Changing building codes to ensure that new structures are less vulnerable to earthquakes is all well and good, but what about older buildings? If someone told you that the answer was wallpaper, you’d think they were crazy, but a team from Karlsruhe Institute of Technology (KIT) in Karlsruhe, Germany has developed a fabric to reinforce older walls. Marketed as “Sisma Calce,” the low-cost seismic fabric is designed to be plastered on walls to reduce earthquake damage or to at least give survivors a better chance of escape from falling debris.
Developed by Lothar Stempniewski and Moritz Urban in association with Bayer Material Science AG, MAPEI S.p.A., and Dr. Günther Kast GmbH & Co. KG, Sisma Calce is made of glass fibers and elastic polypropylene fibers laid in four directions for added strength. It can be retrofitted to older buildings using special plaster to reinforce exterior walls and reduce earthquake-induced stresses to prevent damage to the wall that would allow cracks to form. In a small or medium earthquake, this may be all that is needed.
Should the stresses prove too great and the wall begins to crack and collapse, the polypropylene fibers would hold the wall together long enough to give survivors a chance to reach safety. In the case of moderate to severe earthquakes, the fabric may limit damage enough to allow the building to be repaired.
The fabric is being marketed by the Italian building material manufacturer Röfix, a subsidiary of the German Fixit Group. Meanwhile, Stempniewski and Urban are working on expanding the application of the fabric by adapting it for indoor use and on masonry and concrete walls. According to Stempniewski, “The challenge in the case of concrete is the higher force that must be absorbed. We thus test new materials such as carbon fibers. In doing so, we at the same time lay the foundations for future innovations to be developed by KIT.”