FP03 418 Sealcoat Standalone 2.pdf

SECTION-418 Asphalt Pavement Sealcoat

Description

418.01 This work shall consist of the application of pavement sealing material(s) on existing pavement surfaces .

418.02 Conform to the following Subsections:

Emulsified asphalt 702.03

Water 725.01(c)

Construction Requirements

418.03 Composition of Seal Material. The primary component of seal materials shall be slow setting asphalt emulsion that conforms to either AASHTO M140 or M208. The contractor shall submit a manufacturer’s certificate of compliance with each shipment of asphalt emulsion. Asphalt emulsions shall be mixed with additives that prevent bleeding. The contractor may dilute seal materials with water to improve penetration into the pavement surface or for consistency improvement.

Additive Materials: Materials such as clays, slates, fibers, carbon black and polymers may be added to emulsified asphalt provided the manufacturer’s product literature is reviewed and approved by the CO prior to application. If the seal material is blended with sand, the sand shall be clean, hard, durable, un-coated particles, free from clay lumps and organic matter, with 100 percent passing the No. 16 mesh and a maximum of 5 percent passing the No. 200 mesh. The sand must have a gradation that helps control segregation and promotes suspension during product application. No more than 3 pounds of sand shall be added to each gallon of applied material.

Top Dressing and Blotter Sand: Washed concrete sand meeting AASHTO M6 gradation requirements, unless otherwise approved.

Submit proposed emulsion mix for approval 14 days prior to production.

418.04 Equipment The distribution equipment for all materials shall be capable of placing a uniform consistency of the material, and be capable of applying a uniform application over variable widths, grades and crowns of surface. Self propelled, asphalt distributor, squeegee or slurry seal spreader box, and hand-held spray and squeegee equipment or any combinations thereof maybe required to obtain a satisfactory seal. The required application rate may also require multiple applications to obtains a satisfactory, uniformily, sealed surface. The equipment used for storing and application of liquid and slurry products shall include accurate volume measuring devices and calibrated tank. The CO may require transport or application equipment to be weighed when full and empty if volume measuring equipment is inadequate.

418.05 Surface Preparation Clean the existing surface to be sealed of all loose material, dirt, dust, oil or any type of objectionable surface film that might jeopordize adhesion and a quality final product.

Such accumulations may require removal by pressure washing, grinding, burning or scraping or a combination thereof. The surface will be approved in writing prior to applying the seal.

418.06 Weather Limitations Apply the sealcoat when the air temperature in the shade and the surface temperature are at least 45o F and rising and when the weather is not foggy, rainy, or overcast. Do not apply when there is a danger of freezing within 24 hours.

418.07 Application. Ensure that the seal mix is of the desired consistency, with no signs of segregation as it leaves the mixer and distributor equipment and conforms to the approved job-mix.

Application may be by hand-held spray equipment, asphalt distributor, squeegee or slurry seal spreader box. Seal material Application shall be spread in two directions, 180 degrees from each other.

The CO may require an additional application on small areas of pavement that have more surface voids, where voids have prevented adequate coverage or where uneven application exists.

The minimum ‘residue’ application rate of 1.0 pound per square yard shall be obtained over the entire surface to be treated. Residue will consist of the asphalt cement portion of the emulsified asphalt and non-evaporative additive materials (such as clays, slates, fibers, polymers and sand) that are suspended in the emulsion when applied. Application rates may be adjusted up or down by 0.15 pounds residue per square yard by the CO to compensate for pavement surface absorption and roughness.

The volume of emulsion used shall be readily determined by the contractor prior to, during and after application. Final payment will be based on meeting the specified application rate of residue. The CO will determine the weight of residue per gallon by drying field samples from the project to constant weight.

418.08 Maintenance & Opening to Traffic. Allow treated areas to completely cure before opening to traffic.Traffic control and the prevention of asphalt pickup under traffic is the contractor's responsibility for 10 days following treatment. When directed by the CO, blotter sand shall be applied to the sealed pavement to prevent asphalt pickup by vehicles. The CO may require removal of loose blotter sand by brooming after the maintenance period. After the treatment has been open to traffic for 10 days, the contractor shall repair any areas that are damaged by traffic, or areas that are peeling or cracking.

418.09 Sampling and Testing. Samples of the seal product as applied will be required for the project.

Samples from stored containers may also be required at the COs discretion. Samples will be taken by the contractor as directed by and delivered to the CO in approved plastic 1 gallon containers. A minimum of 3 samples per project will be required on all projects. Testing of the residual will be done by the CO according to the procedures outlined in AASHTO T 59. Results will be used in determining the actual residual seal rate applied. Additional quality testing of the emulsion may be done by the CO at his/her discretion to verify quality requriements.

418.10 Acceptance. As stated under 418.07 above, a minimum residual of 1.0 lb/SY of product will be obtained on the sealed pavement surface. Sampling and testing and as outlined under 418.09 above will be used to determine “residual” and “quality” specification compliance.

Emulsified Asphalt/the final seal product will be evaluated under Subsections 106.03 and 702.09.

Construction of the surfacing seal will be evaluated under Subsection 106.02 and 106.04.

418.11 Measurement Measure the Section 418 items listed in the bid schedule according to subsection 109.02 and the minimum “residual” specified above.

418.12 Payment. The accepted quantities will be paid for at the contract unit price for the Section 418 pay items listed in the bid schedule, with the following exception:

If laboratory quality assurance tests on samples taken during application do not contain enough residue to meet the specified residue application rates established by the CO in Section 418.07, the CO may require the application of more material or may reduce payment. The following factors will be used to determine if the specified application rate has been obtained:

The average unit weight of the field samples, determined by weighing 1000 milliliters to within + 0.1 gram

The percent residue per gallon on a by-weight basis

The total volume of product applied

The specified area

Pay Item Pay Unit

418(01) Seal for Light Traffic Pavements, Application Rate of 1.0 Pounds Residue/S.Y. S.Y.