One of the reasons our concrete seems to fail early is the use of steel rebar that is galvanised. Unless you triple dip rebar into molten zinc (closes pinholes) these small pinholes allow ion transfer = expands the channel because the steel oxide(rust) formed is larger than iron = irresistible expansive force that breaks the cement apart. Cement is good only in compression = it makes poor rope. Romans did use iron rebar that they dipped multiple times in molten lead. Since the Romans did not use road salt = no risk. We also used the bare minimum of cement - the bulk being sand and stones. The small interstices of the stone-cement interface are subject to surface wear and sand grains and stones weather out. Internally they are OK. The Roman cement was monolithic, and had these rehydration sites that could accept water of dehydration to refill gaps with hydrated cement - without mechanical debridement = 1000's of years of endurance.
Modern man should use stainless steel rebar. It would add 5-7% to the cost of a reinforced structure - but it would them last 1000 years.
So politician's greed caused the fail-mode of modern reinforced concrete structures as the rebar rusted and expanded.
Repairing rust broken cement is an ongoing process. In Toronto they have had broken pillars they have sand blasted out and re-cemented. In 15 years = repeat. Stainless steel is the only way for permanent reinforced concrete to survive modern salted traffic.