412Bituminous Prime

412.1 General Description

This work includes preparing and treating an existing surface with bituminous material and blotter material, if required. Treat the surface according to these specifications and conform to the lines shown on the plans or established by the Engineer.

412.1.01 Definitions

General Provisions 101 through 150.

412.1.02 Related References

A. Standard Specifications Section 424—Bituminous Surface Treatment Section 821—Cutback Asphalt B. Referenced Documents General Provisions 101 through 150.

412.1.03 Submittals

General Provisions 101 through 150.

412.2 Materials

Unless otherwise specified, select the types of bituminous materials. The Engineer will determine the grade of materials to be used. The specifications for the bituminous materials include: Material Section Cutback Asphalt, RC-30, RC-70, RC-250 or MC-250, MC-30, or MC-70 821.2.01 Blotter Material (Sand) 412.3.05.G.3

412.2.01 Delivery, Storage, and Handling

General Provisions 101 through 150.

412.3 Construction Requirements

412.3.01 Personnel

General Provisions 101 through 150.

412.3.02 Equipment

Provide equipment that is in good repair, including at least the following units that meet the requirements of Subsection 424.3.02, Equipment. • Pressure distributor • Power broom and blower • Aggregate spreader (if required) • Pneumatic-tired roller

412.3.03 Preparation

See Subsection 412.3.05.B, Condition of Surface.

412.3.04 Fabrication

General Provisions 101 through 150.

412.3.05 Construction

Prime the following bases and other areas: • Cement or lime stabilized bases or sub-bases, regardless of pavement thickness • Soil or aggregate bases or sub-bases on which bituminous surface treatment will be placed • Soil or aggregate bases or sub-bases on which less than 5 in. (125 mm) total thickness of hot mix asphaltic concrete will be placed Prime is not required on driveway construction and paved shoulders. A. Weather Limitations Do not apply bituminous prime under any of these conditions: • Surface is wet. • Air temperature is below 40 ºF (4 ºC) in the shade. • Rain is imminent. • Weather conditions may prevent proper prime coat construction. B. Condition of Surface Ensure that the surface to which the prime is to be applied has been finished to the line, grade, and cross-section specified. Ensure that the surface is uniformly compacted and bonded. Correct surface irregularities according to the specifications for the construction being primed. C. Cleaning Remove from the road loose material, dust, caked clay, and other material that may prevent bonding of the prime with the surface. Use power sweepers or blowers the full width of the prime and 2 ft. (600 mm) more on each side. Where necessary, sweep by hand. D. Moisture Ensure that the surface is only slightly damp. If the surface is too wet, allow it to dry. If it is too dry, the Engineer may require that it be sprinkled lightly just before priming. E. Temperature and Surface Texture The surface texture and condition of the surface determine the bituminous material grades to be used. The following table shows the bituminous material grades and application temperatures as they are applied to various surface textures. Base Texture Tight Average Open Materials and grade MC-30 RC-30 RC-70 or MC-70 RC-250 or MC-250 Application temperature °F (°C) 80–120 (27–49) 105-180 (41–82) 145–220 (63–104) The Engineer will determine the temperature for applying bituminous prime within the limits shown above. Heat and apply bituminous materials as specified in Subsection 424.3.05.D, Heating Bituminous Material and Subsection 424.3.05.E, Applying Bituminous Material. F. Amount and Extent of Prime The Engineer will determine the exact amount of bituminous material to be used within minimum and maximum rates of 0.15 to 0.30 gal/yd² (0.7 to 1.4 liters/m²). Apply the specified amount as follows: 1. Apply the determined amount uniformly and accurately. Ensure that the amount applied to any 0.5-mile (800 m) section is within 5 percent of the amount specified. 2. Apply the prime the full width of the proposed wearing surface that will be superimposed plus 6 in. (150 mm) more on each side. G. Protection, Curing, and Maintenance Do the following after priming the surface: 1. Close to Traffic Do not allow traffic on the primed surface. Leave the surface undisturbed until the prime thoroughly cures and does not pick up under traffic. 2. Roll If the surface becomes soft after it is primed, roll the surface longitudinally with a pneumatic-tired roller at no more than 6 mph (10 kph) until the surface is firmly set. 3. Blot If necessary to prevent the prime from being picked up, spread clean, dry, sharp sand over the surface by hand or mechanically. Apply sand only to places that are tacky and use the least amount needed to prevent pick up. No extra payment for this work or material will be made. 4. Open to Traffic After rolling and sanding (if required), open the primed surface to ordinary traffic subject to the conditions in Subsection 412.3.05.G.1, Close to Traffic. 5. Curing and Maintenance 6. The primed surface is properly cured when it has penetrated the base sufficiently to not be picked up or displaced by traffic. Temperature and weather conditions may increase curing time. Insure the primed surface has cured to the satisfaction of the Engineer prior to its being covered by other construction. 7. Maintain the prime coat and the primed surface course until it is covered by other construction. Repair potholes, scabs, and soft spots prior to covering with other construction. Remove excess bituminous material.

412.3.06 Quality Acceptance

General Provisions 101 through 150.

412.3.07 Contractor Warranty and Maintenance

General Provisions 101 through 150.

412.4 Measurement

Bituminous material for prime is not measured for separate payment.

412.4.01 Limits

General Provisions 101 through 150.

412.5 Payment

Bituminous material for prime is not paid for separately. The cost to clean the surface, furnish, haul and apply materials including water and sand, roll, and perform repairs and maintenance is included in the Unit Price bid for each individual Base Item.

412.5.01 Adjustments

General Provisions 101 through 150.