|This concept for a bone-like concrete bridge spanning New York’s East River was one of several conceptual approaches to bridges presented by architect and engineer Mark Mimram during last month’s Concrete Reborn conference in New York. Mimram’s idea is that bridges can be more than just transportation links between two bodies of land. They can serve as fully inhabitable structures where the horizontal aspect replaces the vertical.|
Nearly 100 architects, engineers, and invited journalists from the U.S., France, China, Poland, Canada, and elsewhere around the world convened in New York City in early October to discuss the role of concrete in green construction and innovative design.
Architect and engineer Mark Mimram discussed the outcomes of his recent research in his keynote address at Concrete Reborn.
Reflecting on the role of infrastructure in city planning, Mimram presented conceptual approaches to bridges (video)  designed in Paris, Shanghai, New York, and Moscow that were to be more than just transportation links between two bodies of land. Instead Mimram offered towers in the form of inhabitable structures where the horizontal aspect replaces the vertical. “We can look at megastructure as a tool to share the landscape of the city,” said Mimram.
All were designed to be built using ultra-high-performance, fiber-reinforced concrete. One in particular, the New York accommodating bridge, featured a bone-like structure that crossed the East River with a girder structure around a central core bearing and supporting a grill, the cavities of which were to be inhabited.
French architect Rudy Ricciotti discussed his La Villa Navarra , an art gallery built into a hillside in Var, France; it is only accessible to visitors via the Internet. The gallery features a 40-meter-wide precast-concrete roof that cantilevers nearly eight meters despite a thickness that gradually tapers to just three centimeters at the edges.
Keynoting the conference at Columbia was architect and Columbia professor Steven Holl , who discussed several of his well-known and current projects, including his concrete exoskeleton student residence  at the Massachusetts Institute of Technology and his addition to the Nelson-Atkins Museum of Art  in Kansas City, Mo. “I've used a lot of concrete, but I've never started with concrete,” said Holl. “I start with an idea.”
While the overall theme of all the presentations was what Columbia School of Architecture, Planning and Preservation Dean Mark Wigley called “the highest aspirations for concrete,” underlying the work was the recent technological strides made with concrete.
Thanks to scientific research and advances in manufacturing, “Concrete is no longer heavy, cold, or even always grey,” said Bruno Lafont, chair and CEO of French materials producer Lafarge Group , which sponsored both events. “Concrete today is beautiful and lively, and enables architectural feats that until now were inconceivable.” He gave as an example his firm's Chronolia, which can be stripped of its forms just four hours after pouring.