|Fort Lauderdale, 2017/11|
Building Integrity presents a short (12 minutes), Aug 3, 2021, “How Reinforced Concrete Structures Age” This topic may be of interest because of the collapse of the tower in Surfside, FL. This is very much about mechanical engineering.
The video has an illustration of typical concrete balconies, where concrete is poured around a matrix of rebar steel.
Similarly, so are other vertical structures. The chemical pH is to be around 13 when the concrete is poured, which protects the metal from rust for a long time. But sometimes water, especially salt water, penetrates enough that lowering of pH occurs and rust can happen, and concrete starts to cracj.
Acid rain would seem to be an issue.