I'm going to pour some concrete to anchor a swing set. The base of the swing set that is being anchored is two 4x4s
with a 2x4 footer crossed perpendicularly to the 4x4s.
I have a bunch of large softball-sized rocks in my yard. I was thinking I could buy less concrete mix, and get rid of some of these rocks, if I threw some of the rocks into the wet concrete.
I assume the concrete will harden around the rocks and they will set together to become a solid mass.
Is my assumption correct? or will the rocks damage the integrity of the concrete anchor?
Here is a drawing of posts and anchor (with rocks depicted)
I poured the cement in June 2015 (about a year and a half ago). The swingset is still standing strong.
The biggest takeaway from this experience is the consistancy of wet cement. I assumed it was like latex paint, but it was more like thick oatmeal or damp sand. It didn't really pour and fill up all available space. I had to spoon it in with a shovel and pat it down into place around the posts.