Predicting High-Cycle Fatigue Damage in Viscoelastic Bituminous Materials Using the Time–Strain Superposition Principle

Abstract

Fatigue crack damage is a primary pavement failure; however, it is an extreme challenge to predict the fatigue damage under high-cycle loading. This paper develops a time–strain superposition principle based on the free volume theory, with a proposed damage density master curve model, to predict high-cycle fatigue damage using multiple low-cycle damage curves. This principle was validated through controlled-strain fatigue experiments, including destructive time-sweep fatigue tests on asphalt binders and repeated direct tension fatigue tests on asphalt mixtures. To address the time and resource-intensive nature of fatigue tests and simulations under high-cycle loading, this study presents an efficient numerical predication of the high-cycle fatigue damage using a viscoelastic damage model and low-cycle simulation results. The results demonstrate the feasibility of predicting high-cycle fatigue damage by employing low-cycle damage results using the time–strain shift model. This offers a potential solution to the computational and experimental prediction of the high-cycle fatigue damage in the viscoelastic bituminous materials. The deterioration of asphalt pavements performance caused by high-cycle fatigue cracking has been a research focus in the pavement field. However, challenges such as long time for fatigue tests, high material costs, lengthy finite element simulation times, and inaccurate results have been encountered. This study develops a damage density prediction model, which generates damage data under low-cycle through finite element simulation based on bituminous material parameters, to predict the trend of high-cycle fatigue damage density development under reference strains. This approach enables rapid simulation and high-cycle damage prediction for different bituminous materials, significantly saving time for testing and simulation, and assisting practitioners in quickly assessing material fatigue performance. Additionally, after finding the maximum tensile strain of each bituminous layer, users can analyze the damage rate of different bituminous material layers of structures using the predictive model developed in this study, to assist with road maintenance.