EXPANDED POLYSTYRENE (EPS) GEOFOAM - AN INTRODUCTION TO MATERIAL BEHAVIOR

The new geosynthetic product category of 'geofoam' was proposed in 1992. It encompasses polymeric and non-polymeric foams that are used in geotechnical applications. Geofoams perform functions that traditional geosynthetic products cannot. In addition, geofoams can be used to complement or enhance the function of other geosynthetics. Thus, geofoams used either alone or with other geosynthetics offer new, cost-effective solutions to a wide variety of geotechnical problems. This paper provides an overview of the geotechnically relevant engineering properties of a specific geofoam material called expanded polystyrene (EPS), which is a type of 'rigid' plastic foam. EPS is the most widely used geofoam material. There is approximately 30 years experience of using it in geotechnical applications, primarily as thermal insulation and ultra-lightweight fill (its density is only about 1% of the density of soil).