Microsurfacing is a mixture of polymer modified emulsified bitumen, aggregate, mineral filler, water and additives. It is applied as a thin layer to repair roads. The components are interdependent and altering one could change the mixture's performance. Microsurfacing provides a weatherproof seal, fills cracks and adheres firmly to the surface. It allows for quick opening of roads to traffic.

1. MICROSURFACING

2. • Micro-surfacing is a mixture of Polymer Modified Emulsified Bitumen,
Dense Graded Crushed Mineral Aggregates, Mineral Filler (normally
Portland Cement), Water and Chemical Additives to facilitate early
setting of mixture. Micro Surfacing is a component system. All
components are dependant on each other for the finished micro
surfaces performance. If one part is altered, it could radically change
the characteristics and the design performance of the system.
Micro-surfacing
Micro-surfacing in Progress

3. Why optforMicro-surfacingtechnologyforroadrepair
The practice of micro-surfacing is the most effective rehabilitation and construction
technology that respective governments and officials can afford. Deteriorated pavements
can be easily repaired using this. It protects the underlying pavement condition and
timely application of emulsion ensures extension of pavement life. Material type,
emulsion type, binder, weather and other factors determine the
effectiveness. Pretreatment of the pavement and the skill of the workmanship are also
important parameters.
The process of micro-surfacing is multi-dimensional and can be analysed from different
perspectives. The important thing is its effectiveness

4. Items Type II (4-6mm) Type III (6-8mm)
Applications
For urban, rural and
residential streets
(< 1500 CVPD)
For state roads,
highways and run
ways (> 1500 CVPD)
Quantity of
Microsurfacing mix
(Kg/m2)
8.4-10.8 11.1-16.3

5. A mixture of Cationic polymer modified asphalt
emulsion, mineral aggregate, mineral filler, water and
other additives properly proportioned, mixed and spread
as a surface treatment.When applied the Micro
Surface shall have a homogeneous appearance, fill
cracks, adhere firmly to the surface and provide a
weatherproof, high friction seal.

6. 1. Useful on Flexible as well as Rigid Pavements
2. Application in thin layer (3-4 mm thick)
3. On top surface of flyovers and bridge decks
4. Approaches of junctions and roundabouts
Usage of Micro-surfacing

7. APPLICATION
METHODOLOGY
Surface Preparation :
Patching and Crack sealing is recommended to restore the pavement structural
integrity and functional performance characteristics. Thereafter cleaning of the
pavement surface to be micro-surface should be done by sweeping a high
pressure washing. Remove rubber crack sealant and thermo-plastic markings.
Cover utility inlets with heavy paper or roofing felt.
Application:
The Microsurfacing system consists of a mixture of cationic modified bitumen
emulsion, mineral aggregate, mineral filler, water and other additives which are
mixed in special paver and spread on the surface in accordance with the given
specifications (as per the given table). The special paver carries all components,
mixes them on site, and spreads the homogenous mixture onto the road surface.
As the machine moves forward, the mixture is continuously fed into a variable-
width spreader box which spreads the material in required width. Edges of the
Microsurfacing are automatically feathered. The new surface is initially dark
brown in colour and changes to the finished black surface as the water is
chemically ejected and the surface cures, permitting traffic within one hour in
most cases. Generally microsurfacing is laid in single layer but when the existing
surface is highly polished, cracked, it is advisable to apply in two or more layers.

8. 1. Pavement should be structurally sound for future traffic
2. Wide alligator cracks, transverse cracks should be repaired prior
to application of micro-surfacifng
3. All deep ruts in excess of 8mm shall be filled up before
application of micro-surfacing
The quantity of treatment depends upon :
i. Pavement Distress
ii. Traffic
iii. Loading
Basic conditions for application
of Micro-surfacing

9. • Quick setting
• Early opening to traffic
• Higher resistance to abrasion
• Can be used for high traffic corridors
• Fast construction
• Less air/noise pollution
• Cost effective
Advantage of Micro-surfacing

10. Production and Application On Roads
Microsurfacing Machine
Lab Mix Design
Emulsion
Emulsion Plant
Emulsifier
& Chem.
Additives
Quarry
Microsurfacing Process
Bitumen
Source
Water
Source
Aggregate Water Cement
Chemical
Retarder
Chemicals
Service
Marketing
Tools
Polymers
Critical components
Micro-surfacing Process

11. 1. Aggregates
2. Mineral Filler
3. Bitumen
Emulsion
4. Water
5. Fibers
(depending of the
application)

12. Aggregates Filler
Water
additive
s
Emulsion
Mix
Spreade
r box
Direction
Mixing time
15 to 45
sec
Brown Mix
and
homogeneous
Black mat
Setting time
2 to 10 minutes
Opening to traffic between 30 - 60 minutes
.Setting time 10 minutes
.Time for traffic opening < 60 minutes

13. Pavemen
t
Conditio
n
Time
(Years)
Slurr
y
Seal
Micro-
Surfacin
g
Chip
Seal
Cold-In
Place
Mill &
Overlay
Reconstructio
n
REDUC
E RECYCL
E
RE-
USE
“The Right Product, On the Right Road, At The Right
Time”
FD
R
Cape
Seal
Note: Selection of product is
very dependent on existing
surface
deterioration and traffic
requirements.

14. Preparation and intervention
Support preparation
Deformations and defects survey
Treatment in fonction of the support condition
Structural deficiencies
Correction before microsurfacing application
Superficials defects: stripping / raveling
Corrections of deformations of the supports
without showing any structural deficiencies
Microsurfacing interventions =
Number of layers in function of
the déformations

15. Mixing and setting time tests
• Allow to determine the compatibilty between the
components
• Determination of the mixing time and setting time.

16. •Benedict cohesion tester: application of a torque on a sample through a
rubber disk with a charge of 200 kPa.
•Cohesion mesured on Microsurfacing samples at differents curing time
(30, 60 and 90 minutes)
Cohesion test

17. Testing after curing
Wet Track abrasion test (WTAT)
oDetermination of the abrasion resistance of the mixture (in
fonction of the bitumen content)
o Simulation of abrasion from the vehicules tires (curves)
o Determination of the minimum bitumen contant
Load wheel tester (LWT) – Bleeding susceptibility
oDetermination of the maximum bitumen content where risks of
bleeding appears

18. Wet track abrasion test (WTAT)

19. Load wheel tester (LWT)

20. Specifics performances tests
o Lateral displacement whit LWT for rutting correction
application

21. MICRO SURFACING SYSTEM COMPONENT
 Micro Surfacing is a component system
 All components are dependent on each other
for the finished micro surfaces performance
 If one part is altered, it could radically change
the characteristics and the design
performance of the system
 Bitumen Emulsion – consists of Bitumen,
emulsifying agent(s), pH adjuster, a polymer.
 The bitumen emulsion is the binder holding
the aggregate together while adhering the
Micro Surface mix to the surface it is applied
to.

22. CORRECTIVEMAINTENANCE
Micro Surface is used for rut filling wheel ruts, scratch course
over raveled surfaces, or a leveling course to improve cross
sectional drainage. Placed prior to a finished surface course.

23.  RUT FILLING
 SCRATCH COURSE
 LEVELING COURSE

24. • Improvement of Riding Quality
• Retardation of Deterioration Process
• Extension in Service Life of Pavement
• Saving in Road User Cost
• Reduction in Environmental Damage by Reduced
Fuel Consumption
• Avoidance of Large Capital Investment for
Reconstruction
Purpose of Maintenance

25. ROADWAY CANIDATE FOR PRESERVATIVE MAINTENANCE
IH-25 NORTH OF LAS CRUCES, NEW MEXICO

26. ROADWAY IN NEED OF CORRECTIVE
MAINTENANCE - RUTS ON STATE HIGHWAY

27. • Asphalt Emulsion – consists of asphalt
cement, emulsifying agent(s), pH adjuster,
a polymer*. Asphalt Emulsion is a cationic
emulsion, designated CSS-1P. The P
designates polymer modification. *A polymer is
required in Micro Surface specifications.
• The asphalt emulsion is the binder holding
the aggregate together while adhering the
Micro Surface mix to the surface it is
applied to.

28. 1. REDUCES THE TEMPERATURE SUSCEPTIBILITY
2. THE MIX CAN BE PLACED IN THICKER LIFTS
WHILE REMAING STABLE
3. THE MIX IS QUICK SETTING
4. ENHANCED DURABILITY.

29. • Aggregates – the major component and most critical of
the mix for long term performance.
• Aggregate source, gradation, and cleanliness factor in
the behavior of the system.
Aggregate Tests required for laboratory mix design:
• Gradation
• Hardness
• Soundness
• Sand Equivalent
• Methylene Blue

30. AGGREGATE SIEVE SPLIT

31. TYPE II 10 – 20 pounds per square yard.
Urban, residential streets, airport runways.
TYPE III 15 – 30 pounds per square yard.
Primary and Interstate routes and corrective
rut filling. *Rut filling may require additional
pounds per sq. yard.
Residual Asphalt Content - typically between 5.5
to 10.5 %.

32. • Mineral Filler – Portland Cement, Hydrated Lime, or
Aluminum Sulfate are used
• The mineral filler contributes the desired mixing and
setting characteristics of the system
• Improves the consistency of the Micro Surface mix

33. • Water – should be a potable resource free of
contaminates that could affect the system mix
• Chemical additives – used to retard or accelerate the
break of the system mix
• Application equipment and practices
• Environmental conditions
• Road conditions
• Weather

34. • Aggregates – the major component and most critical of the mix for
long term performance.
• Aggregate source, gradation, and cleanliness factor in the
behavior of the system.
Aggregate Tests required for laboratory mix design:
• Gradation
• Hardness
• Soundness
• Sand Equivalent
• Methylene Blue

35. AGGREGATE SIEVE
SPLIT

36. TYPE II 10 – 20 pounds per square yard.
Urban, residential streets, airport runways.
TYPE III 15 – 30 pounds per square yard.
Primary and Interstate routes and corrective
rut filling. *Rut filling may require
additional pounds per sq. yard.
Residual Asphalt Content - typically between
5.5 to 10.5 %.

37. • Pavement description, condition, ADT, climate
• Objective – life expectancy and texture requirements
• Selection of Materials – aggregate, emulsion, mineral
filler.
• Laboratory Design
1. Determines theoretical asphalt content
2. Determines theoretical water and filler contents
3. Run Compatibility cup test and Adhesion test
4. Subject trial mixes to physical testing
• Translate optimum design to contractor/buyer

38. ROADWAY IN NEED OF CORRECTIVE
MAINTENANCE - RUTS ON STATE HIGHWAY

42. 1. STOCKPILE SITE
– EMULSION STORAGE
– AGGREGATE STOCKPILE
– AGGREGATE SCREEN AND BELT SCALE
– MINERAL FILLER
– WATER SOURCE/TRAILER
– FRONT END LOADER
– NURSE TRUCKS
– QUALITY EMPLOYEES

43. STOCKPILE SITE FOR
MICRO SURFACING

44. CONTINOUS MICRO PAVER
AND NURSE TRUCK

46. AGGREGATE ELEVATOR TO STORAGE BIN

47. MICRO PAVER
PUGMILL

48. Micro mixture from pug mill
To lay down box

51.  To prevent noise and air pollution when road
maintenance is in progress.
 Utility levels to be kept at the existing levels (increase in
height of pavement to be discouraged)
 General road users should not be disturbed while
maintenance is in progress
 Keeping in view above points micro-surfacing is an
environment friendly maintenance technology.
Suggested Technologies

52. • Prevents reflective cracking
• Seals wide cracks effectively
• Delays in hardening of bitumen due to environment
• Better visibility at night
• No rolling is required
• Preservation of pavements’ structural strength
Advantage of Micro-surfacing

53. Micro Surfacing Slurry Seals
Always cationic Anionic or cationic
Always quick set Slow set (evaporative) or quick set
Faster return to traffic (1 hour or less) Cure can take hours
Always polymer-modified Neat or modified
Requires more robust application
equipment
Less mixing power required
T
wo aggregate gradations (T
ype II and
III)
Three aggregate gradations (T
ypes I, II &
III)
Night work possible No night work (generally)
Stone stacking ability One-stone thickness
Can repair larger
, deeper pavement
defects

54. • Preventive and periodic maintenance
• Rut filling with the help of special rut box
• Improvement in skid resistance and friction on a
concrete road
• Filling up of minor irregularities on surface
Applications

55. Properties of Modified Emulsion for Micro-surfacing

56. Grading of Aggregates for
Micro-surfacing

57. Mixture Requirement

58. Composition of Micro-surfacing mixture
Modified bitumen emulsion 12 %
Aggregates 86 %
Cement 1 %
Additive 1 %
Water 10 %

59. • Prior inspection and rectification of defects
• Inspection of machine and materials
• Calibration of machine
• Control of flow rate of ingredients as per mixture
design at site
• Removal of drag marks with rubber squeegee
• Control of joints (desirable 50 mm overlap)
Quality control guidelines

60. Suggested Quality Control Frequency

61. • Not applicable for air temperature below 100C
• Applicable when pavement and air temperature are
above 80C and rising
• Not applicable when the finished product freezes within
24 hours
Weather Limitations

62. • Required only in case of extremely dry surfaces or
concrete pavements
• Tack coat should consist of one part emulsified bitumen
/ three parts water
• Emulsified bitumen shall be slow setting grade
• Should applied with a standard distributor
• Distributor shall be capable of applying the diluted
emulsion at a rate of 0.2 to 0.3 litre / m2
Tack Coat

63. Comparison of hot mix and
cold mix technology