Effect of glass aggregate size and aggregate gradation on asphalt pavement performance

Various studies are being carried out to bring the waste materials back into the economy. One of these works is the use of waste glass as aggregate in asphalt pavements. In this study, the use of glass waste as aggregate asphalt mixtures was investigated. The maximum glass aggregate size options were selected as 0.075mm, 2.00mm, 4.75mm and 9.5mm. Conventional bitumen, nano clay modified bitumen (3% by weight of bitumen) and hydrated lime modified bitumen (2% by bitumen weight) were used. Mixtures with dense gradation (conventional asphalt concrete) and gap-graded (stone mastic asphalt) were designed according to the Marshall method. The mixtures were evaluated for low temperature cracking, resistance to water damage and permanent deformation behavior with repeated load creep (RCT), indirect tensile strength, modified Lottman and Hamburg wheel tracking (HWTT) tests. It is understood that the use of glass aggregates gives better results for dense graded asphalt mixtures from gap-graded mixtures, the increase in glass aggregate size reduces the water damage resistance of HMA and SMA mixtures, nano clay or hydrated lime modification improves the mechanical properties of the both mixtures, using of 2.00mm sized maximum glass aggregate shows relatively better water damage and deformation properties, there is a meaningful relationship between HWTT with RCT and modified Lottman methods.