Feasibility study of RAP aggregates in cement concrete pavements

The presence of dust, asphalt film and agglomerated particles is considered to be the primary reason for reducing the properties of Reclaimed Asphalt Pavement (RAP)-inclusive concrete. A surface treatment method Abrasion and Attrition (AB&AT) was employed for removing these contaminants. Gaps were identified from the available literatures and efforts have been made to bridge them in order to increase the usage of RAP aggregates in concrete pavements. Six mixes were prepared by partly replacing the Natural Aggregates (NA) with RAP aggregates in different proportions. It was learnt that processing Dirty RAP (DRAP) aggregates by the AB&AT method could remove contaminants considerably as a result of which stronger bonding is exhibited at the interface of the aggregate and hydrated mortar matrix. Incorporation of beneficiated RAP aggregates in concrete improved the workability considerably but it was found to have reduced hardened concrete properties. However, the results were found to lie within the permissible limits for producing concrete mix having 40 MPa compressive strength.