3D Printing Helps Concrete Lighten Up
Crossrail, a massive expansion of the London Underground, is the first big commercial building project to use 3-D printing, according to a June 3 story in The Economist.
Construction firm Laing O'Rourke is using the technique to create hundreds of concrete panels to install in the line's miles of passenger tunnels.
Printing concrete itself doesn't work very well -- weakness develops between the layers of material. But by printing ultra-precise wax molds and casting the Crossrail panels, the builder can achieve complex shapes that are both light and strong, without the flaws that have kept printed concrete from working in large buildings.
And Crossrail is undoubtedly large. The $19 billion (15 billion GBP) project will run more than 100 kilometers (62 miles), adding 10 percent to central London's rail capacity. Workers dug 42 km of new tunnels using eight, 1,000-metric-ton tunnel-boring machines. The first segments of the project opened to users this year, and by the end of next year the finished lines will zip commuters across London.
The full Economist article is here, and you can find more information about Crossrail here.