The effect of mixing sequence on the workability and indirect tensile strength of asphalt concrete

The KGO mixing method was developed 40 years ago. Instead of adding the bitumen at the end of the mixing cycle, the bitumen was poured down first together with the larger aggregates. After mixing the bitumen with the larger aggregates, the reamining aggregates were mixed down. As benefits of the KGO method were mentioned improving the workability and shortening the needed compaction time. In this study it was investigated if the KGO method and a longer mixing time could improve the mechanical properties of asphalt mixtures. To investigate the influence on workability and compactability the indirect tensile strength was determined of gyratory compacted specimens produced with the KGO method and different mixing times. Form the results it can be concluded that a longer mixing time didn’t have an effect om both. A modified mixing sequence has a positive influence on the workability and the indirect tensile strength.