Unstabilized Base

In general, the procedures for construction of unstabilized base involve mixing, placing, compacting, and grading the material. The keys to proper construction of unstabilized base are:

• Material should be blended so as to provide a homogeneous mixture.
• The material should be conditioned with water to maintain optimum moisture content before and during compaction.
• At a minimum, 95 percent of the standard proctor (AASHTO T 99) density should be achieved in the field. For projects designed to carry large volumes of heavy truck traffic,a minimum of 98 percent of modified proctor(AASHTO T 180) density is warranted.
• After compaction, the surface of the base should be trimmed to ± ½ inch of the design profile grade.
• Consistency in placing, compacting, and trimming operations should be ensured to avoid any segregation of aggregates.
• The unstabilized base must be wetted prior to paving of concrete to prevent the dry base material absorbing water from fresh concrete.