Abstract
The fatigue performance and healing ability of asphalt pavements are important for mixture design, rehabilitation, and maintenance of the roads. By analyzing these parameters in an asphalt mixture, it is possible to predict the crack formation and propagation in asphalt pavements and healing of these cracks during the rest periods. The healing effect in asphalt mixtures has been observed and verified by many researchers and different methods exist to evaluate this phenomenon. However, current methods are still inadequate to fully observe and quantify the healing phenomenon in asphalt mixtures. In this study, a digital image correlation (DIC) method is used to calculate the strain map on the surface of cylindrical asphalt specimens during the indirect tensile fatigue test. This strain map is used to detect the location of crack initiations and development of the microcracks during the experiments. Next, the specimens are unloaded and the temperature of the climate chamber is increased to 60 °C for 18 h to investigate the healing phenomenon on the surface of the specimens. It is observed that the strain reduces near the microcrack areas especially at the tip of the microcracks. Furthermore, using DIC it is possible to observe the healing rate and the minimum time required to heal the microcracks on the surface of the specimens.
Highlights
Asphalt mixtures are the most common types of pavements used in the world
The specimens were manufactured in the laboratory according to EN 12697-35:2016 [31] and compacted according to EN 12697-31:2007 [32] using a Gyratory Compactor
Due to the difference between the module of elasticity of the aggregate and binder, the strain obtained due to the difference between the module of elasticity of the aggregate and binder, the strain obtained within the binders is larger than those within the aggregates
Summary
Asphalt mixtures are the most common types of pavements used in the world They are heterogeneous materials that consist of mineral aggregates, filler, bitumen, air voids, and possibly other additives. Once a microcrack is initiated in the specimen, it starts healing and if it is in the proper condition for a certain time it can even close completely [1]. This property is directly related to the temperature and rest time and can strongly influence the fatigue life of the specimens [2]. Asphalt molecules on faces of the microcracks randomly approach, contact, wet, and diffuse to close the microcracks
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
