Comparing FWD initial tests with HVS induced initial and long-term rutting

In 2003 the Western Region of the Swedish Road Administration decided to do a thorough field test of mica-rich materials and light-fill materials as well. A realignment project of busy West Coast Freeway E6 between Gothenburg, Sweden and Oslo, Norway, opened up a suitable testing site in 2003. After laboratory tests of the materials in question, the field test was carried out using a heavy vehicle simulator on some eight instrumented test cells at a future traffic control station. The test sections were each instrumented with six precision deflection meters and two pressure cells at different depths. Temperature and soil moisture readings were also recorded. Static plate loading tests, light and heavy falling weight deflectometer tests were done prior to the heavy vehicle simulator tests. The unbound test cells were covered with 4 centimeters of asphalt, which were held at a constant temperature of ten degrees Celsius throughout the testing. The preliminary results show that the influence of moisture affects the deterioration of the road when mica is present. However, at dry conditions, which prevailed during the field test, the presence of mica does not influence the results much. Even if this outcome was less desirable, the data were nevertheless interesting to analyze from other aspects. The deflections gathered with the falling weight deflectometer showed that the cells were subjected to different degrees of compaction, in turn affecting the rutting rate. Thus, the data constitute a good start for establishing a relationship between the initial and long-term rutting as well based on non-destructive testing.