Expanded polystyrene (EPS) in road construction: Twenty years of Italian experiences

Expanded polystyrene (EPS) is a thermoplastic material, derived from pre-expanded polystyrene beads, that combines an extreme lightweight with versatile strength and thermal insulation. These characteristics made EPS an excellent alternative to natural materials for the feasibility of building and construction projects that would otherwise destined, for time and implementation costs, to be postponed or alienated. Specifically, this technology has been successfully used in road infrastructure sector in the last twenty years in the construction of roads, bridge abutments, lightweight embankments and backfills, above all for the rapid restoration of compromised roads following landslide or calamitous events, representing an interesting and resilient solution in areas exposed to seismic risk or persistent vibratory actions. Thus, the authors want to offer a critical analysis of different EPS road applications in Italy, considering benefits and drawbacks, proposing technical and economic considerations for ideal conditions of use and suggesting failure analysis methods and tools.