Evaluation of Warm Mix Asphalt compactability indices using laboratory compactors from a temperature perspective

In practice, the production temperatures of Warm Mix Asphalt (WMA) mixtures are determined based on practical experiences and recommendations. Thus, the focus of this study is to propose a temperature-sensitive compactabilty assessment method to quantify the temperature needs of WMA mixtures. Therefore, in this study, an image-based testing setup coupled with the Marshall Apparatus was developed to obtain the densification curve of asphalt mixtures considering its sensitivity to temperature changes. Further, the compactability indices typically derived for Superpave Gyratory Compactor (SGC) were adapted for Marshall Compaction. Accordingly, the effect of the temperature on the volumetrics, stability, and compactability indices were analysed for one Hot Mix Asphalt and four different WMA mixtures utilising the proposed methodology. Moreover, similar analyses were implemented for the same mixtures compacted with SGC and compared with the findings of the proposed methodology. While the analysis indicated that SGC compactability indices are not sensitive to relatively small temperature changes, it was concluded that the temperature-compactability relations obtained utilising the proposed methodology are considerably sensitive. Furthermore, the major findings of the study perfectly overlap with the field experiences