Ph.D. thesis: 193 p., 32 tables, 61 figures, 4 appendixes, 147 references.
IMPROVEMENT OF THE METHODOLOGY FOR DETERMINING AND PREDICTING VARIATIONS IN THE PERFORMANCE CHARACTERISTICS OF ASPHALT PAVEMENT UNDER THE INFLUENCE OF DEICING AGENTS IN THE CLIMATE OF NORTHWEST CHINA.
The aim of the work is to improve methods for assessing and predicting changes in the performance characteristics of asphalt pavement, taking into account changes in the physical, hydrophysical and mechanical properties of asphalt concrete, under the influence of deicing agents in the climate of Northwest China.
The object of research is the process of changing the performance characteristics of asphalt pavement.
The subject of the research is to establish the regularities of the complex effect of deicing agents on the properties of asphalt pavement.
Research methods. Experimental studies of the performance characteristics of asphalt pavements under the influence of deicing agents. Generalization of research results using analytical and mathematical-statistical methods of processing the results.
Theoretical studies were carried out on the basis of the equations of mechanics and hydromechanics, as well as using modern software products of Matlab, SPSS, Prism, Python. Experimental studies were performed on a special experimental setup using high-precision measuring instruments. The results of the experiments were processed using the methods of experiment planning and mathematical statistics.
Today, the use of deicing agents on roads is a standard traffic safety measure and is widely used for winter maintenance of various road surfaces, bridges and airport runways.
However, the application of deicing agents is a global problem, prompting scientists and research institutions to conduct studies to determine the impact of deicing agents on roadway structures and the environment.
In the course of the research work, changes in the temperature parameters of asphalt concrete layers were studied, which made it possible to establish the optimal values of the concentration of deicing agents, depending on the freezing point, to assess their effect on the properties of asphalt concrete. The dependencies of changes in the performance characteristics of asphalt pavement on the influence of deicing agents with a concentration of NaCl 20 %, CH4N2O 15 %, CH2CH3OH 20 %, during preliminary freezing-thawing of asphalt concrete samples at temperatures of -5 °C, -15 °C, -25 °C, saturated-moistened and hydrodynamic impact were determined. To conduct the research, a methodology was developed and an experimental hydrodynamic apparatus was manufactured that simulates the process of fluid impact on the road surface from a car tire while driving and allows for modeling of various operating modes to assess changes in road pavement characteristics.
The classical model for predicting the performance characteristics of asphalt pavement GM(1, N) was improved by integrating the basic values using the Simpson formula, which allowed us to obtain a new prediction model NPGM(1, N), the accuracy of which exceeds the analog by 13-16 %, while the maximum value of the relative error when checking for adequacy does not exceed 4.2 %.
