Effect of nanomaterials on the durability of hot mix asphalt
Hawraa j. Aljbouri, Amjad H. Albayati
Abstract
Traffic volume and loads have increased significantly in recent years, coupled with the high summer temperature and the low temperature in winter, premature failure in asphalt concrete pavement becomes the main challenge for pavement construction companies and engineers. The use of modifiers in asphalt concrete mixes become of considerable interest in the improvement of pavement performance and service life. With the advent and evolvement in nanotechnology, many researchers focused on how these materials could serve in rising the serviceability of pavement in terms of reducing rutting, fatigue cracking as well as moisture induced damage. In this study, nanomaterials, including nano silica (NS), nano carbonate calcium (NCC), nano clay (NC), and nano platelet hydroxyapatite (NP), were used to examine the prospect of enhancing the durability and resilience of asphalt mixtures. Specifically, this study aimed to evaluate the effect of adding nanomaterials as a modifier to the bitumen on the Marshall properties, resilient modulus as well as the durability of the asphalt concrete mixture, which was assessed for moisture susceptibility using indirect tensile strength (ITS) and permanent deformation using the uniaxial repeated load test. The investigated nanomaterial dosages were as follows; NS (1, 3 and 5%), NCC (2, 4 and 6%), NC (3, 5 and 7%), and NP (2, 4 and 6%), by weight of asphalt cement. The results were compared with the control mix (CM), i.e., an unmodified mix. The results revealed that nanomaterials significantly improved the properties of asphalt concrete. Also, this work provides a basis for producing more durable mixtures with higher resistance to distress.