>>2920786
thanks anon, this is the kind of distilled advice I hope for coming here
>says it's either scaling or spalling
it is neither, this is a week old undamaged slab. it’s simply a geometric defect in the surface due to a poor troweling job, purely cosmetic. I believe the potential fixes you detailed still apply
>bust out the first 1" underneath the surface of damaged concrete with a chisel and hammer, then undercut the edges so it has something to grab onto
So, in an ordered list, just for my clarification:
>grind the edges of the affected area at an undercut angle (temporary “control joints”) 1” deep
>break up the rest of the area 1” deep using a chisel and hammer
>clean, prime, and hydrate the surface
>fill the recess in with mortar, feather in edges
>broom finish to match the existing
My question is why use mortar over another type of fill? Would using a sand/cement/epoxy mix be any better or worse?