Concrete buildings are losing the
battle against nature’s fury – earthquakes. Although they appear sturdy,
older concrete buildings are vulnerable to the sideways movement of a
major earthquake. Los Angeles officials have known about the dangers for
more than 40 years but have failed to force owners to make their
properties safer. Therefore, university researchers compiled a list of
potentially dangerous concrete buildings within the city. Their findings
point to the fact that society needs to deal with retrofitting
structures.
So what does this have to do with FRP composites? Well, everything.
Since
the late 1980’s, when glass fiber reinforced polymer (FRP) composites
were first applied as external strengthening systems to rehabilitate and
repair reinforced concrete, the construction industry has embraced
these materials as an important tool in the engineers toolbox. Numerous
structures have been seismically retrofitted with glass and carbon FRP
composites ranging from transportation structures (columns, girders,
slabs) to building structures (columns, beams, walls, floors). Both
reinforced concrete and unreinforced masonry are the targets.
There
are still many more structures that need to be fixed and the market
potential is huge. The big challenge is where do society, federal,
state, city, county and other local governments find the money to keep
the public safe in seismic events. What we do know is this; there is
design guidance out there provided by the American Concrete Institute
(ACI) on how to design with FRP composites to repair concrete and
masonry. There will soon be additional design guidance provided for
seismic applications and there are a number of companies already
offering these materials and products. Thousands of installations show
composites are an engineered solution.
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