TESTING THE SUITABILITY OF THE EXTRUDED POLYSTYRENE (STYRODUR) APPLICATION IN THE TRACK SUBSTRUCTURE

Abstract

Extruded polystyrene (XPS) and its excellent thermal insulation properties have been known for over 60 years. Due to its thermal, mechanical, but also deformation properties, XPS has a universal application, not only in the construction industry. This paper presents the results of the first series of experimental measurements of the deformation resistance of the sub-ballast layers with a built-in XPS thermal insulation layer and the sub-ballast layers with a standard structure (crushed aggregate sub-ballast layer). The aim of the first series of experimental measurements was to determine the impact of placing the XPS layer at the subgrade surface level (deformation resistance of subgrade surface E0 = approx. 10MPa or 30MPa) on the deformation resistance of the sub-ballast layers and then to determine the necessary thickness of the sub-ballast layer in relation to the required deformation resistance at the sub-ballast upper surface. Experimental measurements carried out so far show that the application of XPS boards in the sub-ballast layers has almost no or minimal effect on its deformation resistance. Since XPS boards have significantly better thermal technical properties compared to crushed aggregate, considerable savings of this material can be achieved in areas with unfavorable climatic conditions (high values of air frost index).