Comparison of Strength of Recycled Bituminous Pavement in Design and After Execution

Abstract

Foam bitumen-treated reclaimed asphalt pavement (RAP) and cement-treated subbase (CTSB) is a widely used technology around the world, but India is still novice in implementing this technology. Although CTSB has found extensive usage recently, RAP has been minimally used for roads of lesser importance. It is a need to perform an exhaustive study on the RAP uses at the place where there is a growing scarcity of proper material for the construction. RAP and CTSB give the benefit of an extensive reduction in material consumption when compared to other pavement options. The current study focuses on the utilization of new technology in rapidly growing infrastructure. RAP preparation could be in-plant or in situ in hot recycling or cold recycling. In this project case, cold in-plant recycling process has been used for RAP generation. In this paper, the laboratory and field evaluation of a newly laid pavement with bituminous concrete (BC), RAP, and CTSB have been done. The design parameters like the Marshall’s stability, air voids, density, tensile strength, and elasticity/resilient modulus parameters for BC and RAP are evaluated in laboratory by extracting the cylindrical cores from the newly laid pavement. A field study using falling weight deflectometer (FWD) technique has also been successfully conducted for the same pavement to confirm the most important parameter of elastic/resilient moduli adopted for the various pavement layers in pavement design. The back-calculation is done using KGPBACK software developed by IIT Kharagpur. The laboratory and field findings of the elastic/resilient moduli of the materials corroborate with each other. The study shows that the adoption of RAP and CTSB is a cost-effective option for the construction industry.