ABSTRACT
Old low volume roads are often made from local materials. Therefore, the gradation curve of the unbound materials in the pavement is often not according to new regulations, which often results in low bearing capacity. One way to improve the quality of existing materials, and thereby save natural resources, is to do a Full Depth Reclamation with mechanical stabilization.
The objectives of this project were to develop a tool to design amount and type of added material for the mechanical stabilization and to find a method to evaluate the effect on bearing capacity and material quality of a Full Depth Reclamation with mechanical stabilization. Theoretically it should be possible to calculate the resulting gradation curve after the rehabilitation based on the gradation curves of existing and added materials. In practice it is hard to predict the gradation curve of crushed asphalt. Also some crushing, especially of larger particles, can occur during the milling process that will affect the resulting gradation curve. Suggestions on how to deal with this are presented.
Full Depth Reclamation at four different low volume roads in Sweden has been studied where gradation curves before and after the reclamation has been compared. FWD measurements has also been carried out. The study showed that, according to the FWD measurements, there were no immediate improvement in bearing capacity. However, the variance of bearing capacity was much smaller after the maintenance. On one of the roads new FWD measurements were done after two years. Then the bearing capacity had improved considerably.
