SlurrySealAlternativeSpecification.pdf

SPECIAL PROJECT SPECIFICATION

ATTACHMENT B

Section 417 - Seal for Light Traffic Pavements

DESCRIPTION

417.01 Work

This work shall consist of the application of pavement sealing material(s) to areas of pavement surfaces SHOWN ON THE DRAWINGS. The seal may require a top dressing or color treatment AS SHOWN ON THE DRAWINGS.

MATERIALS

417.02 Requirements

Rubberized Crack Filler: Either cold or hot poured crack filler containing rubber or other materials that make it elastic at cold temperatures.

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 improve the consistency.

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 Engineer 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.

417.03

Sampling and Testing

When directed by the Engineer, the contractor shall sample materials that are used in the work. The Engineer will be given the opportunity to witness sampling, and will be responsible for testing.

CONSTRUCTION

417.04 Weather Limitations

Seals shall not be applied when the weather is foggy or when rain threatens, nor when the atmospheric or pavement temperature is below 50oF., unless otherwise directed by the Engineer.

417.05 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 of surface. The required application rate may be obtained by making multiple applications. The equipment used for storing and application of liquid and slurry products shall include accurate volume measuring devices and calibrated tank. The Engineer may require transport or application equipment to be weighed when full and when empty if volume measuring equipment is inadequate.

417.06 Preparation of Surface

Prior to placing the seal coat, the surface of the pavement shall be clean and free from dust, dirt, or other loose foreign matter, grease, oil or any type of objectionable surface film. Accumulations of oil or grease may be removed by pressure washing, grinding, or burning and scraping. Existing painted stripes shall be removed if SHOWN ON THE DRAWINGS.

All cracks wider than 1/8 inch shall be cleaned by removing accumulated dirt and vegetation, and blown out with compressed air to a depth of at least three times the crack width. Transverse cracks over 1/8 inch in width shall be filled with a rubberized crack filler applied in accordance with the manufacturer’s instructions.

Other cracks over 1/8 inch in width may be filled with pavement seal materials prior to application of seal materials over the entire surface.

The surface will be approved in writing by the Engineer prior to applying the seal.

417.07 Seal Application

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 Engineer 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 Engineer 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 Engineer will determine the weight of residue per gallon by drying field samples from the project to constant weight.