What is the definition of spalling?

[jar546]

To break off chips, flakes, separation? Exfoliation of concrete?
Anyway, spalling, it's not just for a northern climate. Here is an example from the tropical climate of south Florida. No freeze / thaw in this photo. That is the bottom of a roof deck you are looking up at.

The piping, however just happens to be a violation of NEC 110.26(E)(1)(a) if you are interested.

 

[Keystone]

Well I'd say your halfway there to the definition being that spalling is correctly spelled... That rebar certainly is shallow,

 

[classicT]

Oxidation of the reinforcement appears to be the culprit responsible for the spalling. "Rusting" (actually oxidation) is an expansive process. Shallow reinforcement and apparent leaks or water infiltration are to blame. Copper pipes are oxidizing as well (possibly sweating or intrusion due to lack of gaskets/flashing?).

And what is with the lack of a sealant or wrap around piping to allow for thermal expansion/contraction?

Also, may need to check the mix design for the concrete...per the Portland Cement Assoc., copper should be protected when it comes in contact with concrete mixtures that contain components high in sulfur, such as cinders and fly-ash, which can create an acid that is highly corrosive to most metals including copper.

 

[ADAguy]

Good photo, many causes

 

[cda]

http://www.interfire.org/features/spalling.asp