UFC 3-250-03
15 May 2001
Table 3-2
Tack Coat Materials and Spray Application Temperatures
Application Temperature EF
Type
Grade
Cutback
RC-70
120-200
RC-250
165-250
Emulsion
RS-1
70-140
MS-1
70-160
HFMS-1
70-160
SS-1
70-160
SS-1h
70-160
CRS-1
125-185
CSS-1
70-160
CSS-1h
70-160
Asphalt cement
200-300 pen
265 +
120-150 pen
270 +
85-100 pen
280 +
AC-2.5
270 +
AC-5
280 +
AC-10
280 +
AR-1000
275 +
AR-2000
285 +
AR-4000
290 +
weather conditions, storage and handling requirements, and curing time. All tack coats should be cured
before placing the new pavement layer.
c. Application rate. Tack coats are usually applied in quantities of 0.23 to 0.68 liters per square
meter (0.05 to 0.15 gallons per square yard) of residual asphalt, but the exact quantities should be
adjusted to suit field conditions. Light applications are preferred since heavy applications can cause
serious pavement slippage and bleeding problems. However, failure to use any tack coat can also
cause pavement slippage problems.
d. Placement. Tack coats should be applied to clean, dust free asphalt pavement courses prior to
placement of the overlying pavement layer. The tack coat should be applied immediately before
placement; therefore, unless an asphalt cement is used, the tack coat must be allowed time to cure. A
tack coat may be required on a base course when the prime coat on that surface has been subjected to
construction traffic or other traffic. A pressure distributor should be used to apply tack coats at an
application temperature which will produce a viscosity between 10 and 60 seconds, Saybolt furol, or
between 20 and 120 centistokes, kinematic viscosity. The suggested spray application temperatures in
degrees Fahrenheit for tack coat materials are shown in table 3-2. When an even or uniform coating is
not obtained, an improved coverage may be possible by making several passes over the freshly applied
tack coat with a pneumatic-tired roller. The tack coat should be completely cured (volatiles or water
3-4
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