Question

use x=5

Question 9 (6 marks) The design traffic of a flexible pavement with a 160 mm asphalt layer and cemented granular base is x x107 HVAGs (Note: x = the last digit of your student number, which is 0,1,2, ...., or 9. Please use '10' if your digit is 'O'.). The allowable traffic projected by the distress (material damage) models of a flexible pavement is as follows: Asphalt fatigue: N = RF[6918(0.856Vb+1.08)/(E0.36 mɛ)]5; Vb=11% Cemented material fatigue: N = RF[(113000€0.804–191)/uɛ] 12 Subgrade permanent deformation: N = [9300/uɛ]? The damage indices established for this road are: Damage index ESA/HVAG SAR5/ESA SAR12/ESA SAR7/ESA Value 0.8 1.2 11 1.6 The material information is shown in the below table: Material Asphalt Cemented material Subgrade E (MPa) 2500 2000 50 με 70 120 300 RF 0.67 0.5 Please compare allowable traffic loadings to design traffic loading (in ESA) and draw the conclusion if the pavement design is acceptable.

Answer 1

solution - Given that, 160mm asphalt layer and cemented granular base is xx 187 HV AGS 1x=5 Design traffic = 5x107 HUAGS -) Nos = 5x107 HVAGS Design traffic loading CESA) f ESA X NOT HVAG ESA =0.8 from the damage indea table HVAG r. Design traffic loading = 0.885x107 ESA = 4x107 ESA 1 Now calculate overall allowable traffic loading :- ☺ cemented materials fatigue, 12 N = RF +191 ME 113000/€0.804

2 from material information shown in the table, for cemented material E = 2000 MPa, ME=120 RP = 0.5 12 " N =0.5 113000/20000.804 +191 120 N = 3.087 x 106 SARIQ convert this standard anle repetions of allowable loading to ESA from the table using SARIQ ESA (11 =) N= 3.08754106 = 2.806 X10SESA - " 2 permanent de formation of subgrade ! - ( a 9300 77 ME ] from the table Me for subgrade - 300

9 300 (อ . ; N= - 2.75X10 SART convert from this standard axle repetions of allowable loading to ESA of allowable loading wing, SART = 106 (from table given) ESA 2.75 1x1000 1.719x 100 ESA 1.6 lu ③ Asphalt fatigue: 5 '6918 Co.8568 V6 +1.08 N = RF ory € 0.36 ME - given Vb = 11%. from -) RF = 0.67 , E = 2500 MPa & ME = 70 the table. 6918 CO.P5 6 XII +1:08375 - N=0.67 X 70 ---+ 2500 0.36 " N = 6.15 6x 108 SAR5

u convert from standard tale repetitions of allowable loading using, cto ESA). SAR5 ESA = 1.2 from the table . Na 6.15 6x 108 = 5.13X 108 ESA 1.2 Here, Total loading - sum of fatigue due to Cemented material + fatigue due to each distress mode [ie. Asphalt fatigue and permanent deformation here from D & W) - Asphalt fatigue = 5.13x108 ESA =) permanent deformation = 1.719 X 100 ESA - Both are greater than design traffic load 4x107 ESA Hence partenent design acceptable. - please give me like €