Evaluation of Fatigue Behavior of Asphalt Layers Containing Nanosilica Modified Tack Coat

Generally, the maintenance of asphalt pavements contributes a significant portion of the national capital of the countries. Rutting and cracking cause extensive damage to asphalt pavements, although fatigue cracks are more common in asphalt pavements. Adhesion and bonding between asphalt layers are among the factors that affect the durability of asphalt pavement and play a major function in maintaining the integrity of the pavement. On the other hand, using nanomaterials is regarded as one of the options to improve the properties and performance of bitumen. Therefore, this study aimed to evaluate the fatigue behavior of asphalt layers containing nanosilica modified tack coat (NSMTC). To this aim, it was used a four-point bending (4 PB) beam fatigue test. The loading is the semisinusoidal type with 10 Hz frequency, without rest, and at a temperature of 20°C. The controlled strain state (at three strain levels of 400, 550, and 700 με) is implemented. The results revealed the increased fatigue life in the specimen of asphalt beam containing NSMTC. At different strain levels (i.e., 400, 550, and 700 με), the fatigue life of beams with NSMTC increased by 18, 15, and 57%, respectively. Furthermore, the cumulative dissipated energy of specimens containing NSMTC increased by 37, 42, and 60% compared to specimens containing unmodified tack coat (UMTC) for strain levels of 400, 550, and 700 με, respectively.