JSS Mahavidyapeetha
Sri Jayachamarajendra College Of Engineering
Mysuru – 570 006
HIGHWAY ENGINEERING
DESIGN DATA HAND BOOK
(Geometric Design and Pavement Design)
Compiled By
Dr. P. Nanjundaswamy
Professor of Civil Engineering
DEP AR TM EN T OF C IVIL EN GIN EER ING
2015
CONTENTS
Page No.
1 GEOMETRIC DESIGN STANDARDS FOR NON-URBAN HIGHWAYS
1.1.
1.2.
1.3.
1.4.
1.5.
1.6.
1.7.
Classification of Non-Urban Roads
Terrain Classification
Design Speed
Cross Section Elements
1.4.1 Cross Slope or Camber
1.4.2 Width of Pavement or Carriageway
1.4.3 Width of Roadway or Formation
1.4.4 Right of Way
1
Sight Distance
1.5.1 Stopping Sight Distance (SSD)
1.5.2 Overtaking Sight Distance (OSD)
3
Horizontal Alignment
1.6.1 Superelevation
1.6.2 Widening of Pavement on Horizontal Curves
1.6.3 Horizontal Transition Curves
1.6.4 Set-back Distance on Horizontal Curves
4
Vertical Alignment
1.7.1 Gradient
1.7.2 Length of Summit Curve
1.7.3 Length of Valley Curve
8
2 DESIGN OF FLEXIBLE PAVEMENTS
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
1–9
Design Traffic
Traffic growth rate
Design Life
Vehicle Damage Factor
Distribution of Commercial traffic over the carriageway
Design Criteria
Design Criteria
Design Charts and Catalogue
Pavement Composition
Final Remarks
1
1
2
2
2
2
3
3
3
4
6
7
8
8
9
9
10 – 18
10
10
10
11
11
12
12
13
18
18
3 ANALYSIS AND DESIGN OF RIGID PAVEMENTS
3.1
3.2
3.3
3.4
3.5
3.6
3.7
19 – 34
Modulus of Subgrade Reaction
Radius of Relative Stiffness
Equivalent Radius of Resisting Section
Critical Load Positions
Stresses and Deflections due to Wheel Load
19
3.5.1 Corner Loading
20
3.5.2 Interior Loading
21
3.5.3 Edge Loading
21
3.5.4 Dual Tires
22
Temperature Stresses
23
3.6.1 Warping Stresses (Westergaard Analysis)
23
3.6.2 Frictional Stresses
24
IRC Recommendations for Design of Plain Jointed Rigid
25
3.7.1 Legal Axle Load Limits
25
3.7.2 Load Safety Factors
25
3.7.3 Tyre Pressure
25
3.7.4 Design Period
25
3.7.5 Design Traffic
25
3.7.6 Characteristics of Sub-grade
26
3.7.7 Characteristics of Concrete
27
3.7.8 Fatigue Behaviour of Cement Concrete
27
3.7.9 Stress Computations
28
3.7.10 Temperature Differential
28
3.7.11 Recommended Design Procedure for Slab Thickness
28
3.7.12 Design of Joints
29
REFERENCES
19
19
20
20
1.
1.1
GEOMETRIC DESIGN STANDARDS FOR NON-URBAN HIGHWAYS
(IRC: 73-1980)
CLASSIFICATION OF NON-URBAN ROADS
Non-urban roads in India are classified into following five categories based on location and
function according to Nagpur road plan:
 National Highways (NH)
 State Highways (SH)
 Major District Roads (MDR)
 Other District Roads (ODR)
 Village Roads (VR)
Present system follows modified classification system as per third 20-year road
development plan. The roads are now classified into following three classes, for the
purpose of transport planning, functional identification, earmarking administrative
jurisdictions and assigning priorities on a road network:
 Primary system
o Expressways and National Highways (NH)
 Secondary system
o State Highways (SH) and Major District Roads (MDR)
 Tertiary system (Rural Roads)
o Other District Roads (ODR) and Village Roads (VR)
1.2
TERRAIN CLASSIFICATION
Table 1.1 Classification of terrains
Terrain Classification Cross slope of the country (%)
Plain
0 – 10
Rolling
10 – 25
Mountainous
25 – 60
Steep
> 60
1.3
DESIGN SPEED
Road
Classification
Table 1.2 Design Speeds on Non-urban Roads
Design Speed (km/h)
Plain
Rolling
Mountainous
Ruling
Min
Ruling
Min
Ruling
Min
Steep
Ruling
Min
Expressways
120
100
100
80
80
60
80
60
NH and SH
100
80
80
65
50
40
40
30
MDR
80
65
65
50
40
30
30
20
ODR
65
50
50
40
30
25
25
20
VR
50
40
40
35
25
20
25
20
1
1.4
CROSS SECTION ELEMENTS
1.4.1 Cross Slope or Camber
Sl
No
1
2
3
4
Table 1.3 Recommended values of camber for different types of road surfaces
Range of Camber in areas of
Types of Road Surface
Heavy rainfall
Light rainfall
Cement concrete and high type bituminous surface 1 in 50 (2.0%) 1 in 60 (1.7%)
Thin bituminous surface
1 in 40 (2.5%) 1 in 50 (2.0%)
Water bound macadam and gravel pavement
1 in 33 (3.0%) 1 in 40 (2.5%)
Earth Road
1 in 25 (4.0%) 1 in 33 (3.0%)
1.4.2 Width of Pavement or Carriageway
Table 1.4 Recommended values for width of carriageway
Sl
Class of Road
Width of Carriageway (m)
No
1 Single lane
3.75
2 Two lanes, without raised kerbs
7.0
3 Two lanes, with raised kerbs
7.5
4 Intermediate carriageway (except on important roads)
5.5
5 Multi-lane pavements
3.5 m per lane
Notes:
 The lane width of Expressways is 3.75 m in plain and rolling terrains and 3.5 m in
mountainous terrian
 The width of single lane for village roads may be decreased to 3.0 m
 On urban roads without kerbs the single lane width may be decreased to 3.5 m and
in access roads to residential areas to 3.0 m
 The minimum width recommended for kerbed urban road is 5.5 m
1.4.3 Width of Roadway or Formation
Table 1.5 Recommended values for width of roadway of various classes of roads
Roadway width (m)
Sl
Mountainous
Road Classification
Plain & Rolling
No
& Steep
terrain
terrain
National & State Highways
1
a. Single Lane
12.0
6.25
b. Two Lane
12.0
8.80
Major District Roads
2
a. Single Lane
9.0
4.75
b. Two Lane
9.0
--Other District Roads
3
a. Single Lane
7.5
4.75
b. Two Lane
9.0
--4 Village Roads – single lane
7.5
4.0
2
1.4.4 Right of Way
Sl
No
1
2
3
4
5
1.5
Table 1.6 Recommended land width for different classes of non-urban roads
Mountainous &
Plain & rolling terrain
steep terrain
Road Classification
Open
Built-up
Open areas
Built-up areas
areas
areas
Normal Range Normal Range Normal Normal
Expressways
90
60/30
National & State Highways
45
30-60
30
30-60
24
20
Major District Roads
25
25-30
20
15-25
18
15
Other District Roads
15
15-25
15
15-20
15
12
Village Roads
12
12-18
10
10-15
9
9
SIGHT DISTANCE
1.5.1 Stopping Sight Distance (SSD)
SSD = Lag distance + Braking distance
=
=
=
=
=
=
+
2 ( ± 0.01 )
(1.1)
Design speed (m/s)
Reaction time of driver (s) (2.5 seconds as per IRC guidelines)
Design longitudinal friction coefficient (Refer Table 1.7)
Acceleration due to gravity = 9.8 m/s2
Gradient of road (%) (+ for ascending and – for descending)
Table 1.7 Recommended longitudinal friction coefficient for providing SSD
Speed (km/h)
20-30
40
50
60
65
80
Longitudinal friction coefficient
0.40
0.38
0.37
0.36
0.36
0.35
≥100
0.35
Table 1.8 Recommended Stopping Sight Distance for different speeds
Speed (km/h)
20
25
30
40
50
60
65
80
SSD (m)
20
25
30
45
60
80
90
120
100
180
1.5.2 Overtaking Sight Distance (OSD)
=
+(
=
∗
=(
= (0.2
∗
+
+
+2 )+
(1.2a)
(1.2b)
− 16) (As per IRC guidelines)
(1.2c)
∗
(1.2d)
+ 6) (As per IRC guidelines)
=
4 ⁄
(1.2e)
3
∗
∗
=
=
=
=
=
=
=
=
Design speed or Speed of overtaking vehicle (m/s)
Speed of overtaken vehicle (m/s)
Reaction time of driver (s) (2.0 seconds as per IRC guidelines)
Time taken for overtaking operation (s)
The minimum spacing between vehicles (m)
Design speed or Speed of overtaking vehicle (km/h)
Speed of overtaken vehicle (km/h)
Average acceleration during overtaking (m/s2)
Table 1.9 Maximum overtaking acceleration at different speeds
Speed (km/h)
25
30
40
50
65
80
(kmph/s)
5.00
4.80
4.45
4.00
3.28
2.56
Max
overtaking Acc
(m/s2)
1.41
1.30
1.24
1.11
0.92
0.72
100
1.92
0.53
Table 1.10 Overtaking Sight Distance on two-lane highways for different speeds
Speed (km/h)
40
50
60
65
80
100
SSD (m)
165
235
300
340
470
640
Note:

= + for one-way roads

= + + for two-way roads
 Intermediate Sight Distance (ISD) = 2 SSD
 Head Light Distance (HSD) = SSD
1.6
HORIZONTAL ALIGNMENT
1.6.1 Superelevation (e)
+
=
=
=
=
=
=
(1.3)
Rate of superelevation
Design value of transverse or lateral friction coefficient (0.15 as per IRC guidelines)
Design speed vehicle (m/s)
Radius of the horizontal curve (m)
Acceleration due to gravity = 9.8 m/s2
Maximum Superelevation
In order to account for mixed traffic conditions in India, IRC has defined the maximum limit
) as given in Table 1.11
of superelevation (
Table 1.11 Recommended maximum limit of superelevation
7%
- Plain and rolling terrains and in snow bound areas
10 %
- Hill roads not bound by snow
4%
- Urban road stretches with frequent intersections
4
Minimum Superelevation
From drainage considerations it is necessary to have a minimum cross slope to drain off the
surface water. If the design superelevation works out to be less than the camber of the
road surface, then the minimum superelevation to be provided on horizontal curve may be
limited to the camber of the surface. Thus, after elimination of the crown a uniform cross
slope equal to the camber is maintained from outer to inner edge of pavement at the
circular curve.
In very flat curves with large radius, the normal cambered section may be retained on the
curves. However, in such cases, a check is performed for negative superelevation against
allowable lateral friction coefficient.
The IRC recommendation giving the radii of horizontal curves beyond which normal
cambered section may be maintained and no superelevation is required at horizontal
curves, are presented in Table 1.12, for various design speeds and rates of cross slope.
Table 1.12 Recommended radii beyond which superelevation is not required
Radius (m) of horizontal curve for camber of
Design Speed
(km/h)
4%
3%
2.5%
2%
1.7%
20
50
60
70
90
100
25
70
90
110
140
150
30
100
130
160
200
240
35
140
180
220
270
320
40
180
240
280
350
420
50
280
370
450
550
650
60
470
620
750
950
1100
80
700
950
1100
1400
1700
100
1100
1500
1800
2200
1600
Design of Superelevation (as per IRC guidelines)

The superelevation is calculated for 75% of design speed neglecting the friction
=
(0.75 )
(1.4)

If the calculated value of ‘e’ is less than the specified maximum limit of superelevation
(
) the value so obtained is considered as design value of superelevation.

If the calculated value of ‘e’ exceeds
then
is considered as design value of
superelevation and developed lateral friction coefficient is verified at the full value of
design speed.
5
=
(1.5)
−

If
calculated is less than 0.15, then

If not, either the radius of the horizontal curve has to be increased or the speed has to
be restricted to the safe value given in equation 1.6 which will be less than the design
speed.
(
=

is accepted as the design superelevation.
(1.6)
+ )
Appropriate warning sign and speed limit regulation sign are installed to restrict and
regulate the speed to at such curves.
1.6.2 Widening of Pavement on Horizontal Curves
Extra width = Mechanical widening + Psychological widening
=
+
(1.7a)
∗
=
∗
=
=
=
=
2
+
(1.7b)
9.5√
Number of traffic lanes
Length of wheel base (m) (normally 6.1 m or 6.0 m)
Radius of horizontal curve (m)
Design speed (km/h)
Table 1.13 Recommended Extra Width of pavement at horizontal curves
Radius of Curve (m)
< 20
20 – 40
41 – 60
61 – 100
101 – 300
> 300
Extra width on twolane pavement (m)
1.5
1.5
1.2
0.9
0.6
Nil
Extra width on single
lane pavement (m)
0.9
0.6
0.6
Nil
Nil
Nil
Note: For multi-lane roads, the pavement widening is calculated by adding half the extra
width of two-lane roads to each lane of multi-lane road
6
1.6.3 Horizontal Transition Curves
Length of Transition Curve ( )
A. Rate of Change of Centrifugal Acceleration
(1.8a)
=
=
80
(75 +
[0.5 ≤
∗)
≤ 0.8]
(1.8b)
B. Rate of Introduction of Superelevation
=
2
=
(
+
2
)
= (
+
)
=
ℎ
(1.9a)
ℎ
(1.9b)
C. Empirical formula
=
2.7
∗
(1.10a)
∗
(1.10b)
=
= Design speed (m/s)
= Rate of change of centrifugal acceleration (m/s3)
= Radius of horizontal curve (m)
∗
= Design speed (km/h)
=
Rate at which superelevation is introduced
(150 – Normal, 100 – Built up areas and 60 – Hill roads)
= Amount of Superelevation or Total raising of pavement (m)
= Rate of superelevation
= Width of pavement (m)
= Extra width of pavement (m)
Note: Shift of transition curve is given by
=
7
1.6.4 Set-back Distance on Horizontal Curves (m’)
When
≥
=
2
When
=
−( − )
(1.11a)
2
180
2 ( − )
(1.11b)
<
=
−( − )
2
=
2
+
( −
2
)
(1.12a)
2
180
2 ( − )
(1.12b)
= Length of the Curve (m)
= Sight Distance (m) (either SSD or OSD or ISD)
= Radius of horizontal curve (m)
= Distance between centerline of road to centerline of inside lane (m)
= Angle subtended at the center of horizontal curve (degrees)
1.7
Vertical Alignment
1.7.1 Gradient
Table 1.14 Gradients for roads in different terrains
Ruling
gradient
Limiting
gradient
Exceptional
gradient
Plain or Rolling
3.3 %
(1 in 30)
5.0 %
(1 in 20)
6.7 %
(1 in 15)
Mountainous terrain and steep terrain having
elevation more than 3000 m above MSL
5.0 %
(1 in 20)
6.0 %
(1 in 16.7)
7.0 %
(1 in 14.3)
steep terrain up to 3000 m height above MSL
6.0 %
(1 in 16.7)
7.0 %
(1 in 14.3)
8.0 %
(1 in 12.5)
Type of terrain
8
1.7.2 Length of Summit Curve (L)
When
≥
=
(1.13)
√2 + √2ℎ
When
<
=2 −
=
=
=
=
ℎ
Note:
√2 + √2ℎ
(1.14)
Deviation angle (algebraic difference in grades)
Sight Distance (m) (either SSD or OSD or ISD)
Height of eye level of driver above roadway surface (m)
Height of subject above roadway surface (m)
For SSD
= 1.20
ℎ = 0.15
ℎ
√2 + √2ℎ
= 4.4
For OSD or ISD
= 1.20
ℎ = 1.20
ℎ
√2 + √2ℎ
= 9.6
1.7.3 Length of Valley Curve (L)
A. Comfort Condition
.
(1.15)
=2
B. Head Light Sight Distance
When
≥
=
When
(2ℎ + 2 tan )
<
=2 −
ℎ
(1.16)
=
=
=
=
(2ℎ + 2 tan )
(1.17)
Deviation angle (algebraic difference in grades)
Head light sight Distance (m) (HSD = SSD)
Height of head lights above roadway surface (m)
Inclination of head light beam with horizontal
Note: ℎ = 0.75
=1 ℎ
(2ℎ + 2 tan ) = (1.5 + 0.035 )
9
2.
DESIGN OF FLEXIBLE PAVEMENTS (IRC : 37-2001)
2.1
DESIGN TRAFFIC
The design traffic is considered in terms of cumulative number of standard axles (in the lane
carrying maximum traffic) to be carried during the design life of pavement using
=
N
A
D
F
n
r
[( + ) − ]
∗
∗
∗
(2.1 a)
The cumulative number of standard axles to be catered for in the design life in
terms of msa
Initial traffic in the year of completion of construction in terms of the number
of commercial vehicles per day
Lane distribution factor
Vehicle damage factor
Design life in years
Annual growth rate of commercial vehicles
The traffic in the year of completion is estimated using
P
x
2.2
= ( + )
Number of commercial vehicles as per last count
Number of years between the last count and the year of completion of
construction
(2.1 b)
TRAFFIC GROWTH RATE
Traffic growth rates should be estimated
by studying the past trends of traffic growth, and
by establishing econometric models, as per the procedure outlined in IRC:108
“Guidelines for traffic prediction on rural highways”.
If adequate data is not available, it is recommended that an average annual growth rate of
7.5 percent may be adopted.
2.3
DESIGN LIFE
For the design of pavement, the design life is defined in terms of the cumulative number of
standard axles that can be carried before strengthening of pavement is necessary.
It is recommended that pavements for National Highways (NH) and State Highways (SH)
should be design for a life of 15 years. Expressways and Urban roads nay be designed for a
longer life of 20 years. For other categories of roads, a design life of 10 to 15 years may be
adopted.
10
2.4
VEHICLE DAMAGE FACTOR
+
=
+
+
+
+
+
+
+ ……
+
=
+ ……
(2.2 a)
+ ……
+ ……
(2.2 b)
(2.2 c)
=
Standard Axle Load
Single Axle : 8160 kg
Tandem Axle : 14968 kg
Where sufficient information on axle loads is not available and project does not warrant
conducting an axle load survey, the indicative values of vehicle damage factor as given
below may be used.
Table 2.1 Indicative VDF Values (Table 1 of IRC:37-2001)
Terrain
Initial traffic volume
(CVPD)
Rolling/Plain
Hilly
0-150
1.5
0.5
150-1500
3.5
1.5
More than 1500
4.5
2.5
2.5
DISTRIBUTION OF COMMERCIAL TRAFFIC OVER THE CARRIAGEWAY
In the absence of adequate and conclusive data for Indian conditions, it is recommended to
assume the following distribution.
Table 2.2 Indicative Lane Distribution Values
Percentage of trucks in Design Lane
No. of Traffic lanes
in two directions
Undivided Roads
(Single Carriageway)
Divided Roads
(Dual Carriageway)
1
100
100
2
75
75
3
----
60
4
40
45
11
2.6
DESIGN CRITERIA
The flexible pavements has been modeled as a three layer structure and stresses and strains
at critical locations have been computed using the linear elastic model. To consider the
aspects of performance, the following three types of pavement distress resulting from
repeated (cyclic) application of traffic loads are considered:
 Vertical compressive strain at the top of the sub-grade which can cause sub-grade
deformation resulting in permanent deformation at the pavement surface.
 Horizontal tensile strain or stress at the bottom of the bituminous layer which can
cause fracture of the bituminous layer.
 Pavement deformation within the bituminous layer.
Figure 2.1 : Critical Locations in Pavement
While the permanent deformation within the bituminous layer can be controlled by meeting
the mix design requirements, thickness of granular and bituminous layers are selected using
the analytical design approach so that strains at the critical points are within the allowable
limits. For calculating tensile strains at the bottom of the bituminous layer, the stiffness of
dense bituminous macadam (DBM) layer with 60/70 bitumen has been used in the analysis.
2.7
FAILURE CRITERIA
As shown in figure 2.11, A and B are the critical locations for tensile strains (εt). Maximum
value of the strain is adopted for design. C is the critical location for the vertical subgrade
strain (εz) since the maximum value of the εz occurs mostly at C.
Fatigue Criteria:
Bituminous surfacing of pavements display flexural fatigue cracking if the tensile strain at
the bottom of the bituminous layer is beyond certain limit. The relation between the fatigue
life of the pavement and the tensile strain in the bottom of the bituminous layer is
expressed as
12
.
.
= .
Nf
εt
E
(2.3)
Allowable number of load repetitions to produce 20% cracked surface area
Tensile strain at the bottom of surface layer (micro strain)
Elastic modulus of bituminous surfacing (MPa)
Rutting Criteria:
The allowable number of load repetitions to control permanent deformation can be
expressed as
.
= .
Nr
εz
(2.4)
Allowable number of load repetitions to produce rutting of 20 mm
Vertical subgrade strain (micro strain)
Standard axle load considered is 80 kN. One dual wheel set with a wheel load of 20kN,
center-to-center tyre spacing of 310 mm and tyre pressure of 0.56 MPa is considered for
analysis.
2.8
DESIGN CHARTS AND CATALOGUE
Based on the performance of existing designs and using analytical approach, simple design
charts (Figure 2.2 and 2.3) and a catalogue of pavement designs are added in the code. The
pavement designs are given for subgrade CBR values ranging from 2% to 10% and design
traffic ranging from 1 msa to 150 msa for an average annual pavement temperature of 35 C.
The later thicknesses obtained from the analysis have been slightly modified to adapt the
designs to stage construction. Using the following simple input parameters, appropriate
designs could be chosen for the given traffic and soil strength:


Design traffic in terms of cumulative number of standard axles; and
CBR value of subgrade.
The designs relate to ten levels of design traffic 1, 2, 3, 4, 5, 10, 20, 30, 50, 100 and 150 msa.
For intermediate traffic ranges, the pavement layer thickness may be interpolated linearly.
For traffic exceeding 150 msa, the pavement design appropriate to 150 msa may be chosen
and further strengthening carried out to extend the life at appropriate time based on
pavement deflection measurements as per IRC : 81.
13
Figure 2.2 : Pavement Thickness Design Chart for Traffic 1-10 msa
Figure 2.3 : Pavement Thickness Design Chart for Traffic 10-150 msa
14
Pavement Design Catalogue
Cumulative
Traffic
(msa)
Total
Pavement
Thickness
(mm)
PAVEMENT COMPOSITION (mm)
Bituminous Surfacing
Granular
Granular
Wearing
Binder
Base
Sub-base
Course
Course
CBR 2 %
1
660
20 PC
------
225
435
2
715
20 PC
50 BM
225
440
3
750
20 PC
60 BM
250
440
5
795
25 SDBC
70 DBM
250
450
10
850
40 BC
100 DBM
20
880
40 BC
130 DBM
30
900
40 BC
150 DBM
50
925
40 BC
175 DBM
250
460
100
955
40 BC
195 DBM
150
975
50 BC
215 DBM
CBR 3 %
1
550
20 PC
------
225
435
2
610
20 PC
50 BM
225
335
3
645
20 PC
60 BM
250
335
5
690
25 SDBC
60 DBM
250
335
10
760
40 BC
90 DBM
20
790
40 BC
120 DBM
30
810
40 BC
140 DBM
50
830
40 BC
160 DBM
250
380
100
860
50 BC
180 DBM
150
890
50 BC
210 DBM
CBR 4%
1
480
20 PC
------
225
255
2
540
20 PC
50 BM
225
265
3
580
20 PC
50 BM
250
280
5
620
25 SDBC
60 DBM
250
285
10
700
40 BC
80 DBM
20
730
40 BC
110 DBM
30
750
40 BC
130 DBM
50
780
40 BC
160 DBM
250
330
100
800
50 BC
170 DBM
150
820
50 BC
190 DBM
15
Pavement Design Catalogue
Cumulative
Traffic
(msa)
Total
Pavement
Thickness
(mm)
PAVEMENT COMPOSITION (mm)
Bituminous Surfacing
Granular
Granular
Wearing
Binder
Base
Sub-base
Course
Course
CBR 5%
1
430
20 PC
------
225
205
2
490
20 PC
50 BM
225
215
3
530
20 PC
50 BM
250
230
5
580
25 SDBC
55 DBM
250
250
10
660
40 BC
70 DBM
20
690
40 BC
100 DBM
30
710
40 BC
120 DBM
50
730
40 BC
140 DBM
250
300
100
750
50 BC
150 DBM
150
770
50 BC
170 DBM
CBR 6 %
1
390
20 PC
------
225
165
2
450
20 PC
50 BM
225
175
3
490
20 PC
50 BM
250
190
5
535
25 SDBC
50 DBM
250
210
10
615
40 BC
65 DBM
20
640
40 BC
90 DBM
30
655
40 BC
105 DBM
50
675
40 BC
125 DBM
250
260
100
700
50 BC
140 DBM
150
720
50 BC
160 DBM
CBR 7%
1
375
20 PC
------
225
150
2
425
20 PC
50 BM
225
150
3
460
20 PC
50 BM
250
160
5
505
25 SDBC
50 DBM
250
180
10
580
40 BC
60 DBM
20
610
40 BC
90 DBM
30
630
40 BC
110 DBM
50
650
40 BC
130 DBM
250
230
100
675
50 BC
145 DBM
150
695
50 BC
165 DBM
16
Pavement Design Catalogue
Cumulative
Traffic
(msa)
Total
Pavement
Thickness
(mm)
PAVEMENT COMPOSITION (mm)
Bituminous Surfacing
Granular
Granular
Wearing
Binder
Base
Sub-base
Course
Course
CBR 8%
1
375
20 PC
------
225
150
2
425
20 PC
50 BM
225
150
3
450
20 PC
50 BM
250
150
5
475
25 SDBC
50 DBM
250
150
10
550
40 BC
60 DBM
20
575
40 BC
85 DBM
30
590
40 BC
100 DBM
50
610
40 BC
120 DBM
250
200
100
640
50 BC
140 DBM
150
660
50 BC
160 DBM
CBR 9%
1
375
20 PC
------
225
150
2
425
20 PC
50 BM
225
150
3
450
20 PC
50 BM
250
150
5
475
25 SDBC
50 DBM
250
150
10
540
40 BC
50 DBM
20
570
40 BC
80 DBM
30
585
40 BC
95 DBM
50
605
40 BC
115 DBM
250
200
100
635
50 BC
135 DBM
150
655
50 BC
155 DBM
CBR 10 %
1
375
20 PC
------
225
150
2
425
20 PC
50 BM
225
150
3
450
20 PC
50 BM
250
150
5
475
25 SDBC
50 DBM
250
150
10
540
40 BC
50 DBM
20
565
40 BC
75 DBM
30
580
40 BC
90 DBM
50
600
40 BC
110 DBM
250
200
100
630
50 BC
130 DBM
150
650
50 BC
150 DBM
17
2.9
PAVEMENT COMPOSITION
Sub-base Course
 Natural sand, gravel, laterite, brick metal, crushed stone or combinations thereof
 Minimum CBR :
 20% upto 2 msa traffic
 30% exceeding 2 msa
 Minimum Thickness
 150 mm for traffic < 10 msa
 200 mm for traffic ≥ 10 msa
 If subgrade CBR < 2%, design for subgrade CBR of 2% and provide a 150 mm thick
capping layer of minimum CBR 10% in addition to sub-base
Base Course
 Unbound granular material – WBM, WMM or other equivalent granular construction
conforming to IRC/MORT&H specifications
 Minimum Thickness
 225 mm for traffic ≤ 2 msa
 250 mm for traffic > 2 msa
 If WBM is used and traffic > 10 msa, minimum thickness is 300 mm (4 layers of 75
mm each)
Bituminous Surfacing
 Wearing course or Binder course+wearing course
 Wearing course : Surface dressing, open-graded premix carpet, mix seal surfacing,
SDBC and BC
 Binder course : BM, DBM, mix seal surfacing, SDBC and BC
 Wearing surface used is open-graded premix carpet of thickness upto 25 mm, it
should not be counted towards the total thickness
2.10 FINAL REMARKS




The present guidelines follows mechanistic empirical approach and developed new
set of designs up to 150 msa
Thickness charts are still available for CBR values of up to 10% only
Design charts are available for only a pavement temperature of 35o C
The contribution of individual component layers is still not realized fully with the
system of catalogue thicknesses. The same can be done with the analytical tool for
design.
18
3.
ANALYSIS AND DESIGN OF RIGID PAVEMENTS
3.1
MODULUS OF SUBGRADE REACTION (K)
(3.1 a)
=
p
∆
∆
Pressure sustained by a rigid plate of diameter 75 cm at design deflection ∆
Design deflection = 0.125 cm
 Allowance for Worst Subgrade Moisture
(3.1 b)
=
pus
ps
K
Ks
Pressure required in the plate bearing test for design deflection of 0.125 cm
which produces a deformation of δ in unsoaked consolidation test
Pressure required to produce the same deformation δ in the soaked
consolidation test
Modulus of subgrade reaction for the prevailing moisture condition
Corrected modulus of subgrade reaction for worst subgrade moisture
 Correction for Small Plate Size
(3.1 c)
=
K1
K
3.2
Modulus of subgrade reaction determined using plate of radius a1
Corrected modulus of subgrade reaction for standard plate of radius a
RADIUS OF RELATIVE STIFFNESS ( )
(3.2)
=
E
μ
h
K
3.3
( − )
Modulus of elasticity of cement concrete
Poisson’s ratio of concrete = 0.15
Slab thickness
Modulus of subgrade reaction
EQUIVALENT RADIUS OF RESISTING SECTION (b)
=
A
H
.
+
− .
=
Radius of wheel load distribution
Slab thickness
< 1.724 ℎ
(3.3)
≥ .
19
3.4
CRITICAL LOAD POSITIONS
The three typical locations namely the interior, edge and corner, where differing conditions
of slab continuity exist, are treated as critical load positions.
Figure 3.1: Critical Load Positions
3.5
STRESSES AND DEFLECTIONS DUE TO WHEEL LOAD
3.5.1 Corner Loading
Westergaard (1926)
=
∆ =
.
√
−
(3.4 a)
√
. − .
(3.4 b)
Westergaard analysis modified by Kelly
=
.
√
−
(3.4 c)
Ioannides et al (1985)
.
=
∆ =
−
.
− .
(3.4 d)
(3.4 e)
20
3.5.2 Interior Loading
Westergaard (1926)
( + )
=
∆=
+
+ .
(3.5 a)
− .
(3.5 b)
3.5.3 Edge Loading
Westergaard (1926)
=
.
(3.6 a)
+ .
Westergaard’s analysis Modified by Teller and Sutherland (1948)
=
.
( + .
)
(3.6 b)
( )− .
+
Ioannides et al (1985) – Semicircular loaded area
=
( + )
( + )
+ .
∆ =
−
+ .
−
( .
+ .
+
( +
)
)
(3.6 c)
(3.6 d)
When μ = 0.15
=
.
+ .
∆ =
.
− .
+ .
(3.6 e)
(3.6 f)
21
Ioannides et al (1985) – Circular loaded area
( + )
( + )
=
+ .
+ .
∆ =
−
−
( .
+
−
+ .
+
.
( +
)
)
(3.6 g)
(3.6 h)
When μ = 0.15
=
.
+ .
∆ =
σc, σi, σe
∆c, ∆i, ∆e
h
P
K
a
l
b
c
E
μ
.
− .
− .
(3.6 i)
(3.6 j)
Maximum stress at corner, interior and edge loading respectively
Maximum deflection at corner, interior and edge loading respectively
Slab thickness
Wheel load
Modulus of subgrade reaction
Radius of wheel load distribution
Radius of relative stiffness
Radius of resisting section
Side length of square contact area = 1.772a
Modulus of elasticity of cement concrete
Poisson’s ratio of concrete = 0.15
3.5.4 Dual Tires
Figure 3.2: Method for Converting Duals into a Circular Area
22
If Pd is the load on one tire and q is the contact pressure, the area of each tire is
=[ ( .
) +( .
)( .
)] = .
=
.
(3.7 a)
The area of equivalent circle is
= ( .
)+(
) = .
− .
+
(3.7 b)
The radius of contact area
=
3.6
.
.
+
(3.7 c)
.
TEMPERATURE STRESSES
3.6.1 Warping Stresses (Westergaard Analysis)
Interior
+
−
=
(3.8 a)
Edge
=
=
(3.8 b)
Corner
=
σtc, σti, σte
( − )
Maximum warping stress at corner, interior and edge region respectively
a
Radius of wheel load distribution
l
Radius of relative stiffness
E
Modulus of elasticity of cement concrete
μ
Poisson’s ratio of concrete = 0.15
α
Thermal coefficient of concrete
Cx, Cy,
(3.8 c)
Bradbury warping stress coefficient
23
L/l
C
L/l
C
1
0.000
7
1.030
2
0.040
8
1.077
3
0.175
9
1.080
4
0.440
10
1.075
5
0.720
11
1.050
6
0.920
12
1.000
Figure 3.3: Warping Stress Coefficient or Stress Correction Factor for Finite Slab
(Bradbury – 1938 and IRC : 58-2002)
3.6.2 Frictional Stresses
=
(3.9 a)
Or
=
σtf
Frictional Stress developed in cement concrete pavement
h
Slab Thickness
B
Slab width
L
Slab length
f
Coefficient of subgrade restraint (maximum value is about 1.5)
γc
Unit weight of concrete (about 2400 kg/m3)
(3.9 b)
24
3.7
IRC RECOMMENDATIONS FOR DESIGN OF PLAIN JOINTED RIGID
PAVEMENTS FOR HIGHWAYS (IRC : 58-2002)
3.7.1 Legal Axle Load Limits
Single
Tandem
Tridem
10.2 tonnes
19.0 tonnes
24.0 tonnes
3.7.2 Load Safety Factors
Expressway/NH/SH/MDR
Lesser importance with lower truck traffic
Residential and other streets
1.2
1.1
1.0
3.7.3 Tyre Pressure
Range 0.7 to 1.0 MPa
No significant effect on pavements ≥ 20cm thick
0.8 MPa is adopted
3.7.4 Design Period
Normal – 30 years
Accurate prediction not possible – 20 years
3.7.5 Design Traffic
a. 2-lane 2-way road – 25% of total for fatigue design
b. 4-lane or multi-lane divided traffic – 25% of total traffic in the direction of
predominant traffic.
c. New highway links where no traffic data is available - data from roads similar
classification and importance
d. Average annual growth rate – 7.5%
e. Cumulative Number of Repetitions of Axles
=
[( + ) − ]
= ( + )
A
R
N
P
X
(3.10 a)
(3.10 b)
Initial number of axles per day in the year when the road is operational
Annual rate of growth of commercial traffic
Design period in years
Number of commercial vehicles as per last count
Number of years between the last count and the year of completion of
construction
25
3.7.6 Characteristics of Sub-grade
Modulus of sub-grade reaction (K)
a.
b.
c.
d.
e.
Pressure sustained per unit deflection
Plate bearing test (IS : 9214 – 1974)
Limiting design deflection = 1.25mm
K75 = 0.5 k30
One test/km/lane
Approximate K-Value
Approximate K-value corresponding to CBR values for homogeneous soil subgrade
Soaked CBR (%)
2
3
4
5
7
10
15
20
k-Value (kg/cm3)
2.1
2.8
3.5
4.2
4.8
5.5
6.2
6.9
50
100
14.0 22.2
k-values over Granular and Cemented Sub-bases
Effective k (kg/cm3)
k-Value of subgrade Untreated granular sub-base
Cement treated sub-base of
3
(kg/cm )
of thickness in cm
thickness in cm
15
22.5
30
10
15
20
2.8
3.9
4.4
5.3
7.6
10.8
14.1
5.6
6.3
7.5
8.8
12.7
17.3
22.5
8.4
9.2
10.2
11.9
-
-
-
k-value over Dry Lean Concrete Sub-base
k-Value of subgrade (kg/cm3)
2.1
2.8
4.2
4.8
5.5
6.2
Effective k over 100 mm DLC (kg/cm3)
5.6
9.7
16.6
20.8
27.8
38.9
Effective k over 150 mm DLC (kg/cm3)
9.7
13.8
20.8
27.7
41.7
-
26
3.7.7 Characteristics of Concrete
 Modulus of Elasticity
 Experimentally determined value
 3.0 x 105 kg/cm2 for M40 Concrete
 Poisson’s ratio
µ = 0.15
 Flexural strength of Cement Concrete
fcr = 45 kg/cm2 for M40 Concrete
 Coefficient of thermal expansion
α = 10 x 10-6 per °C
3.7.8 Fatigue Behaviour of Cement Concrete
=
=
.
− .
.
.
−
=
.
N
SR
for SR < 0.45
(3.11 a)
when 0.45 ≤ SR ≤ 0.55
(3.11 b)
for SR > 0.55
(3.11 c)
Fatigue life
Stress ratio
Stress Ratio and Allowable Repetitions in Cement Concrete
Stress Ratio
Allowable
Repetitions
Stress Ratio
0.45
0.46
0.47
0.48
0.49
0.50
0.51
0.52
0.53
0.54
0.55
0.56
0.57
0.58
62,790,761
14,335,236
5,202,474
2,402,754
1,286,914
762,043
485,184
326,334
229,127
166,533
124,526
94,065
71,229
53,937
0.59
0.60
0.61
0.62
0.63
0.64
0.65
0.66
0.67
0.68
0.69
0.70
0.71
0.72
Allowable
Repetitions
40,842
30,927
23,419
17,733
13,428
10,168
7,700
5,830
4,415
3,343
2,532
1,917
1,452
1,099
Stress Ratio
0.73
0.74
0.75
0.76
0.77
0.78
0.79
0.80
0.81
0.82
0.83
0.84
0.85
---
Allowable
Repetitions
832
630
477
361
274
207
157
119
90
68
52
39
30
----
27
3.7.9 Stress Computations
Edge Stress
 Due to Load – Picket & Ray’s chart
 Due to Temperature –Westergaard’s equation (Equation 2.7 b)
Corner Stress
 Due to Load –Westergaard’s analysis modified by Kelly (Equation 2.3 c)
 Due to temperature – negligible and hence ignored
3.7.10Temperature Differential
Recommended Temperature Differentials for Concrete
3.7.11Recommended Design Procedure for Slab Thickness
 Stipulate design values for the various parameters
 Decide types and spacing between joints
 Select a trial design thickness of pavement
 Compute the repetitions of axle loads of different magnitudes during design period
 Calculate cumulative fatigue damage (CFD)
 If CFD is more than 1.0 revise the thickness
 Check for load+temperature stress at edge with modulus of rupture
 Check for corner stress
28
3.8
Design of Joints
Expansion Joint
If δ' is the maximum expansion in a slab of length Le with a temperature rise from T1 to T2,
then δ' = Le α (T1 to T2) where α is the coefficient of thermal expansion of concrete.
Expansion joint gap δ = 2 δ'
Maximum expansion joint gap = 25 mm
Maximum Spacing between expansion joints
for rough interface layer
140 m
– all slab thicknesses
for smooth interface layer
when pavement is constructed in summer
90 m
– upto 200 mm thick slab
120 m
– upto 250 mm thick slab
when pavement is constructed in winter
50 m
– upto 200 mm thick slab
60 m
– upto 250 mm thick slab
Contraction Joint
=
σtc
Allowable tensile stress in concrete
h
Slab thickness
B
Slab width
Lc
Slab length or spacing b/w contraction joints
γc
Unit weight of concrete
f
Coefficient of subgrade restraint (max 1.5)
(3.12)
If Reinforcement is provided, replace LHS by σts As
Maximum Spacing between contraction joints
for unreinforced slabs
4.5 m
– all slab thicknesses
for reinforced slabs
13 m
– for 150 mm thick slab
14 m
– for 200 mm thick slab
29
Dowel Bar Design

Load transfer capacity of a single dowel bar in
 Shear
= .
 Bending
=
 Bearing
P'
d
Ld
δ
Fs
Ff
Fb

=
(3.13 a)
(3.13 b)
+ .
. (
+ .
(3.13 c)
)
Load transfer capacity of a single dowel bar, kg
Diameter of dowel bar, cm
Total length of embedment of dowel bar, cm
Joint width, cm
Permissible shear stress in dowel bar, kg/cm2
Permissible flexural stress in dowel bar, kg/cm2
Permissible bearing stress in concrete, kg/cm2
Balanced design for equal capacity in bending and bearing gives
=
+ .
+ .
(3.14)

Minimum dowel length L = Ld + δ

Load capacity of dowel system = 40% of wheel load

Required load capacity factor =

Effective distance upto which there is load transfer = 1.8 (radius of relative stiffness)

Variation of capacity factor linear from 1.0 under the load to 0.0 at effective distance

Design spacing = The spacing which conforms to required capacity factor
%
( ′)
Recommended Dimensions of Dowel Bars for Rigid Pavements (Axle Load of 10.2t)
Slab thickness, cm
Dowel Bar Details
Diameter, mm
Length, mm
Spacing, mm
20
25
500
250
25
25
500
300
30
32
500
300
35
32
500
300
Note : Dowel bars shall not be provided for slabs of less than 15 cm thickness
30
3.9
Tie Bar Design
Area of steel per unit length of joint is obtained by equating the total friction to the total
tension developed in the tie bars
=
(3.15)
Length of embedment required to develop a bond strength equal to working stress of steel
=
or
=
(3.16)
Allowable tensile stress in steel = 1400 kg/cm2
Area of tie bar
distance b/w the joint and nearest free edge
Slab thickness
Unit weight of concrete
Coefficient of subgrade restraint (max 1.5)
Length of tie bar
Perimeter of tie bar
Diameter of tie bar
Allowable bond stress in concrete
= 24.6 kg/cm2 for deformed tie bars
= 17.5 kg/cm2 for plain tie bars
σts
As
B
h
γc
f
Lt
P
d
σbc
Details of Tie Bars for Longitudinal Joint of Two-Lane Rigid Pavements
Slab
Thickness
cm
15
20
25
30
35
Tie bar details, cm
Diameter
mm
8
10
10
12
12
16
12
16
12
16
Max. spacing, cm
Plain
Deformed
bars
bars
33
53
52
83
39
62
56
90
45
72
80
128
37
60
66
106
32
51
57
91
Minimum Length, cm
Plain
Deformed
bars
bars
44
48
51
56
51
56
58
64
58
64
72
80
58
64
72
80
57
64
72
80
Note: The recommended details are based on the following values of design parameters
σts
Allowable tensile stress in steel
=
=
2000 kg/cm2 for deformed bars
1250 kg/cm2 for plain bars
σbc
Allowable bond stress in concrete
=
=
24.6 kg/cm2 for deformed bars
17.5 kg/cm2 for plain bars
31
EDGE LOAD STRESSES IN RIGID PAVEMENT (kg/cm2)
K
kg/cm3
16
18
20
22
Slab Thickness (mm)
24
26
28
30
32
34
36
8.698
8.302
8.006
7.494
6.692
7.886
7.529
7.252
6.798
6.070
7.191
6.868
6.625
6.203
5.539
6.590
6.297
6.075
5.689
5.081
11.179
10.653
10.261
9.584
8.529
10.148
9.672
9.317
8.702
7.744
9.264
8.832
8.509
7.948
7.073
8.500
8.106
7.810
7.297
60494
13.578
12.925
12.439
11.601
10.291
12.335
11.743
11.302
10.541
9.354
11.269
10.731
10.329
9.634
8.550
10.347
9.855
9.487
8.851
7.856
15.917
15.138
14.559
13.561
11.992
14.467
13.762
13.237
12.330
10.911
13.225
12.582
12.103
11.276
9.982
12.150
11.562
11.123
10.364
9.178
18.208
17.306
16.634
15.472
13.640
16.558
15.740
15.131
14.078
12.423
15.142
14.397
13.841
12.881
11.375
13.917
13.235
12.725
11.845
10.466
20.461
19.434
18.668
17.342
15.244
18.614
17.684
16.990
15.790
13.896
17.029
16.181
15.549
14.456
12.734
15.656
14.880
14.301
13.299
11.724
22.680
21.528
20.668
19.174
16.808
20.641
19.598
18.820
17.470
15.334
18.889
17.939
17.231
16.003
14.062
17.371
16.502
15.853
14.729
12.956
SINGLE AXLE LOAD
Single Axle Load – 6 tons
6.0
8.0
10.0
15.0
30.0
22.490
21.457
20.684
19.331
17.131
18.824
17.961
17.319
16.203
14.410
16.054
15.319
14.771
13.824
12.322
13.902
13.264
12.790
11.972
10.684
12.191
11.631
11.215
10.497
9.373
10.802
10.307
9.938
9.301
8.307
9.656
9.215
8.886
8.317
7.427
Single Axle Load – 8 tons
6.0
8.0
10.0
15.0
30.0
28.615
27.246
26.216
24.405
21.450
24.000
22.862
22.012
20.527
18.122
20.502
19.533
18.812
17.560
15.553
17.779
16.939
16.315
15.236
13.524
15.610
14.872
14.325
13.379
11.892
13.849
13.195
12.709
11.870
10.559
12.396
11.811
11.376
10.626
9.454
Single Axle Load – 10 tons
6.0
8.0
10.0
15.0
30.0
34.471
32.755
31.461
29.184
25.492
28.971
27.552
26.488
24.623
21.604
24.785
23.583
22.684
21.117
18.594
21.519
20.478
19.703
18.358
16.210
18.912
17.999
17.320
16.146
14.284
16.794
15.983
15.381
14.342
12.706
15.044
14.319
13.780
12.851
11.394
Single Axle Load – 12 tons
6.0
8.0
10.0
15.0
30.0
40.103
38.034
36.475
33.739
29.329
33.774
32.067
30.785
28.537
24.918
28.939
27.496
26.415
24.527
21.493
25.153
23.909
22.980
21.363
18.774
22.126
21.037
20.225
18.817
16.575
19.662
18.697
17.978
16.736
14.767
17.625
16.761
16.119
15.010
13.261
Single Axle Load – 14 tons
6.0
8.0
10.0
15.0
30.0
45.547
43.126
41.306
38.121
32.998
38.432
36.434
34.933
32.307
28.101
32.979
31.293
30.028
27.817
24.281
28.697
27.247
26.161
24.264
21.243
6.0
8.0
10.0
15.0
30.0
50.833
48.065
45.989
42.365
36.521
42.964
40.675
38.957
35.961
31.173
36.921
34.988
33.538
31.009
26.981
32.164
30.503
29.259
27.090
23.637
6.0
8.0
10.0
15.0
30.0
55.986
52.878
50.552
46.488
39.915
47.388
44.810
42.879
39.520
34.147
40.775
38.595
36.962
34.120
29.604
35.560
33.687
32.284
29.841
25.996
25.267
23.999
23.053
21.407
18.783
22.469
21.347
20.511
19.061
16.757
20.152
19.150
18.404
17.112
15.067
Single Axle Load – 16 tons
28.344
26.895
25.812
23.925
20.923
25.223
23.944
22.988
21.328
18.688
22.635
21.493
20.642
19.165
16.822
Single Axle Load – 18 tons
31.364
29.732
28.511
26.383
23.009
27.930
26.491
25.414
23.542
20.570
25.079
23.796
22.838
21.173
18.532
32
EDGE LOAD STRESSES IN RIGID PAVEMENT (kg/cm2)
K
kg/cm3
16
18
20
22
Slab Thickness (mm)
24
26
28
30
32
34
36
24.869
23.591
22.634
20.972
18.339
22.642
21.485
20.621
19.120
16.742
20.726
19.674
18.888
17.524
15.364
19.066
18.104
17.385
16.137
14.164
27.030
25.623
24.571
22.739
19.841
24.618
23.348
22.396
20.743
18.124
22.543
21.388
20.524
19.021
16.642
20.743
19.686
18.897
17.524
15.350
29.165
27.630
26.480
24.479
21.318
26.573
25.187
24.149
22.342
19.484
24.341
23.082
22.139
20.498
17.898
22.402
21.252
20.391
18.892
16.517
7.810
7.282
6.902
6.293
5.461
7.201
6.706
6.355
5.777
4.981
6.674
6.215
5.881
5.336
4.578
6.215
5.783
5.473
4.958
4.233
9.998
9.295
8.792
7.986
6.889
9.238
8.576
8.109
7.344
6.295
8.577
7.964
7.518
6.795
5.793
8.002
7.422
7.009
6.324
5.365
12.105
11.230
10.606
9.605
8.244
11.200
10.378
9.795
8.845
7.545
10.413
9.648
9.093
8.196
6.952
9.727
9.004
8.488
7.636
6.447
SINGLE AXLE LOAD
Single Axle Load – 20 tons
6.0
8.0
10.0
15.0
30.0
61.027
57.585
55.008
50.503
43.199
51.719
48.856
46.716
42.996
37.031
44.552
42.126
40.312
37.162
32.157
38.894
36.807
35.246
32.532
28.241
6.0
8.0
10.0
15.0
30.0
65.973
62.198
59.370
54.418
46.389
55.968
52.825
50.478
46.397
39.836
48.260
45.592
43.599
40.143
34.646
42.168
39.871
38.152
35.172
30.464
6.0
8.0
10.0
15.0
30.0
70.833
66.726
63.645
58.243
49.497
60.147
56.727
54.174
49.729
42.573
51.908
48.999
46.830
43.071
37.077
45.392
42.884
41.011
37.768
32.640
34.333
32.516
31.155
28.789
25.048
30.595
28.994
27.795
25.710
22.411
27.486
26.062
24.996
23.142
20.206
Single Axle Load – 22 tons
37.254
35.251
33.752
31.149
27.045
33.220
31.456
30.135
27.839
24.216
29.862
28.293
27.119
25.075
21.847
Single Axle Load – 24 tons
40.131
37.943
36.307
33.470
29.004
35.809
33.881
32.438
29.932
25.990
32.206
30.492
29.209
26.978
23.461
TANDEM AXLE LOAD
Tandem Axle Load – 12 tons
6.0
8.0
10.0
15.0
30.0
18.268
17.422
16.839
15.915
14.597
15.392
14.600
14.056
13.204
12.040
13.278
12.535
12.023
11.222
10.154
6.0
8.0
10.0
15.0
30.0
22.993
21.873
21.096
19.854
18.075
19.429
18.385
17.667
16.533
14.965
16.805
15.827
15.154
14.094
12.663
6.0
8.0
10.0
15.0
30.0
27.452
26.046
25.067
23.499
21.275
23.265
21.963
21.064
19.636
17.661
20.171
18.957
18.118
16.790
14.985
11.666
10.970
10.486
9.728
8.724
10.398
9.746
9.290
8.571
7.617
9.368
8.763
8.336
7.653
6.742
8.523
7.953
7.554
6.907
6.038
Tandem Axle Load – 16 tons
14.801
13.883
13.248
12.248
10.914
13.223
12.362
11.762
10.814
9.553
11.942
11.139
10.574
9.675
8.474
10.888
10.133
9.603
8.750
7.603
Tandem Axle Load – 20 tons
17.802
16.664
15.876
14.628
12.951
15.932
14.864
14.122
12.943
11.365
14.416
13.417
12.717
11.602
10.104
13.162
12.226
11.567
10.511
9.083
33
EDGE LOAD STRESSES IN RIGID PAVEMENT (kg/cm2)
K
kg/cm3
16
18
20
22
Slab Thickness (mm)
24
26
28
30
32
34
36
14.153
13.108
12.365
11.170
9.539
13.108
12.127
11.431
10.298
8.743
12.201
11.284
10.685
9.553
8.067
11.408
10.543
9.926
8.909
7.490
16.155
14.940
14.079
12.687
10.782
14.977
13.838
13.027
11.711
9.897
13.952
12.885
12.121
10.875
9.144
13.054
12.050
11.331
10.150
8.499
18.119
16.734
15.754
14.164
11.981
16.811
15.515
14.589
13.089
11.012
15.672
14.457
13.587
12.167
10.188
14.673
13.530
12.710
11.365
9.480
20.051
18.495
17.394
15.604
13.143
18.617
17.163
16.123
14.435
12.093
17.368
16.003
15.028
13.431
11.202
16.268
14.987
14.067
12.557
10.434
21.953
20.226
19.002
17.011
14.271
20.398
18.785
17.629
15.753
13.145
19.041
17.526
16.445
14.671
12.189
17.843
16.425
15.403
13.727
11.365
22.894
21.081
19.795
17.703
14.825
21.279
19.587
18.373
16.402
13.662
19.870
18.280
17.146
15.282
12.675
18.624
17.137
16.065
14.305
11.823
23.829
21.929
20.581
18.388
15.371
22.156
20.383
19.111
17.045
14.172
20.694
19.030
17.841
15.888
13.154
19.401
17.845
16.721
14.878
12.275
TANDEM AXLE LOAD
Tandem Axle Load – 24 tons
6.0
8.0
10.0
15.0
30.0
31.690
29.991
28.810
26.924
24.271
26.936
25.369
24.284
22.558
20.190
23.409
21.953
20.943
19.341
17.166
6.0
8.0
10.0
15.0
30.0
35.744
33.752
32.372
30.179
27.100
30.465
28.630
27.357
25.339
22.588
26.537
24.834
23.651
21.773
19.239
6.0
8.0
10.0
15.0
30.0
39.642
37.364
35.790
33.296
29.783
33.871
31.768
30.309
28.006
24.877
29.569
27.616
26.258
24.109
21.224
6.0
8.0
10.0
15.0
30.0
43.411
40.852
39.089
36.294
32.339
37.172
34.801
33.161
30.579
27.069
32.515
30.312
28.781
26.365
23.132
6.0
8.0
10.0
15.0
30.0
47.070
44.237
42.285
39.185
34.785
40.381
37.747
35.929
33.071
29.172
35.385
32.934
31.232
28.555
24.972
6.0
8.0
10.0
15.0
30.0
48.864
45.894
43.848
40.593
35.972
41.955
39.191
37.285
34.290
30.194
36.795
34.220
32.434
29.626
25.868
6.0
8.0
10.0
15.0
30.0
50.636
47.531
45.388
41.978
37.137
43.511
40.618
38.624
35.490
31.197
38.189
35.491
33.622
30.685
26.748
20.698
19.339
18.394
16.893
14.868
18.554
17.280
16.394
14.979
13.076
16.814
15.622
14.785
13.451
11.649
15.371
14.255
13.467
12.206
10.492
Tandem Axle Load – 28 tons
23.508
21.922
20.818
19.060
16.691
21.105
19.623
18.589
16.935
14.705
19.153
17.765
16.791
15.235
13.124
17.528
16.232
15.315
13.815
11.841
Tandem Axle Load – 32 tons
26.242
24.427
23.159
21.144
18.438
23.595
21.902
20.717
18.822
16.288
21.439
19.856
18.743
16.960
14.541
19.641
18.163
17.117
15.438
13.139
Tandem Axle Load – 36 tons
28.908
26.860
25.429
23.160
20.123
26.030
24.123
22.785
20.649
17.777
23.680
21.899
20.645
18.634
15.909
21.717
20.056
18.878
16.983
14.394
Tandem Axle Load – 40 tons
31.513
29.231
27.638
25.117
21.754
28.415
26.292
24.802
22.425
19.240
25.881
23.899
22.504
20.264
17.237
23.757
21.912
20.602
18.492
15.613
Tandem Axle Load – 42 tons
32.793
30.396
28.721
26.076
22.550
29.590
27.359
25.792
23.297
19.956
26.966
24.884
23.418
21.065
17.888
24.766
22.828
21.451
19.233
16.210
Tandem Axle Load – 44 tons
34.061
31.547
29.793
27.024
23.335
30.754
28.415
26.772
24.157
20.662
28.041
25.860
24.323
21.856
18.531
25.767
23.735
22.292
19.966
16.801
34
References
IRC: 73 – 1980 “Geometric Design Standards for Rural (Non-urban) Highways”, Indian
Roads Congress, New Delhi
IRC: 37 – 2001 “Guidelines for the Design of Flexible Pavements”, Second Revision, Indian
Roads Congress, New Delhi
IRC: 58 – 2002 “Guidelines for the Design of Plain Jointed Rigid Pavements for Highways”,
Second Revision, Indian Roads Congress, New Delhi
Khanna S K, Justo C E G and Veeraragavan A (2014) “Highway Engineering” Nem Chand &
Bros, Roorkee
Rajib B. Mallick and Tahar El-Korchi (2009) “Pavement Engineering – Principles and
Practice”, CRC Press, Taylor & Francis Group
Yang H Huang (2004) “Pavement Analysis and Design”, 2nd edition, Prentice Hall
Yoder and Witzack (1975) “Principles of Pavement Design”, 2nd edition, John Wileys and
Sons
35