on keeping the thing as monolithic as possible- maybe coat the first slab in a cement slurry before laying the surface layer, use a retarder?
It's my first attempt at a fairly large area, got it planned out ok and I'll probably be doing the mixing and laying unless I can find a mate to labour with consistent enough mixing skills!
