Superpave Mixture Design: Compaction Requirements
TRAFFIC,
MILLION
ESALs
< 0.3
<1
<3
< 10
< 30
< 100
100
VFA REQUIREMENTS
@ 4% AIR VOIDS
SUPERPAVE GYRATORY COMPACTION EFFORT
AVERAGE DESIGN HIGH AIR TEMPERATURE
< 39° C
39° – 40° C
41° – 42° C
N int
7
7
7
8
8
9
9
N des
68
76
86
96
109
126
142
N max
104
117
134
152
174
204
233
N int
7
7
8
8
9
9
10
N des
74
83
95
106
121
139
158
N max
114
129
150
169
195
228
262
N int
7
7
8
8
9
9
10
N des
78
88
100
113
128
146
165
VMA REQUIREMENTS @ 4% AIR VOIDS
NOMINAL MAXIMUM
AGGREGATE SIZE (mm)
9.5
12.5
19.0
25.0
37.5
MINIMUM VMA ( % )
15
14
13
12
11
42° – 43° C
N max
121
138
158
181
208
240
275
N int
7
8
8
9
9
10
10
N des
82
93
105
119
135
153
177
N max
127
146
167
192
220
253
288
TRAFFIC,
MILLION
ESALs
< 0.3
<1
<3
< 10
< 30
< 100
• 100
COMPACTION KEY
SUPERPAVE GYRATORY
N int
N des
COMPACTION
89%
96%
PERCENT OF Gmm
DESIGN
VFA
(%)
70 – 80
65 – 78
65 – 78
65 – 75
65 – 75
65 – 75
65 – 75
N max
98%
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Gravity Model
AjFijKij
Tij = Pi > /
AjFijKij H
j
where
Tij = number of trips that are produced in zone i and attracted to zone j
Pi = total number of trips produced in zone i
Aj = number of trips attracted to zone j
Fij = a value that is an inverse function of travel time between zones i and j
Kij VRFLRHFRQRPLFDGMXVWPHQWIDFWRUIRULQWHUFKDQJHij
Logit Models
n
Ux = / aiXi
i=1
where
Ux = utility of mode x
n = number of attributes
Xi = attribute value (time, cost, and so forth)
ai FRHI¿FLHQWYDOXHIRUDWWULEXWHVLQHJDWLYHVLQFHWKHYDOXHVDUHGLVXWLOLWLHV
If two modes, auto (A ) and transit (T), are being considered, the probability of selecting the auto mode A can be written as
P_ Ai =
eUA
e + eUT
UA
P_ x i =
eUx
/ eUxi
n
e=1
170
CIVIL ENGINEERING