Abstract
The Bibi Test Road is located on National Route 36 on the way from Tomakomai to Sapporo. The Civil Engineering Research Institute constructed 8 types of layer structures in July 1990. This study describes performances of pavements by researching changes observed in 4 types of sections.
It was proved that rutting significantly affects MCI, and these factors are correlated to the number of equivalent 5 t (49 kN) wheel load. The studded tire regulations were promulgated during the research period and their influence was observed. It was found that the thicker the layer, the larger the rutting of pavement surfaces, and the smaller the design traffic volume, the greater clibgidence of the subbase course.
