To be clear, the article is discussing reinforced concrete—concrete made with steel rebar, which rusts.

Unreinforced concrete can and does last for many hundred years. Reinforced concrete, not so much.

FTA:

“Early 20th-century engineers thought reinforced concrete structures would last a very long time – perhaps 1,000 years. In reality, their life span is more like 50-100 years, and sometimes less. Building codes and policies generally require buildings to survive for several decades, but deterioration can begin in as little as 10 years.”