Determination of the calculated thickness of thermal insulation made of ash and slag waste

Abstract

The roadbed of a railway track is often subject to deformations, this is due to changes in its thermophysical, physical and mechanical and physicochemical characteristics. The development of deformations due to the settlement of thawing soils and the swelling of freezing soils is a complex multifactorial process. To combat the swelling of freezing soils and the settlement of thawing soils, a heat-insulating layer of extruded polystyrene foam boards is currently used. However, as operating experience shows, this material has a number of disadvantages that directly affect the stability of the roadbed. One of the possible substitute materials for roadbed thermal insulation can be considered a new material based on ash and slag waste. According to the results of laboratory studies, this material has heat capacity and thermal conductivity indicators that are slightly worse than those of extruded polystyrene foam, but the strength under uniaxial compression is significantly higher. The article provides their qualitative and quantitative characteristics. This article presents the results of calculations carried out in the Frost 3D Universal software package to determine the optimal thickness of a heat-insulating layer based on ash and slag waste. In order to establish the dependence of the thickness of the new material on the sum of degree-days of negative temperatures per year, the calculations were carried out under different climatic conditions. Based on the calculation results, it was found that the new material can be used as a protective heat-insulating layer in the body of the embankment of the roadbed to prevent swelling of the soils located below the heat-insulating layer. A trend line was found, expressed by a functional dependence, to determine the thickness of the heat insulation under different climatic conditions.