Laboratory Evaluation of Damage Behavior of Warm Mix Asphalt Containing Steel Slag Aggregates

A number of completed or ongoing studies on warm mix asphalt (WMA) and steel slag (SS) asphalt mixtures have been conducted all over the world. This paper presents the results of a laboratory study aimed at verifying the damage behavior of WMA mixtures containing electric arc furnace (EAF) steel slag. The SS was used as the fine and coarse portions of aggregate gradation in hot mix asphalt (HMA) mixtures and as the coarse portion of aggregate gradation in a WMA mixture. The physical, chemical, and mechanical properties of aggregates and binders were evaluated to identify their effects on the moisture susceptibility, fatigue, and rutting behavior of asphalt mixtures. The moisture susceptibility of the asphalt mixtures was also evaluated using four different methods, including Marshall stability ratio, resilient modulus ratio, tensile strength ratio, and fracture energy ratio, and the fatigue and rutting behavior of the mixtures was evaluated using four point beam fatigue and dynamic creep tests, respectively. The results generally indicated that the use of coarse SS aggregate in WMA mixtures enhances the resistance of asphalt mixtures to moisture damage and permanent deformation. Also, WMA mixtures containing SS aggregates as the coarse portion of aggregates has better fatigue performance than HMA mixtures. Hence, the WMA mixture containing EAF steel slag aggregates is recommended as an eco-friendly, economical, and suitable mixture for pavement industries. (C) 2017 American Society of Civil Engineers.