Start Free Trial Already a member? Log in The NAHB Green conference is being held this week (April 29 to May 1, 2012) in Nashville, Tennessee. Several GBA employees and bloggers — including Dan Morrison, Michael Chandler, Peter Yost, Ted Clifton, and me — are attending.Nashville has a number of famous buildings, including a full-scale replica of the Parthenon. Nashville’s Parthenon isn’t made of quarried marble, however; it’s made of concrete. So how’s the concrete quality? Do the columns resemble marble?Like vinyl siding (which looks like freshly painted clapboard, but only from a distance), the concrete columns of Nashville’s Parthenon are less convincing up close than they are from 200 yards away. The columns have a kind of exposed-aggregate, sandy finish rather than a smooth-as-marble finish.Whenever I place concrete, I aim for quality — even if I’m just filling a few Sonotubes. I want to get out the air bubbles and create a smooth finish — and I make sure the rebar is properly placed.Why is it that modern buildings with concrete faÃ§ades so often have terrible concrete quality? I’m thinking, for example, of Paul Rudolph’s Art & Architecture building at Yale, a brutalist disaster with concrete so sloppy that the rusting rebar and reinforcing mesh are exposed to the elements.The NAHB Green conference is being held at the Nashville Convention Center, and many attendees are staying at the attached 25-story hotel, the Renaissance Nashville. The skyscraper is only 20 years old, but its concrete faÃ§ade is already streaked with rust from projecting steel tie rods or mesh. (See the photo below.) It’s hard to say whether these unsightly concrete disasters are due to an architect’s ignorance or builder sloppiness. In any case, the concrete buildings of Nashville are no match for those on the Acropolis of Athens.This year’s… This article is only available to GBA Prime Members Sign up for a free trial and get instant access to this article as well as GBA’s complete library of premium articles and construction details.