Rebar corrosion signs and symptoms together with rust streaks and popping may perhaps imply expanding steel

https://simonslrq299.almoheet-travel.com/concrete-spall-repair-techniques-dry-pack-stitching-and-mortar-systems

Rebar corrosion indications reminiscent of rust streaks and popping would suggest increasing metallic. Removing all affected concrete is helping steer clear of repeated spalls.