15 May 2001
feature that normally requires stabilization for construction stability or for adequate structural strength to
serve as a base for a flexible pavement.
a. Design. The amount of asphalt used should only be enough to coat the aggregate and hold it in
place and not fill any voids. Normally about 2 to 2-1/2 percent (by weight of total mixture) asphalt is
sufficient for stabilization. As a rule, the more open graded the material is, the lower the asphalt content
required for stabilization. The asphalt used should be similar to the grade normally used in that location.
If possible a higher viscosity (stiffer) asphalt may be used to provide increased stability.
b. Construction. A stabilized OGM should be placed with a paver to minimize segregation and
achieve the proper grade and thickness. Usually an asphalt cement is used as the binder and the OGM
is run through a hot-mix asphalt plant to achieve proper coating and to allow for placement. Liquid
asphalts (emulsions or cutbacks) can be used if conditions warrant. An OGM will not require a large
compactive effort. The mixture should only be rolled to seat the aggregate in place.