1. Micro-surfacing SRF Consulting Group, Inc. SemMaterials
Sponsored by: Minnesota LTAP Center
Presented by: Michael Marti, P.E.
SRF Consulting Group, Inc.
Dan Wegman, P.E.
SemMaterials
The objective of this presentation is to give a basic overview of Micro-surfacing, a Koch XP micro-surfacing technology.
SRF Consulting Group, Inc.

2. History of Micro-surfacing
Developed in Europe in 1970’s
Introduced in U.S. in 1980
Now used in more than 30 states
Used for rut filling and texturing
Micro-surfacing was developed in Europe in the 1970s and introduced in the US in 1980 in Kansas. Since then it is now used in more than 30 states. Micro-surfacing has been used for rut filling and texturing their moderate- to heavy volume roads.
SRF Consulting Group, Inc.

3. What is Micro-surfacing?
Surface treatment 3/8” to 1/2” thick
Sometimes mislabeled as a polymer modified slurry seal
Advantages over slurry seal are
Chemical breaking process
Faster curing time
Can be applied at night
Can be placed in a thicker layer
Micro-surfacing can also be viewed as a polymer-modified cold paving slurry seal system. Micro-surfacing is different from conventional slurry seals in that it cures faster and can be placed in a thicker layer than slurry seals, and may allow a 25-40% reduction in bonder content.
SRF Consulting Group, Inc.

4. What is Micro-surfacing?
It is a mixture of
Polymer modified emulsion
Crushed aggregate
Mineral filler
Water
Additive
Micro-surfacing can be used on asphalt and portland concrete pavements for rut filling, to restore skid resistance, to reprofile, and to provide a wear course.
SRF Consulting Group, Inc.

5. Micro-surfacing Paving Machine
Mineral filler
Crushed Aggregate
Polymer-modified Emulsion,
Water, and Chemical Additive
Conveyor
Mixer .
Micro-surfacing mix
Water Spraybar
Spreader box
SRF Consulting Group, Inc.

6. Micro-Surfacing Application
Cement additive water
Polymer Modified Emulsion
Crushed aggregate
Water Flows
Spreader box
Mixture Brown &
Homogeneous
Breaking Time
60 to 120 seconds
Mixture Black
Mixing time 15 to 45 seconds
Direction
Traffic in Approximately One Hour

7. How is Micro-surfacing used?
On asphalt and concrete pavements it can
fill ruts
restore skid resistance
address oxidized, raveled, and flushed surfaces
reprofile (leveling)
provides wear course
be used as an interlayer
Micro-surfacing can be used on asphalt and portland concrete pavements for rut filling, to restore skid resistance, to reprofile, and to provide a wear course.
SRF Consulting Group, Inc.

8. Performance varies with...
Micro-surfacing
Performance varies with...
Climate
Traffic
Existing pavement
Materials / mixture design
Construction quality
The performance of Micro-surfacing is affected by various factors, such as climate, traffic loading, existing pavement conditions, the quality of materials and mixture design, and construction quality.
SRF Consulting Group, Inc.

9. Condition of existing pavement
Micro-surfacing
Condition of existing pavement
Structurally sound
Moderate- and high-volume roads
To achieve a successful micro-surfacing application, the existing pavement should be structurally sound. The pavement should also be stable, with no excessive irregularities or shoving. Micro-surfacing can be used on both moderate- and high-volume roads.
SRF Consulting Group, Inc.

10. Weather conditions Air temperature at least 50°F
Micro-surfacing
Weather conditions
Air temperature at least 50°F
Pavement temperature at least 50°F
No rain
No freezing within 24 hours
Micro-surfacing should not be placed if air or pavement temperature is below 50°F (10°C), if it is raining, or if the temperature is supposed to drop below 0°C within 24 hours of placement.
Extremely hot, dry weather can cause the surface to break too fast, which will cause water retention and slow down interior curing. Hot weather requires a change in formulation to allow for extended mixing times so the micro-surfacing can be properly applied.
SRF Consulting Group, Inc.

11. Construction considerations
Micro-surfacing
Construction considerations
Repair / seal joints and cracks; cure
Clean the surface of the road
Tack coat
dry or raveled surface
concrete
Potholes, joints, and cracks should be repaired and sealed before the application of micro-surfacing. Repairs should be allowed to cure and should not be allowed to build up on the surface. Otherwise, the sealant could be torn by the screeds during the application of micro-surfacing, leaving drags or tear marks. The road should then be cleaned. A tack coat is required if the roads are extremely dry or raveled, or if the road is concrete.
SRF Consulting Group, Inc.

12. Micro-surfacing performance
Wheel rut resistance - Excellent
Skid resistance - Excellent
Raveling resistance - Good
Treatment for flushing - Good
Interlayer - Good
Resistance to reflection cracks - Low
When properly designed, constructed, and used on structurally sound existing pavements, micro-surfacing generally performs well in resisting ruts for 4 to 7 years. Micro-surfacing provides excellent skid resistance and has been used by many states to address raveling with good results. Micro-surfacing, like other thin treatments and overlays, does not prevent long-term resistance to reflective cracking. Some states use micro-surfacing to address flushing on asphalt pavements. Some states report good performance from micro-surfacing as an interlayer, but this is not a standard use of this treatment.
SRF Consulting Group, Inc.

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SRF Consulting Group, Inc.

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SRF Consulting Group, Inc.

17. Micro-surfacing
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Micro-surfacing is a thin surface paving system composed of polymer-modified asphalt emulsion, 100 percent crushed aggregate, mineral filler, water, and field control additives as needed. It is applied as a thin mm surface treatment.
SRF Consulting Group, Inc.

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SRF Consulting Group, Inc.

22. Rut Box

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