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GeoFoam(TM): 1-2 lb/ft3 Geotechnical EPS

Dyplast GeoFoamTM (1-2 lb/ft3) refers to large rigid cellular EPS blocks used in Geotechnical engineering applications. Dyplast GeoFoam has very low density compared to soil, cement, or rock, good insulation, low hydraulic conductivity, as well as strength and deformation properties that complement soil behavior. Dyplast GeoFoam has a wide variety of benefits, including:

  • accelerates construction,
  • expands possible solutions for difficult soil problems,
  • has excellent load distribution characteristics, and
  • reduces construction costs.

Uses include bridge construction, highway construction, landscaping, parking structures, airport runways, earthen dams, and load control on buried pipes. Dyplast Products can provide material in blocks up to 20 feet long, 4 feet wide, and 40 inches thick to maximize the construction process.

Also, read our GeoFoam Case Study regarding the Sharpes Ferry Bridge Project in Florida.

GeoFoam has many different and varied applications, yet the main applications include:

Slope Stabilization Geotechnical engineers have long recognized the utility of lightweight fill to reduce mass and associated gravitational driving forces. Dyplast GeoFoam can be from 50-100 times less massive than other fills and soils.

Embankments Dyplast GeoFoam embankments do not require pre-loading and removal normally associated with embankment construction on soft ground. Side slopes at 2:1 or even in vertical finish can be developed because Dyplast GeoFoam imposes very light loads on the foundation.

Retaining Structures Placement of Dyplast GeoFoam behind retaining structures and below grade wall can offer advantages of reduced lateral pressure, lower settlements, improved waterproofing, and better insulation.

Utility Protection Dyplast GeoFoam has been used to control loading on rigid buried pipes by development of an induced trench condition.

Pavement Insulation The design of highway or airport pavements may be governed by subgrade stress/deformation criteria or frost heave protection requirements.

Shallow Foundations The use of Dyplast GeoFoam allows construction of buildings with frost protected shallow foundations.

Landscape Design The use of Dyplast GeoFoam expedites the design and construction of decorative formations without adding weight.

GeoFoam is also available in densities from 2-3 lb/ft3.

Dyplast GeoFoam (Expanded Polystyrene) Minimum Physical Properties per ASTM D6817

Density, minimum  lb/ft3 D303 or D1622 0.9 1.15 1.35 1.8
Compressive 1% Deformation: (Minimum) lb/in2 D1621 >3.6 >5.8 >7.30 >10.9
Compressive 5% Deformation: Actual (Minimum) lb/in2 D1621 >8.0 >13.1 >16.7 >24.7
Compressive 10% Deformation: Actual (Minimum) lb/in2 D1621 >10.2 >16.0 >19.6 >29.00
Flexural Strength lb/in2 C203 >25.0 >30.0 >40.0 >50.0
Oxygen Index % D 2863 >24 >24 >24 >24

ASTM D7180 (the Standard Guide for Use of Expanded Polystyrene (EPS) Geofoam in Geotechnical Projects) states that "the typical limit for many EPS geofoam projects is to consider the compressive resistance at 1% strain. The compressive behavior at 1% strain is within the elastic region of EPS geofoam and provides acceptable short-term deflections in addition to limiting long-term creep deformation, and behaves as a linear elastic material up to a strain of about 1%." As a result, the design recommendation of the majority of geotechnical engineers is to limit loading to the compressive resistance at 1% strain. Note, however that Dyplast GeoFoam at 1.5 and 2.0 lb/ft3 densities has been tested by independent laboratory and found to have Compressive Resistance that exceeds the minimum requirements for ASTM D6817 even at higher deformations of 5% and 10%. Yet each end-user must ensure the design engineer considers the specific characteristics of the project.