UFC 3-250-03
15 May 2001
Table 2-13
Recommended SMA Coarse and Fine Aggregate Properties (After NAPA 1994)
Property
Specifications
Requirement
Coarse Aggregate:
Los Angles abrasion, %
ASTM C 131, AASHTO T 96
30 max.
Flat and elongated, + No. 4
ASTM D 4791
3 to 1 (length to thickness), %
20 max.
5 to 1 (length to thickness), %
5 max.
Fractured faces, + No. 4
One fractured face, %
100 min.
Two fractured faces, %
90 min.
Absorption, %
ASTM C 127, AASHTO T 85
2 max.
Coarse and fine durability index
ASTM D 3744, AASHTO T 210
40 min.
Sulfate soundness loss, 5 cycles
AASHTO T 104, ASTM D 3744
Sodium sulfate, %
15 max.
or Magnesium sulfate, %
20 max.
Fine Aggregate:
Crushed manufactured fines, %
100 min.
Sulfate soundness loss, 5 cycles
Sodium sulfate, %
15 max.
Liquid limit
AASHTO T 89, ASTM D 4318
25 max.
polymers. A large percentage of SMA has been placed with a combination of fibers and asphalt
polymer.
(b) Fiber stabilizers. Tables 2-14 and 2-15 provide the requirements and test procedures
to be used with cellulose and mineral fibers, respectively. The dosage rates normally used for cellulose
fibers is 0.3 percent by weight of the total mix and for mineral fibers is 0.4 percent by weight of the total
mix. The recommended tolerance for the fibers is approximately 10 percent of the required fiber weight.
(c) Asphalt-polymer stabilizers. SMA mixtures have been placed using a polymer to
modify the asphalt cement and stabilize the mixture so that fibers are not required. There have also
been instances where a polymer and a fiber have been used in conjunction to stabilize SMA mixtures.
Manufacturer's design and construction recommendations should be followed as the standard SMA
guidelines may not be applicable for asphalt-polymer stabilizers.
(4) Asphalt. The asphalt cement shall comply with the requirements of ASTM D 946, ASTM
D 3381, or AASHTO MP-1. The asphalt cement used shall be the grade normally used in the area. The
temperature of the asphalt cement at the time of mixing shall be that required to achieve a viscosity of
170 20 centistokes. Where a polymer modified asphalt cement is used, manufacturer's
recommendations for mixing temperature shall be followed.
c. MIXTURE DESIGN. The optimum asphalt content shall be determined with procedures similar
to those outlined in Hot-Mix Asphalt. Table 2-16 contains the recommended mix design requirements
2-34
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