PART 1 - GENERAL

1.01 SECTION INCLUDES

A. Description of Work: Bituminous seal coats shall consist of one or more applications of binder bitumen with one or more successive application of cover aggregate, and constructed only when the surface pavement and air temperatures are above 20°C (70°F).

B. Bituminous Seal Coat (BSC) Pavement

1.02 DESCRIPTION OF WORK

A. Work shall include preparation of surface, heating of bituminous materials and placing of the seal coat.

1.03 SUBMITTALS

A. Submit under provisions of Division 1.

B. Material Submittal: Upon request the contractor will provide Material Certifications to the Jurisdictional Engineer.

1.04 SUBSTITUTIONS

A. Use only materials conforming to these specifications unless permitted otherwise by Jurisdictional Engineer.

B. Obtain approval of Jurisdictional Engineer for all substitutions prior to use.

1.05 DELIVERY, STORAGE, HANDLING AND SALVAGING

A. Aggregate Storage: Prevent contamination and intermingling.

1.06 SCHEDULING AND CONFLICTS

A. Attend a preconstruction meeting if required by Jurisdictional Engineer.

B. Submit plan for construction sequence and schedule prior to commencing construction.

1.07 RESTRICTION ON OPERATIONS

A. Wet/Night Conditions: Seal coat shall not be placed on a wet surface or in night conditions.

B. Spread the binder bitumen on an area no greater than can be covered with aggregate and initially rolled within two (2) minutes. The bitumen spreader and aggregate spreader shall be as close as possible, but not more than 150 feet apart.

C. Date Restrictions: Seal coats shall not be applied after September 30 or when the surface pavement and air temperature are below (70°F).

1.08 MEASUREMENT FOR PAYMENT

The measurement and payments for bituminous seal coat pavement includes surface preparation, furnishing and placing of materials including fillets at intersecting roads, drives and turnouts. All measurement for payment will be made by the Jurisdictional Engineer or authorized representative.

A. Bituminous Seal Coat by Area: Bituminous seal coat shall be measured and paid in square yards.

B. Bituminous Seal Coat by Units

1. Cover Aggregate: The quantity of cover aggregate spread on the road surface, fillets and turnouts shall be measured in tons.

2. Binder Bitumen: The quantity of binder bitumen used in the work, including road surface, fillets and turnouts as provided in measurements of distributors, tank cars or trucks shall be measured in gallons. When quantities computed from field measurements checks within 1% of bill gallons, payment will be based on billed gallons. When quantities computed from field measurement differ from billed gallons by more than 1%, payment will be based on field measurements.

C. Preparation of Surface

1. Preparation of existing granular surface by scarifying to the required depth shall be paid for by the square yard.

2. Existing surface shall be cleaned of all foreign material and shall be considered incidental to other work.

PART 2 - MATERIALS AND EQUIPMENT

2.01 MATERIALS

Materials used in bituminous seal coat work shall comply with the following requirements:

A. Aggregates: The aggregate cover shall be clean or washed aggregate and shall be composed of hard durable gravel crushed stone or mixture, with abrasion loss by AASHTO96 Method C not exceeding 40. Gradation shall be as follows:

Percent Passing
Sieve	1/2"		3/8"		Sand
Size	Min	Max	Min	Max	Min	Max
3/4"	100
1/2"	97	100	100
3/8"	40	90	90	100	100
No. 4	5	30	10	55
No. 8	0	15	0	20	60	90
No. 30			0	7		40
No. 200	0	2	0	1.5	0	1.5

B. Bituminous Material: Unless the contract documents stipulate a specific grade, the binder bitumen used shall be Cationic Emulsion CRS-2, complying with requirements of ASTM D 2397. Cut back asphalt MC-800 ORMC 3000 may also be used as directed.

2.02 EQUIPMENT:

The equipment used shall be of types approved by the engineer and shall be kept in satisfactory working condition.

A. Aggregate Spreaders: Aggregate spreaders shall be self propelled, mounted on pneumatic tires, with a width of spread not less than 12 feet. The unit shall be capable of spreading aggregate specified above at a rate desired form 10 to 30 pounds per square yard of surface covered without contact of the wheels of the spreader with the treated surface until the aggregate has been spread.

B. Bitumen Distributors: Distributors shall be mounted on dependable motor trucks equipped with pneumatic tires. Distributors shall be provided with burners with heating coils and an accurate thermometer indicating temperature of the bitumen in the tank. Distributors shall supply bitumen to spray bars to produce an even spray at rates varying from 0.3 gallon to .5 gallon per square yard in a smooth uniform coating at a forward speed of up to 20 mph. The spray bars shall be adjustable vertically and shall provide a total spray width of not less than 12 feet. Distributors shall operate according to manufacturer's instructions for use for spray bar height above surface, nozzle size and angle of spray fan, and tables of rates of distribution in gallons per square yard for tachometer readings. Distributor calibration shall be verified before being used.

C. Brooms: A power-driven rotary broom is required for cleaning surfaces before bitumen is applied. Such brooms shall be driven by an auxiliary motor or by power take-off.

D. Rollers: Pneumatic tire rollers shall be used and shall be self-propelled, with tires not smaller than 7.50 x 15 size. Rollers shall be loaded to produce a compressive force of not less than 200 pounds per inch width of the roller. Tire inflation shall not be less than 60 psi. Steel rollers shall not be used unless authorized by the Jurisdictional Engineer, and then only for finishing work.