IMPROVEMENT OF THE ROUGHNESS FORECASTING MODEL OF COATING OF NON-RIGID ROAD PAVEMENT COATING

Abstract

To ensure safe, comfortable driving at high speeds, a strong, even surface is required for the entire life of the pavement. In this regard, the issue of predicting changes in the equality of coverage over time is very important. The article considers the peculiarities of changing the longitudinal equality of the road surface. Purpose is to improve the model of forecasting the equality of non-rigid pavement. Methods – analytical and experimental. The analysis of existing decisions on the issue of forecasting the equality of coverage is performed. The most important factors influencing the change in the equality of road coverage have been identified. Based on the analysis of theoretical models and a number of experimental data, an improved model for predicting the equality of coverage of non-rigid pavement is proposed. MathCAD and MS Excel were involved in the development of an improved model that takes into account the most important factors. The model of change of coverage roughness, where increase in the roughness index over time is considered as a function of such parameters, is improved: the modulus of pavement elasticity (actual or required); the number of load cycles for t years of pavement operation; the share of trucks in the traffic flow; the factor of safety margin of the pavement structure. The adequacy of the developed model of changing the roughness of coverage is confirmed by statistical processing of experimental data obtained by the thesis author and other researchers on public roads with different service life, and calculated data under the theoretical model. The Pearson correlation coefficient between experimental and calculated data is more than 0.95, which indicates the adequacy of the developed model. Compared to the well-known models of forecasting coverage roughness, the improved model allows to apply a wider range of values of the general equivalent modulus of elasticity of pavement design (from 100 MPa to 600 MPa) and to receive forecast values of roughness for service life of non-rigid pavement over 5 years.