1. Flexible Pavement Design (JKR Method)
BFC IGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
CHAPTER 3
PAVEMENT DESIGN:
Flexible Pavement Design (JKR Method)

2. FACTORS THAT INFLUENCE PAVEMENT DESIGN
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
FACTORS THAT INFLUENCE PAVEMENT DESIGN
Traffic Loading
Magnitude of axle load
Wheel configuration
Volume and composition of axle loads
Tyre pressure and contact area
(2) Material Characteristics
(3) Climate or Environment

3. DETERMINATION OF DESIGN TRAFFIC
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
DETERMINATION OF DESIGN TRAFFIC
Traffic data is a key input for structural design of pavements.
Standard axle or wheel load
Traffic spectrum and traffic volume – standard axle during design life
Equivalent Standard Axle Load (ESAL) in Malaysia – 80 kN
Commercial vehicle (CV)
CONSIDERATION OF TRAFFIC DATA
Number of CV during Year 1 of Design Period – is the expected completion of construction
Vehicle class and axle distribution
Directional and lane distribution factors
Traffic Growth factors

4. Single Axle Tandem Axle Tridem Axle Traffic Loading
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Single Axle
Tandem Axle
Tridem Axle
Traffic Loading

5. Load Factor LS = 80kN, 8.16 tonne, 18,000 lb Lorry 9 tonnes
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Load Factor
LS = 80kN, 8.16 tonne, 18,000 lb
Lorry 9 tonnes
Car 1.5 tonne
Bus 18 tonnes
Trailer 26 tonnes

6. Material characteristics
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Material characteristics a)
Equal thickness
Different material
Different resultant pressures b)
Different thicknesses
Different material stiffnesses
Equal resultant pressure
* It shows how materials characteristics affect the thickness design

7. / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Climatic / Environmental Effect
/ / / / / / / / / / / / / / / / / / / / / / / / / / / / / / / /
/ / / / / / / / / / / / / / / / / / / / / / / / / / / /
/ / / / / / / / / / / / / / / / / / / / / / / / / / /
Seepage from highlands
Water ponding
Seepage through shoulder
Seepage through pavement
Water content rises in subgrade
Subgrade looses strength and stability
If subgrade is too weak, pavement will fail

8. JKR ARAHAN TEKNIK (JALAN) 5/85 DESIGN METHOD
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
JKR ARAHAN TEKNIK (JALAN) 5/85 DESIGN METHOD
PROCEDURE:
Design life is usually taken as 10 years.
Traffic Estimation:
Initial Annual Commercial Vehicle Traffic per direction, Vo
where ADT = average daily traffic
Pc = percentage of commercial vehicles
D = directional distribution (usually 0.50)
L = lane distribution (usually 1.00)

9. Total Number of Commercial Vehicles per direction, Vc
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Total Number of Commercial Vehicles per direction, Vc
where r = traffic growth rate
x = design life
Total Equivalent Standard Axles, ESA
ESA = Vc x e where e = equivalent factor (Table 3.5)
Daily Traffic Flow at the end of the design period, Vx
Vx = V1 (1 + r)x where V1 = ADT / (per direction)

10. Maximum Hourly Capacity, c c = I x R x T
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
3. Capacity Estimation
Maximum Hourly Capacity, c
c = I x R x T
where I = ideal hourly capacity (Table 3.6)
R = roadway reduction factor (Table 3.7)
T = traffic reduction factor (Table 3.8)
Daily Capacity, C
C = 10 x c (assume c is 10% of C)
Check C > Vx
If C > Vx  capacity will not be exceeded at the end of the design period (OK)
If C < Vx  capacity will be exceeded by the end of the design period (not OK)
When C < Vx happens, need to reduce design period.
Years required to reach capacity,

11. Calculate thickness, TA. TA = a1 D1 + a2 D2 + a3 D3
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Calculate thickness, TA.
TA = a1 D1 + a2 D2 + a3 D3
where a1, a2, a3 = structural coefficients (Table 3.9)
d1, d2 , d3 = layer depth (based on Tables 3.10, 3.11, 3.12)
5. Determine the equivalent thickness, TA’ using Thickness Nomograph
Based on subgrade CBR, ESA and TA values (Figure 3.5).
If CBR varies within the 1 m depth of the subgrade, the mean CBR is calculated:
Make sure TA > TA’

12. BFC 31802 HIGHWAY ENGINEERING Lecturer: Mr
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Let’s try Example
Yeah!

13. The following conditions are given:- Class of road = R5
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
EXAMPLE CALCULATION
Question:
The following conditions are given:-
Class of road = R5
Initial daily traffic volume (ADT) = 6,600
Percentage of commercial vehicles = 15%
Annual growth rate = 7%
Equivalence factor = 2.0
Subgrade CBR = 5%
Rolling terrain

14. Table 3.5: Guide for Equivalence Factor
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Table 3.5: Guide for Equivalence Factor
Percentage of selected heavy goods vehicles
0 – 15%
16 – 50%
51 – 100%
Type of road Equivalence Factor
Local
1.2
Trunk
2.0
3.0
3.7
Table 3.6: Maximum Hourly Capacity under ideal conditions
Road Type
Passenger Vehicle Unit per hour
Multilane
Two Lanes (bothways)
Three Lanes (bothways)
2000 per lane
2000 total for bothways
4000 total for bothways

15. Table 3.7: Carriageway Roadway Reduction Factor Carriageway Width
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Table 3.7: Carriageway Roadway Reduction Factor
Carriageway Width
Shoulder Width
2.00 m
1.50 m
1.25 m
1.00 m
7.5 m
7.0 m
6.0 m
5.0 m
1.00
0.88
0.81
0.72
0.97
0.86
0.78
0.70
0.94
0.83
0.76
0.67
0.90
0.79
0.73
0.64
Table 3.8: Traffic Reduction Factor
Type of Terrain
Factor
Flat
Rolling
Mountainous
T = 100/(100+Pc)
T = 100/(100+2Pc)
T = 100/(100+5Pc)

16. Table 3.9: Structural Layer Coefficient Component Type of Layer
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Table 3.9: Structural Layer Coefficient
Component
Type of Layer
Property
Coefficient
Wearing and Binder Course
Asphalt Concrete
1.00
Base Course
Dense Bituminous Macadam
Type 1 : Stability
> 400 kg
0.8
Type 2: Stability
> 300 kg
0.55
Cement Stabilized
Unconfined compressive strength (7 days) kg/m2
0.45
Mechanically Stabilized crushed aggregate
80%
0.32
Subbase
Sand, Laterite etc
20%
0.23
Crushed aggregate
30%
0.25
60%
0.28

17. Table 3.10: Structural Layer Coefficient Type of Layer
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Table 3.10: Structural Layer Coefficient
Type of Layer
Minimum Thickness
Wearing Course
4 cm
Binder Course
5 cm
Base Course
Bituminous
Wet Mix
10 cm
Cement Treated
Subbase
Granular
15 cm

18. Total thick of bituminous layer
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin
Table 3-11: Standard and Construction Layer Thickness
Type of Layer
Standard Thickness
One layer lift
Wearing Course
4-5 cm
Binder Course
5-10 cm
Base Course
Bituminous
5-20 cm
5-15 cm
Wet Mix
10-20 cm
10-15 cm
Cement Treated
Subbase
Granular
10-30 cm
15-20 cm
Table 3.12: Minimum Thickness of Bituminous Layer TA
Total thick of bituminous layer
< 17.5 cm
17.5 – 22.5 cm
23.0 – 29.5 cm
> 30.0 cm
5.0 cm
10.0 cm
15.0 cm
17.5 cm

19. BFC 31802 HIGHWAY ENGINEERING Lecturer: Mr
BFC HIGHWAY ENGINEERING Lecturer: Mr. Mustafa Kamal bin Shamshuddin