Effect of Waste Iron Powder on Properties of Asphalt Concrete Mixtures: State of the Art

It is no secret to the world the big danger of industrial waste on the environment. One of the most effective ways for the disposal of these materials is using them in road construction. Iron powder is an industrial waste material that is obtained from steel manufacturing. Accordingly, this paper presents a systematic review for evaluating the effect of waste Iron powder on asphalt concrete mixtures and shows the most suitable percentage of Iron powder as a filling material. It is concluded that there is a consensus by researchers that the addition of Iron powder improves the properties of the modified asphalt mixture compared with reference one. Particularly, it increases the stability, flow, and voids in mineral aggregate (VMA), decreases air voids, and there is no clear effect on voids filled with asphalt (VFA). Additionally, it increases the mixture's resistance to fatigue, shoving, and rutting. Also, with increasing percent of Iron powder, the indirect tensile strength increases. It is found that the most suitable percent of Iron powder to be added is 50% by weight of mineral filler which leads to increasing the stability by 24% and flow by 18%. Finally, it is found there is no negative impact of using Iron powder in pavement construction on the environment.