how to make cement??

[paul_salvaterra]

hi,  i have massonary washed  sand and 3/4 inch stone can i buy portland cement and make cement.  what ratio or porportions for say 2500 psi
for fence posts  and simple post footers for a shed
ty

[jraabe]

"General-purpose concrete can be made as easy as 1-2-3, one part cement, two parts fine aggregate, and three parts coarse aggregate. Add water to create an oatmeal-like consistency (too much water can weaken the mix)."

from here: http://www.onthehouse.com/wp/19990503