Abstract
Expanded polystyrene (EPS) has offered solutions to many civil engineering problems associated with pavement construction. Issues, such as the construction of pavements on low bearing capacity subgrade soils (such as peats and clays), or in regions with severe winters, and the construction of pavements over underground services, have all been overcome with the use of EPS geofoam. This material is used for many pavement applications. These include the use of EPS geofoam as a lightweight fill, as a thermal insulator, a vibration dampener, and for the protection of underground services. Unfortunately, there are a number of barriers that are stopping the use of EPS geofoam from becoming standard worldwide. More has to be done to develop and proliferate technical knowledge to avoid the inefficient, and even the incorrect use of EPS geofoam. There is also room for research in the development of new and innovative applications for the use of EPS geofoam, and for the development of updated standards and test procedures. To facilitate research in these areas, this review paper discusses the design considerations, limitations, and quality assurance procedures for the use of EPS in pavement applications, while paying special attention to the areas of weakness for which recommendations are made. Furthermore, this review paper details historic case studies in which EPS was used, as well as discusses the mechanical properties of EPS, and, finally, its manufacturing process.
1. Introduction
Expanded polystyrene (EPS) is a polymeric geosynthetic material with a cellular closed cell structure. Its manufacture involves the heating of expandable beads of polystyrene with steam, and the placement of these heated expanded polystyrene beads into moulds to create prismatic blocks of EPS [1]. These blocks are manufactured for use in a variety of civil engineering applications. One of its primary applications is in pavement construction to counter the issue of low bearing capacity subgrade soils, an application that has been very successful, and, consequently, has been widely adopted and utilised for more than four decades [2]. Other applications of EPS include thermal insulation, compressible inclusion, slope stability, bridge abutment construction, stadium seating construction, and even noise/vibration dampening [3–5].
9. Conclusion
Expanded polystyrene appears to be a versatile material that can be used in a myriad of geotechnical engineering applications, particularly in pavement construction. This is possible due to the interesting mechanical properties of EPS geofoam. Most notably, its lightweight character, which allows it to be an excellent fill material, its low thermal conductivity, which makes it a suitable pavement insulator in cold climates, its compressibility, which facilitates its application in the protection of underground services, and finally, its vibration dampening qualities that makes it a potential vibration dampener.
