Spent 2 years using too wet of a mix on my slabs and wondered why I kept getting cracking near the edges

A old timer at the ready mix plant finally told me to back off the water by about 2 gallons per yard and my last driveway pour didn't have a single hairline crack along the forms has anyone else been running wetter than they should and only realized it after someone called them out?

2 comments

2 Comments

mason7981mo ago

2 gallons per yard? That's wild, I've been running a full 3 gallons too wet for like five years and just thought concrete was supposed to crack.

nathan_webb1mo ago

Wait hold on, 3 gallons a yard is actually fine for most flatwork. You want that slump high so it flows into every corner of the forms without honeycombing. I've poured driveways at 3.2 gallons and they're still holding up after eight winters with just hairline cracks. The real issue is people blaming water content when their subgrade prep is garbage or they're not cutting control joints deep enough. Code around here actually lets you hit 4 gallons on some low-strength mixes for footings and nobody complains.