1. Topic –
Types of Pavement construction
procedure
SUBJECT- Highway Construction and Management : TE506
FACULTY GUIDE- Prof. Pinakin N. Patel
PREPARED BY:-
Bhavik A. Shah
Abhishek R. Shah
Bhavesh N. Parmar
Ravindra S. Lodh
CIVIL ENGG. DEPARTMENT
BIRLA VISHVAKARMA MAHAVIDYALAYA ENGG. COLLEGE
VALLABH VIDYANAGAR-388120
M.TECH - TRANSPORTATION ENGINEERING
(17TS809)
(17TS810)
(17TS811)
(17TS812)
2. Table Of Contents
Construction of continuously reinforced
Prestressed Pavement
Steel Fibre Reinforced (SFRC) Pavements
IRC, MOST, ACI specifications
Ferro cement
Ferro-fibro-Crete Pavement
Overlay construction
3. Construction Of Continuously Reinforced
Continuously reinforced concrete pavements (CRCP) is a type of concrete
pavement that does not require any transverse contraction joints.
Transverse cracks are expected in the slab, usually at intervals of 1.5 - 6 ft (0.5 - 1.8
m).
CRCP designs generally cost more than JPCP or JRCP designs initially due to
increased quantities of steel.
CRCP utilizes reinforcing steel to effectively eliminate transverse joints in favour of
very tightly maintained cracks.
Once CRCP roads are constructed they need not to be taken care of for the next
50-60 years.
The performance of continuously reinforced concrete pavement (CRCP)
constructed in 1995 that utilized recycled concrete aggregate (RCA) as both coarse
and fine aggregates.
4. CRCP Characteristics
No joints
Steel reinforcement bars
Numerous transverse cracks
History
First used in 1921
Experimental sections in the 1940’s
More than 28,000 miles in the USA
5. Why Continuously Reinforced Concrete
Pavements?
Smoothness
Low maintenance costs
No transverse joints
Thinner slab thickness relative to jointed concrete pavement
Long Life
14. Construction Issues
Concrete mix design
Concrete shrinkage
Lower zero stress temperature!
Mix temperature (water, aggregates)
Mix proportions (max. size aggregate)
Curing
Minimize climatic effects
Solar radiation, wind, evaporation
Base temperature (asphalt concrete)
15. Conclusion of CRCP
Compared to flexible pavement, CRCP gives additional design
life of at least 10 years.
The demerit of CRCP is its high initial cost & difficulty in
repair works required to be done if not constructed properly.
Joint less concrete pavement, CRCP offers excellent smooth
Riding surface for the vehicles that maximizes the comfort for
the passengers.
16. Prestressed Pavement
The pre application of a compressive stress to the concrete
greatly reduces the tensile stresses caused by traffic and thus
decrease the thickness of concrete required.
Has less probability of cracking and fewer transverse joints
and therefore results in less maintenance and longer
pavement life.
Used more frequently for airport pavements than for highway
pavements because the saving of thickness for airport
pavements is much greater than for highways.
18. Advantages of Prestressed Pavements
In conventional reinforced concrete pavements, permissible stresses for
both steel and concrete are limited to only a fraction of what would be
reasonable for either material by itself. Even with low steel stresses,
concrete cracks in tension zone due to shrinkage and load, before the
steel can develop its tensile force.
In prestressed concrete pavements, this incompatibility of the two
materials is overcome by stretching the steel to a high stress while it is
free to move independently of the concrete and then transferring this
force to the concrete by bond or end anchorage. The only limit of stretch
is the ultimate strength of each material, and the entire concrete section is
made available to resist the load.
The prestress gives the section a higher shear strength.
19. CONT….
The number of joints is reduced, and this will contribute to savings in the
cost of joints, reduction in pumping, improvement in riding quality, and
lesser possibility of water entering the subgrade from the surface.
Since prestressed concrete pavements are thinner in section, there will be
savings in the cost of materials, and consequent reduction in transport
cost of materials. Prestressed concrete pavements have greater flexibility,
and therefore, adapt themselves to the uneven conditions of the subgrade
without causing any damage.
Due to thin sections, the stresses due to temperature gradient are not
appreciable.
20. CONT…
Due to its reduced self-weight and improved carrying capacity, it can be
used over poor subgrades.
The tensile strength of concrete is increased by the amount of prestress.
Prestressed slabs are especially suited for airport pavements. since long.
smooth, jointless slabs facilitate the take-off and landing of modern jet
planes.
In addition, the problem arising out of the materials in the joints getting
damaged due to the hot blast from present-day aircraft will be alleviated
to a great extent.
21. Some Drawbacks of PCP
The difficulty of repairing services beneath the slab, since if a trench is cut
across the Prestressed slab the whole of the prestressing in the vicinity of
the trench is lost; this is a matter of particular importance in the case of
urban roads.
The construction of the prestressed slabs require expert supervision by
experienced personnel
It poses certain constructional difficulties at bends and curves.
23. Steel Fibre Reinforced (SFRC) Pavements
Steel Fibre Reinforced Concrete (SFRC) is concrete containing dispersed
steel fibres.
The most significant influence of the incorporation of steel fibres in
concrete is to delay and control the tensile cracking of the composite
material. Concrete is a brittle material that will not carry loads under pure
bending when cracked.
By incorporating steel fibres the mechanical properties of the concrete is
changed resulting in significant load carrying capacity after the concrete
has cracked (Chen, 2004).
24. Steel Fibres
The typical diameter lies in the range of 0.25-0.75 mm hook end steel
fibres are being used in this project. Length of these fibres is 30 mm and
the aspect ratio of 55. Density of steel fibre is 7900 kg/cum.
25. Properties Improved by of STEEL FIBRES
Flexural Strength: Flexural bending strength can be increased of up to 3
times more compared to conventional concrete.
Fatigue Resistance: Almost 1 1/2 times increase in fatigue strength.
Impact Resistance: Greater resistance to damage in case of a heavy
impact.
Permeability: The material is less porous.
Abrasion Resistance: More effective composition against abrasion and
spalling.
Shrinkage: Shrinkage cracks can be eliminated.
Corrosion: Corrosion may affect the material but it will be limited in
certain areas
26. Properties of SRFC
The post-cracking strength of SFRC can be attributed to the crack controlling
mechanism provided by steel fibres. The steel fibres across the crack transmit some
of the tensile stresses across the crack while steel fibres at the tip of the crack resist
the growth of these cracks.
The ability of the steel fibres to resist crack propagation is primarily dependent on
the bond between the concrete and the fibres as well as the fibre distribution
(spacing and orientation).
27. Advantages of SFRC
Fast and perfect mixable fibres and High performance and
crack resistance
Optimize costs with lower fibre dosages
Steel fibres reinforced concrete against impact forces, thereby
improving the toughness characteristics of hardened
concrete.
28. Drawbacks of SRFC
Great reduction in workability.
High Cost of Material.
Generally they do not increase the flexural strength of concrete, and so cannot
replace the moment resisting reinforcement.
29. Specifications
WHAT IS SPECIFICATION??
A detailed description of the design and materials used to make
something.
A specification is often a type of technical standard.
WHY??
Specifications are a means of ensuring equipment and installation
compliance with governing standards such as IRC, ASTM, ACI, FAA, and
AASTHO to name just a few.
30. Specifications for construction procedure
of pavements.
IRC – Indian Road Congress
ACI – American Concrete Institute
MORTH – Ministry of Road Transport and Highways
31. IRC
IRC 015 - Standard Specifications and Code of Practice for Construction of
Concrete Roads (Fourth Revision)
IRC 043 - Recommended Practice for Tools, Equipment and Appliances for
Concrete Pavement Construction
IRC 063 - Tentative Guidelines for the Use of Low Grade Aggregates and Soil
Aggregates Mixtures in Road Pavement Construction
IRC 072 - Recommended Practice for Use and Upkeep of Equipment, Tools
and Appliances for Bituminous Pavement Construction
IRC 088 - Recommended Practice for Lime Flyash Stabilised Soil Base/Sub-
Base in Pavement Construction
IRC SP 046 - Guidelines for Design and Construction of Fibre Reinforced
Concrete for Pavements (First Revision)
IRC SP 062 - Guidelines for the Design and Construction of Cement Concrete Pavement
for Low Volume Roads (First Revision)
33. CONSTRUCTION Of RCC Pavement
Fully Mechanised Construction
The batching plant shall include minimum four bins, weighing hoppers, and scales
for the fine aggregate and for each size of coarse aggregate. If cement is used in
bulk, a separate scale for cement shall be included. The weighing hoppers shall be
properly sealed and vented to preclude dust during operation. Approved safety
devices shall be provided and maintained for the protection of all personnel
engaged in plant operation, inspection and testing. The batch plant shall be
equipped with a suitable non-resettable batch counter which will correctly indicate
the number of batches proportioned
34. CONT…
Batching by weight only is recommended. However, if batching by volume is
permitted, as a special case, separate measuring boxes shall be provided for the
different aggregates. The boxes shall be of strong construction provided with
handles for convenient lifting and loading into the mixer. They shall be of such size
that it should be possible to measure out the requisite quantity and capable of
being lifted by two men.
Each box shall be provided with a straight edge of required length for striking off
after filling. If so directed by the Engineer, improved facilities, such as, tipping
boxes of accurate capacity working on run-out rails arranged for direct delivery
into the hopper of the mixer shall be provided by the construction agency. In
volume batching, suitable allowance shall be made for the bulking of fine
aggregate due to the presence of water. For this purpose, the bulking shall be
determined as per relevant Indian Standard Specification.
35. Mixers
Mixers shall fre pan type, reversible type with single or twin shaft or any other mixer
capable of combining the aggregates, cement, water and admixtures into a thoroughly
mixed and uniform mass within the specific mixing period, and of discharging the
mixture, without segregation. In twin shaft mixer, mixing time is normally very low
(about 6 cubic materials may be mixed in 20-30 seconds). Facility i.e hydrometers for
the measurement of the density of the admixtures shall be available at site.
Each stationary mixer shall be equipped with an approved timing device which will
automatically lock the discharge lever when the drum has been charged and release it
at the end of the mixing period. The device shall be equipped with a bell or other
suitable warning device adjusted to give a clearly audible signal each time the lock is
released. In case of failure of the timing device, the mixer may be used for the balance
of the day while it is being repaired, provided that each batch is mixed for 90 seconds or
as per the manufacturer's recommendation. The mixer shall be equipped with a suitable
non-resettable batch counter which shall correctly indicate the number of batches
mixed.
36. Placing of concrete
Concrete mixed in central mixing plant shall be transported to the site without
delay and the concrete which has been mixed too long before laying will be
rejected and shall be removed from the site.
The total time taken from the addition of the water to the mix, until the completion
of the surface finishing and texturing shall not exceed 120 minutes when concrete
temperature is less than 25°C and 1 00 minutes when the concrete temperature is
between 25°C to 30°C. Trucks/Tippers delivering concrete shall not run directly on
plastic sheet nor shall they run on completed slabs until after 28 days of placing of
concrete.
37. Construction by slip form paver
The slip form paving train shall consist of power machine which spreads, compacts
and finishes the concrete in a continuous operation. The slip form paving machine
shall compact the concrete by internal vibration and shape it between the side
forms with either a conforming plate or by vibrating and oscillating finishing
beams.
The concrete shall be deposited without segregation in front of slip form paver
across the whole width and to a height which at all times is in excess of the
required surcharge. The deposited concrete shall be struck off to the necessary
average and differential surcharge by means of the strike off plate or a screw auger
device extending across the whole width of the slab. The equipment for striking off
the concrete shall be capable of being rapidly adjusted for changes of the average
and differential surcharge necessitated by change in slab thickness or cross fall.
38. Other Process
Texturing
Curing
Also Clause for Semi-Mechanised and Labour-Oriented
Construction Technique
Quality Control.
39. ACI
ACI defines an ACI reference specification as a standardized mandatory-language
document prescribing materials, dimensions, and workmanship, incorporated by
reference in Contract Documents, with information in the Mandatory Requirements
Checklist required to be provided in the Project Specification.
A reference specification provides most of the detailed construction requirements
that the Architect/Engineer (A/E) must convey to the Contractor.
Specifications related to Concrete
40. Ferro - Cement
Ferro cement is a form of reinforced concrete using
closely spaced multiple layers of mesh and/or small
diameter rods completely infiltrated with, or encapsulated
inmotor.
42. Materials Used In Ferro Cement
Cement mortar mix
Skeleton steel
Steel mesh reinforcement or Fibre-reinforced
polymeric meshes
43. Properties Of Ferro Cement
It is a very durable, cheap and versatile material.
Low w/c ratio produces an impermeable structures
less shrinkage, and low weight.
high tensile strength and stiffness
better impact and punching shear resistance
undergo large deformations before cracking or high
deflections
44. Process Of Ferro-cement Construction
Fabricating the skeletal framing system
Applying rods and meshes
Plastering
Curing
45. Cost Effectiveness
Depends on type economic system and applications.
Relative cost of labour.
Doesn’t need heavy plant or machinery.
Low cost construction materials are used.
46. Applications
Floors And Roofs
Waterproofing
Transport System
Agriculture Structures
Fire resistant structures
Soil stabilization
Man hole covers
Wall cupboards
pipes
47. Advantages Of Ferro-Cement:
20% savings on materials and cost
Suitability for pre-casting
Flexibility in cutting, drilling and jointing
Very appropriate for developing countries, labor intensive
Good impermeability
Fabricated into any desired shape.
Ease of construction, low weight andlong lifetime.
Better resistance against earthquake.
48. Disadvantages of Ferro-Cement:
Corrosion of the reinforcing materials dueto the incomplete coverage of metal by
mortar.
It is difficult to fasten to Ferro-cement with bolts, screws, welding and nail etc.
Large no of labors required.
Cost of semi-skilled and unskilled labors is high.
Tying rods and mesh together is especially tedious and time consuming.
Low ductility
Susceptibility to stress rupture failure
It can be punctured by collision with pointed objects.
49. Ferro-fibro-Crete Pavement
The concept of ferro-fibrocrete is best illustrated by reference to a beam (Figure 1).
The higher tensile strength and superior crack control properties of ferro-fibrocrete
(consisting of Ferro cement strengthened with mesh, regular reinforcing bars, and
random fibres) are most advantageously used in the bottom-most fibres of the
beam. Hence it is logical to provide a thin ferro-fibrocrete ribbon to serve as the
tension flange.
Taking advantage of the ferro-fibrocrete in the tension flange, with its higher
tension strength and superior crack-control quality, the prestressing force to be
used can be considerably reduced.
50. Potential Applications of
Ferro-Fibrocrete
Prestressed ferro-fibrocrete beams conforming to class 2 and class 3
groups.
Water-retaining structures wherein ferro-fibrocrete will chiefly be in hoop-
tension.
Hybrid structures such as long-span thin hanging ribbons of ferro-
fibrocrete in which the structure acts as a beam-cable and is subjected to
both tension and bending
51. Types of Overlays and Their Functions
Purposes of Overlay:
To correct surface deficiencies, such as:
To improve skid resistance
To enhance appearance
To reduce surface roughness
To improve surface drainage
To retard climate-related deterioration (such as hardening of asphalt
surface)
To improve structural capacity.
52. Types of Overlay
Asphalt overlays on asphalt pavement
Asphalt overlays on PCC pavement
Porous asphalt friction course on PCC pavement
Unbonded PCC overlay on PCC pavement
Partially bonded PCC overlay on PCC pavement
Bonded PCC overlay on PCC pavement
Unbonded PCC overlay on asphalt pavement
Bonded PCC overlay on asphalt pavement
53. Asphalt overlays on asphalt pavement
Advantages:
To add load carrying capacity.
To remove deteriorated surface (if milling is done before overlay.)
Disadvantages:
If overlay is put on cracked pavement without milling, reflective
cracking will occur.
If the problem is due to inadequate mixture (e.g. rutting due to an
inadequate mixture), overlaying with the same mixture will not solve
the problem.
54. Asphalt overlays on PCC pavement
Advantages:
Less expensive than concrete overlay.
Disadvantages:
Reflective cracking from joints and existing cracks in concrete
pavement will occur.
55. Care Taken While Overlaying
Rutting on an existing asphalt pavement to be overlaid. Pavement needs
to be adequately milled to remove ruts before overlay.
56. CONT…
Severe alligator cracking on existing asphalt pavement.
The cracked layer needs to be milled off before overlay to prevent
reflective cracking.
59. Partially bonded PCC overlay on PCC
pavement
Advantages:
Better structural capacity as compared with the unbonded PCC overlay.
Disadvantages:
If the existing PCC pavement had load transfer problem at the joint, the
overlay will try to carry the full load across the joint to the adjacent slab. Since
these overlays are relatively thin and not designed to take the full load, it will
cause the partially bonded overlay to crack.
Existing pavement needs to be repaired to eliminate all cracks before overlay.
60. Bonded PCC overlay on PCC pavement
Advantages:.
Better structural capacity as compared with unbonded or partially
bonded PCC overlay.
Disadvantages:
Existing PCC pavement needs to be repaired to eliminate all cracks
before overlay.
Not suitable if there are problems with joint load transfer in the
existing PCC pavement
61. Unbonded PCC overlay on asphalt pavement
Advantages:
PCC is stronger than asphalt concrete to resist rutting or cracking due
to high pressures from tires.
Disadvantages:
Thick overlay is needed. The required overlay thickness is about the
same as that for a new concrete pavement.
62. Bonded PCC Overlay on Asphalt Pavement
Advantages:
Thinner overlay can be used, compared with unbonded PCC overlay.
PCC is stronger than AC to resist high pressures from tires.
Disadvantages:
The existing asphalt pavement needs to be uncracked.
The PCC needs to be well bonded to the asphalt concrete for the
composite pavement to be effective.
63. Cracked concrete slab needs to be repaired before
bonded or partially bonded PCC overlay
64. Cracked concrete slab corner needs to be repaired
before bonded or partially bonded PCC overlay.
65. Cost of overlay as a function of % area patched
before overlay
66. Steps in Design of Overlays
Measurement and estimation of the strength of the existing pavement
Design life of overlaid pavement
Estimation of the traffic to be carried by the overlaid pavement
Determination of the thickness and the type of overlay
69. References
IRC 015 - STANDARD SPECIFICATIONS AND CODE OF PRACTICE FOR
CONSTRUCTION OF CONCRETE ROADS.
STEEL FIBRE REINFORCED CONCRETE FOR ROAD PAVEMENT
APPLICATIONS by W A ELSAIGH, E P KEARSLEY and J M ROBBERTS -
University of Pretoria
Prestressed concrete pavements, by S. C. Goyal and Shri Prakash - Indian
Concrete Journal, Vol. 42, No.9, Sept. 1968
https://www.slideshare.net/amoldpawar9/session-ii-pavements
70. THANK YOU For Bearing.
Bhavik A. Shah (17TS809)
Abhishek R. Shah (17TS810)
Bhavesh N. Parmar (17TS811)
Ravindra S. Lodh (17TS812)