A performance-related design for hot-mix asphalt (HMA) incorporating multiple design parameters

Traditionally, the mix design was majorly the trial and error process of optimising aggregate gradation and asphalt content. With the progress of concept and technology, the number of design gyrations (N-des) has been gradually regarded as another important design variable. This research explored the potential advantage of mixes designed incorporating multiple design parameters. The paper is divided into two parts. Part 1 designed the varied aggregate gradations with different levels of N-des to evaluate the effect of incorporating the N-des variable in a traditional process. Part 2 further explored the possible combinations of multiple design parameters, involving binder type, N-des, RAP addition and aggregate gradation. The result showed that by selecting a suitable level of N-des, the performance of mixes with different aggregate gradations can be well balanced to a certain extent. Besides, the performance of HMAs may be largely improved and some marginal materials can be reutilised by selecting a suitable combination of multiple design parameters.