Section 32 01 13 Bituminous Seal .pdf

SECTION 32 01 13

BITUMINOUS SEAL AND FOG COATS

08/08

PART 1 GENERAL

1.1 MEASUREMENT AND PAYMENT PROCEDURES

Bituminous material and aggregate to be paid for will be the measured square yards of asphalt slurry seal placed and accepted.

1.1.3 Payment

The quantities of aggregate and bituminous material, determined as specified above, will be paid for at the respective contract unit prices.

Payment will constitute full compensation for all operations necessary to complete the work as specified herein.

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

ASTM INTERNATIONAL (ASTM)

ASTM C 136 (2006) Standard Test Method for Sieve Analysis of Fine and Coarse Aggregates

ASTM D 2397 (2005) Standard Specification for Cationic Emulsified Asphalt

ASTM D 977 (2005) Emulsified Asphalt

U.S. FEDERAL HIGHWAY ADMINISTRATION (FHWA)

MUTCD (2000) Manual of Uniform Traffic Control Devices

1.3 SYSTEM DESCRIPTION

1.3.1 Equipment, Plant and Tools

Equipment, plant and tools used in the work are subject to approval and shall be maintained in a satisfactory working condition at all times.

Provide equipment which is adequate and has the capability of producing the results specified.

1.3.2 Bituminous Distributors

Provide distributors that have pneumatic tires of sufficient size and number to prevent rutting, shoving, or otherwise damaging any part of the pavement structure. Design and equip the distributor to distribute the bituminous material in a uniform double or triple lap at the specified temperature, at readily determined and controlled rates from 0.05 to 2.0 gallons/square yard, with a pressure range of 25 to 75 psi with an allowable variation from the specified rate of not more than plus or minus 5 percent, and at variable widths. Include in the distributor equipment a separate power unit for the bitumen pump, full-circulation spray bars, tachometer, pressure gauges, volume-measuring devices, adequate heaters for heating of materials to the proper application temperature, a thermometer for reading the temperature of tank contents, and a hand-held hose attachment suitable for applying bituminous material manually to areas inaccessible to the distributor.

1.3.3 Aggregate Spreader

The aggregate-spreading equipment shall be adjustable and capable of uniformly spreading aggregate at the specified rate in a single-pass operation over the surface to be sealed.

1.3.4 Pneumatic-Tired Roller

Provide a pneumatic-tired roller of sufficient size to seat the cover aggregate into the bituminous material without fracturing the aggregate particles. The rollers shall have a total compacting width of not less than 5 feet. The gross weight shall be adjustable within 200 to 350 psi of compacting width.

1.3.5 Power Brooms and Power Blowers

Provide power brooms and power blowers suitable for cleaning surfaces to which the seal coat is to be applied.

1.3.9 Power Rollers

Provide self-propelled tandem and three-wheel type rollers, weighing not less than 5 tons and suitable for rolling bituminous pavements. The wheels of the rollers shall be equipped with adjustable scrapers. Equip the rollers with water tanks and sprinkling apparatus for keeping the wheels wet in order to prevent adherence of the bituminous material to the wheels.

1.3.10 Single-Pass, Surface-Treatment Machines

Provide machines capable of spraying bituminous material and spreading aggregate in one pass; of distributing the bituminous material uniformly, at even heat, and in controlled amounts; and inmediately spreading aggregates uniformly, in controlled amounts, over the surface to be sealed.

1.3.11 Vacuum Sweepers for Fog Seal

Provide self-propelled, vacuum pickup sweeper capable of removing loose sand, water, and debris from pavement surface.

1.4 SUBMITTALS

Government approval is required for submittals with a "G" designation;

submittals not having a "G" designation are for information only. Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES:

SD-03 Product Data

Waybills and Delivery Tickets

Waybills and delivery tickets, during the progress of the work.

Before the final statement is allowed, file certified waybills and delivery tickets for all materials used in the work covered by this section.

Equipment List

List of equipment used in the project along with calibration reports.

Inspection Reports

Reports of climatic temperature during application of fog seal, emulsion temperature and rate.

PART 2 PRODUCTS

2.1 BITUMINOUS MATERIAL FOR SEAL COAT

Bituminous material shall be emulsified asphalt conforming to ASTM D 977, type SS-1; or to ASTM D 2397, type CSS-1.

2.2 AGGREGATE FOR SEAL COAT

Provide aggregate consisting of crushed stone, crushed gravel, sand and screenings. The aggregate shall conform to the gradation shown in TABLE I. The aggregate gradation shall be allowed the tolerances given in TABLE

II.

TABLE I. AGGREGATE GRADATIONS

(Percent by Weight Passing Square-Mesh Sieves)

Gradation Gradation Gradation Sieve Size No. 1 No. 2 No. 3

1/2 in. 100 -- -- 3/8 in. 85-100 100 -- No. 4 10-30 85-100 100 No. 8 0-10 10-40 10-40 No. 16 0-5 0-10 0-10 No. 50 -- 0-5 0-5

TABLE II. AGGREGATE GRADATION TOLERANCES

Material Tolerances

Aggregate passing the 3/8-in. sieve Plus or minus and larger sieves 5 percent

Aggregate passing the No. 4 and Plus or minus smaller sieves 3 percent

2.2.1 Coarse Aggregate

Coarse aggregate shall consist of clean, sound, durable particles meeting the following requirements.

2.2.1.6 Crushed Aggregate

Crushed aggregate retained on the No. 4 sieve and each coarser sieve shall contain at least 75 percent by weight of crushed pieces having one or more fractured faces with the area of each face equal to at least 75 percent of the smaller midsectional area of the aggregate particle. When two fractures are contiguous, the angle between the planes of fractures shall be at least 30 degrees to count as two fractured faces.

2.2.2 Fine Aggregate

Fine aggregate shall consist of clean, sound, durable particles of crushed stone, durable particles of crushed stone, slag, or gravel. The aggregate shall meet its requirements for stripping, abrasion resistance and percent friable particles as specified for coarse aggregate.

2.3 ANTISTRIPPING AGENT

The use of antistripping agent is subject to prior approval by the Contracting Officer.

2.4 EMULSIFIED ASPHALT FOR FOG SEAL

Emulsified asphalt for Fog Seal shall conform to ASTM D 977, SS-1 for anionic and ASTM D 2397CSS-1 for cationic materials.

2.5 WATER

Provide fresh, clean, and potable water.

PART 3 EXECUTION

3.1 PREPARATION OF SURFACE

Repair damaged surface and fill cracks before starting work. Immediately before starting work, remove all loose material, dirt, clay, or other objectionable material from the surface to be treated with power brooms or power blowers, if needed. Paint firmly bonded to the surface that has the chalk removed may remain. Material removed from the surface shall not be mixed with the cover aggregate.

3.2 SEAL COAT APPLICATION

3.2.1 Rate

Spread the bituminous material in the quantities shown in TABLE III. The exact quantities within the range specified, which may be varied to suit field conditions, will be determined by the Contractor and approved by the Contracting Officer prior to use.

TABLE III. APPLICATION OF MATERIAL

TABLE III. APPLICATION OF MATERIAL

(Quantities Per Square Yard)

Gradation No. Bitumen, gallons Aggregate, pounds

(Quantities Per Square Yard)

Gradation No. Bitumen, gallons Aggregate, pounds

1 0.15-0.20 15-20 2 0.10-0.15 10-15 3 0.10-0.15 10-15

3.2.3 Application of Bituminous Material

Following the preparation and inspection of the pavement surface, apply the seal coat material at the specified rates. Uniformly apply the bituminous material in a single pass of the distributor and with either a double or triple lap spray over the surface to be sealed. Spread building paper on the surface for a sufficient distance back from the ends of each application so that flow through the spray bar may be started and stopped on the paper and so that all sprays will be operating at the proper pressure on the surface to be sealed. Immediately after the application, remove the building paper. Properly treat with bituminous material spots missed by the distributor. No smoking, fires, or flames, other than the heaters that are a part of the equipment, will be permitted within 25 feet of heating, distributing, and transferring operations of bituminous material other than bituminous emulsions.

3.2.4 Aggregate Application Rate

Spread the aggregate in the quantities shown in TABLE III. The exact quantities within the range specified, which may be varied to suit field conditions, will be determined by the Contractor, and approved by the Contracting Officer prior to use. The aggregate weights shown in this table are those of aggregate having a specific gravity of 2.65. If the specific gravity of the aggregate to be used is less than 2.55 or greater than 2.75, make adjustments in the number of pounds of aggregate required per square yard to insure a constant volume of aggregate per square yard of treatment.

3.2.5 Application of Aggregate

Spread the specified quantity of cover aggregate uniformly over the bituminous material. Before the bituminous material is applied, sufficient aggregate to cover the distributor load of bituminous material shall be on trucks at the site of the work. No bituminous material shall be down more than 3 minutes before it is covered with aggregate. Spreading shall be done uniformly with aggregate-spreading equipment. Trucks spreading aggregate shall be operated backwards, covering the bituminous material ahead of the truck wheels. Areas having insufficient cover shall be lightly recovered with additional aggregate by hand during the operations whenever necessary.

3.2.6 Rolling and Brooming

Begin rolling operations immediately following the application of cover aggregate. Perform rolling using pneumatic-tired rollers. Operate the rollers at a speed that will not displace the aggregate. Continue rolling until the aggregate is uniformly distributed and keyed into the bituminous material. All surplus aggregate shall be swept off the surface and removed not less than 24 hours nor more than 4 days after rolling is completed.

3.3 FIELD QUALITY CONTROL - SEAL COAT

3.3.1 Tests

Perform field tests in sufficient numbers to assure that the specifications are being met. Testing is the responsibility of the Contractor and shall be performed by an approved commercial laboratory. The following number of tests, if performed at the appropriate time, will be the minimum acceptable for each type of operation.

3.3.1.1 Gradation

Perform gradation tests in accordance with ASTM C 136. Perform a minimum of one gradation for each day's run.

3.4 TRIAL APPLICATION - SEAL COAT

Prior to applying the seal coat, place a test section at least 100 feet long by 20 feet wide using the approved job materials and roll them in accordance with the specified requirements. Perform tests to determine the application rates of the bitumen and aggregate. If the tests indicate that the seal coat test section does not conform to the specification requirements, make necessary adjustments to the application equipment and to the spreading and rolling procedures, and construct additional test sections for conformance to the specifications. Where test sections do not conform to specification requirements, remove seal coat at no expense to the Government; no separate payment will be made for seal coat materials and labor, either in placement or removal of any test section. Perform quality control sampling and testing during construction as required in paragraph FIELD QUALITY CONTROL above.

3.5 FOG SEAL APPLICATION

3.5.3 Inspection Reports

Furnish a written report citing climatic temperature during application, emulsion temperature during application, and rate of emulsion application.

3.5.4 Application

Following preparation of the surface, apply the water diluted asphalt emulsion at the rate determined from the trial application. Maintain application temperature of emulsified asphalt between 75 and 160 degrees F.

To obtain uniform application of the fog seal at the junction of previous and subsequent applications, spread building paper on the surface of the applied material for a sufficient distance back from the ends of each application so that flow from the spray bar may be started and stopped on the paper, and so that all sprayers will operate at full force.

Immediately after application, remove and properly dispose of the building paper. Treat spots unavoidably missed with the hand spray equipment. Base bids on application of diluted emulsion at 0.14 gsy. If the actual amount required is more or less than 0.14 gsy, an adjustment in the contract price will be made as provided by the contract.

3.6 SITE PROTECTION

During applications, protect adjacent buildings, structures, vehicles, manhole covers, inlet grates, and trees to prevent being spattered or marred.

3.7 TRAFFIC CONTROL

Protect freshly placed coatings from damage by traffic. Provide sufficient warning signs and barricades to prevent traffic over freshly treated surfaces. Protect treated areas from traffic for at least 24 hours after final application of coatings, or for such time as necessary to prevent picking up. Immediately prior to opening to traffic, roll the entire treated area with a self-propelled pneumatic-tired roller. Provide warning signs and barricades for proper traffic control, in accordance with MUTCD.

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