1. A mixture of asphalt emulsion, crushed aggregate, mineral
filler, water and other additives properly proportioned, mixed and
spread as a surface treatment. When applied the slurry seal shall
have a homogeneous appearance, fill minor cracks, adhere firmly to
the surface and provide a weatherproof friction course.
2. Very cost effective surface treatment that extends the life
of a pavement 5-7 years + Restores surface texture Will ultimately
be placed at no more than 1.5 times the thickness of the largest
stone Treatment that preserves the underlying pavement from further
oxidation related to climatic conditions. Fast application. A
typical residential street will take 15 minutes to place and 2-4
hours to cure to a point that will again support traffic.
3. Proven Technology
4. Early loss of surface fines Protect the pavement from
further oxidation by providing a new wearing layer Only minor
cracking present. Anything grater than 1/8 gets filled prior to
slurry application Alligator cracking and Pot Holes are repaired.
Be careful of placing slurry over fresh patches.
6. PCI 80 and above Cracks greater that 1/8 filled Alligator
cracking has been repaired No rutting Only minor surface fines
loss
7. Keep the public in the loop. Try not to package a slurry
project with an overlay project Winter slurry color will vary more
than summer. Give it time. Most power steering scuffs will heal
over time. (Most slurries will take a change of all seasons to
complete its cure) Initial shed or light raveling will occur (large
stones that do not lay down may kick out)
8. Caltrans Standard Specifications Section 37
http://dot.ca.gov/hq/esc/oe/construction_stan dards.html Greenbook
Section 203 http://www.bnibooks.com/products/standard-
specifications-public-works-construction International Slurry
Surfacing Association http://slurry.org/
9. Verification of material compatibility Provides starting
point for start up of the project. Targets optimum mixture but
allows for minor adjustment in the field.
10. Too Much oil will provide a long lasting surface but result
in flushing and shoving Too little oil will result in color
variation and excessive rock loss up to and including 100%
raveling. Most materials will provide a good product outside of the
recommendation as long as you evaluate the data. Particularly on
the slightly high side of the oil content.
11. Aggregate (manufactured) Type 1 Type 2 Type 3 Latex Mineral
Fillers / Additives Emulsion Other Microsurfacing Tire Rubber
Modified RAP
12. Residential Streets Parking Lots Airports
13. Finest gradation of aggregate 1/8 top size Fractured faces
Generally parking lots and bike lanes Placed 8-12 lbs per square yd
Low speed traffic or high foot traffic type areas Airports
14. Residential Streets County Roads Shoulders
15. Mid size aggregate top size Fractured faces Typically used
on rural county roads, arterial roads, Collectors and primarily
residential. Application rate 10-20 lbs/SY
16. 4 Lane Highways Interstates 2 Lane Highways
17. Most course gradation Max stone 3/8 Fractured faces
Application Rate 13-30 lbs/SY Typically used on highways, rural
county roads, arterial and collector roadways.
18. Benefits Increases the softening point of the residual
asphalt Improves early strength of seal (Reduces Power steering
burns) Adds elastomeric properties to the residual binder (Better
stone retention) Typical addition rate of 2.5% of the emulsion
19. Cement Can act as a retarder or accelerator of break
depending on emulsion and aggregate properties. Generally will make
the mix tougher at least initially Is not compatible with all
aggregate sources Aluminum Sulfate Generally acts as a retarder of
break time in the field. Can act as a viscosity builder in the
slurry preventing separation of the oil and rock during
application.
20. Generally a CQS-1H Cationic Quick Set (To a limited degree
it uses the mineral to assist in the break) Compatible with most
aggregates (negative charge offers resistance to stripping) Other
options could be a QS, SS or CSS
21. Tire Rubber Slurry Color Multiple products Some old Some
New Micro Surfacing Next Generation Night time Multiple Stone depth
Chemical Break Multi Layer 2 over 3 Cape Seal (Slurry on top of
Chip) RAP Close to a type 2 gradation Lower Oil Content Recycled
Green Value Color
22. Truck Mount Better in residential and tight areas Most
commonly used Multiple Manufactures Typically multiple trucks per
project that require calibration and adjustment Continuous Machines
Same capabilities with the addition of the ability to resupply
while placing slurry Highways, Freeways Same machine places the
entire project Reduced transverse joints.
23. Gate settings (Determine rock to oil relationship and
product application rates) Oil Water Fines Feeder (Cement) Sulfate
Feeder
24. Sets the depth of the slurry Provides the uniform surface
texture of the slurry May or May not be augured Varied widths
25. Hand held Squeegees Oil Tankers Rock Trucks Loaders
Conveyors Sweeper Traffic Control
26. Things to consider Time of the year (Weather Conditions)
Have large cracks been filled Is the surface clean and dry Trash
trucks Schools and school traffic Sufficient Traffic Control
Application rate over surface conditions Equipment Calibration
27. Things to Consider 50 F and rising Slight breeze may be
beneficial. High winds may make it a challenge to keep the surface
clean Sunlight needed to cure. Much shorter work windows in the
cold months. Minimize hand work Overlaps should not be in the
typical wheel paths Chance of Rain?
28. You only get what you inspect Understand the process and
the materials Use a check list
http://www.fhwa.dot.gov/pavement/preservation/ppcl13.cfm If you
have any questions lean on industry: Most suppliers and contractors
are more than wiling to spend some time and answer your questions.
Learn what 25 tons of aggregate looks like in a stock pile (verify
application rate) Traffic Control Joints Hand work Starts /
Stops
29. International Slurry Surfacing Association The Greenbook
Standard Specifications for Public Works Construction Caltrans
Specifications section 37 and MTAG Chapter 8 FP2
30. Todd Vargason Ergon Asphalt and Emulsion
[email protected] 909-829-0505
