This document discusses various types of pavement distress and maintenance. It begins by outlining different types of distress that can occur in flexible and rigid pavements such as alligator cracking, rutting, longitudinal cracking, and joint spalling. It then describes various maintenance activities like patching and overlaying to address these distresses. Evaluation methods like the Benkelman beam test are also covered. Strengthening techniques for pavements include different types of overlays to support increased loads. Proper design and construction of pavement layers is emphasized to prevent failures.

1. M.Senthamizhan
Assistant Professor / Civil
Alagappa Chettiar Government College of Engineering and Technology, Karaikudi
Tamilnadu

2. CONTENT
 Pavement Distress in Flexible Pavement
 Pavement Distress in Rigid Pavement
 Types of Maintenance
 Pavement Evaluation
Strengthening of Pavements

3. If any one of the above
mentioned layers becomes
unstable or weak then it will
result in failure of flexible
pavement. Therefore it is very
important to design and
construct each layer with
utmost care.

4. Inadequate Stability or Strength
 Loss of binding action
 Loss of base course materials
Inadequate wearing course
Use of inferior materials and crushing of base
course materials
 Lack of lateral confinement for the granular base
course.

5. Alligator (Map) Cracking
Consolidation of pavement layers
Shear failure
Longitudinal cracking
Frost heaving
Lack of binding to the lower course
Reflection cracking
Formation of waves and corrugation

6. Alligator Cracks
It is known as map cracking or crocodile cracking or
Fatigue failure. Since it appears similar as alligator skin
so it is called as alligator cracks.
The failure can be due to weakness in the surface, base
or sub grade; a surface or base that is too thin; poor
drainage or the combination of all three.
The main reason of this type of failure is the repetitive
application of heavy movement of traffic.

7. Alligator Cracks

8. CONSOLIDATION OF PAVEMENT LAYERS
(RUTTING)
 Formation of ruts falls in this type of failure. A rut is
a depression or groove worn into a road by the
travel of wheels.
 Repeated application of load along the same wheel
path resulting longitudinal ruts.
 Wearing of the surface course along the wheel
path resulting shallow ruts.

9. CONSOLIDATION OF PAVEMENT LAYERS (RUTTING)

10. CONSOLIDATION OF PAVEMENT LAYERS (RUTTING)

11. SHEAR FAILURE CRACKING
Shear failure causes upheaval of pavement
material by forming a fracture or cracking.
 Excessive wheel loading
 Low shearing resistance of pavement mixture

12. SHEAR FAILURE CRACKING

13. LONGITUDINAL CRACKING
This type of cracks extents to the full
thickness of pavement.
Differential volume changes in subgrade soil
Settlement of fill materials
Sliding of side slopes

14. LONGITUDINAL CRACKING

15. FROST HEAVING
Frost heaving causes upheaval of localized
portion of a pavement. The extent of frost heaving
depends upon the ground water table and climatic
condition.

16. FROST HEAVING

17. LACK OF BINDING WITH LOWER LAYER
(POTHOLES & SLIPPAGE)
When there is lack of binding between
surface course and underlying layer, some portion of
surface course looses up materials creating patches
and potholes. Slippage cracking is one form of this
type of failure.
Lack of prime coat or tack coat in between
two layers is the primary reason behind this type of
failure.

18. LACK OF BINDING WITH LOWER LAYER (POTHOLES & SLIPPAGE)

19. REFLECTION CRACKING
This type of failure occurs, when
bituminous surface course is laid over the
existing cement concrete pavement with some
cracks. This crack is reflected in the same
pattern on bituminous surface.

20. REFLECTION CRACKING

21. REFLECTION CRACKING

22. FORMATION OF WAVES & CORRUGATION
Transverse undulations appear at regular intervals due
to the unstable surface course caused by stop-and-go traffic.

23. FORMATION OF WAVES & CORRUGATION

24. If any one of the above
mentioned layers becomes
unstable or weak then it will
result in failure of Rigid
pavement. Therefore it is very
important to design and
construct each layer with
utmost care.

25. Deficiency of Pavement materials
Structural inadequacy of the pavement system.

26.  Scaling of cement concrete
 Shrinkage cracks
 Spalling of Joints
 Warping Cracks
 Mud Pumping

27. SCALING OF CEMENT CONCRETE
Scaling of rigid pavement simply means,
peeling off or flaking off of the top layer or skin of the
concrete surface. This may be due to the following
reasons
 Improper mix design
 Excessive vibration during compaction of concrete
 Laitance of concrete
 Performing finishing operation while bleed water is
on surface

28. SCALING OF CEMENT CONCRETE

29. SHRINKAGE CRACKS
Formation of hairline shallow cracks on concrete slab
is the indication of shrinkage cracks.
Shrinkage cracks develop on concrete surface during
the setting & curing operation. These cracks may
form in longitudinal as well as in transverse
direction.

30. SHRINKAGE CRACKS

31. JOINT SPALLING
Joint spalling is the breakdown of the slab
near edge of the joint. Normally it occurs within 0.5
m of the joints.
 Faulty alignment of incompressible material below
concrete slab
 Insufficient strength of concrete slab near joints
 Freeze-thaw cycle
 Excessive stress at joint due to wheel load

32. JOINT SPALLING

33. WARPING CRACKS
In hot weather, concrete slab tends to expand. Therefore
the joints should be so designed to accommodate this expansion.
When joints are not designed properly, it prevents expansion of
concrete slab and therefore results in development of excessive
stress. This stress cause formation of warping cracks of the
concrete slab near the joint edge.
This type of crack can be prevented by providing proper
reinforcement at the longitudinal and transverse joints. Hinge
joints are generally used to relieve the stress due to warping.

34. WARPING CRACKS

35. MUD PUMPING
When material present below the road slab ejects out
through the joints or cracks, it is called pumping. When soil slurry
comes out it is called mud pumping.
 Infiltration of water through the joints, cracks or edge of the
pavement forms soil slurry. Movement of heavy vehicles on
pavement forces this soil slurry to come out causing mud
pumping.
 When there is void space between slab and the underlying base
of sub-grade layer
 Poor joint sealer allowing infiltration of water
 Repeated wheel loading causing erosion of underlying material

36. MUD PUMPING

37.  Routine Maintenance / Repairs
These include filling up of pot holes and
patch, repairs, maintenances of shoulders and the
cross slope, up keep of the road side drains and
clearing chocked culverts, maintenance of
miscellanies items like road signs, arboriculture etc.,

38.  Periodic Maintenance
These include renewals of wearing course of
pavement surface and preventive maintenance of
various items
Special Repairs
These include strengthening of pavement
structure or overlay construction, reconstruction of
pavement, widening of roads, repairs of damages
caused by floods, providing additional safety
measures like islands etc.

39.  Problems Occurred in Earthen Road
1. Formation of dust in dry Weather
2. Formation of Longitudinal ruts along wheel path
or vehicles
3. Formation of cross ruts along the surface after
monsoons due to surface water.

41.  Patch Repairs.
a. Carried out on the damaged or improper road
surfaces
b. Localized depression may be removed
c. Inadequate or defective binding materials causes
removal of aggregates during monsoon.

42. PATCH REPAIR

43. Maintenance of Bituminous Road (Removal of path Hole)

44. Bituminous Surfaces Treatment
A bituminous surface treatment (BST), also known as
a seal coat or chip seal, is a thin protective wearing surface that
is applied to a pavement or base course.
BSTs can provide all of the following:
1. A waterproof layer to protect the underlying pavement.
2. Increased skid resistance.
3. A filler for existing cracks or raveled surfaces.
4. An anti-glare surface during wet weather and an increased
reflective surface for night driving.

45. Bituminous Surfaces Treatment

46. Bituminous Surfaces Treatment

47.  Very little maintenance of joints only is needed
 Main defect in this type is formation of cracks
1. The dirt, sand and other loose particles at the cracks
are thoroughly cleaned using a sharp tool, stiff brush
and pressure blower.
2. Kerosene oil is applied on the cleaned cracks to
facilitate proper bounding of the sealing material.
3. The cracks are then filled by suitable grade bitumen
sealing compound, heated to liquid consistency

48. 4. The sealer is placed upto about 3mm above the level of
the slab along the cracks and a layer of sand is spread
over it to protect the sealer temporarily only at a particular
location
The repair consist of removal of the sealer and
deteriorated filler and sealer materials from the expansion
joints cleaning up, replacements with new filler board and
sealing the top of the joints with suitable sealer material

50. It involves a thoroughly study of various
factors such as subgrade support, pavement
composition and its thickness, traffic loading and
environmental conditions.
(i) Structural Evaluation of pavements
(ii) Evaluation of pavements surface condition

51. • Pavement deteriorate functionally and structurally with time due to
traffic loading and the different climatic condition.
• It is necessary to evaluate the condition of existing pavement in terms
of functionally and structurally.
Instrument : Benkelman Beam

53. 1. Benkelman beam –
• Consist of slender beam of length 3.66 m.
• Pivoted at 2.44 m from probe.
• distance from pivot to dial gauge 1.22 m.
• Distance from pivot to front leg 25 cm.
• Distance from pivot to rear leg 1.66 m.

55. 2. Loaded truck
• Weight of truck 12 t
• Rear axle load 8170 kg(dual tyre)
• Spacing between tyres 30-40 mm.
• Inflation pressure 5.6 kg/sq.cm.

56. 3. Accessories –
• Tyre pressure measuring gauge.
• Thermometer(0-100 °c) with 1 ° division.
• Measuring tape.etc

59. 1. Select the points and marked.
2. The dual wheel of the truck is centered above the mark.
3. The probe of the benkelman beam is placed between the dual
tyres at the marked position.

60. 4. Dial gauge is set at 1 cm.
5. Initial reading (s) is recorded when rate of deformation is less than or equal to
0.025 mm/min.

61. 6. Truck is slowly driven (at speed 8-10 m/s appr.) at a distance of 2.7 m. and
stopped.
7. Intermediate reading (I) is recorded.
8. Truck is driven forward a further 9 m.
9. Final reading (F) is recorded.
10.Pavement temperature is recorded atleast once in each hour.
11.Tyre pressure is checked at 2-3 hrs interval during a day.

65.  If the pavement have to support increased wheel loads
and load repetition
 Unexpected economic growth in that region
 If the existing pavements have completely deteriorated
 Overlays are categorized based on the type of existing
pavement and that of the overlay:
(a) Flexible overlay over flexible pavements
(b) Rigid overlay over rigid pavements
(c) Flexible overlay over rigid pavements
(d) Rigid overlay over flexible pavements.

67. Flexible overlay over flexible pavements