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

The new geosynthetic product category of 'geofoam' was proposed in 199 2. It encompasses polymeric and non-polymeric foams that are used in g eotechnical applications. Geofoams perform functions that traditional geosynthetic products cannot. In addition, geofoams can be used to com plement or enhance the function of other geosynthetics. Thus, geofoams used either alone or with other geosynthetics offer new, cost-effecti ve solutions to a wide variety of geotechnical problems. This paper pr ovides an overview of the geotechnically relevant engineering properti es of a specific geofoam material called expanded polystyrene (EPS), w hich is a type of 'rigid' plastic foam. EPS is the most widely used ge ofoam material. There is approximately 30 years experience of using it in geotechnical applications, primarily as thermal insulation and ult ra-lightweight fill (its density is only about 1% of the density of so il).