Use of RAP Stabilized by Hot Mix Recycling Agents in Bituminous Road Construction

The composition of bitumen plays a vital role in deciding durability of bituminous roads. During the aging process, its composition changes with passage of time. Napthene aromatics are converted to polar aromatics and these in turn to asphaltenes those are responsible for brittleness of bitumen in Recycled Asphalt Pavement (RAP). Therefore, restoration of physico-chemical deficiencies of oxidized bitumen by incorporation of appropriate dose of recycling agent is essential for desired performance of pavement. In the present study, RAP samples have been collected and laboratory studies have been carried out to optimize the percentage of usable RAP. Recycling agent has also been used in this study and the dosage of the recycling agent has been found as 10% by the weight of the bitumen present in RAP. The paper describes the comparison of properties of mixture with recycling agents, which has been prepared in laboratory and commercially available on the RAP material, and their performance has been compared with virgin mixes. Various performance tests such as Retained Stability, Indirect Tensile Strength (ITS) and Tensile Strength Ratio (TSR), Resilient Modulus test has been carried out to compare the performance of RAP modified mixes and virgin mixes. This paper presents the results of performance tests carried out on bituminous mixes with RAP and virgin mixes and their result. The laboratory results indicate that the bituminous mixes with RAP and recycling agent provide better performance compared to virgin mixes.