Laboratory rutting tests for AC20 under the condition of different temperatures (30°C, 45°C and 60°C), wheel pressures and wheel running speeds were carried out with an improved wheel rutting tester whose wheel running speed can be adjusted. The test results show that (1) the rut index value of AC20 under the condition of 45°C, heavy loading and low speed can be inferior to that under the condition of 60°C, standard loading and standard speed; (2) it is difficult to induce rut for the AC20 at 30°C even under the condition of heavy loading...
