Investigating the effects of ageing condition and type of aggregates on the properties of asphalt mixtures

In this study, asphalt mixtures made by steel slag (SSA), copper slag (CSA), limestone (LA) and siliceous (SA) aggregates were subjected to different aging conditions; and were evaluated using Marshall, indirect tensile strength (ITS), Cantabro abrasion loss and semi-circular bending (SCB) tests. Results reveal that the moisture damage, raveling and fracture resistance of asphalt mixture decrease with aging and the ITS and Marshall properties improve with aging. After 7-day long-term aging, the TSR of the mixtures made by LA, SA, SSA and CSA, decreases, 28.8%, 48.5%, 8.8% and 15%, respectively, while, the ITS in dry condition increases, 61.9%, 33%, 62% and 81%, respectively. The fracture properties and moisture damage resistance of asphalt concrete made by SSA and CSA are less affected by aging than those made by LA and SA. Statistical analysis revealed that the effect of aggregate type, aging condition and their interaction on the mixture properties is significant.