Asphalt Institute Method Mechanistic-Empirical Methodology Material Trial Layer Properties Thicknesses Structural Models Climate Pavement Traffic Information Response Information Failure Criteria Satisfactory Unsatisfactory Final Layer Thicknesses Mechanistic-Empirical Methodology Material Trial Layer Properties Thicknesses Climate Structural Models Models Climate Pavement Traffic Information Response Information Failure Criteria Satisfactory Unsatisfactory Final Layer Thicknesses 1
Asphalt Institute Methodology E ac , E bs , E sg h ac ν ac , ν bs , ν sg h bs Freeze/Thaw DAMA Asphalt Temp (LEA) max asphalt ε t MAAT CR, CP, YW max subgrade ε c (°F) ESALS N f (fatigue) N d (rutting) Satisfactory Unsatisfactory Final Layer Thicknesses Fatigue Failure Criterion ( ) − = ε 3.291 − * 0.854 N 0.0796 E f t Fatigue Failure Criterion ( ) − − = ε 3.291 * 0.854 N 0.00432 C C E d 1 2 t = C 18.4 1 ⎛ ⎞ V − b 4.84 ⎜ 0.69 ⎟ + = ⎝ ⎠ V V C 10 a b 2 2
Rutting Failure Criterion ( ) − = × − ε 4.477 9 N 1.365 10 d c Traffic Table 6.15 ( )( )( )( ) ( ) = ESAL ADT T DL GY 365 T f Table 6.13 Table 6.4 Table 6.9 Table 6.10 Asphalt Modulus % passing Vol. air Asphalt #200 sieve content % viscosity ( ) = + − − + λ + − * c c log E c c P f 3 c V c c f 7 1 2 200 4 a 5 6 ) ( ) ( + + − − log 0.5 c c f c c V T 9 10 c c f 13 8 11 12 b Vol. binder Asphalt Loading content (%) temp. freq. 3
Asphalt Modulus ( ) = + − − + λ + − * c c log E c c P f 3 c V c c f 7 1 2 200 4 a 5 6 ) ( ) ( + + − − 0.5 c c log f c c V T 9 10 c c f 13 8 b 11 12 c 1 = 5.553883, c 2 = 0.028829, c 3 = 0.1703, c 4 = 0.03476 c 5 = 0.070377, c 6 = 0.931757, c 7 = 0.02774, c 8 = 0.695, c 9 = 1.3 c 10 = 0.49825, c 11 = 0.000005, c 12 = 0.00189, c 13 = 1.1 Climatic Regions Viscosity, λ MAAT Asphalt Frost (10 6 poise) (ºF) Grades Effects 45 AC-5, AC-10 0.6 Yes 60 AC-10, AC-20 1.6 Possible 75 AC-40 5.0 No Mean Monthly Air Temperatures Memphis, TN (MAAT = 60°F) Jan 45˚F May 56˚F Sept 78˚F Feb 38˚F Jun 70˚F Oct 73˚F Mar 43˚F Jul 78˚F Nov 58˚F Apr 45˚F Aug 81˚F Dec 54˚F 4
Pavement Temperatures 40 35 Asphalt Air 30 25 Temperature (C) 20 15 10 5 0 -5 08/01/97 08/01/98 08/01/99 08/01/00 08/01/01 Asphalt Temperature Mean monthly air temperature (˚F) ⎛ ⎞ 1 34 = + − + ⎜ ⎟ M M 1 6 + + p a ⎝ ⎠ z 4 z 4 Mean monthly asphalt temp. (˚F) Depth (in) Pavement Temperature Temperature (F) 0 10 20 30 40 50 60 70 80 90 0 5 Air Pavement Air Pavement 10 Depth (in) 15 20 Ground 25 5
Nonlinear Base Modulus = − − − 0.471 0.041 0.139 0.287 0.868 E 10.447 h h E E K 2 1 2 1 3 1 6
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