How much gravel under concrete?

bgott · Dec 1, 2002

Most of the time you don't have enough. Last week I got a second load to finish a job I started and then I had too much. When you have too much you'll be dreaming up places to use and it seems like it will never go away!

Mosey · Dec 1, 2002

MikePA - I did some measuring and thought I had it figured right, so I just ordered 10 yards - I actually thought it would be too much! I recently got my driveway paved, so I didn't want a dump truck tearing up the new pavement. I think I'm just going to have to downsize my plans and go with a 20' wide building instead of a 24' wide one.

emery · Dec 9, 2002

Just a thought, you will forever miss that extra 4'. You only have to build it once and then can use it forever!
Good luck

oombala · Dec 21, 2002

i see you have the dirt mounded up.
why not take the extra gravel and pour it around the mound, to help with erosion?
wont have to mow it and if weeds pop up hit em with round up.

Anonymous Poster · Dec 25, 2002

Green & soundguy are right on. I will be putting in a commercial access to my property probably next year and the Missouri Dept of Trans provided me with specs/plans. Commercial requires an 8" slab on 6" of gravel. The others have already indicated the type of gravel. If I were doing a drive, I would think 6" on 4" of gravel to be the minimum. A couple extra inches doesn't cost much compared to having it crack up. Of course, if you REALLY want a perm. road, read Vitruvius. Those Romans really knew how to build a road. Some of theirs are still being using 2000 years later!!!!! Wonder how many of our roads will be. Take care. JEH

jmattox1 · Jan 13, 2003

It is amazing especially in IN that no one has mention pea gravel. Pouring concrete with my father years ago he always used pea gravel for a base. It will not hold moisture the way sand does, its' almost completely compacted when it hits the hole/area.

When pouring concrete I have always overkilled on base. For a 24X24 garage floor we used 24" of pea gravel. 24 years later not 1 crack in it.

just my two cents worth

Mosey · Jan 13, 2003

Welcome to TBN Jon. Thanks, I'll inquire about pea gravel next time I need something.

ness09 · Dec 20, 2012

hi every one please help me... my boss ask me of what kind of gravel to be used after grouting to reached the strength of 25MPa.. pls help me.... i need it now...

vtsnowedin · Dec 20, 2012

You do realise your posting on a nine year old thread? 25MPa ? metric something or other. Gravel is tested for compaction in pounds per cubic foot or the metric equivalent. For strength they use things like California bearing ratios. After grouting what? Need more input.

k0ua · Dec 20, 2012

vtsnowedin said:
You do realise your posting on a nine year old thread? 25MPa ? metric something or other. Gravel is tested for compaction in pounds per cubic foot or the metric equivalent. For strength they use things like California bearing ratios. After grouting what? Need more input.

The only thing I THINK I understand is the unit of measure... he is talking about 3650 lbs per square inch.

3650 Psi = 25165864.1085 Pascals or about the 25M Pa he posted about.