Utilization aspects of extruded polystyrene and expanded clay aggregate in road frost protection structures

The article addresses the issues concerning the impact of negative temperatures on the load-bearing capacity and durability of road elements. It describes methods aimed at mitigating the adverse effects of frost through the utilization of thermal insulation materials with low thermal conductivity. Special attention is given to the significant influence of low air temperatures on the durability and operational characteristics of roads. Under such conditions, the phenomenon of frost heave may also occur. The article presents an overview of the general principles of road structure frost protection applied in the design practice in Poland. Additionally, it highlights the necessity to adapt existing regulations in response to climate change, as well as the need for updating and validating normative recommendations. A considerable portion of the article is devoted to discussing the utilization of thermal insulation properties of extruded polystyrene and expanded clay in road construction. The high efficacy of these materials, particularly extruded polystyrene, in providing insulation for the lower structural layers of roads is demonstrated due to their low thermal conductivity. A comparative analysis between the use of extruded polystyrene and expanded clay for anti-frost protection in roads is also conducted using a graphical method. Furthermore, general considerations for the design of road structure components employing insulating materials to ensure effective frost protection are presented. The paper highlights a great importance of the issue to international research community, as the discussed topics are current and vital for road designers, contractors, and users in numerous countries. Finally, the authors draw conclusions that underscore the significance of the investigated issues for road users, designers, and contractors involved in road infrastructure.