Effects of Iron Ore Tailing on Performance of Hot-Mix Asphalt

Abstract

In Brazil, large quantities of iron ore tailings (IOT) are produced as a result of iron mining, which may affect the environment negatively. This work evaluated the use of IOT in hot mix asphalt type C (HMA-C). For this purpose, IOT was incorporated as a filler (at 1% in relation to the total mass of HMA-C). The hot asphalt mix with IOT (called HMA-IOT) was designed and compared with a control HMA-C. The behavior of the mixtures under monotonic (indirect tensile strength, ITS, and the Marshall stability test), under dynamic (fatigue and resilient modulus tests), and static (static creep test) loading conditions was evaluated. Also, the resistance to induced moisture damage (tensile strength ratio, TSR) was calculated. As a general conclusion, it was shown that the use of IOT in HMA improves its mechanical response without increasing mixing and compaction temperatures and using less effective asphalt binder content. This could provide a new form of environmentally safe disposal of IOTs.