Concrete wall spalling - causes?

[Kom3]

Hi, I have concrete that is spalling from a wall in an industrial yard. I don't know what caused it. There appears to be no leak from the roof or impact. I am left guessing it is just spalling due to moisture from the environment getting in over time and causing the rebar to rust and concrete to spall. The building pre-dates world war II so it is old. I will tell them to patch it and apply fresh coat of paint to the building. Thoughts if there might be more to this? Picture attached.

 

[Ingenuity]

Depending on the clear cover, given the age of the structure I would test for carbonation with phenolphthalein indicator solution on a ‘fresh’ fractured concrete piece.

 

[lexpatrie]

You need to judge for yourself the criticality of that rebar, otherwise, it never had chamfer so it made it's own chamfer plus a bonus, could be freeze thaw as well if northern and some vestige suggests water concentration (a former solidly frozen downspout)? Looks unlikely in this scenario, but there's a window above?

 

[TRAK.Structural]

As part of the repair I would specify a corrosion inhibitor to be applied and a bonding agent.