'Earthquake Wallpaper' Holds Together Brick Walls
Researchers inspect glass fiber fabric, a part of a wallpaper made to reinforce brick buildings against earthquakes.
CREDIT: Screenshot from "'Earthquake wallpaper' can save lives" by BayerTVinternational
Researchers in Germany have created wallpaper that holds brick walls together during an earthquake, keeping bricks from falling and giving people time to run out of the building. "Our goal was to give people more time to get out safely into the open in the event of an earthquake," one of the wallpaper's developers, Lothar Stempniewski, said through a translator in a video by Bayer MaterialScience. Stempniewski is a building materials researcher at the Karlsruhe Institute of Technology in Germany.
Masonry is a cheap and common building material that can carry heavy loads, as long as the force on them comes straight down from above. But it isn't sturdy during the side-to-side shaking of earthquakes, so it's one of the building materials most likely to fail even during moderate quakes. Brick walls bend and develop cracks, Stempniewski explained.
Karlsruhe researchers thought they could reinforce brick walls together with layer of glass fiber fabric, which is made of many woven filaments that are elastic and resistant to cracking. The fabric should distribute earthquake forces all along the wall, reducing the stress on weak places in the wall near doorframes or windows, according to Bayer's research magazine.
Yet the institute researchers also needed a way of sticking the fabric to walls. Regular wallpaper paste pulled off the walls during shaking, according to the magazine. Bayer MaterialScience formulated an adhesive with polyurethane beads that are actually tiny balls of molecule-scale chains. When the adhesive contacts a brick wall, the polyurethane beads fill in cracks, then merge with one another, anchoring themselves to the wall. The glass fabric, laid over the adhesive, gets wrapped up in the beads' molecular chains.
In tests, Karlsruhe researchers found that brick walls covered with their wallpaper stayed intact during shaking. Even if the wall cracks inside the wallpaper, the paper holds it together from the outside.
The wallpaper is ready for people to use and it should be easy to apply, said Michael Engel, Bayer's project manager for the wallpaper research. Bayer and Karlsruhe will find partners to start selling the wallpaper sometime this year, according to the Bayer video.