Come and have a go if you think you're hard enough
First, let’s praise the unsung hero that makes so much possible for concrete in the buildings we’re reviewing here: every deep vertical fin acting as a tall column, every long-span floor-supporting beam, and every sweeping cantilever staircase. The outward, caveman bravura of visible concrete is only made possible (reinforced concrete is brought to you today...) by the understated strength of those wonderful steel reinforcing bars.
Ask what concrete wants to be and it’s similar to Kahn’s brick: an arch (or a dome or a vault). Ask what reinforced concrete wants to be? Answer: anything you damn well want.
Creating space and volume with a singular—albeit composite—material has a purity that even us technically focused engineers can admire. Composite materials have existed for millennia with adobe/cob construction joining of mud-type matrices with straw or stick fibers. Same thing is true with the aggregate/cement/water matrix joined with steel bars, except steel brings all-important strength and ductility into the mix. Modern-day fiber-reinforced plastics are a further development, but of all structural materials only reinforced concrete lets you form it, fill it, and strip it.
Not only that, but it’ll be your finish as well. No need for multiple separate barriers and their associated connections. Here you have enclosure, structure, and safety as one; it’s a one-man band playing a symphony.
So what to do when faced with all this choice? Can the embarrassment of riches prevent focus? I would suggest it’s here that heroism is needed—to boldly go where no material has gone before. It’s like doing a Michelangelo on a large scale and exposing the building from inside the mass pour of concrete. Is it easy? Of course not. I hope you were paying attention—this is heroic stuff.
Heroic and yet so unwieldy. It’s the John Wayne of construction. Boston buildings like Le Corbusier’s Carpenter Center and Sert’s Boston University buildings are the perfect melding of architecture and structure with little room in the relationship for “the others”—the power supply, ductwork, lights, and other MEP accoutrements. Look up to the ceiling soffit: love those sculptural/structural concrete coffers... hate those inserted light fixtures with visible zigzag conduit. I think these days we’re getting better at integrating the various technical disciplines in design, but maybe at the expense of some drama—as though we’re not quite ready for complicated heroes.
And what of the human touch? Do people lovingly caress exposed concrete surfaces? They do downstairs at Boston City Hall, and you can see the results of four decades of hand grease. Somehow it’s not quite equivalent to smoothed stone sculptures or architecture at historic sites. I was lucky enough to go to an eight hundred year old high school in London that had wonderful dipped stone stairs on the way to the school tuck shop (I assume OSHA would consider them a slip hazard). Most of the buildings in this exhibit are forty-something. They’re still figuring themselves out, and we have to give them, and ourselves, time. We may be only a few decades away from seeing and enjoying them as noble elders—ahh, and then they’ll be part of the establishment!
Paul Kassabian is a structural engineer at Simpson, Gumpertz & Heger and works on projects such as art installations, buildings, and large-scale structures. While in the United Kingdom, Paul worked on a range of award-winning footbridge structures and at a steel fabricator firm. Paul is a graduate-level lecturer in the Civil Engineering Department at MIT.