PRIME COATS FOR ASPHALT PAVEMENTS

CEMP-ET

DEPARTMENT OF THE ARMY

ETL 1110-3-497

U.S. ARMY CORPS OF ENGINEERS

Washington, DC 20314-1000

Technical Letter

No. 1110-3-497

24 February 1999

Engineering and Design

PRIME COATS FOR ASPHALT PAVEMENTS

1. Purpose. This Engineer Technical Letter (ETL) provides guidance and clarification on the

need for asphalt pavement prime coats.

2. Applicability. This letter is applicable to all HQUSACE elements and USACE commands

having military construction and design responsibility. The criteria in this ETL supersede all

criteria in all existing manuals and guide specifications insofar as need for the use of prime coat.

3. References.

a. ER 1110-345-100, "Design Policy for Military Construction."

b. TM 5-822-8/AFM 88-6, Chap. 9, July 1987, "Bituminous Pavements Standard Practice."

c. TM 5-825-2/AFM 88-6, Chap. 2/DM 21.3, Aug 1978, "Flexible Pavement Design For

Airfields."

d. CEGS 02748, "Bituminous Tack and Prime Coats."

4. Distribution. Approved for public release; distribution is unlimited.

5. Background. Existing construction and engineering criteria concerning whether or not to use

a prime coat has been ambiguous and conflicting. This ETL provides guidance and clarification

on the use of prime coats.

6. Action.

a. Pending publication of revised technical manuals and guide specifications, the following

paragraphs are to be incorporated into CEGS 02748 Bituminous Tack and Prime Coats and used

as guidance for design.

(1) Prime coats are required if it will be at least seven days before a surface layer is

constructed on the underlying compacted material. The type of liquid asphalt and application rate

will depend on the grading of the underlying material, and shall be as specified in this specification

section. This will be paid for as described in the Bid Schedule.