Chip Seal Best Practices by: Larry Galehouse, P.E., P.S., Director National Center for Pavement Preservation

Introduction Chapter 1

SEC DEFINITIONS. (a)Definitions- Section 101(a) of title 23, United States Code, is amended— ‘‘(2) ASSET MANAGEMENT.—The term ‘asset management’ means a strategic and systematic process of operating, maintaining, and improving physical assets, with a focus on both engineering and economic analysis based upon quality information, to identify a structured sequence of maintenance, preservation, repair, rehabilitation, and replacement actions that will achieve and sustain a desired state of good repair over the lifecycle of the assets at minimum practicable cost.’’;

SEC MAINTENANCE Section 116 of title 23, United States Code, is amended— (a) Definitions- In this section, the following definitions apply: ‘‘(2) PAVEMENT PRESERVATION PROGRAMS AND ACTIVITIES.— The term ‘pavement preservation programs and activities’ means programs and activities employing a network level, long-term strategy that enhances pavement performance by using an integrated, cost-effective set of practices that extend pavement life, improve safety, and meet road user expectations.’’;

keeps good pavements lasting longer extends agency budgets (costing less than traditional approaches) is cost-effective –empirical evidence –pavement management data

PCI 10 40% Drop in Quality 75% of Life 12% of Life Failed Very Poor Poor Fair Good Excellent 20 Spending $1 on preventive maintenance here… 100 ….eliminates or delays spending $6 to $10 on rehabilitation or reconstruction here…

Chip Seal with Polymer No Maintenance Years since Original Construction (Bituminous Pavement with Aggregate Base) Average Surface Rating (4 Best – 0 Worst)

Candidate Selection

Conditions Addressed Moisture Infiltration Longitudinal cracking Transverse cracking Block cracking Friction Loss Bleeding IRI <95 Limitations Longer set time Costs (yd 2 ) $1.50 – 2.50

Working (moving) cracks formed by temperature changes in pavement/sub grades Working cracks move ⅛” (3mm) or more Generally perpendicular to center line Form between 2 & 7 years on asphalt pavement, 1 & 3 years on composite pavement

Non-working (little movement) crack move less than ⅛” Generally parallel to center line Form between 2 & 5 years on asphalt pavement, 1 & 3 years on composite pavement Caused by thermal movement and construction joints

Non-working (little movement) crack Caused by repeated traffic loading Seen in heavy traffic areas with poor pavement structure Indicator of structural failure

Expected Results

Date from the 1920’s and originally designed as wearing courses for low volume gravel roads Evolved into maintenance treatments for low and high volume roads to protect asphalt layer from damage and provide a skid resistant surface

Cure Time Flying Chips Noise Considerations Weather Consideration Performance Ride Quality (will not improve)

Experience overseas different than North America Rely on emulsified asphalt in the U.S. Climate most critical to selection –Emulsions better in hot weather –Asphalt binders better in cool weather

CharacteristicNorth AmericaOverseas PhilosophyArtScience Agency RealmMaintenanceConstruction ForcesIn-HouseContractor DesignRecipeEngineering Principles RiskAgencyContractor Pavement SelectionVariableTextured (Sand Circle) Surface HardnessNoYes OutcomeUncertainPredictable

139, , ,575 39,482 35,950 Lane Miles USAustraliaUKCanadaNZ

Years United StatesCanadaAU, NZ, UK, SA

Art Variable Conditions Judgmental Adjustments Experienced Personnel Variable Results Science Uniform Conditions Few Adjustments Flexible Personnel Predictable Results Experience

Flushing, bleeding, raveling, shelling? Variations between regions, within agencies, and from practitioner to practitioner. Terminology variations impact decision making, evaluation, and corrective actions.

Chip Seals Aggregate: Pay Unit – Square Yard Emulsified Asphalt: Pay Unit – Gallon Diluted Emulsified Asphalt of Fog Seal: Pay Unit - Gallon Payment.... includes furnishing all materials, equipment, labor, and incidentals to complete the work. Chip Seals Aggregate: Pay Unit – Square Yard Emulsified Asphalt: Pay Unit – Gallon Diluted Emulsified Asphalt of Fog Seal: Pay Unit - Gallon Payment.... includes furnishing all materials, equipment, labor, and incidentals to complete the work.

Questions?