India, Sept. 5 -- A crack in a concrete wall is called a defect. An engineer sees something deeper: a message from time. It tells us that materials age and even strong structures exist within design limits. Civil engineering, therefore, is more than construction. It is an encounter with impermanence.

Every structure carries the certainty of deterioration. Concrete weathers, steel corrodes, roads develop potholes, bridges experience fatigue, dams accumulate sediment and foundations settle. We celebrate a bridge or highway, photograph the ribbon-cutting and then overlook the quieter responsibility: maintenance.

No bridge is permanent. A design life of 50, 75 or 100 years is not a promise of immortality. It is an engineering expectation ba...