EVALUATION OF SASOBIT MODIFIED RECYCLED ASPHALT PAVEMENT

Abstract

Recycling of bituminous pavements is a sustainable solution for the environment. The reuse of old distressed bituminous pavement material also called as reclaimed asphalt pavement (RAP) material is a proven environment friendly technology. Previous literature indicated noticeable reduction in greenhouse gases (GHG) by using RAP material instead of virgin materials. However, to activate the hard binder of RAP material, specific amount of heat is provided to warm the RAP material. Further, the ageing of aged binder is also an important concern in the recycling of asphalt pavements. The warm mix asphalt (WMA) technology helps to lower the mixing and compaction temperature which prevents over ageing of the aged binder of the RAP material. In the present study, Sasobit, an organic based WMA additive, was used in a rejuvenated recycled mix having 40% RAP content. Three dosages of Sasobit viz. 3%,4% and 5% were taken. The base binder grade was a 60/70 Pen grade. It was concluded that by adding the Sasobit, the mixing and compaction temperature of recycled mixes can be lowered. The empirical, fundamental and rheological study was carried out on laboratory blended and recovered binders (from cylindrical specimens before and after long term oven ageing). Moreover, Marshall Stability (MS) and Flow Value (FV), Indirect Tensile Strength (ITS), Indirect Tensile Stiffness Modulus (ITSM) and Indirect Tensile Cracking Test (IDEAL-CT) were conducted on short and long-term oven aged samples. The results of recycled mixes were found satisfactory in comparison to the conventional hot mix asphalt (HMA) technology with the inclusion of Sasobit.