20 mm aggregate,sharp sand
You have about 2 hours working time after mixing,so how much do you think you can lay and level inside that time?
If you are doingit in stages,you may need to put expansion joints in (wood,cork or similar,that can compress when the concrete expands)
Concrete gains 98% of it's strength in 2 days - it takes about 2 years to gain the other 2 !!
Don't do it when too cold (if the water content freezes,the concrete will crack)
Don't do it when too hot (drying out too quickly will crack it - cover it with damp sheet/sacks to avoid this)
And remeber to leave time to float it off (3 or 4 hours after laying it) in the same day - unless you just want a tamped,slightly rippled finish.
You have about 2 hours working time after mixing,so how much do you think you can lay and level inside that time?
If you are doingit in stages,you may need to put expansion joints in (wood,cork or similar,that can compress when the concrete expands)
Concrete gains 98% of it's strength in 2 days - it takes about 2 years to gain the other 2 !!
Don't do it when too cold (if the water content freezes,the concrete will crack)
Don't do it when too hot (drying out too quickly will crack it - cover it with damp sheet/sacks to avoid this)
And remeber to leave time to float it off (3 or 4 hours after laying it) in the same day - unless you just want a tamped,slightly rippled finish.
