The Hamburg type dual arm immersion wheel tracker is widely used to evaluate the resistance to rutting and moisture susceptibility of asphalt mixtures following either EN12697-22 or AASHTO-T324.
The device was developed in the 1970s by Esso A.G. of Hamburg, Germany. It was based on the TRL wheel tracker which is also now included in EN12697-22. Originally the Hamburg test was used by the City of Hamburg to measure rutting susceptibility. The test was performed for 9,540 wheel passes at either 40 or 50°C. Water was used to obtain the required test temperature rather than air. The City of Hamburg later increased the number of wheel passes to 19,200 and found that some mixtures began to deteriorate from moisture damage. Greater than 10,000 wheel passes was generally needed to show the effects of moisture damage.
Specimens can be prepared in the laboratory, or cores taken from the road can be used. Loaded steel or rubber wheels track a sample under regulated load, speed and temperature, whilst the development of the rut is constantly monitored and recorded throughout the test.