Lessing Density Requirement and Adjusting Density Pay Factors for Asphalt Pavement in Poor Sublayer Condition

Asphalt compaction is an essential task that can affect the quality of the constructed asphalt pavement (e.g., cracking, crumbling, and uneven surface). On moving sublayers (e.g., subgrade in poor condition or soft cold in-place recycling asphalt), it is difficult to compact asphalt as the sublayers absorb compaction energy. The higher density of up to 98 %Gmm results in a higher pay factor (as per INDOT Standard specification, 2022). The contractors are paid by pay factor based on the density of the surface layer., hence, contractors target a higher density. If contractors aim for a higher density on poor sublayer conditions, it can cause issues such as density segregation and aggregation crushing. The problem is that we do not know the scientifical and statistical correlation between sublayer conditions and the density of the surface, and the density pay factor in the current specification does not consider sublayer conditions. Therefore, the goal of this research is to investigate a correlation between asphalt density (%Gmm) and sublayer conditions. And to recommend adjusting the density pay factor in the specification depending on the correlation.