Pavement Maintenance II

1
Pavement Maintenance II

• Part 1a SurfaceTreatments

2
Objective

• Investigate types of surface treatments and
  where they are most beneficial.

3
Surface TreatmentsPurpose

• Typically used to
• Seal cracks
• Waterproof surface
• Improve friction
• Improve rideability
• Rejuvenate surface

4
Candidate for?

5
Surface TreatmentsTypes

• Fog Seal
• Slurry Seal
• Chip Seal
• Cape Seal
• Scrub Seal

6
Fog Seal
Description

• Light application of diluted, slow-setting
  asphalt emulsion without aggregate cover.

Purpose

• Seal pavement
• Inhibit raveling
• Enrich hardened/oxidized asphalt
• Provide delineation with shoulder

7
Fog Seal Benefits

• Seals small cracks surface voids
• Prevents raveling of chip seals
• Prevents snow plow damage
• Darkens new chip seals

8
Fog Seal
Feasibility
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
Feasible
Not Appropriate
9
Fog Seal
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
10
Fog Seal

• A fog seal is one of our least expensive tools to
  use and also one of our least used tools. It
  consists of the following steps
• Clean the pavement surface.
• Then clean it again!
• Provide for traffic control.
• Spray the liquid asphalt.
• After allowing for cure time blot up any puddling.

11
Fog Seal
12
Fog Seal

• Most common product used CSS-1 dilute
• Cost for CSS-1 dilute in Boise 112.00 per
  ton.
• Cost to apply a fog seal 0.10 to 0.20 per
  square yard
• A maximum of a three year life

13
Slurry Seal
Description
Mixture of well-graded aggregate and slow setting
asphalt emulsion
Purpose

• Seal surface cracks.
• Correct raveling/oxidation.
• Fill minor surface irregularities and restore
  friction.
• Good application to use in subdivisions where
  curb exposure is an issue.

14
Slurry Seal
Feasibility
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
Feasible
Not Appropriate
15
Slurry Seal
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
16
Slurry Seal

• A slurry seal utilizes an emulsified asphalt and
  a small aggregate that is mixed through a mobile
  pug mill and then is squeegeed onto the pavement.
  It consists of the following steps
• Clean the pavement surface.
• Work is normally performed under a road closure.
• Apply the slurry seal.
• Wait for cure time. (Usually about???)

17
Slurry Seal
18
Slurry Seal
19
Slurry Seal

• Most common seal used Type II (1/4-10)
• Cost to apply 0.85-1.20 per square yard.
• Has an average of a five to ten year life.
• Should seal cracks prior to applying slurry seal.
• Requires very clean rock.

20
Chip Seal
Description
Application of asphalt and aggregate chips rolled
onto the pavement
Purpose

• Seal pavement
• Enrich hardened/oxidized asphalt
• Retard reflection cracking on HMA overlays
• Improve surface friction

21
Chip Seal
Feasibility
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
Feasible
Not Appropriate
22
Chip Seal
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
23
Chip Seal

• A Chip Seal provides a little heavier seal and
  consists of a spray applied liquid asphalt and
  then rock added to it. A typical Chip Seal
  consists of the following steps
• Clean the pavement surface.
• Provide for traffic control.
• Spray the liquid asphalt.
• Apply the rock into the asphalt
• Roll with pneumatic rollers.
• Sweep loose rock up.

24
Chip Seal
25
Chip Seal

• Most common product used Polymer modified
  emulsion.
• Cost for emulsion in Boise 160.00 per ton.
• Cost to apply a chip seal 0.90 to 1.40 per
  yard.
• A typical life of 7 to 12 years.

26
Chip Seals--Rules of Thumb

• Dont use on bleeding or rutted pavements
• Pre-fog seal any new patches
• Use clean chips
• Wait for warm weather (gt70ºF)
• Spread chips immediately behind emulsion spray
• Roll slowly (walking speed) with rubber roller

27
Cape Seal

• Combination of a chip seal, a slurry seal and
  usually a crack seal application.
• Good process to use where curb exposure is a
  concern.

28
Cape Seal

• Clark Co 1993

29
Macro Sealing

• Application of asphalt and aggregate chips rolled
  onto the pavement
• Single machine applied
• Eliminates distance between distributor and chip
  spreader
• Same results as a chip seal

30
Macro Surfacing
31
Scrub Seal
Description
Application of sand or small-sized aggregate on
broomed layer of polymer-modified asphalt
Purpose

• Fill and seal small cracks and voids
• Enrich hardened/oxidized asphalt
• Preparation for another treatment

32
Scrub Seal
Feasibility
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
Feasible
Not Appropriate
33
Scrub Seal
Extent of Problem
Distress Type
Major
Minor
Fatigue Cracking Linear Block Cracking Stable
Rutting Raveling Flushing/Bleeding Roughness Frict
ion Loss Moisture Damage Shoving
34
Scrub Seal

• Developed by ADOT
• Designed to arrest light deterioration
• Fills cracks without the labor intensive work
• Rejuvenates properties of the old asphalt lost
  due to oxidation

35
Scrub Seal - How to apply

• Asphalt agent applied by distributor
• Scrubbed into the cracks surface
• Sand is then applied over asphalt and scrubbed
  into cracks surface again.
• Rolled with a pneumatic roller
• Traffic removes excess sand
• Road opened in about 2 hours

36
Review

• Investigate types of surface treatments and
  where they are most beneficial.

37
Surface Treatments Types - Review

• Fog Seal
• Slurry Seal
• Chip Seal
• Cape Seal
• Scrub Seal

38
Review cont.

• 2 layers of rock on layer of asphalt
• 60 - 70 aggregate coverage
• Adjust for existing pavement condition
• Go lighter on new AC patches
• Take time to calibrate
• Binder protects road - Chips protect the binder
• Cubicle chips better than flat chips
• Always have clean surface / Equip.

39
Questions?
Surface Treatments