Researchers of Amirkabir University of Technology, with the support of Iran National Science Foundation, investigated the fatigue performance of asphalt mixture with a multi-scale approach.

Khodadadi, who holds a master’s degree and a PhD in civil engineering - transportation from Amirkabir University of Technology, explained about this project: “Due to the high volume of traffic, the asphalt pavements of high-capacity roads are under heavy vehicle loads, and these heavy loads lead to the formation of fatigue cracks. Today, the pressure caused by large single wheels on the pavement and the frequent movement of heavy vehicles in the traffic congestion of high-capacity arterial roads have increased, and these issues have led to the growth of the destructive effects of current traffic.”

He further stated: “Fatigue is one of the most common pavement failures, which is affected by various factors, such as the specifications, granulation of stone materials and bitumen used. In the last three decades, modifiers have been used to overcome the problems of pure bitumen with limited chemical-physical, rheological and adhesion properties.”

This researcher further said: “Modified bitumen can have many benefits in the construction, repair and improvement operations of pavements by improving the performance characteristics of bitumen and increasing the lifespan and service time of pavement. Meanwhile, several tests are used to determine the performance and predict the properties of bitumen and asphalt mixture against various types of failures.”

He stated: “Considering the importance of fatigue failure and the fact that this type of failure is always one of the most important concerns of engineers, the study of this failure was prioritized in this research. Also, according to the country’s need for sustainable infrastructure, especially in the field of asphalt paving, where the limitation of financial resources and environmental concerns are very visible, it is necessary for engineers to look for a solution to improve the efficiency of asphalt mixture and predict its performance better by finding the best practical materials in this infrastructure as well as finding new sustainable materials.”

Khodadadi further pointed out the goals of this project and said: “The main goal of this research was to investigate the fatigue performance of asphalt mixture in different scales so that the performance of the final mixture can be understood by having information at low scales. The comparison between the life of different scales of asphalt mixture was among the other goals of this project. Also, this project investigated the ability of numerical modeling in predicting the performance of asphalt mixture and optimization solutions to reach a solution closer to the laboratory results.”

He added: “Asphalt pavements, optimization of asphalt mixture compositions and more accurate life cycle cost analysis using the fatigue life approach obtained from the multi-scale method were among the results of this project.”

In the end, Khodadadi noted: “To conduct this research, we needed application software belonging to France. For this reason and because this software was not available to everyone, we had to get this software in different ways. Also, the laboratory equipment required for the project was only available in Amirkabir University of Technology.”