The use of EPS geofoam in civil engineering applications continues to grow significantly around the world. Global shipments of EPS geofoam products are projected to increase 5% per year from 2018-2023, driven in large part to demand in the transportation sector. EPS geofoam is commonly used in the construction of railways, airport runways, roads, bridges and highways as a structural fill material. Its compressive strength and lightweight characteristics make it an attractive alternative to soil and other fill materials.

Several design considerations must be taken in account when specifying the use of EPS geofoam in transportation, including protection against the risk of exposure to hydrocarbons, solvents, gases and vapors such as methane and radon. Organic compounds present in materials like gasoline, oil, asphalt and sealants are of concern when it comes to protecting EPS geofoam from chemical attack because of the risk of exposure to these chemicals along roads and highways.

Today, geomembranes specified to protect EPS geofoam from chemical attack are selected based upon chemical compatibility and resistivity criteria. A study was conducted to assess the effectiveness of current geomembrane materials typically specified to protect EPS geofoam from chemical attack against gasoline. The results of the study would suggest that although these materials exhibited chemical resistant properties, they did not adequately protect EPS geofoam from rapid and significant deterioration due to exposure to the vapor migration of organic compounds present in gasoline.

The purpose of this paper is to examine and attempt to define chemical compatibility, chemical resistivity and chemical barrier in the context of the properties and characteristics of both legacy and advanced geomembrane materials and to illustrate their effectiveness in protecting EPS geofoam from chemical attack.

Technical Paper Publication: This technical paper was originally published and presented in the Geosynthetics Conference 2019 proceedings in Houston, TX.