It’s not really concrete, but a cement top coat used for refinishing concrete surfaces. The refinishing cement is really intended for fairly smooth slabs, but the slab in the catio is very rough concrete, so getting a really smooth top coat didn’t happen.
A lone leaf decided it needed to break in the new cement floor, since I have the cats locked out of the catio while the cement cures. In the second photo, there are three dominant shades of gray. I mixed the first batch of cement following the instructions exactly, and the mixture ended up being too thick, so while it poured out of the bucket, it started setting up almost immediately, making it difficult to spread, and almost impossible to smooth as per the instructions (it’s the darkest shade of gray along the back wall).
I made the second batch soupier than the first, but I got it a little too soupy, so it spread thinner than I wanted it to (lighter shade of gray in the middle). On the third batch I got the mixture figured out so it spread well at the thickness I needed, and I was able to get it a little smoother (middle shade of gray in the foreground). I used the same mixture for the the next 8 batches needed to cover the entire slab. I also ended up spreading and smoothing the cement on my hands and knees with a hand trowel. Our air is so dry here, that even the wetter mixtures started setting up as soon as I poured them out of the bucket, making it difficult to spread with the 18 inch-wide cement spreader the instructions suggested I use.
While I was photographing the new floor, I noticed my little chainsaw and level on a bonsai shelf made a nice composition. The last two photos are the candles we have behind the couch in the sunroom unlit and lit.