[Cerium]

A properly designed concrete structure will include enough clear cover (that is the distance between the surface and the reinforcement) to avoid water reaching the reinforcement. It should also take precautions such as roofing to avoid water interacting with the concrete in the first place.

LEED certification includes a credit called "good bones" which recognizes that although exterior trends change, the concrete bulk of a building can be reused if kept in good condition. A new facade can completely rejuvinate an otherwise dated structure. Most concrete building construction focuses on creating large open floors with columns to provide the largest flexibility in floor plan.

An additional interesting trend I've been seeing in Chinese construction is the construction of structures with double the standard height between floors. These buildings can be finished with units with features such as high ceilings and loft spaces that most high-rise units cannot accommodate.

[logfromblammo]

It's not always the reinforcement. It can also be the accumulated result of decades of very slow reactions happening in the cement binder, or between the binder and the aggregate, generally also driven by moisture and gases penetrating the pores in the concrete, so cracks and spalling accelerate the process.

If it was just the rebar, we could replace the iron rebar with drawn basalt fiber rebar.

Perhaps in the future, structural concrete will be covered in an outer layer of ceramic that is subsequently vitrified at a certain stage in curing. You keep your building from collapsing by burning it in a towering inferno first.

[gjem97]

That's good context, thanks. We're quite near a salt water estuary here, I imagine the humidity and salt in the air also makes a difference...

Another thing you can do relatively cheaply (I think) is powered cathodic protection. I don't know if they bothered to do that on this building.