Originally Posted by
Frank Bombardiere
I thought it looked like spalling and advised them verbally that it likely needs parging before it gets worse, but I am now writing the report and wanted to get some opinions to help me out. Thanks
It's too late for pare coating.
That crack means the concrete on one side of the crack (the side toward you) is loose from the side toward the rest of the slab.
The only repair is to chip out all of the loose and spalled concrete and repair it with new concrete. They typical way I've see it done is they pneumatically place (shoot) gunite to build it back up. Kinda like shooting a gunite pool (see photo on:
REED Gunite Machines. ) .
Also:
http://www.sika.gr/PDF/Concrete%20Repair.pdf
The "cause" is that the steel in the footing rusted, pushing the concrete away from the rest of the footing (thickened slab edge). That slab as been structurally affected and degraded.