Comprehensive studies on Influence of Fillers on RAP Incorporated Dense Bituminous Mix-II

Sustainable pavement construction has become increasingly important in India due to rapid infrastructure growth and the depletion of natural aggregates. This study investigates the performance of Dense Bituminous Macadam (DBM-II) mixes incorporating Reclaimed Asphalt Pavement (RAP) at 10%, 20%, and 30% replacement levels, with different fillers (stone dust, fly ash, and Ground Granulated Blast Furnace Slag) and bitumen VG-30 as binders. Laboratory investigations were carried out to evaluate the mechanical and durability characteristics of the mixes through Marshall Stability, Retained Marshall Stability (RMS), Indirect Tensile Strength (ITS), Tensile Strength Ratio (TSR) and Cantabro Abrasion Loss (CAL) and Resilient Modulus (MR). Results indicated that virgin binder demand reduced with RAP incorporation, although Marshall Stability decreased slightly due to the stiff aged binder in RAP. GGBS mixes consistently demonstrated superior stability, tensile strength, moisture resistance, and abrasion resistance compared to stone dust and fly ash mixes. All mixes satisfied MoRTH requirements for stability (>900 kg), RMS (>80%), TSR (>80%) and abrasion loss confirming their suitability for field applications. Overall, the findings establish that DBM-II mixes with up to 30% RAP, particularly when combined with GGBS filler, can deliver durable and environmentally sustainable pavement solutions.