UFC 3-250-03
15 May 2001
Table B-1
Determination of Optimum Asphalt Content
Selection Point
Asphalt Emulsion Added
Peak of stability curve
0.5 percent
Peak of unit-weight curve
1.0 percent
4 percent voids in total mix
1.0 percent
75 percent total voids filled with asphalt
0.0 percent
Average
0.6 percent
B-2. HOT-MIX RECYCLING PROBLEM. The middle 24 meters (75 feet) of a runway is to be removed
full depth (7.5 centimeters, 3 inches) and replaced with a recycled asphalt mixture containing 50 percent
reclaimed asphalt pavement. Develop the design mix.
a. Step 1. Obtain samples of the in-place pavement (use jackhammer or other acceptable means)
along with samples of the new aggregates to be used and the new asphalt and recycled agent, if
needed.
b. Step 2. Run sieve analyses on all aggregates including aggregate extracted from sample of the
in-place asphalt mixture. If an adequate history upon which to evaluate the new aggregate is not
available, use the standard tests as outlined in TM 5-822-8/AFM 88-6, Chap. 8 (Future AFJMAN 32-
1028), and TM 5-825-2/AFJMAN 32-1014. The history of the performance of the old aggregate should
suffice for its evaluation. The aggregate gradations for this example are shown in table B-2.
Table B-2
Aggregate Gradations
Percent Passing
Reclaimed Asphalt
New Coarse
New Fine
New Natural
Sieve Size
Pavement
Aggregate
Aggregate
Sand
19 mm (3/4 inch)
100
100
100
100
12.7 mm (1/2 inch)
95
95
100
100
9.5 mm (3/8 inch)
83
75
100
100
4.75 mm (No. 4)
63
12
100
98
2.36 mm (No. 8)
52
2
79
95
1.18 mm (No. 16)
40
0
57
89
600 Fm (No. 30)
29
0
42
77
300 Fm (No. 50)
21
0
30
48
150 Fm (No. 100)
12
0
18
12
75 Fm (No. 200)
6.0
0
8.0
4.5
B-2
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