Quote:
Originally Posted by Salty
So, how much concrete to lay 1800 sq. yards 3.5 " thick? What mix...3000, 3500 or 4000#?
|
1800 sq ft x 3.5"/12 = 525 cu ft.
525 cu ft / 27 cu ft per yd = 19.44 yards of concrete.
Ordering 20 yards of concrete and you could end up just a little short.....depending on your measurements.
What mix.....I would go with at least 3500#. But ask them what is the price difference, 4000# may only cost a little more. I would only use 3000# concrete where it will have very light load. Such as a patio or slab to put a small storage building on.
I was at work when my drive was poured and I ended up having 2 spots where after a rain, there is little [1' x 2'] water ~ 1/8" deep. It is not much, but it does create a slick spot. IMO....it would be much better to have a crown in the center or sloping to one side on the concrete to be sure it drains well.
Concrete takes a long time before it is "strong". The concrete, under ideal conditions, should "cure" slowly. Most of the curing [or drying] process takes place in the first few days and has about 70 % (if I remember correctly) of it's strength after ~7 days. After about a month, it has ~ 90 % of it's strength. 20 years later it is still getting stronger. These number could be off some.....can anyone correct me?
To slowly cure.....espically when it is 95 deg outside and the sun shinning on the concrete....it would be good to keep the concete surface wet for the first 24 to 48 hours. This is not required...just good to do and may help delay any cracking in the driveway. I said....Delay....because some cacking is inevitable. I have seen driveways covered with visqueen (sp?) to hole in the moisture to slow down the curing process.