Geofoam

Applications

Geofoam applications have two primary categories. Geofoam falls within the Insulation category if thermal resistivity (R-value) is a major function of the material. Geofoam falls with the Lightweight Fill category if R-value is not a major function of the material.

Insulation

Geofoam insulation is used to protect vital infrastructure from damage caused by either permafrost thaw or seasonal frost action. Projects typically require multiple inches of insulation thickness. Since the late 1960s, rigid polystyrene insulation has been used to protect infrastructure from damage caused by permafrost thaw and seasonal frost heaving.

In permafrost areas, the goal is to keep the permafrost frozen. Insulation impedes heat moving down into the permafrost during the warmer months, illustrated with the Summer heat arrows, above. Heat gain causes permafrost thaw and settlement, which can result in damage to infrastructure located above the permafrost.
In seasonal frost areas, the goal is to prevent soil under the insulation from freezing. Insulation impedes heat escape up out of the underlying native soil during colder months, illustrated with the Winter heat arrows above. Heat loss causes soil to freeze, expand, and heave during the winter. In the spring, surface heat causes frost heaves to thaw and settle. This seasonal frost action cycle can result in infrastructure damage.

In both scenarios, geofoam insulation is used to protect infrastructure by mitigating the movement of unwanted heat.

Lightweight Fill

Geofoam lightweight fill is often used for construction on soft ground to reduce settlements or reduce loading for slope stabilization, retaining wall, or abutment backfill. Projects typically require multiple feet of lightweight fill thickness. In these types of applications, resisting heat flow (R-value) is not usually a primary function of the material.

Geofoam is used to replace undesirable soils. The material is about 1% of the weight of soil and substantially lighter than other fill alternatives. Lighter weight reduces associated gravitational driving forces that cause destabilization on adjacent and underlying soils and structures. The high compressive strength of geofoam is also a good substitute for soils with high settling potential.

Geofoam Infrastructure Application Examples

Airport Runway/Airfield
Roadway
Railway

Culvert
Pipeline
Ice Pad
Bridge Abutment
Retaining Wall

Slope Stabilization