Assessing the Effect of Reclaimed Asphalt Pavement on Mechanical Properties of Dry-Lean Concrete

Reclaimed asphalt pavement (RAP) in rigid pavements has been used for pavement quality course (PQC), but there are very few investigations available on assessing the effect of RAP gradation in dry-lean concrete (DLC) layers. RAP poses various environmental concerns including disposal and hence it becomes imperative to incorporate this waste material in the construction of subbase layers such as DLC. This paper reports the influence of RAP on the density and strength properties of DLC. In this study, RAP was proportioned on the basis of black curve gradation (BCG) and true curve gradation (TCG). Mix parameters such as density and compressive strength were studied to quantify the effect of RAP using the fractionation method. Fractionated reclaimed asphalt pavement (FRAP) was found to be significant in influencing the behavior of DLC. The first fraction to achieve the benchmark of 7-day DLC compressive strength was 60% fractionated RAP (FRAP), followed by lower percentages. Statistical inferences indicated that, along with moisture content, RAP significantly influences the structural behavior of DLC composites. However, the effect of RAP was insignificant with respect to density. Additionally, a simple economic analysis was adopted, which indicated that FRAP is economically feasible for the construction of DLC layers in rigid pavements.