Laboratory investigation of moisture susceptibility of warm-mix asphalt mixtures containing steel slag aggregates

Abstract

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. Moisture damage is one of the major concerns for both WMA and SS asphalt mixtures. This paper presents the results of a laboratory study aimed at verifying moisture susceptibility of WMA mixtures containing SS aggregates. The physical, chemical, and mechanical properties of aggregates and binders were evaluated to identify their effects on moisture susceptibility of asphalt mixtures. The moisture susceptibility of the asphalt mixtures was also evaluated by four different methods, including Marshall Stability Ratio, Resilient Modulus Ratio, Tensile Strength Ratio and Fracture Energy Ratio. The results generally indicated that use of coarse SS aggregate in WMA mixtures enhances the resistance of asphalt mixtures to moisture damage. Hence, use of steel slag aggregate in production of WMA mixture is recommended.

Keywords::

• warm-mix asphalt
• sasobit
• rediset
• fracture energy
• steel slag