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Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

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Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators
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Page 1: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators

Page 2: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Learning Outcomes

1. List benefits of fog seals, scrub seals, sand seals, and rejuvenators

2. Describe recommended materials

3. Describe recommended construction procedures

4. List key quality control activities

Page 3: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Learning Outcomes (cont.)

5. Describe potential construction and performance problems

6. Identify troubleshooting solutions

Page 4: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Description

Spray application of asphalt emulsionTreatment differences

– Emulsion type– Use of aggregate – Method of embedment

Application rate, timing, and construction quality are critical

Page 5: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Benefits

Slowed aging processWaterproofed surfacePrevention of stone lossIncreased surface frictionBetter surface appearance

Page 6: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

[Nitrogen Bases]

[Paraffins]

Asphalt Components

Page 7: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

What is an emulsion?

Mixture of asphalt binder, water, and emulsifying agent

50 to 75% of mix is asphalt“Breaking”—separation of water

and asphalt“Curing”—development of asphalt

mechanical properties

Page 8: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

EmulsionIngredients

Asphalt– Slow setting: up to 43% water– Rapid setting: up to 35% water

Water: Impurities can be harmfulEmulsifying agent (surfactant)

Page 9: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

EmulsionClassification

Electrical chargeSpeed of break: slow (SS), medium

(MS), and rapid set (RS)Asphalt relative viscosity: hard (h) or

soft (s)Polymer-modified asphalt (P or L)

Page 10: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

CRS - 2

cationic

CSS - 1h hard asphalt

HFMS - 2s

65% asphalt

with solvent

EmulsionClassification Names

cationic

high-float

medium-setting(anionic)

slow-setting

rapid-setting

high viscosity(65% asphalt)

57% asphalt

Page 11: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

EmulsionType

SlowSetting

MediumSetting

RapidSetting

Anionic SS-1SS-1h

MS-1MS-2MS-2h

HFMS-1HFMS-2

HFMS-2hHFMS-2s

RS-1RS-2

HFRS-2

Cationic CSS-1CSS-1h

CMS-2CMS-2h

CRS-1CRS-2

EmulsionClassification

Page 12: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

EmulsionDistribution of Asphalt Particles

0.0037 mm (0.000145 in)

Page 13: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

EmulsionTerminology

Original emulsion—asphalt, water, and emulsifying agent

Diluted emulsion—original emulsion diluted by additional water

Residual asphalt content—amount of asphalt left after water has evaporated

Page 14: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Aggregate

Applied to sand and scrub sealsClean material, smaller than 2 mm

(0.08 in)

Page 15: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seals

Page 16: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog SealsDescription

Light application of diluted slow-setting asphalt emulsion

Common uses– Seal aged surface– Improve lane delineation

Cost: 0.15 to 0.20 $/m2 (0.12 to 0.17 $/yd2)

Typical treatment life: 1 to 2 years

Page 17: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog SealsApplication Considerations

Seal must penetrate surface voidsEnvironment affects both break

and future performanceAllowing traffic before break is

hazardous!

Page 18: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog SealsSuitable Surfaces

Heavily aged, dense-graded HMA

Open-graded HMA

Page 19: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Dense-graded HMAwith closed surfaceDense-graded HMAwith closed surface

Fog SealsUnsuitable Surface

Page 20: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog SealsBefore and After

Fog seal over existing chip seal

Page 21: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal Construction

1. Surface preparation

2. Material preparation

3. Emulsion application

4. Sand blotter and sweeping (if necessary)

Page 22: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionConfirmation of Site Conditions

Consideration of site conditions is essential to proper curing

Little or no chance of rainTemperature conditions

– Air: 5 °C (40 °F)– Pavement: 15 °C (60 °F)

Page 23: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionPavement Surface Preparation

Page 24: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionMaterials Preparation

Slow setting emulsion recommended

Check compatibility of water used to dilute the emulsion

Dilute emulsion no more than 24 hours before application

Page 25: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionEmulsion Application

Page 26: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionEmulsion Application—Distributor Calibration

Pre-constructionPump rateApplication rateCoverage test

Page 27: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionEmulsion Application

Application rate: 0.45 to 0.70 l/m2 (0.10 to 0.15 gal/yd2)

Spray temperature range: 20 to 70 °C (70 to 160 °F)

Page 28: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Spray Bar and Nozzles

Single Overlap

Fog Seal ConstructionAsphalt Distributor—Spray Bar Height

hh

Roadway SurfaceDouble Overlap

Roadway SurfaceTriple Overlap

Roadway Surface

h

Page 29: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

15o 45o 90o

TravelDirection

Lateral Coverage

Fog Seal ConstructionAsphalt Distributor—Spray Nozzles

Page 30: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seal ConstructionPost Treatment Procedures

Sand blotter and sweeping (if necessary)

Pavement should NOT be opened to traffic until adequate friction is restored

Page 31: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand SealsDescription

Spray emulsion followed by a light covering of sand

Improves friction“Locks” a chip sealCost: 0.40 to 0.80 $/m2

(0.33 to 0.66 $/yd2)Typical treatment life: 3 to 6 years

Page 32: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand SealsApplication Considerations

Low-speed, lower volume roadsTypically 2 to 5 mm (0.1 to 0.2 in)

thickNot as good a delineator as fog

seal

Page 33: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand Seal Construction

1. Surface preparation

2. Material preparation

3. Emulsion application

4. Sand application

5. Rolling

Page 34: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand Seal ConstructionEmulsion Application

Rapid setting typical, no dilutionApplication rate: 0.70 to 1.25 l/m2

(0.15 to 0.28 gal/yd2)Spray temperature range:

RS-1 20 to 60 °C (70 to 140 °F)

MS-1, HFMS-1 20 to 70 °C (70 to 160 °F)

RS-2, HFRS-2,

CRS-1, CRS-2

50 to 85 °C (125 to 185 °F)

Page 35: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand Seal ConstructionApplication of Sand

Clean, typically < 2 mm (0.08 in)Application rate: 5.5 to 12 kg/m2

(10 to 22 lb/yd2)Surface temperature: >15 °C (60 °F)Sand applied with a spreader

immediately after spray emulsion

Page 36: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Sand Seal ConstructionPost Treatment Procedures

Embedment with pneumatic-tired rollers

Open to traffic: ~ 2 hours

Page 37: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seals

Page 38: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub SealsDescription

Spray applied emulsion, drag-broomed, lightly sanded, drag-broomed again, and rolled

Fills surface voids and cracksCost: 0.60 to 1.00 $/m2

(0.50 to 0.83 $/yd2)Typical treatment life: 3 to 6 years

Page 39: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub SealsApplication Considerations

Low to moderate volume roadwaysBrushing works emulsion into

pavement surfaceCan be applied in multiple layersThickness from 10 to 40 mm

(0.4 to 1.5 in)

Page 40: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seal Construction

1. Surface and material preparation

2. Emulsion application

3. Initial drag-brooming of surface

4. Sand application

5. Second drag-brooming of surface

6. Rolling

Page 41: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seal ConstructionEmulsion Application

Polymer-modified emulsionApplication rate: 0.63 to 0.82 l/m2

(0.14 to 0.18 gal/yd2)Emulsion temperature: 44 to 71°C

(110 to 160 °F)Pavement temperature: 21 to 32 °C

(70 to 90 °F)

Page 42: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seal ConstructionInitial Drag-Brooming of Surface

Page 43: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seal ConstructionSand Application

Application rate: 6.5 to 8.1 kg/m2 (12 to 15 lb/yd2)

Minimum of two roller passes

Page 44: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Scrub Seal ConstructionSecond Drag-Brooming and Rolling

Page 45: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Rejuvenators

Emulsions that include asphalt, polymer latex, and other additives

Softens existing binderTrade names:

– Reclamite– PASS– Topien C

Page 46: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Rejuvenator Application

Page 47: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Rejuvenator ApplicationApplication of Sand

Page 48: Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators.

Fog Seals, Sand Seals, Scrub Seals, and Rejuvenators

QUESTIONS?


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