Concrete construction no longer lasts thousands of years, like the Pantheon in Rome. Instead, its lifespan is roughly 50-100 years, thanks to the way in which modern concrete is reinforced.
Why it matters: That means a multi-trillion-dollar bill is coming due right around now, in the form of concrete construction that needs noisy, dirty, expensive repair.
The big picture: As Robert Courland explains in “Concrete Planet,” modern concrete is poured around steel rebar, which gives it tensile strength. But tiny cracks — found in all concrete — cause water to start rusting the steel, which then expands, cracking the concrete.
By the numbers: One of the most famous concrete buildings in America, Frank Lloyd Wright’s Fallingwater, cost $155,000 to build in 1936 — about $2 million in 2001 dollars. The cost of repairs in 2001 came to $11.5 million.