Evaluation of internal resistance in hot-mix asphalt (HMA) concrete

Accurate quantification of aggregate properties is essential for understanding their influence on hot-mix asphalt (HMA) concrete and for selecting aggregates to produce high-quality paving mixture. The objectives of this study are to develop a method to measure internal resistance in HMA mixtures and to evaluate the effect of different gradations on the rutting of mixes. Analysis showed that a HMA mix could be made more resistant to rutting by specifying an adequate range of the fine aggregate passing through the 4.75-mm (No. 4) sieve. The lower the fine aggregate percentage, the greater the difference between the coarse aggregate void volume and the total volume of fines. This indicated that the aggregate interlocking greatly occurred in the coarse aggregate. The image evaluation of aggregate morphological characteristic demonstrated that a stable aggregate skeleton resulted in more internal resistance.