There is a difference between Cement, Concrete, sand mix and mortar mix.
The 94 lb. bag of cement, is pure portland cement, seldom used by itself, since it will crumble apart if no aggregate and/or sand is mix in with it.
Concrete mix comes in 60# and 80# bags.
Concrete mix is about 10 to 15 percent cement, 60 to 75 percent aggregate and 15 to 20 percent water.
I suspect you mixed (5) 80# bags of concrete, not cement? is that correct?
5 x 80 = 400 lbs.
Some of the water added to any mix evaporates back out of the mix.
For an 80 pound bag, you might figure you'd pick up another 5 lbs.
5 x 85 = 425 lbs.
Let's figure it up one other way, by cubic foot. (5) 80 lb. bags makes 3 cubic foot, right on the button. A cubic foot of concrete weighs between 140# and 150#. Concrete is an inexact science, since mixtures vary.
So, for 3 Cubic Feet, you will get cured concrete that weighs somewhere between 420 lbs. and 450 lbs.
Paul Christenson,
There are approx. 7.48 gallons per cubic foot, as you stated.
A 55 gallon drum is approx. 7.35 Cubic Feet of volume. ( 55 / 7.48=7.351)
Filled with Concrete, at 150# per cubic foot, a full 55 gallon drum will weigh in the neighborhood of 1,100# (7.35 x 150 = 1100 )
Happy Thanksgiving everyone!!!
.