Leave it to the Dutch to create the world’s first 3-D printed concrete bridge. 800 layers of pre-stressed reinforced concrete spanning 26’, and designed for bicyclists. (It is in the Netherlands after all). The bridge uses less concrete than in traditional construction and took three months to print out. For more information, https://www.theguardian.com/technology/2017/oct/18/world-first-3d-printed-bridge-cyclists-netherlands
It’s a developing technology that may well shake up the construction industry’s old school building practices.