Selecting the correct EPS Geofoam density grade is one of the most important design decisions for any geofoam project.
Step 1: Determine the Design Load
Calculate the vertical stress that will be applied to the top surface of the geofoam, including pavement structure weight, surcharge loads, and traffic loads.
Step 2: Apply a Factor of Safety
Use the compressive resistance at 1% strain as the allowable stress to keep deformations within the elastic range.
Step 3: Match Load to Grade
Compare your required compressive resistance to the ASTM D6817 values for each grade and select the lowest grade that meets your requirement.
Step 4: Consider Application-Specific Factors
For bridge approaches and heavy truck traffic, a higher grade is often prudent. For residential pool backfill, EPS 12 or EPS 15 may be sufficient.
Common Grade Selections by Application
EPS 19 is the most commonly specified grade for roadway embankments. EPS 22 is preferred for bridge approaches. EPS 12 and EPS 15 suit residential applications.
Key Takeaways
- Base grade selection on the compressive resistance at 1% strain from ASTM D6817
- EPS 19 is the most common grade for roadway and civil fill applications
- Apply a factor of safety — use the 1% strain value as your allowable stress
- Higher grades are appropriate for bridge approaches and heavy traffic areas
Have a Project That Needs Geofoam?
Submit your details and get connected with supply options in your area.