Pavement Maintenance II Part 1a: SurfaceTreatments Idaho Roads Scholar Program.

Pavement Maintenance IIPart 1a: SurfaceTreatments

Idaho Roads Scholar Program

Objective

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

Surface Treatments:Purpose

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

Candidate for…?

Surface TreatmentsTypes

Fog Seal Slurry Seal Chip Seal Cape Seal Scrub Seal

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

Description

Purpose Seal pavement Inhibit raveling Enrich

hardened/oxidized asphalt

Provide delineation with shoulder

Fog Seal

Fog Seal Benefits

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

Fog Seal

Distress TypeFatigue Cracking

Linear & Block Cracking“Stable” Rutting

RavelingFlushing/Bleeding

RoughnessFriction Loss

Moisture DamageShoving

Extent of ProblemMinor Major

Feasible

Not Appropriate

FeasibilityFeasibility

Fog Seal







Effective

Marginal

No Impact

EffectivenessEffectiveness

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.

Fog Seal

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

Slurry Seal

Mixture of well-graded aggregate and slow setting asphalt emulsion

Description

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.

Slurry Seal







Feasible

Not Appropriate


Slurry Seal







Effective

Marginal

No Impact


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???)

Slurry Seal

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.

Chip Seal

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

Description

Chip Seal







Feasible

Not Appropriate


Chip Seal







Effective

Marginal

No Impact


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.

Chip Seal

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.

Chip Seals--Rules of Thumb Don’t use on bleeding or rutted

pavements Pre-fog seal any new patches Use clean chips Wait for warm weather (>70ºF) Spread chips immediately behind

emulsion spray Roll slowly (walking speed) with

rubber roller

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.

Cape Seal

Clark Co 1993

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

Macro Surfacing

Scrub Seal

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

Description

Scrub Seal







Feasible

Not Appropriate


Scrub Seal







Effective

Marginal

No Impact


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

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

Review

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

Surface Treatments Types - Review

Fog Seal Slurry Seal Chip Seal Cape Seal Scrub Seal

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.

Questions?

Surface

Treatments

Pavement Maintenance II Part 1a: SurfaceTreatments Idaho Roads Scholar Program.

Documents

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