Concrete – Layered with crushed stone for concrete slab, but heavy rain came

concretefoundationslab

We just got done compacting dirt, filling with 3/4" crushed stones and compacted it again ready to pour concrete. However, extremely heavy rain came.

These guys are telling me they really just need a couple of days to dry before pouring with concrete, but I just wanted to do some DD before I commit.

Firstly, has anything been ruined because of the rain timing? Will the heavy rain affect the integrity of the slab once it's in? Would I have to compact it again or start over?

Or does it actually benefit because the water might help settle the stones more? The dirt has a high clay content.

And how long should I wait until we pour concrete?

Best Answer

If the gravel is that thick it would need to be compacted to keep it from settling over time. It should be done in stages (lifts). Add a layer, tamp that then add a layer and tamp that until it reaches the height needed. An engineer provides this type of info regarding how much gravel at a time for each lift. I know this is not what you asked, but it is good to know.

With that in mind, I do not understand why the wait on the pour since the gravel is so deep, and the contractor is just using that as an excuse. Perhaps it will put his schedule behind if he did your job the next day. He is most likely going to the other jobs he already had scheduled for the next few days until he gets a new opportunity to pour your slab