Thanks so much, that’s very reassuring.

Honeycombing does occur against forms, and is typically not a structural problem. This is a bit much though, which means they did not vibrate the pour, which also means it may not have settled properly around rebar. Though the footing looks a bit small for the sonotube size, so I'm not even sure if there is rebar that (should be) is turned to the footing. Also not sure if the footing is sitting on ledge and pinned to it.

My bet no rebar in there.

Thanks. We had an engineer take a look and he said it was okay. Rebar was used. He said the compressive strength of the concrete he poured for the columns was 27 MPA - greatly exceeding the 15 MPA minimum in the plans. He is guaranteeing that it’s structural. I guess we will see…

Just curious, did the engineer conduct any type of concrete hardness test or is he just basing it on the concrete that was ordered for the MPA? If the engineer said it's fine, he's probably right. I would request a letter from the engineer essentially certifying the integrity of that column.

This could have been easily prevented by using a concrete vibrator or even just simply tapping the forms with a hammer as soon as the concrete is poured.

If your concerned about aesthetics, you can always just cover that up with stucco.

Good Luck!