3' wide, about 31'----4' wide, about 24'
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.
How much concrete is required to fill 100 cu feet
260 kg/cu m
Your dimensions 3' x 3' x 4" equate to .1 cubic yard. One cu yd of concrete weighs from 2000 to 3500 lbs, depending on the mix. Commercial concrete is around 3200 lbs per cu yd, so your .1 cu yd would weigh 320 lbs.
Look up concrete in Wikipedia for detailed information. Concrete for a foundation or floor is generally mixed in the proportion 1 part cement, 2 parts sand, and 4 parts gravel (or crushed stone). Crushed stone is better than water worn stone as its irregular shape makes for stronger concrete. If a bag of cement is approximately 1 cu. ft., a 1:2:4 mixture calls requires 1 bag cement, 2 cu. ft. sand and 4 cu. ft. stone Since the sand and cement fills the voids of the stone the above quantities yield 4½ cu. ft. concrete. The concrete mixture is mixed, by hand with a shovel or in a portable powered concrete mixer, with water just sufficient to provide a workable mixture for the work in hand. Care is needed not to use too much water as this weakens the final concrete.
5,000,000 cu yards
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.
How much concrete is required to fill 100 cu feet
0.246914 cu. yards (6.666667 cu. ft ) of concrete is needed.
.02469 cu yd
53 and 1/3 cubic feet, concrete is normally sold buy the cubic yard, this would be 1.975 cubic yards. Figure on 2.25 CU yards to be safe. You do not want to run short when pouring concrete.
260 kg/cu m
13.5 cu ft
1 cu. yd of cured concrete is about 3600lbs. 1 cu. ft of cured concrete is about 134 lbs. (rounded up) 4 ft x 4 ft x 5/6 ft = 13 1/3 cu. ft 13 1/3 cu. ft = 1787lbs (rounded up)
360 cu ft or if the "4" is inches, not feet, one twelfth of that, ie 30 cu ft
Your dimensions 3' x 3' x 4" equate to .1 cubic yard. One cu yd of concrete weighs from 2000 to 3500 lbs, depending on the mix. Commercial concrete is around 3200 lbs per cu yd, so your .1 cu yd would weigh 320 lbs.
For a hole 36" deep X 18" diameter, you would need approx. 1/5 cu. yd. concrete.