This problem can be categorized as the scaling of a concrete surface or better known as "Spalling of concrete". This problem or damage occurs due to improper concreting or not providing proper clear cover to the slab reinforcement. So, now that damage has taken place, it is recommended to provide a minimum of 2 inches 1:3:6 P.C.C. mortar plastering along with sika latex or any waterproofing polymer.
The alternative proposal is shotcreting of the exposed reinforcement of this damaged slab surface.