Flow in Aggregate - Binder Mixes

摘要

The main purpose of this research was to develop concepts for a unified approach in bituminous mix design using different aggregates. A hypothesis was proposed suggesting that aggregate gradation by 'packing volume' instead of size is a unifying description of rock pieces. To test the above hypothesis, three types and three sizes of rocks were used, first in dry condition, and afterwards mixed with asphalt. Vibratory compaction experiments combined with tests in tension, compression, and cyclic deformation were performed and the results were evaluated by the use of regression, analysis of variance, and a contact-area model equation. All the work was concerned with mono-volume (one-size) rocks only. Three rates of deformation at three temperatures were used, staying largely in the flow region of mix behavior. The results show that the aggregate-packing-volume and flow-asphalt concepts can be used to design aggregate-binder mixes which behave similarly, whether they contain crushed or rounded aggregate. Analytic means, using the contact-are model, permit a reasonably close prediction of tensile and compressive strength. A foundation has been laid for a unified approach to mix design. (Author)