Pea gravel in my concrete mix ruined a driveway pour last Friday

I ran out of my usual 3/4 inch aggregate and decided to use pea gravel I had left over from another job. Mixed it into a 4 inch slab for a residential driveway in Eugene and it looked fine at first. Once I started finishing, the surface kept tearing up and the mix felt weak, like it had no structure. Took me an extra 2 hours to get a halfway decent broom finish. Has anyone else tried substituting aggregate sizes and ended up with a mess?

3 comments

3 Comments

miller.rowan25d ago

Wow, pea gravel for a driveway slab? That's wild, man. Pea gravel has basically no interlock, so your mix is just a bunch of round rocks rolling around in paste instead of locking together. No wonder it tore up on you, that sounds like a nightmare to finish.

robin59124d ago

Wait, isn't pea gravel actually pretty common in some places for driveways though? I've seen it used a lot on the West Coast where they mix it with a bit of sand and cement to get a cheaper pour that still holds up okay in mild winters. It's definitely not ideal for heavy traffic or freeze-thaw cycles like you'd get up north, but for a low-budget slab in a moderate climate it can work if the aggregate is well graded.

taylorshah24d ago

I've seen pea gravel work fine in Arizona for decades though.