Application of Recycled Asphalt Shingles (RAS) in Hot Mix Asphalt: Evaluation of Material Performance Properties

Abstract

This study The increasing generation of waste asphalt shingles and reclaimed asphalt pavement (RAP) necessitates sustainable recycling strategies in pavement construction. This study evaluates the material performance properties of hot mix asphalt (HMA) incorporating 31.53% recycled asphalt shingles (RAS) combined with RAP and virgin aggregates, modified with 0.50% rejuvenator. Laboratory performance tests included rutting resistance, fatigue resistance, moisture susceptibility, and viscoelastic properties of the RAS-modified binder. Results demonstrated satisfactory rutting resistance with a representative rut depth of approximately 4.0 mm, remaining below the common 5.5 mm benchmark reported by NCAT for recycled mixes with rejuvenator. Fatigue resistance was moderate to satisfactory with approximately 700 cycles to failure, attributed to rejuvenator-induced flexibility restoration in aged binder. Moisture susceptibility testing yielded a Tensile Strength Ratio (TSR) of 0.80 or above, meeting the threshold requirement and indicating acceptable resistance to stripping, enhanced by 1.94% lime addition. Viscoelastic analysis revealed a stiff but balanced binder response, providing adequate deformation resistance while retaining sufficient flexibility. The findings confirm that RAP + RAS modified HMA with rejuvenator exhibits acceptable mechanical and durability performance for practical pavement applications.