Notched Asphalt Mixture Behavior under Waveform Loading Using Semi-Circular Bending Test (SCB)

The purpose of this study is to investigate the behavior of notched asphalt sections by using semicircular bending test. To do this, in order to adapt the test conditions to real conditions, a Haversine loading with two different loading duration and a rest period with a ratio of one at a constant temperature of 20°C was used. Asphalt specimens used in this experiment are in two different grading with a nominal maximum aggregate size of 12.5 mm and 25 mm. In order to carry out the investigations, the vertical displacement and crack opening in each loading cycle were recorded and analyzed in two stages of loading. The results showed that in both loading stages, the effect of the maximum diameter of the aggregates on the vertical displacements and the crack opening depended on the loading duration (speed). In the shorter loading duration and the first loading stages, the mixture with the smaller aggregate diameters and, in the second loading stages, the mixture with larger aggregate diameters, exhibited a better resistance to the rutting. In both stages of loading, crack propagation is faster than vertical displacement, which can indicate a faster growth of fatigue cracking than rutting in notched sections.