Questions about Rebar Anomalies and Maintenance in Concrete Structures

[jikewang]

Hi all,
I'm very interested in how anomalies in embedded rebars within concrete walls are detected and assessed, and would appreciate insights from professionals in this field.
I have a few key questions:

• What are the most common rebar anomalies inside concrete walls? Is rebar corrosion the main concern?
  What detection methods are typically used, electrochemical?
  
  
• Are non-corrosion anomalies also important to monitor?
  • Can rebar fracture occur in practice (e.g., due to earthquakes or severe corrosion), and is it a real concern?
  • What about bending of rebar or spacing shifts between rebars, do small deviations impact structural safety or require attention?

Any feedback would be greatly appreciated.
Thank you!