Investigation on segregation characteristics of thermosetting epoxy asphalt mixture during the compaction.

Mixture segregation is a common defect in the construction of epoxy asphalt mixture (EAM) deck pavement. The segregation can affect the compaction quality of EAM deck pavement, while the compaction action can also change the segregation degree in the EAM. Therefore, the appropriate compaction technique can decrease the mixture segregation. The objective of this study is to investigate the mutual effect of mixture segregation and EAM compaction. To achieve this goal, the Superpave gyratory compaction (SGC) test was conducted, and a field compaction DEM (Discrete element method) model for EAM on the steel bridge deck was developed using a partitioned deposition method, to study the segregation characteristics of EAM during the compaction. Results show that the partitioned distribution segregation of aggregate in the EAM decreases first and then increases with the increase of gyration compactions. As a thermosetting material, the segregation is more likely to occur in the lowly cured EAM during the compaction process. In the field compaction, the initial vertical distribution segregation of loose EAM has a significantly negative effect on the compaction quality of EAM deck pavement, while the compaction action could also influence the segregation degree of EAM. Under the over repeated compaction, the increasing 1segregation degree of fine EAM particles and too tight contact between EAM particles make the extrusion separation of asphalt mastic between the coarse particles, which could result in the surface bleeding problem. The findings from this study are helpful to decrease mixture segregation and improve compaction quality of EAM deck pavement.. [ABSTRACT FROM AUTHOR]