You will need a minimum of 2.42 cubic yards of cement.
12 bags or about 7 yards i think
2,000,000,000,000,000,000,000,000,000,000,000,000 sacks
We just recieved a bill for sidewalk repair. 5/16/2012 all calculations are for 4 inch thick concrete $7.87/SQFT new $9.35/SQFT remove and replace $4.48/LF Concrete Saw Cutting
depends what its made of
(22*6)/2 =66 qubic ft
18x32 feet by 4 inches thick: 7.1 cubic yards. For a 6-inch slab, 10.7 cubic yards.
A half inch thick steel plate, A half inch thick plywood, Brick, Concrete Block
81 Square feet.
A square foot of concrete has no weight because a square foot has no thickness. A cubic foot of concrete would weigh 65 Kg (143 lb) If you ASSUMED that concrete driveways, paths, etc. are all the same thickness , which they are NOT, then let us say they are 4 inch thick (10cm) In that case, then 1Square Ft of Concrete would weigh one third of the figure given above. Therefore it weighs 48 lb which is the same as 22 Kg.. Density of Concrete is 34.4 gram per cubic Inch or 1.216 ounce per cubic inch. (since you seem to be wanting to use Imperial measure)
Well, you make a sidewalk from concrete, not just cement. Concrete consists of cement, sand, gravel and water. You will need 5.5 cubic feet of concrete. A standard sidewalk grade of concrete would be 1 part cement, 2 parts sand, 3 parts gravel- so the sidewalk needs 0.91 cu ft of cement- about 87 pounds worth- plus sand and gravel. If you want to buy the premixed bags of concrete (like Sacrete), you will need about 17 of the 40 pounds bags. And you did not ask, but 3 inches is kind of skinny- I would go for at least a 4 inch thick sidewalk.
A yard of concrete is a cubic yard and cannot be converted directly to square feet of coverage. You must first determine the depth or thickness that the concrete will be. For instance, since 1 cubic yard equals 27 cubic feet, a 1 foot thick layer of concrete will cover 9 square yards of area. A 4 inch (1/3 foot) thick layer would cover 27 square feet of area.
80
532.4074 yards of concrete, round up to 533 yards.