Geofoam FAQ
Why do I need this product?
Using Falcon Geofoam allows building over unstable areas that might otherwise sink
from the weight of the construction materials or traffic. It can reduce the lateral
stress of embankments on bridges or buildings, allowing the engineer to reduce concrete,
rebar, struts, etc originally designed to hold back that soil weight. The product
can replace a portion of the concrete in applications like stadium tiered seating
or steps. Rather than stabilizing soil through exchange (time delays) or compaction
(money), the site can begin construction immediately. Pipes or culverts under roadways
can be constructed with less concern for crushing, as shaped Falcon Geofoam can
be customized to fit around the pipe just like shaped EPS is used as packaging.
How does it work?
Falcon Geofoam has impressive compressive resistance while contributing little weight
of its own. The product can be supplied in various sizes and shapes, but is typically
a large block (32"x48"x96"). Blocks are layered in the cavity or alongside a bridge,
sometimes held together with construction fasteners, sometimes covered by a geomembrane.
Once covered with soil, gravel, and/or concrete, the foam spreads the pressure from
above over a wide area while exerting little lateral force on nearby structures.
This is how it stabilizes soils that would otherwise sink, and protects structures
from being pushed by embankments.
Is it safe?
Falcon Geofoam is an inert plastic, comprised of polystyrene (think coffee cups),
air, and a small amount (less than 1%) of flame retardant. A typical block weighs
less than 200 pounds, is easily maneuvered into place, and has no sharp edges (it
is foam!). Blocks should be battened down while waiting for use, since strong winds
can actually pick them up.
Is the performance warranted?
Falcon Geofoam is warranted to meet the minimum physical properties for the product
grade required by the client. We encourage the client implement a sampling program
for large projects, to verify that the product meets specification from start to
finish. However, the performance of the PROJECT is not warranted, that is up to
the client engineer to select the appropriate product grade for the forces that
will be encountered in use.
How has it been tested?
Falcon Geofoam is tested for compressive resistance on an ongoing basis, using 2"x2"x2"
cubes per ASTM D6817. Unlike a piece of commodity expanded polystyrene that might
be used to insulate a basement wall, Falcon Geofoam must meet strict performance
requirements at the lowest level of compressive resistance, 1% deformation. Almost
any EPS product will perform the same at 10% deformation on a density comparison
basis for compressive resistance. But minor defects in the EPS show up in the 1-2%
deformation range that can result in failure. This difference is very important!
It is in this deformation range that the foam will "bounce back" from the load exerted
on it. Many EPS molders test at 10% deformation; these results mean nothing in a
geofoam application!
Is it code approved?
The Federal Highway Administration and AASHTO have adopted geofoam as an approved
construction product and technique to reduce costs and decrease project time. Several
prominent uses of the product include protecting the car tunnel under the river
in Boston's "Big Dig" project, stabilizing soil under a highway for the Utah winter
Olympics some years ago, and stabilizing a landfill so that an entire mall could
be constructed in Detroit. All of these projects used hundreds of truckloads of
geofoam each.
Is it 3rd party certified?
Falcon Geofoam is 3rd party listed with Underwriters Laboratories for physical properties
per ASTM D6817. This means that on a continual basis, their auditors visit our plants
to confirm we meet performance requirements specific to geofoam applications. UL
and other 3rd party agencies have long audited EPS suppliers for burning (E84) and
gross physical properties (C578) - BEING CERTIFIED AGAINST THESE STANDARDS MEANS
NOTHING FOR GEOFOAM APPLICATIONS. Before considering a supplier, check that they
are 3rd party certified against ASTM D6817, "Standard Specification for Rigid Cellular
Geofoam".
What are typical applications?
Bridge abutments and underfill, slope stabilization, levees, dams, berms, roadway
stabilization, railway stabilization, culverts, landscaping, noise reduction walls,
road widening, retaining walls, ultra lightweight fill, stadium and theater seating,
airports, marine structures, seismic stabilization, pipeline protection, fluid transmission
and draining, vibration dampening, compressive inclusion, land reclamation, plaza
decks. Anywhere that allot of weight needs to be spread out or reduced below grade,
or it is cost effective to fill a void with an alternate weight bearing product.
What are the recommended installation guidelines?
Our Engineering Department can help with efficient layouts to maximize use of the
product strength while minimizing costs. Designing a fill solution without considering
the material efficiency and freight maximization is very costly. Often we have adjusted
the size of the product for the client so that the lowest cost is maintained. Helpful
handling and installation golden rules can be found in ASTM D7180, "Standard Guide
for Use of Expanded Polystyrene (EPS) Geofoam in Geotechnical Projects". The buoyancy of EPS is about 60 pounds per cubic foot, so it is critical that sufficient ballast weight be applied to offset water table issues where present.
What precautions should be exercised when using Falcon Geofoam?
Avoid contact with solvents as some solvents may dissolve the product. Protect from
solvents using a geomembrane. The product contains a flame retardant, but is combustible,
so don't smoke around it or expose it to flames, sparks, or other ignition sources. Blocks of geofoam are light enough to be blown by wind or to float in high water. This can potentially create hazards to personnel and equipment. Care should be taken to ensure the material is properly secured for the conditions at the job site.
What are other benefits of Falcon Geofoam and EPS (Expanded Polystyrene) in general?
Falcon Geofoam can be customized to the dimensions and strength (compressive resistance)
required for the job, vs the commodity approach of most other rigid foam products.
It does not contain a gas that will deplete over time, such as formaldehyde, CFC,
HCFC, or any other gas, just air. This means the thermal insulation value does not
degrade, nor does the product contribute to global warming, something other rigid
foam insulations cannot claim.