Prediction Models of Shear Parameters and Dynamic Creep Instability for Asphalt Mixture under Different High Temperatures.

Junxiu Lv,Xiaoyuan Zhang

doi:10.3390/polym13152542

Abstract

This study mainly investigates the prediction models of shear parameters and dynamic creep instability for asphalt mixture under different high temperatures to reveal the instability mechanism of the rutting for asphalt pavement. Cohesive force c and internal friction angle φ in the shear strength parameters for asphalt mixture were obtained by the triaxial compressive strength test. Then, through analyzing the influence of different temperatures on parameters c and φ, the prediction models of shear strength parameters related to temperature were developed. Meanwhile, the corresponding forecast model related to confining pressure and shear strength parameters was obtained by simplifying the calculation method of shear stress level on the failure surface under cyclic loading. Thus, the relationship of shear stress level with temperature was established. Furthermore, the cyclic time FN of dynamic creep instability at 60 °C was obtained by the triaxial dynamic creep test, and the effects of confining pressure and shear stress level were considered. Results showed that FN decreases exponentially with the increase in stress levels under the same confining pressure and increases with the increase in confining pressure. The ratio between shear stress level and corresponding shear strength under the same confining pressure was introduced; thus, the relationship curve of FN with shear stress level can eliminate the effect of different confining pressures. The instability prediction model of FN for asphalt mixture was established using exponential model fitting analysis, and the rationality of the model was verified. Finally, the change rule of the parameters in the instability prediction model was investigated by further changing the temperature, and the instability forecast model in the range of high temperature for the same gradation mixture was established by the interpolation calculation.

Highlights

As a comprehensive effect of traffic volume increase, channelized traffic, and sustained high-temperature weather, rutting has become one of the main pavement diseases, and the asphalt pavement with semi-rigid base is generally adopted in China [1,2]
The usage perspective of the existing highway in Jiangsu province of China indicates that the rutting instability of asphalt pavement will occur in six to 10 years, where the instability time is related to the mixture type, load level, temperature, pavement structure, and other factors
Lack of high-temperature stability for asphalt mixture is the fundamental cause of the rutting disease, which seriously influences the quality of asphalt pavement

Summary

Introduction

As a comprehensive effect of traffic volume increase, channelized traffic, and sustained high-temperature weather, rutting has become one of the main pavement diseases, and the asphalt pavement with semi-rigid base is generally adopted in China [1,2]. Rutting occurs mainly in the asphalt layer because of the high strength from the semi-rigid base. The usage perspective of the existing highway in Jiangsu province of China indicates that the rutting instability of asphalt pavement will occur in six to 10 years, where the instability time is related to the mixture type, load level, temperature, pavement structure, and other factors. Improving the mixture performance indicators is greatly important in determining the reasonable preventive maintenance time and extending the rutting instability time of asphalt pavement

Test Methods of High-Temperature Deformation

Instability Mechanism of High-Temperature Deformation

Objective

Scheme of the TDCT

Creep Instability Life and Its Prediction Model of Asphalt Mixture