Experimental and Numerical Verification of the Railway Track Substructure with Innovative Thermal Insulation Materials.

Libor Izvolt,Marian Drusa,Marta Kadela,Peter Dobes,Michaela Holesova

doi:10.3390/ma15010160

Libor Izvolt, Marian Drusa + Show 3 more

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https://doi.org/10.3390/ma15010160

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Abstract

The article aims to present the modified structural composition of the sub-ballast layers of the railway substructure, in which a part of the natural materials for the establishment of sub-ballast or protective layers of crushed aggregate is replaced by thermal insulation and reinforcing material (layer of composite foamed concrete and extruded polystyrene board). In this purpose, the experimental field test was constructed and the bearing capacity of the modified sub-ballast layers’ structure and temperature parameters were analyzed. A significant increase in the original static modulus of deformation on the surface of composite foamed concrete was obtained (3.5 times and 18 times for weaker and strengthen subsoil, respectively). Based on real temperature measurement, it was determined the high consistency of the results of numerical analyses and experimental test (0.002 m for the maximum freezing depth of the railway line layers and maximum ±0.5 °C for temperature in the railway track substructure–subsoil system). Based on results of numerical analyses, modified railway substructure with built-in thermal insulating extruded materials (foamed concrete and extruded polystyrene) were considered. A nomogram for the implementation of the design of thicknesses of individual structural layers of a modified railway sub-ballast layers dependent on climate load, and a mathematical model suitable for the design of thicknesses of structural sub-ballast layers of railway line were created.

Highlights

Publisher’s Note: MDPI stays neutralThe growing urbanization of cities and agglomerations, which is associated with an increase in the number of people living an urban way of life, is simultaneously causing an increased demand for the transport of goods and people
It should be noted that that segments differ from each other by the different bearing capacity segments A and B differ from each other by the different bearing capacity deterdetermined the level of subgrade sub-surface, but by bydifferent the different thickness the mined at theatlevel of subgrade sub-surface, and the thickness of theofcomcomposite layer of foamed concrete
The aim of the article was the optimization of railway track substructure by using innovative layers system to reduce the consumption of natural aggregate as an exhausting resource and the costs

Summary

Introduction

Publisher’s Note: MDPI stays neutralThe growing urbanization of cities and agglomerations, which is associated with an increase in the number of people living an urban way of life, is simultaneously causing an increased demand for the transport of goods and people. Support of transport must be conformed with the initiative of lower energy consumption, and lower noise production and greenhouse gas emissions, the so-called green transport [1]. Railways can play an important role in meeting the needs of the population in travel for work, recreation, sports, or tourism, because rail transport is more ecological, economical, but it is reliable and very safe for long distances. Year of Rail”, with the aim of promoting the use of railway transport as one of the most sustainable modes of transport. In 2018, railway transport in the EU accounted for only. 0.4% of total greenhouse gas emissions from transport; for comparison, road transport produced 71.8% [2]. Ensuring reliable and safe tracks for railways (especially for high-speed railways) requires components of the railway superstructure and substructure with sufficiently high with regard to jurisdictional claims in published maps and institutional affiliations

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