In the article the analysis of methods of calculating non-rigid road pavements according to the criterion of elastic deflection. The possibility of using different solutions (Burmister, Korsunsky, Ivanov, etc.) to calculate the deflection of layers of monolithic and granular materials is evaluated. Based on this analysis, the formulas for calculating the equivalent modulus of elasticity of a two-layer system, the upper layer of which is made of monolithic or granular material, are recommended. The authors made the modification of formulas for calculating the deflection of asphalt concrete layers and the equivalent modulus of elasticity on their surface. The modification was made by introducing into the calculated dependences a scalar quantity, called damage. To calculate the damage, the principle of equivalence of deformations is recommended, in which the damage is determined using the relations of elastic modules of the damaged and solid body. To calculate the elastic modulus of the damaged body, a functional dependence on the number of loads was obtained.

The article assesses the possibility of using ash and slag mixture for the construction of a road bed. To this end, the traditional and modern methods of calculation of road surfaces are analyzed, which allow establishing the parameters of strength and deformability that require experimental determination. Experimental determination of strength and deformability parameters is performed by laboratory tests. For the implementation of tests the authors make samples of ash and slag mixture of different density. During the experiments, the metal stamp is pressed into the model and the experimental dependences of the sediment on the pressure are determined. This makes it possible to calculate the California Bearing Ratio, the deformation modulus, and to establish the pressures at which the mixture of ash and slag operates under compaction or shear conditions. Mathematical models are developed to calculate the parameters of strength and deformability from the value of pressure.

In the report ways of application of the theory of shakedown of material to calculation of coverings and the bases of pavements from the granulated materials are considered. The basic limits of shakedown are given, which include the limits of resilient, elastic and plastic shakedown. The results of three-axis tests are given, on the basis of which the character of accumulation of residual deformation is divided into damped, steady and progressive. These data allow to predict the nature of deformation and provide damped deformation of the granular material, limiting the stress at the most dangerous point.