Which mall is it? You can PM me if you don’t want to give the location away.
Yeah, any talk of “affordable housing” has a lot of pushback, because people are afraid of “those people,” whoever “those people” may be, moving in.
I’ve been a certified construction manager for over 20 years in public works projects. This is why we require shop drawings and submittals from contractors, where they tell us exactly what materials they plan to use, including detailed concrete mixes. This is also why we pay for construction inspectors whose job it is to make sure the contractor builds the project in accordance with the plans and specifications, and that the concrete that shows up conforms to the approved submittal.
Architects do the exact same thing, and often hire construction managers to do the construction administration and inspection for building projects.
If what you describe happened on one of my projects, we would shut the contractor down. Along with not paying them for the substandard work.