B.E. (Civil Engineering) Eighth Semester (C.B.S.

)
Elective - II : Pavement Analysis & Design
P. Pages : 4 NIR/KW/18/3615
Time : Three Hours *1375* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Solve Question 1 OR Questions No. 2.
3. Solve Question 3 OR Questions No. 4.
4. Solve Question 5 OR Questions No. 6.
5. Solve Question 7 OR Questions No. 8.
6. Solve Question 9 OR Questions No. 10.
7. Solve Question 11 OR Questions No. 12.
8. Due credit will be given to neatness and adequate dimensions.
9. Assume suitable data whenever necessary.
10. Illustrate your answers whenever necessary with the help of neat sketches.

1. a) With neat sketch enumerate the functions and importance of each component layers both 6
in flexible and rigid pavements.
b) Estimate ESWL for dual – in – tandem wheel assembly for an aircraft for following data : 7
i) Gear load = 26000 kg
ii) Tyre pressure = 9.4kg / cm2
iii) Dual spacing = 350 mm
iv) Tandem spacing = 450 mm
v) Flexible crust thickness = 70 cm, 85 cm.
OR
2. a) What are the functions of the individual layers of flexible and rigid pavements? 6
b) The axle load distribution of commercial vehicles on a highway is as under : 7

Axle load Distribution Axle load Distribution

group (kg) group (kg)
< 1000 08 7000 – 9000 13
1000 – 3000 20 9000 – 11000 12
3000 – 5000 14 11000 – 13000 10.5
5000 – 7000 15 13000 – 15000 7.5
Calculate the standard axles to be used in design for strengthening the pavement when the
current traffic on a two lane road is 1750 C.V.D. The rate of growth is 7.0% per annum and
the period of construction is 2 years. The design life is 20 years after the construction.
Assume the legal axle load as 8000 kg.

3. a) A subgrade soil sample has the following properties, compute the group index and discuss 6
its suitability as subgrade :
i) Passing 425 micron = 82%
ii) Passing 75 micron = 65%
iii) Liquid limit = 53%
iv) Plastic limit = 28%
b) Explain CBR test with neat sketch. 7
OR
NIR/KW/18/3615 1 P.T.O
4. a) Explain north Dakota cone test with its applications. Calculate cone bearing value from 8
following data :
Load (kg) Cone penetration
(mm)
4.5 15.2
9.0 31.7
18.0 51.3
36.0 68.3
Half Angle of cone = 7º45'

b) A bituminous mix has the following composition for a typical Marshall’s sample : 6
i) Theoretical density = 2.740 g/cc
ii) Bulk density = 2.585 g/cc
iii) Bitumen content by weight mix = 4.954%
iv) Specific gravity of Bitumen = 1.008
Calculate the following :
i) Percent Air voids.
ii) Percent voids in mineral Aggregates
iii) Percent voids filled with Binder

5. a) From the following data of field CBR test conducted on a subgrade soil during the month 7
of May, estimate flexible pavement thickness required for preliminary proposal, for a
design wheel load of 5050 kg at a tyre pressure of 6.75kg / cm2 :-

Penetration (mm) 0.0 0.5 1.25 2.5 3.75 5.0 7.5 10.0 12.5
Load (kg) 0.0 14.5 49.2 132.7 266.6 420.0 645.4 766.1 843.3

b) A plate load test was conducted on subgrade and also on 20 cm thick base with 30 cm dia. 6
2
Plate. Pressure at 5 mm deformation in both the test was recorded as 2.1kg / cm and
4.5kg / cm2 respectively. For a flexible pavement of 30 cm base course, find the pavement
deformation, stress at the subgrade under the wheel load of 5000 kg acting at a tyre pressure
of 6.1kg / cm2 . Assume Poisson’s ratio of subgrade as 0.36 Ref. attached chart.

OR

NIR/KW/18/3615 2
6. a) Design a flexible pavement for design traffic volume of 3500 CVD, if the permissible 9
deflection is 0.5 cm by triaxial method. Use following data :
i) Wheel load = 5500 kg.
ii) Tyre pressure = 7 kg / cm2
iii) Annual rainfall = 98 cm
iv) Modulus of elasticity of :
Subgrade = 75kg / cm2
Subbase = 390kg / cm2
Base = 1900kg / cm2
Bituminous surfacing = 4500kg / cm2
v) Rainfall coeff. = 0.9
vi) Traffic coeff. = 8/6

b) Write short note on method of Airfield pavement design. 4

7. a) Explain the procedure for design of expansion joints in rigid pavement. Sketch the joints. 6

b) From the yield line theory what maximum Aircraft Gear load a rigid pavement slab of 350 7
mm thickness can carry at critical areas at tyre contact radius of 220 mm? Grade of concrete
is M : 300 and ‘K’ of subgrade soil = 8.0kg / cm3 . Also locate the position of failure and
draw failure pattern.
OR
8. Design a rigid pavement for 2 – lane highway from following data : 13
i) Design wheel data = 5100 kg
ii) Tyre pressure = 6.0kg / cm2
iii) Modulus of subgrade reaction = 7.5kg / cm2
iv) Grade of concrete = M250
v) Temperature Gradient = 0.6ºC/cm
vi) Panel dimensions = 3.0m  6.0m
vii) Initial traffic volume = 860 CVD
viii) Delay for opening to traffic = 2 years.
ix) Design life = 20 years
x) Annual growth rate = 7%

9. a) Write short note on : 6

i) Serviceability Index
ii) Profilographs

b) Design bituminous overlay for a pavement section 3 km long the Benkelman Beam test is 7
conducted at a rate of one test for 250 m length over a two section. The following values of
deflection are recorded 1.44, 1.52, 1.56, 1.76, 1.92, 1.84, 1.72, 1.68, 1.94, 1.52, 1.44, 1.54
mm. Compute the thickness of overlay taking allowable deflection is 0.8 mm. Assume
growth rate of 9.5%. Temperature during test was 28ºC. Present traffic volume of 3450
CVD.

OR

NIR/KW/18/3615 3 P.T.O
10. a) Explain plate load test for evaluation of modulus of subgrade reaction and corrections to 6
be applied.

b) A plate load test with 30 cm dia. plate conducted on a subgrade gave following data : 8

Deformation Load on a plate

(mm) (kg)
0.25 630
0.50 1250
0.75 1910
1.00 2352
1.25 2785
1.50 3505
1.75 4070
2.00 4610

Estimate the modulus of subgrade reaction.

11. a) Explain maintenance and rehabilitation of pavements. 6

b) Briefly write a note on cost evaluation of pavement. 7

OR

12. a) Explain strengthening of pavements. 6

b) Write a short note on : 7

i) Specification & cost estimate of IRC.

ii) Airfield pavements.

************

NIR/KW/18/3615 4
 B.E. (Civil Engineering) Eighth Semester (C.B.S.)
Elective-II : Pavement Analysis & Design

P. Pages : 6 NJR/KS/18/4670
Time : Three Hours *0801* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Due credit will be given to neatness and adequate dimensions.
3. Assume suitable data whenever necessary.
4. Illustrate your answers whenever necessary with the help of neat sketches.
5. Use of non programmable calculator is permitted.

1. a) Compare Highway & Airfield Pavements. 5

b) Find ESWL 5
i) Wheel Arrangement = dual ii) Load on dual = 5000 kg
iii) Tyre pressure = 6.5kg / cm2 iv) Clear distance of dual = 12 cm
v) Pavement Thickness = 60 cm.

c) What are the different airport traffic areas? 3

OR

2. a) Clearly distinguish between flexible and rigid pavements. 8

b) Calculate total fatigue in design life of 20 years from the following axle load survey data. 5
Assume traffic growth rate as 7.5% per annum and delay in opening to traffic as 2 years.
Axle Load Traffic Volume LEF
(Kg) (ADT)
<1100 192 0.002
2100 131 0.003
4100 156 0.025
6100 121 0.33
8100 147 1.00
10100 82 1.70
12100 67 4.25
14100 51 7.46

3. a) Explain plate load test for evaluating modulus of subgrade reaction and corrections to be 7
applied.

b) A plate load test was conducted on a subgrade and also on 20cm thick base with 30cm dia. 7
2
Plate. Pressure for 5mm deformation in both tests was recorded as 2.3kg / cm and
4.5kg / cm2 respectively. For a flexible pavement of 30 cm base coarse, find the pavement
deformation and vertical & radial stress. under the load of 5100kg of wheel acting with a
tyre pressure of 6.2kg / cm2 . Assume s = 0.38.

OR

NJR/KS/18/4670 1 P.T.O
4. a) i) % of soil passing through 75 micron = 65% 8
ii) Liquid limit = 55%
iii) Plastic limit = 20%
Find GI of soil & classify soil. Also state the applications of group index.

b) Explain in detail the stress analysis for single layered flexible pavement. 6

5. a) Design a flexible pavement for a 2 lane highway for the following data. 7
i) Present traffic = 575 CVD
ii) Design life = 20 yrs.
iii) Delay d = 2 yrs.
iv) Growth rate r = 5.5%
v) VDF = 2.2
vi) CBR of subgrade = 5%
vii) Minimum surfacing = 75mm
Also state limitations of normal CBR method.

b) Design a flexible highway pavement of maximum surface deflection not exceeding 2.5mm 7
from the following data.
i) Wheel Load = 4800kg
ii) Tyre pressure = 6.5kg / cm2
iii) E of surfacing = 6000kg / cm2
iv) E of base coarse = 2000kg / cm2
v) E of subbase = 400kg / cm2
vi) E of subgrade = 90kg / cm2
vii) Traffic coefficient = 8/6
viii) Saturation coefficient = 1.1

OR

6. a) Following observations were recorded in a North Dalkota cone test. Find the CBV and 7
discuss the advantages and applications. Half angle of cone is 7º45' Find the total
thickness of pavement
Sr. No. Load (kg) Observed Penetration (mm)
1 4.5 26
2 9.0 37.8
3 18.0 54.5
4 36.0 79.5

b) A plate load test conducted with a 30cm dia. steel plate on a subgrade and also on 20cm 7
TK. base recorded a pressure of 1.4kg / cm2 and 4.5kg / cm2 respectively for 5mm
deformation.
Using the same material, design a flexible pavement for a wheel Load of 5200 kg at
5.5kg / cm2 tyre pressure if allowable deformation is 5mm.
Assume s = 0.4

NJR/KS/18/4670 2
7. a) Find the spacing of expansion joint and contraction joint for the following data 7
r = 2300 kg / m3
Sc = 0.85 kg / cm 2
F = 1.55
 = 2.5cm
T = 35º C
 = 9.5  10−6 / º C
Also design tie bar joint for the following data
lane width = 3.5m
TK. of concrete pavement h = 20cm
St = 1400 kg / cm2
SB = 24 kg / cm2 .

b) Write short note on McLeod method of design. 6

OR

8. Design 2 lane pavement for traffic. 13

Vp = 860CVD
n = 20yrs
r = 7%
P = 4600kg
p = 5.8kg / cm 2
grade of concrete = M30
R = 42 kg / cm 2
K s = 8.2 kg / cm 2 / cm
temperature gradient = 0.46ºC/cm
panel dimension = (3.5 x 6)m.

9. a) Following observations were recorded in a Benkelmen Beam deflection test for a certain 7
selection of a state highway

1.38, 1.52, 1.64, 1.31, 1.70, 1.92,

1.68, 1.20, 1.84, 1.93, 1.46, 1.55mm
Design a Bituminous overlay if maximum allowable deflection is 1mm. Assume layer
equivalency factor.

b) Explain CBR test in detail for pavement testing. 6

OR

10. Write short notes on any three. 13

i) Profilometers.

NJR/KS/18/4670 3 P.T.O
 ii) Present serviceability Index.

iii) Condition survey.

iv) Benkelmen Beam deflection Test.

11. a) What are the various ways for strengthening of pavements? 7

b) Write short note on repair, maintenance and rehabilitation of pavements. 6

OR

12. a) A bullock cart rim is more damaging when compared to pneumatic rubber tyre, explain. 6

b) Write short note on repetition of load. 7

NJR/KS/18/4670 4
 Fig. No. 6 (b)
& Q. No. 3(b)

NJR/KS/18/4670 5 P.T.O
 Fig. Q. No. 5 (a)

************

NJR/KS/18/4670 6
 B.E. (Civil Engineering) Eighth Semester (C.B.S.)
Elective-II : Pavement Analysis & Design
P. Pages : 3 NRJ/KW/17/4670
Time : Three Hours *0234* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Solve Question 1 OR Questions No. 2.
3. Solve Question 3 OR Questions No. 4.
4. Solve Question 5 OR Questions No. 6.
5. Solve Question 7 OR Questions No. 8.
6. Solve Question 9 OR Questions No. 10.
7. Solve Question 11 OR Questions No. 12.
8. Due credit will be given to neatness and adequate dimensions.
9. Assume suitable data whenever necessary.
10. Diagrams and chemical equations should be given whenever necessary.
11. Illustrate your answers whenever necessary with the help of neat sketches.
12. Use of non programmable calculator is permitted.

1. a) Clearly distinguish between Highway and Airfield Pavements. 6

b) Discuss the effects of repeated application of loads on pavement. Explain equivalent 7

wheel load factors for load repetitions.
OR
2. a) With neat sketches enumerate the function and importance of each component layer both 6
in flexible and rigid pavements.

b) Estimate the ESWL for dual - in tendon wheel assembly for an aircraft Data : 7
i) Gear Load = 26800 kg
ii) Tyre Pressure = 10.6 kg / cm2
iii) Dual spacing = 225 mm clear
iv) Tendon spacing = 350 mm clear
v) Flexible crust thickness = 550, 750, 900 mm

3. a) Estimate the group index of subgrade soil from following data and discuss the rating as 7
subgrade.
i) Passing 425 micron = 75%
ii) Passing 75 micron = 60%
iii) Liquid limit = 51%
iv) Plastic limit = 28%

b) Calculate the cone bearing value from the following data of North Dakota cone test 7
(Half Angle of cone = 7 º 45 )

Load (kg) Cone penetration (mm)

4.5 2.91
9.0 4.09
18.0 5.96
36.0 8.35
OR

NRJ/KW/17/4670 1 P.T.O
4. The following results were noted in a laboratory CBR tests conducted on subgrade soil : 14

Penetration (mm) 0 0.5 1.0 1.5 2.0 3.0 4 5 7 7.5 10 12.5

Load (kg) 0 6 18 32 50 60 65 75 80 90 95 100

It is desired to use the following materials for different pavement layers :

i) Compacted soil subgrade having CBR = 10%
ii) Poorly graded gravels having CBR = 22%
iii) Well graded gravels having CBR = 90%
The traffic survey indicates present ADT of commercial vehicle as 1400 with construction
period of 2 years. The design life is 10 years with the expected traffic growth rate of 10%.
Suggest the suitable crust composition with neat sketch.

5. a) Explain AASHTO method of flexible pavement design. 5

b) The pressure for 5 mm deformation in both tests was recorded as 2.5 kg / cm2 and 9

4.7 kg / cm2 resp. for flexible pavement of 30 cm base course, find the pavement
deformation, vertical and radial stress, stress at the subgrade under the load of 6100 kg
acting at a tyre pressure of 6.2 kg / cm2 . Assume, Poisson's ratio of subgrade as (0.38). A
plate load test was conducted on subgrade and also on 20 cm thick base with 30 cm diameter
plate.

OR

6. Design a flexible pavement for design traffic volume of 3770 CVD, if the permissible 14
deflection of 0.5 cm by Triaxial method. Data Given :
i) Wheel load = 6200 kg.
ii) Tyre pressure = 6.6 kg / cm2
iii) Annual Rainfall = 92 cm
iv) Modulus of elasticity of : subgrade = 80 kg / cm2
Sub base = 415 kg / cm2 , Base = 1950 kg / cm2
v) Bituminous surfacing = 4400 kg / cm2
vi) Traffic coefficient = 8/6
vii) Rainfall coefficient = 0.9

7. a) Explain P.C.A. method of design of rigid pavement with neat sketches of charts. 6

b) Write short note on LCN method of Airfield pavement design. 7

OR

8. Estimate the load factor at all the regions of runway concrete pavement of 275 mm thickness 13
2
under ESWL = 26,000 kg at 10.5 kg / cm tyre pressure. Assume grade of concrete M : 300
and K for subgrade soil = 8.0 kg / cm3 . Also locate the position of failure and draw failure
pattern.

NRJ/KW/17/4670 2
9. a) Design a pavement in M : 300 concrete for 2 lane highway expected to carry projected 9
traffic of 1870 CVD of ESWL = 5100 kg at 6.8 kg / cm2 tyre pressure from following data:
i) K for subgrade = 5.7 kg / cm2 / cm
ii) E for concrete = 3.110 4 kg / cm2
iii) Poisson's ratio of concrete = 0.18
iv) Contraction joint spacing = 5.25 m
v) Temperature gradient = 0.95º C / cm
vi) Subgrade Restraint Coefficient = 1.35
vii) Temperature coefficient :

Lx; y 4 5 6 7 8 9 10 11 12 & more

Cx, y 0.44 0.72 0.92 1.03 1.07 1.08 1.07 1.05 1.02

b) Explain in detail design of expansion joint and longitudinal tie bar joint for rigid pavement. 4
OR
10. a) Design a bituminous overlay for a pavement section 3 km long the Benkelman Beam test is 6
conducted at a rate of one test for 250 m length over a two section. The following valves of
deflection are recorded 1.38, 1.52, 1.67, 1.31, 1.7, 1.92, 1.68, 1.2, 1.84, 1.93, 1.46, 1.55 mm.
The test temp, of pavement is 26ºC. Present traffic volume is 750 CVD. Assume growth
rate of 9.5% per year for service life of 10 years with delay of 1 year.

b) A plate load test with 30 cm dia plate conducted a subgrade give following data : 7
Deformation (mm) 0.25 0.5 0.75 1.0 1.25 1.50 1.75 2.0
Load on plate (kg) 200 480 730 1005 1240 1475 1720 1975
Estimate the modulus of Subgrade Reaction.

11. Design a rigid pavement for 2 - lane highway from following data : 13
i) Design wheel load = 5100 kg
ii) Tyre pressure = 6.2 kg / cm2
iii) Modulus of subgrade reaction = 7.5 kg / cm2
iv) Grade of concrete = M 250
v) Temp gradient = 0.6 º C / cm
vi) Panel dimensions = 3.0 m 6.0 m
vii) Initial traffic volume = 860 CVD
viii) Design Life = 20 years.
OR
12. Check the Adequacy of rigid pavement from IRC criteria.
i) Slab thickness 150 mm
ii) 'E' for concrete = 3  105 kg / cm2
iii) Poisson's ratio of concrete 0.15
iv) Thermal Expansion coeff. 10  10 6 / º C
v) MOR of concrete 48 kg / cm2
vi) Anticipated thermal Gradient across slab 0.5 º C / cm .
vii) 'K' for subgrade soil 6.5 kg / cm2 / cm
viii) Cx and Cy 0.82 and 0.45 respectively.
ix) Wheel load (ESWL) 5100 kg.
x) Tyre pressure = 6.0 kg / cm2
Assume any other data suitable if necessary.
************

NRJ/KW/17/4670 3 P.T.O
NRJ/KW/17/4670 4
 B.E.Eighth Semester (Civil Engineering) (C.B.S.)
Elective - II : Pavement Analysis & Design
P. Pages : 5 NKT/KS/17/7532
Time : Three Hours *0727* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Solve Question 1 OR Questions No. 2.
3. Solve Question 3 OR Questions No. 4.
4. Solve Question 5 OR Questions No. 6.
5. Solve Question 7 OR Questions No. 8.
6. Solve Question 9 OR Questions No. 10.
7. Solve Question 11 OR Questions No. 12.
8. Due credit will be given to neatness and adequate dimensions.
9. Assume suitable data whenever necessary.
10. Illustrate your answers whenever necessary with the help of neat sketches.
11. Use of non programmable calculator is permitted.

1. a) Discuss the various stress influencing factors in Flexible and Rigid pavement. 6

b) What is ESWL ? Estimate the ESWL for dual-in-tandem wheel assembly for an aircraft. 7
Data :
i) Gear load = 35000 kg
ii) Tyre pressure = 10.5 kg/cm2
iii) Tandem spacing = 250 mm
iv) Dual spacing = 180 mm
v) Flexible crust thickness = 65 cm, 80 cm, 115 cm

OR

2. a) Explain the concept of ESWL and explain the assumptions on which it is based. 4

b) Clearly distinguish between Airfield and Highway pavement. 4

c) Calculate total fatigue from given traffic data with 15 year life ad 2 years construction 5
period with growth rate of 6%.
Axle load Kg 1150 2050 4000 6150 8100 10150 12100
Avg. Daily traffic 130 85 110 150 160 85 60
ADT

3. a) Explain in detail Marshall's method of Bituminous Mix Design. 6

b) Soil subgrade sample collected from the site was analysed and the result obtained are as 7
given below. Design the pavement section by Group Index method for the anticipated
traffic volume of over 300 CVD.
i) Passing 425 micron 82%
ii) Passing 75 micron 65%
iii) Liquid limit 53%
iv) Plastic limit 28%
OR

NKT/KS/17/7532 1 P.T.O
4. a) Explain plate load test for evaluating modulus of subgrade reaction and corrections to be 7
applied.
b) Calculate the cone bearing value from following data of North Dakota Cone test. Half 6
angle of cone is 7°45' :
Load (kg) Penetration (mm)
4.5 22.3
9.0 35.1
18.0 53.4
36.0 72.5

5. a) What is difference between AASHTO & IRC methods of classification of bitumen ? 6

b) The following observations were noted in a laboratory CBR tests conducted on subgrade 8
soil. Calculate CBR of the soil and hence design the pavement.
Penetration (mm) Load (kg)
0.0 0
0.5 9
1.0 34
1.5 69
2.0 91
2.5 106
3.0 131
4.0 154
5.0 176
7.5 200
10.0 230
12.5 240
It is further proposed to use the following material for different.
Pavement layers :
Compacted soil with 8% CBR
Poorly graded gravel with 25% CBR
Well graded gravel with 85% CBR
The traffic survey revealed the present ADT of commercial vehicle as 1400. The annual
rate of growth of traffic is found to be 7.5%, the pavement construction is to be completed
in three years after the best traffic count. Design the pavement section using CBR method
as recommended by IRC, assuming 15 years service life. (Use CBR design chart)

OR

6. a) What is the objective of Triaxial Compression test ? Explain the test in detail. 6
b) Determine the required thickness of an airfield flexible pavement based on Burmister's 8
Theory using the following plate load test data and other input parameters :
• Diameter of plate used = 75 cm
• Pressure observed at 1.25 mm deflection when the plate load test is conducted on
the sub-grade = 0.82 kg/cm2
• Pressure observed at 1.25 mm deflection when the plate load test is conducted
on a base course of 16 cm thickness = 2.1 kg/cm2
• Design wheel load = 23000 kg
• Tyre pressure = 15 kg/cm2
(i) If allowable deflection = 0.125 cm and (ii) If allowable deflection = 0.50 cm

NKT/KS/17/7532 2
7. a) Write in detail about different kinds of stresses in rigid pavements. 6

b) For the above pavement calculate safe spacing of contraction and expansion joints and 7
design a longitudinal Tie-bar joint from following data :
i) Permissible shrinkage stress in C. C. = 0.85 kg/cm2
ii) Width of Expansion joint = 25 mm
iii) Seasonal Temperature variation m = 45°C
iv) Permissible tensile stress inn Tie-bar = 2000 kg/cm2
v) Bond stress in steel = 25 kg/cm2
vi) Lane width = 3.0 m.

OR

8. a) Explain LCN method of Airfield pavement design. 6

b) Explain PCA method of rigid pavement design in detail. 7

9. a) State the need & scope of plate load test. What are the standard specifications of the test. 6

b) Benkelman Beam Deflection studies were carried out on 15 points using a dual wheel load 7
of 4085 kg & 5.6 kg/cm2 pressure. If the traffic consist of 750 CVD, determine the thickness
of bituminous overlay required, if the pavement temperature during the test was 30°C and
moisture content is 1.3. Assume annual rate of growth of traffic as 7.5% Adopt IRC
guideline. Deflection values in mm are given bellows.
1.4, 1.32, 1.25, 1.35, 1.48, 1.6, 1.65, 1.55, 1.45, 1.4, 1.36, 1.46, 1.5, 1.52, 1.45.

OR

10. a) Define the following terms : 4

i) Field Density ii) Profilometer

b) Design a rigid pavement for a two lane highway from the given data : 9
Design wheel load = 5100 kg
Radius of contact area = 15 cm
Grade of concrete = M30
Modulus of subgrade reaction = 8 kg/cm2
Cx = 0.92
Cy = 0.72
Temperature Gradient = 0.6°C/cm
Assume any other required suitable data.

11. Check the adequacy of rigid pavement from IRC criteria : 14

i) Slab thickness 150 mm
ii) 'E' of concrete 3 x 105 kg/cm2
iii) Poissons ratio of concrete 0.15
iv) Thermal expansion coefficient 10 x 10-6/°C
v) M.O.R. of concrete 48 kg/cm2
vi) Anticipated thermal gradient across slab 0.5°C/cm
vii) 'K' of subgrade soil 6.5 kg/cm2/cm
viii) Cx & Cy 0.82 & 0.45 resp.
ix) Wheel load 3000 kg
x) Tyre pressure 4.5 kg/cm2

NKT/KS/17/7532 3 P.T.O
 OR

12. a) Explain the various methods used for the maintenance and rehabilitation of flexible and 7
Rigid pavements.

b) Design a dowel bar system for the following data : 7

i) Pavement thickness = 200 mm
ii) Radius of relative stiffness = 55 cm
iii) Width of relative expansion joint gap = 20 mm
iv) Permissible shear stress in dowel bar (Fs) = 1000 kg/cm2
v) Permissible flexural stress in dowel bar (Ff) = 1400 kg/cm2
vi) Bearing stress in concrete (Fb) = 100 kg/cm2
vii) Wheel load = 4000 kg

NKT/KS/17/7532 4
 **********

NKT/KS/17/7532 5 P.T.O
 B.E. Eighth Semester (Civil Engineering) (C.B.S.)
Elective - II : Pavement Analysis & Design

P. Pages : 4 KNT/KW/16/7532
Time : Three Hours *0319* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Solve Question 1 OR Questions No. 2.
3. Solve Question 3 OR Questions No. 4.
4. Solve Question 5 OR Questions No. 6.
5. Solve Question 7 OR Questions No. 8.
6. Solve Question 9 OR Questions No. 10.
7. Solve Question 11 OR Questions No. 12.
8. Due credit will be given to neatness and adequate dimensions.
9. Assume suitable data whenever necessary.
10. Diagrams and chemical equations should be given whenever necessary.
11. Illustrate your answers whenever necessary with the help of neat sketches.
12. Use of non programmable calculator is permitted.

1. a) Cleary distinguish between Highway and Airfield pavements. 6

b) Estimate the ESWL for Dual-in-tandem wheel assembly for an aircraft with the following 7
data :
Gear load 30000 kg
Tyre pressure 9.8 kg/cm2
Dual spacing 300 mm clear
Tandem spacing 450 mm clear
Crust thickness 500, 750 and 800 mm
OR
2. a) Compare flexible and rigid pavements. 6

b) Estimate total fatigue in a service life of 15 years in terms of standard axle load of 7
8100 kg. Assume growth rate of traffic as 7.5 percent per annum and delay in opening to
traffic of 2 years.
Axle load Group Present ADT Eg. load factor
<1000 kg 160 0.0025
1-3t 220 0.03
3-5t 170 0.35
5-7t 158 0.60
7-9t 189 1.00
9 - 11 t 108 2.32
11 - 13 t 82 4.52
13 - 15 t 68 7.60
> 15 t 07 12.80

KNT/KW/16/7532 1 P.T.O
3. a) Estimate the group index of subgrade soil from following data and discuss its rating as 7
subgrade :
i) Passing 425 micron 73%
ii) Passing 75 micron 58%
iii) Liquid Limit 54%
iv) Plastic Limit 26%

b) Calculate cone bearing value for following data : 7

Load (kg) Cone penetration (mm)

4.5 21.9
9.0 32.7
18.0 51.3
36.0 71.6
Assume that the half angle of cone is 7º45'.
OR

4. a) Estimate the vertical compressive stress at depth = 24 cm and surface deflection for a 7
subgrade with the following data
i) Wheel load = 3200 kg at 4.5 kg/cm2 T.P.
ii) E of subgrade = 250 kg/cm2.
iii) Poisson's Ratio = 0.47

b) A flexible pavement is to be constructed over subgrade CBR of 5%. Estimate total crust 7
thickness if maximum wheel load is 8000 kg at T.P. = 6.5 kg/cm2.

5. a) A plate load test conducted with 30 cm dia. plate on subgrade and also on 20 cm thick 7
base recorded a load of 1800 kg and 5400 kg respectively for 2.5 mm deformation. Design
the pavement section for a wheel load of 5200 kg at 5.1 kg/cm2 tyre pressure for allowable
deformation of 3.5 mm. Assume Poisson's ratio of subgrade = 0.48.

KNT/KW/16/7532 2
 b) The CBR test carried out on a subgrade soil gave following readings. 7

Penetration (mm) Load (kg) Penetration (mm) Load (Kg)

0.0 0.0 4.0 74.0
0.5 5.0 5.0 75.5
1.0 12.0 7.5 92.3
1.5 32.0 10.0 103.4
2.0 43.0 12.5 112.6
2.5 48.0
3.0 56.0

The different pavement materials available near the construction site are as follows.
i) Sandy soil of CBR = 12%
ii) Soil - Kankar mix of CBR = 20%
iii) Crusted Gravel of CBR = 80%
Design a flexible pavement if initial traffic is 300 CVD, traffic growth rate is 7.5% and
design life of pavement 20 yrs. Minimum bituminous surfacing be 5 cm.

OR

6. a) Design a flexible highway pavement if maximum surface deflection is not to exceed 1.5 7
mm from following data :
i) Wheel load - 4000 kg at T. P. = 5.5 kg/cm2
ii) 'E' of surface - 2000 kg/cm2
iii) 'E' of base course - 1000 kg/cm2
iv) 'E' of sub base - 4000 kg/cm2
v) 'E' of subgrade - 100 kg/cm2
vi) Traffic coefficient - 1.6
vii) Saturation coefficient - 0.80

KNT/KW/16/7532 3 P.T.O
 b) Explain LCN method of Air field pavement design. 7

7. Design a Rigid pavement for a two lane highway from the given data : 13
i) Wheel load 5100 kg
ii) Tyre pressure 5.7 kg/cm2
iii) Grade of concrete M30
iv) Modulus of subgrade reaction 7.2 kg/cm2/cm
v) CX = 0.8, CY = 0.7
vi) Temperature gradient 0.52 ºC/cm
vii) Projected traffic volume 2500 CVD.

OR

8. a) Estimate the load factor at all regions of runway concrete pavement of 300 mm thickness 7
under ESWL = 12000 kg at 8.5 kg/cm2 tyre pressure. Assume grade of concrete M30 and
'K' for subgrade soil = 7.5 kg/cm2/cm.

b) Explain in detail AASHO method of Rigid pavement design. 6

9. a) Explain plate load test for evaluation of modulus of subgrade reaction and correction to be 7
applied.

b) Explain the following. 6

i) Serviceability Index.
ii) Profilometers.
OR

10. a) Explain Benkelman Beam Test in detail. 7

b) Explain Marshall's method of Bituminous mix Design. 6

11. a) Following observation were recorded in a Benkalman Beam deflection investigation for 7
certain section of a state highway 1.42, 1.34, 1.28, 1.30, 1.61, 1.58, 1.54, 0.96, 1.44, 1.36,
1.54, 1.45mm (corrected values). Design a bituminous overlay if maximum allowable
deflection is 0.80 mm. Assume layer equivalency factor.

b) Explain maintenance & Rehabilitation of pavements. 6

OR

12. a) Explain strengthening of Existing pavements and design of overlap. 7

b) What are IRC specification for the highway pavements. 6

**********

KNT/KW/16/7532 4
 B.E. (Civil Engineering) Eighth Semester (C.B.S.)
Elective – II : Pavement Analysis & Design

P. Pages : 4 TKN/KS/16/7618
Time : Three Hours *0685* Max. Marks : 80
_____________________________________________________________________
Notes : 1. All questions carry marks as indicated.
2. Solve Question 1 OR Questions No. 2.
3. Solve Question 3 OR Questions No. 4.
4. Solve Question 5 OR Questions No. 6.
5. Solve Question 7 OR Questions No. 8.
6. Solve Question 9 OR Questions No. 10.
7. Solve Question 11 OR Questions No. 12.
8. Due credit will be given to neatness and adequate dimensions.
9. Assume suitable data whenever necessary.
10. Diagrams and chemical equations should be given whenever necessary.
11. Illustrate your answers whenever necessary with the help of neat sketches.
12. Use of non programmable calculator is permitted.

1. a) Discuss the effects of repeated applications of loads on pavements. Explain equivalent 6

wheel load factors for load repetitions.

b) Clearly distinguish between Highway and Airfield pavements. 7

OR
2. a) With neat sketches enumerate the functions and importance of each component layer both 7
in flexible and rigid pavements.

b) Calculate ESWL for aircraft gear from the following data: 6

i) Wheel configuration = Dual in tandem.
ii) Gear load = 42500kg.
iii) Tyre pressure = 11kg/cm2
iv) Clear spacing of duals = 225mm
v) Clear spacing of tandems = 375mm
vi) Flexible pavement thickness = 1250 mm.

3. a) Estimate the group index of subgrade soil from following data and discuss its rating as 7
subgrade.
i) Passing 425 micron = 75%
ii) Passing 75 micron = 60%
iii) Liquid limit = 51%
iv) Plastic limit = 28%.

b) Calculate the cone bearing value from the following data of North Dakota cone test 7
(Half angle of cone = 7º45)
Load (Kg) Cone penetration (mm)
4.5 2.91
9.0 4.09
18.0 5.96
36.0 8.35
OR

TKN/KS/16/7618 1 P.T.O
4. The following results were noted in a laboratory CBR tests conducted on sub grade soil:- 14
Penetration (mm) 0 0.5 1 1.5 2 2.5 3 4 5 7.5 10 12.5
Load (Kg) 0 6 18 32 50 60 65 75 80 90 95 100
It is desired to use the following materials for different pavement layers:
i) Compacted soil sub grade having CBR = 10%
ii) Poorly graded gravels having CBR = 22%
iii) Well graded gravels having CBR = 90%
The traffic survey indicates present ADT of commercial vehicle as 1400 with construction
period of 2 years. The design life is 10 years with the expected traffic growth rate of 10%.
Suggest the suitable crust composition with neat sketch. (C.B.R. Design chart is attached).

5. a) Explain AASHTO method of flexible pavement design. 5

b) The pressure for 5 mm deformation in both tests was recorded as 2.3 kg/cm2 and 4.5 kg/cm2 9
resp. For flexible pavement of 30 cm base course, find the pavement deformation, vertical
and radial stress, stress at the subgrade under the load of 5100 kg acting at a tyre pressure
of 6.2 kg/cm2. Assume Poisson's ratio of subgrade as 0.38. (Ref. Chart given). A plate load
test was conducted on subgrade and also on 20 cm thick base with 30 cm diameter plate.

OR

TKN/KS/16/7618 2
6. Design a flexible pavement for design traffic volume of 3770 CVD, if the permissible 14
deflection is 0.5cm by Triaxial Method. Data:
i) Wheel load = 5200kg
ii) Tyre pressure = 6.5 kg/cm2
iii) Annual rainfall = 92cm
iv) Modules of elasticity of : Sub grade = 80 kg/cm2, Sub base = 415 kg/cm2, Base =
1950 kg/cm2
v) Bituminous surfacing = 4400 kg/cm2
vi) Traffic coefficient = 8/6
vii) Rainfall coefficient = 0.9.

7. a) Explain P.C.A. method of design of rigid pavement with neat sketches of charts. 7

b) Write short note on LCN method of Airfield pavement design. 6

OR
8. Estimate the load factor at all the regions of runway concrete pavement of 275 mm thickness 13
under ESWL = 20,000 kg at 10.5 kg/cm2 tyre pressure. Assume grade of concrete M : 300
and K for subgrade soil = 8.0 kg/cm3. Also locate the position of failure and draw failure
pattern.

9. a) With neat sketches explain how you will determine modulus of subgrade reaction by plate 6
load test. How is the value influenced by plate diameter and the moisture content?

b) Design a bituminous overlay for a pavement section 3 km long the Benkelman Beam test is 7
conducted at a rate of one test for 250m length over a two section. The following values of
deflection are recorded 1.38, 1.52, 1.67, 1.31, 1.7, 1.92, 1.68, 1.2, 1.84, 1.93, 1.46, 1.55mm.
The test temp, of pavement is 26ºC. Present traffic volume is 750 CVD. Assume growth
rate of 9.5% per year for service life of 10 years with delay of 1 year.
OR
10. a) Write short note on profilometers. 4

b) A plate load test with 30cm dia plate conducted a subgrade gave following data:- 9

Deformation Load on plate

(mm) (Kg)
0.25 200
0.50 480
0.75 730
1.00 1005
1.25 1240
1.50 1475
1.75 1720
2.00 1975
Estimate the modulus of subgrade reaction.

11. Design a rigid pavement-for 2-lane highway from following data: 13

i) Design wheel load = 5100kg

ii) Tyre pressure = 6.0 kg/cm2

iii) Modulus of subgrade reaction = 7.5 kg/cm2

TKN/KS/16/7618 3 P.T.O
 iv) Grade of concrete = M250

v) Temperature Gradient = 0.6º C/cm

vi) Panel dimensions = 3.0 m x 6.0 m

vii) Initial traffic volume = 860 CVD

viii) Design life = 20 years.

OR

12. Check the adequacy of rigid pavement from IRC criteria. 13

i) Slab thickness 150 mm

ii) 'E' of concrete 3 X 105 kg/cm2

iii) Poissons ratio of concrete 0.15

iv) Thermal expansion coeff. 10 x 10/ºC

v) M. O. R. of concrete 48 kg/cm2

vi) Anticipated Thermal Gradient across slab 0.5ºC/cm

vii) 'K' of subgrade soil 6.5 kg/cm2/cm

viii) Cx and Cy 0.82 and 0.45 respectively.

ix) Wheel load (ESWL) 5100kg

x) Tyre pressure = 6.0 kg/cm2

Assume any other data suitable if necessary.

************

TKN/KS/16/7618 4