Lesson 5/Learning Event 1
Learning Event 1
The Corps of Engineers has established tables for gradation specification limits for bituminous
pavements. Selecting a gradation specification is based on the following:
Use of the Mix: surface course, binder course, road-mix, etc.
Type of Binder: asphalt cement, or tar
Tire pressure: high pressure (over 100 psi) or low pressure (100 psi and under)
Maximum Size of Aggregate: based on maximum size of material in stockpiles or
maximum size based on thickness of pavement course to be placed. Maximum size for
surface course placed with mechanical spreader is one-half the thickness of the surface
course. Maximum size for binder course placed with mechanical spreader is two-thirds
the thickness of the binder course with a maximum of 1 1/2 inch.
The tables for gradation specification limits for bituminous pavements are listed below. The
tabtlables oTj th0.Tcadation0s0 ecif2cati488li48its1baTed onsthje maximum08zTcof 1 ggr1ga4e. 8T1 e 8ix (taTm (th
( es sh )w e gr Tc 1 p 1 1 i 19 on m9. 2 s m ( T -)Tj -0.0 si e a 80 e 1 t9 4 h 4 s9
tables cover the following conditions: