The aim of the project is to explore a concept based on performance optimization of road pavement structures with various fractions of subgrade layer and asphalt pavement thickness.
The project has a total of 14 test sections located in K1 and K2 in the northbound direction on road E4 between Skånes Fagerhult and Markaryd. These were observed with measurements 2004 to 2010. The follow-up was effected by cross profile measurements and falling weight measurements.
The follow-up was carried out on 8 test sections á 100 m and 6 test sections á 40 m. The asphalt pavement in the right (slow) lane consists of 40 mm wearing course, 45 mm bitumen base course and 95 mm bitumen roadbase with 80 mm gravel roadbase beneath. The asphalt pavement in the left (fast) lane has the same wearing and bitumen base course but not any bitumen roadbase. The subbase vary between the sections from 60 cm crushed rock 0-300 mm to 42 cm crushed rock 0-150 mm or crushed rock 0-90 mm. All the test sections are situated on embankment of varied height.
The road was opened for traffic in 2004, but was then trafficked on the bitumen base course. The wearing course was constructed late in summer 2005 after about one year of traffic. The road served 4 years until the summer of 2009 when the wearing course of the right lane was maintained with a remixing. In the left lane no maintenance was done.
The first measurement at the test sections with the new wearing course was conducted in the spring of 2006 after it had been in service approximately 1 year. In spring 2009 a profile measurement was done before the maintenance operation. The latest profile measurement was carried out in autumn 2010. The rut depth has been calculated according the thread principle.