How many bags of portland cement is needed to mix 1 cubic yds.?

Answer 1

4 bags

Answer 2

One popular formula for making concrete is the "1-2-3": 1 part portland, 2 parts sand, 3 parts gravel. A 94# bag of portland (approximately 1 cubic foot) would yield 6 cubic feet of concrete. 3 cubic yards of concrete x 27 (cubic feet per yard) = 81 cubic feet; 81 / 6 (cubic feet of concrete per bag) = 13.5 bags of portland.

This Formula

1 cubic yards of concrete=

One popular formula for making concrete is the "1-2-3": 1 part portland, 2 parts sand, 3 parts gravel. A 94# bag of portland (approximately 1 cubic foot) would yield 6 cubic feet of concrete. 1cubic yards of concrete x 27 (cubic feet per yard)

27 cubic feet; 27 / 6 (cubic feet of concrete per bag) = 4.5 bags of portland cement

Mucca suggested:

this mixture would be fine for setting fence posts, but not for pouring a foundation. concrete mix is often measured in "sacks", that is number of sacks per cubic yard. The number of sacks of portland cement per cubic yard determines the strength of the finished product.

For casual use 1-2-3 works fine. if you were pouring a driveway you might consider how much stress will be applied, the thickness of the slab, even how cold it gets in winter to determine the mix.

I called a concrete supplier today to find out how much ten yards of concrete would cost to have delivered. He asked what mix I would need. I told him I wanted a slab for a garage. He suggested a six yard mix, that is six 94 lb sacks of portland cement per cubic yard. (he quoted ($99 a yard plus $4 per mile from the plant in November 2010 in northern Nevada)

So for more than casual use you need to do some research to find the proper mixture. Work with someone with experience or do a lot of digging, or both.

Portland Cement Association at cement.org is one place to start

Answer 3

Depends on what strenth you want (PSI) 5 sack would be about 2800-3000PSI (Footer mix) 6 sack would be 3300 - 3700 PSI (exterior sidewalk or driveway mix)