Research on evaluation method of asphalt mixture workability based on minimum mixing energy consumption

Abstract

The workability evaluation of hot mix asphalt mixtures is of particular importance for the uniformity analysis of asphalt mixtures and influence of later asphalt pavement properties. Currently, workability tests and evaluation systems for hot mix asphalt mixtures are not perfect. In this study, we have developed a testing device, proposed an evaluation index, and established an evaluation system for asphalt mixture workability. The compaction degree, asphalt distribution uniformity evaluation index (ADU), aggregate distribution uniformity evaluation index (HA), and coated uniformity of asphalt film evaluation index (CUAF) were measured to verify the workability evaluation index of asphalt mixture. Test results demonstrated that the newly developed asphalt mixture workability testing device and workability evaluation index accurately quantified the shift law of asphalt mixture workability during mixing process. The variation of the workability law was affected by asphalt type, mixture type, and mixing temperature. Compactness, ADU, HA and CUAF were closely correlated with workability evaluation indexes, and R2 values were 0.73, 0.77, 0.94 and 0.8, respectively. Validation results of the workability evaluation index of compactness, ADU, HA, and CUAF showed that the newly proposed workability evaluation index for asphalt mixture was feasible and effective.