World’s longest 3D-printed concrete bridge certified in China

A team at the Tsinghua University School of Architecture built an 86.3-foot-long (26.3-meter-long) concrete pedestrian bridge across a canal in Shanghai’s Baoshan district. Designed by Professor Xu Weiguo and his team at the university and built by Shanghai Wisdom Bay Investment Management Company, the bridge design is based on China’s oldest standing bridge — the 1,400-year-old Anji (or Zhaozhou) Bridge in Zhaoxian. While the ancient Anji bridge took more than 10 years to build, this 3D-printed bridge was completed in just under 19 days.

The new 3D-printed bridge was recently certified by the Guinness World Records as the world’s longest 3D-printed concrete bridge. This bridge is longer than Madrids’ Alcobendas Bridge, which previously held the title at 39 feet (12 meters) long. The world’s very first 3D-printed concrete bridge, 26 feet (8 meters) long with integrated steel wires in prestressed concrete layers, was built in the Netherlands by the Eindhoven University of Technology. In addition to Professor Weiguo’s 3D-printed concrete bridge, Shanghai is also home to a 49 foot (15 meters) long 3D-printed polymer pedestrian bridge that took 35 days to build.

The new 3D-printed bridge in Shanghai involved the printing of 176 concrete units by two robotic-arm 3D-printing systems in under 450 hours. The two arms have separate functions, with one stirring and pushing the concrete, and the other controlling the print-path and operating system. The printing used a composite of polyethylene fiber concrete and admixtures. The structure of the bridge is composed of 44 hollowed concrete-printed units, with a deck design inspired by brain coral, while the sides are composed of 68 units, with no templates or reinforcing bars required.