Test evaluation of rutting performance indicators of asphalt mixtures

Rutting indicators of asphalt mixtures were evaluated using wheel tracking testing results of AC-13 and AC-20 asphalt mixtures. A short term rutting period of 2520 cycles could be adequate for simulating heavy traffic and for prediction of long term rutting. Secondary rutting based indicators had higher rutting correlation coefficients than primary rutting based indicators (PRBI). The reliability of PRBI indicated that mixtures could be characterised based on primary rutting. The rutting at 2 cycles could be used for quick rutting prediction, but since the earliest recorded cycle was 2, it was hypothesised that even one cycle could as well be equally significant. A/C index, complex stability index and shear index were the most reliable indicators based on validating results of recycled hot mix asphalt mixtures. However, only A/C index could reliably screen mixtures with nearly the same secondary rutting rates. It was considered the best indicator, which could as well assess the performance of indirect rutting indicators. Its limiting mixture design values could be determined and validated. (C) 2017 Elsevier Ltd. All rights reserved.