SLIDE 1
Mechanistic-Empirical Methodology
Structural Models Pavement Response Failure Criteria Trial Layer Thicknesses Material Properties Climate Information Final Layer Thicknesses
Satisfactory
Traffic Information
Unsatisfactory
Asphalt Institute Method Mechanistic-Empirical Methodology Material - - PDF document
Asphalt Institute Method Mechanistic-Empirical Methodology Material - - PDF document
Asphalt Institute Method Mechanistic-Empirical Methodology Material Trial Layer Properties Thicknesses Structural Models Climate Pavement Traffic Information Response Information Failure Criteria Satisfactory Unsatisfactory Final
SLIDE 2
SLIDE 3
Mechanistic-Empirical Methodology
Structural Models Pavement Response Failure Criteria Trial Layer Thicknesses Material Properties Climate Information Final Layer Thicknesses
Satisfactory
Traffic Information
Unsatisfactory
Climate Models
SLIDE 4
Asphalt Institute Methodology
DAMA (LEA)
max asphalt εt max subgrade εc
Nf (fatigue) Nd (rutting) hac hbs Eac, Ebs, Esg νac, νbs, νsg MAAT (°F) Final Layer Thicknesses
Satisfactory
CR, CP, YW ESALS
Unsatisfactory
Freeze/Thaw Asphalt Temp
SLIDE 5
Fatigue Failure Criterion
( )
3.291 * 0.854 f t
N 0.0796 E
− −
= ε
SLIDE 6
Fatigue Failure Criterion
( )
3.291 * 0.854 d 1 2 t
N 0.00432 C C E
− −
= ε
b a b
V 4.84 0.69 V V 2
C 10
⎛ ⎞ − ⎜ ⎟ + ⎝ ⎠
=
1
C 18.4 =
SLIDE 7
Rutting Failure Criterion
( )
4.477 9 d c
N 1.365 10
− −
= × ε
SLIDE 8
Traffic
( )( )( )( ) ( )
f
ESAL ADT T DL GY 365 T =
Table 6.15 Table 6.13 Table 6.4 Table 6.9 Table 6.10
SLIDE 9
Asphalt Modulus
( )
( )(
)
3 7 9 10 13
* 1 2 200 4 5 6 log 0.5 8 11 12
log
c c a c c f c b
E c c P f c V c c f c V T c c f
− − + −
= + − + λ + + −
- Vol. air
content % Asphalt viscosity % passing #200 sieve
- Vol. binder
content (%) Asphalt temp. Loading freq.
SLIDE 10
Asphalt Modulus
( )
( )(
)
3 7 9 10 13
* 1 2 200 4 5 6 log 0.5 8 11 12
log
c c a c c f c b
E c c P f c V c c f c V T c c f
− − + −
= + − + λ + + −
c1 = 5.553883, c2 = 0.028829, c3 = 0.1703, c4 = 0.03476 c5 = 0.070377, c6 = 0.931757, c7 = 0.02774, c8 = 0.695, c9 = 1.3 c10 = 0.49825, c11 = 0.000005, c12 = 0.00189, c13 = 1.1
SLIDE 11
Climatic Regions
No 5.0 AC-40 75 Possible 1.6 AC-10, AC-20 60 Yes 0.6 AC-5, AC-10 45 Frost Effects Viscosity, λ (106 poise) Asphalt Grades MAAT (ºF)
SLIDE 12
Mean Monthly Air Temperatures
54˚F Dec 81˚F Aug 45˚F Apr 58˚F Nov 78˚F Jul 43˚F Mar 73˚F Oct 70˚F Jun 38˚F Feb 78˚F Sept 56˚F May 45˚F Jan
Memphis, TN (MAAT = 60°F)
SLIDE 13
Pavement Temperatures
- 5
5 10 15 20 25 30 35 40 08/01/97 08/01/98 08/01/99 08/01/00 08/01/01 Temperature (C) Asphalt Air
SLIDE 14
Asphalt Temperature
1 34 1 6 4 4
p a
M M z z ⎛ ⎞ = + − + ⎜ ⎟ + + ⎝ ⎠
Mean monthly air temperature (˚F) Mean monthly asphalt temp. (˚F) Depth (in)
SLIDE 15
Pavement Temperature
5 10 15 20 25 10 20 30 40 50 60 70 80 90 Temperature (F) Depth (in)
Air Air Pavement Pavement Ground
SLIDE 16
Nonlinear Base Modulus
0.471 0.041 0.139 0.287 0.868 2 1 2 1 3 1
10.447 E h h E E K
− − −