New geosynthetic materials such as inorganic fibers, composites and plastics are being used more frequently in construction engineering, and with greater results, than ever before. Today, they are just as likely to be used as structural steel and concrete.
In civil engineering applications, the use of EPS geofoam typically saves both time and money. EPS is unaffected by weather and is environmentally safe.
Its service life is comparable to other conventional construction materials and will retain its physical properties under engineered conditions of use.
What is EPS Geofoam?
EPS Geofoam describes low-density (between 15 and 22 km/m3) cellular plastic foam solids used in geotechnical applications such as lightweight fill for construction on soft ground, slope stabilization, and retaining wall or abutment backfill. It is also used for roadway and runway subgrade insulation and foundation insulation. Polystyrene is the main polymer used to produce Geofoam, which is created in a two-stage, molded-bead process. Geofoam is typically produced in blocks that can be cut into various shapes and sizes to suit specific projects. It can also be produced in a range of densities to meet varying project needs. Today, Tri State Foam's Geofoam and its counterparts are just as likely to be used as structural steel and concrete.
The two key properties that make EPS Geofoam so attractive in design and construction are its low density for stress and deformation-related construction problems, and its thermal insulation properties that help combat frost-heave problems. EPS is unaffected by weather and is environmentally safe. Its service life is comparable to other conventional construction materials and will retain its physical properties under engineered conditions of use. Using EPS Geofoam in your project will typically save both time and money.
Other notable EPS Geofoam properties are:
- High compressive strength: Makes Geofoam durable and resistant to damage over time
- Low moisture absorption: The rates of moisture absorption increase as density increases, but still remain minimal
- Low interface friction: In direct shear tests, the interface friction between sand and Geofoam is comparable to the internal friction of sand alone
Inside Geofoam
The two key properties that make EPS geofoam so attractive in design and construction are its low density for stress and deformation-related construction problems, as well as its thermal insulation properties that help combat frost-heave problems.
The density of geofoam is controlled during the manufacturing process, and ranges from 15 to 22 kg/m3 for lightweight fill applications. This low density is only about 1 to 2 percent of the density of soil and rock, making geofoam a superior, ultra-lightweight fill material that significantly reduces the stress on underlying subgrades. The lighter load reduces settlements and boosts stability against bearing and slope failures.
Because geofoam is about 99 percent air by volume, it is a very efficient thermal insulator. In addition, geofoam can be produced with higher densities to obtain the higher R-values preferred for insulation purposes, as well as to achieve lower deformation.
Geofoam has been used in road and airfield pavements and railway track systems, beneath refrigerated storage buildings, sports arenas and storage tanks to prevent ground freezing and heaving, and in below-ground building segments to reduce seasonal heating and cooling requirements.
Other notable EPS geofoam properties are:
- High compressive strength: Makes geofoam durable and resistant to damage over time
- Low moisture absorption: The rates of moisture absorption increase as density increases, but still remain minimal
- Low interface friction: In direct shear tests, the interface friction between sand and geofoam is comparable to the internal friction of sand alone
Applications of EPS Geofoam
Geofoam has been used in road and airfield pavements and railway track systems, beneath refrigerated storage buildings, in sports arenas and storage tanks to prevent ground freezing and heaving, and in below-ground building segments to reduce seasonal heating and cooling requirements. In addition, Geofoam can be produced with higher densities to obtain the higher R-values preferred for insulation purposes, as well as to achieve lower deformation.
Outlined below are specific applications of Geofoam in geotechnical construction.
Road Embankments
Traditional lightweight materials used in embankment construction include chipped bark, sawdust, dried peat, fly ash, slag, cinders, cellular concrete, lightweight aggregates, shredded tires, and seashells. Tri State Foam's EPS Geofoam will outperform these traditional options because it is up to 50 times less massive, thus providing maximum available right-of-way, faster construction schedules, lower traffic impact, clean construction near waterways, reduced labor costs, and minimal future maintenance.
Retaining Wall or Abutment Backfill
Placing EPS Geofoam behind retaining structures and below-grade walls reduces lateral pressure, lowers settlements, improves waterproofing, and provides better insulation. The low density and relatively high compressibility of Geofoam also limit horizontal forces against retaining structures during earthquakes.
Slope Stabilization
Our EPS Geofoam is 50 to 100 times less dense than natural soil which allows Geofoam to be highly effective in improving the stability and safety of slope construction, minimizing the potential of failure surfaces between driving blocks and resisting blocks in a slope.
Pavement Insulation
EPS Geofoam is used successfully as highway and airport pavement subgrade insulation to reduce subgrade stress and deformation as well as to protect against frost-heaving.
Frost-Protected Shallow Foundations
"Working with Tri-State Foam was a great experience. The shipment and installation went very well with the assistance of their well knowledge staff. The spend two days on site working hand in hand with our men to make sure the installation was correct and teach our company a new construction procedure." -Brian Laub, Project Manager, Wohlsen Construction Company
Adding an EPS Geofoam subfloor to a construction project increases the value of the project by offering protection against vegetation, weather, and moisture damage while providing an insulating and stable base. The durable quality of EPS foam allows Geofoam to be useful in constructing lightweight and stable subflooring for any building construction job.
Tri State Foam's custom cutting capabilities allow for channels within the Geofoam to be cut to allow for piping, electrical wire, or plumbing to be inexpensively run through a subfloor if necessary.
At Tri State Foam, we will work closely with your own staff of workers to make sure that insulation is completed correctly and quality matches your expectations.
In cold climate regions, building foundations are required to extend below depths of expected frost penetration. This typically requires housing construction with basements or crawl space below floor grade; however, by using EPS Geofoam, homes can be built in cold climates with slab-on-grade support. Frost-protected shallow foundations significantly reduce construction costs as well as energy costs.
Stadium Seating
"I am pleased to say that my first experience with Tri-State Foam has been exceptional. The quality of the product and precision to which it was cut was phenomenal. We used the foam to build up auditorium seating in a 12 theater complex for use with a concrete topping. The layout required radial risers, ramps, and intermediate stairs. The foam performed well and was easily installed. The best part of the experience was the willingness and flexibility of the Tri-State staff to accommodate my ever changing schedule and deliver on site promptly with minimal lead time. The next time I have a job requiring foam I already know where my first call will be going." -Lloyd E. Thomas, Jr., Project Manager, S.B. Ballard Construction Company
Tri State Foam's customization capabilities allow for any number of unique applications of EPS Foam to be created. One way which EPS can be used in this manner is by creating easy to install stadium-style seating. The qualities of EPS lend itself to use indoors or outdoors with minimal erosion effects due to surrounding soil composition or weather damage.
Replacing EPS foam easy, inexpensive, and usually only needs to be done every 20 years or even longer for unexposed EPS.
Tri State Foam takes pride in the quality of its product and will work closely with you, as a client, to ensure that all Geofoam is installed correctly and meets your expectations.
