Cement concrete has been, been a necessary element of all construction projects. Not only does it promise a robust output, it also has a very long life. It can be successfully deployed to indoor, outdoor, domestic, commercial & even industrial projects. However, concrete poses the inherent problem of cracks, which tend to expose the foundation within. Take your stem walls for example. Whenever the upper concrete chips off, the supporting rebar is exposed to the atmosphere. If this exposure is allowed to continue for a long time, it may lead to the formation of rust over the rebar.
To deal with this problem, use a chisel to chip the concrete surrounding the rebar. Allow a sufficient clearance. Then sandblast the rust accumulated. Once done, you can cover the scene with a mixture of concrete and sealer. Check your wall – you may have more rebars sticking out which need immediate attention.