407.03 Fog Seal and Tack Coat
406.05 Method of Measuremen T
The Resident Engineer will measure the weight of Open -Graded Friction Surface Course not exceeding the calculated we ight obtained by multiplying the unit weight from the job mix formula by the completed length of OGFSC and the area of the typical cross section shown on the Plans.
406.06 Basis of Payment
The Department will pay for each pay item at the contract unit pric e per the specified pay unit as follows: Pay Item: Pay Unit OPEN -GRADED FRICTION SURFACE COURSE Ton [Metric Ton] The Department will pay for tack in accordance with Section 407, “Fog Seal and Tack Coat.” The Department will adjust payment for asphalt binder in accordance with Subsection 411.06.B, “Price Adjustments for Asphalt Binder.”
407.01 Description
This work consists of preparing and treating an existing bituminous or concrete surface with bituminous material. Original Emulsion. A mixture of asphalt, water, and a small amount of emulsifying agent to maintain a uniform blend. Diluted Emulsion. An original emulsion diluted with additional water to reduce the viscosity and to allow easier spraying, typically used for fog seals. Residual Asphalt Content. The amount of asphalt remaining on the pavement surface after all of the water, b oth in the original emulsion and any additional water, has evaporated.
407.02 Materials
Provide materials in accordance with Subsection 708.03, “Asphalt Materials. ”
407.03 Equipment
Provide distributors, heating equipme nt, and supply tanks in accordance with Subsection 401.03, “Equipment.” FOG SEAL AND TACK COAT 407.04
407.04 Construction Methods
A.General Clean the existing roadbed surface before placing tack coat. Paint a thin, uniform tack coat on all surface s of curbs and gutters, manholes, and other structures that will come in contact with hot mix asphalt. Ensure the tack coat applications minimize damage and inconvenience to traffic and allow one-way traffic without pickup or tracking the bituminous mater ial. Do not apply tack coat during wet or cold weather, or in windy conditions that would cause the tack coat emulsion to drift. Do not apply tack coat to wet surfaces with free standing water. The Department will allow tack coat application to damp surf aces. The Resident Engineer must approve of the following before application: Quantity, Rate of application, Temperature, and Areas to be treated.
B.Fog Seal Apply the fog seal at a rate of 0.100 gal/yd² [0.455 L/m²] of diluted emulsion diluted at 5:1 wat er to original emulsion. Alter the application rate or dilution ratio as directed by the Resident Engineer (based on weather, type of emulsion, and surface type or layer).
C.Tack Coat Apply the tack coat or NT tack material as shown in Table 407:1, unles s otherwise required by the Contract. Alter the application rate as directed by the Resident Engineer (based on weather and surface type or layer). Use the highest rate in the table for the surface type or layer (top or bottom). Table 407:1 Tack Application Rates Surface Type/Layer Original Emulsion gal/yd2 [L/m2] Residual gal/yd2 [L/m2] New Asphalt (bottom) 0.060 [0.270] 0.035 [0.160] Old Asphalt (bottom) 0.085 [0.385] 0.050 [0.225] Milled (bottom) 0.085 [0.385] 0.050 [0.225] New Fabric (bottom) — 0.200 [0.905] PFC, OGFSC (top) 0.100 [0.455] 0.060 [0.270] UTBWC (top) 0.200 [0.905] 0.120 [0.545] PCC (bottom) 0.075 [0.340] 0.045 [0.205] Ensure that the tack breaks before the application of the next surfacing layer.
408.03 Prime Coat
Re-apply tack at a rate that ensures proper bonding if the tack loses its adhesive properties or is damaged by traffic before being covered by the next surfacing layer, as directed by the Resident Engineer, at no additional cost to the Department.
407.05 Method of Measurement
The Resident Engineer will measure the volume of Emulsion for Fog Sea l, Tack Coat , and NT Tack Material as delivered, before dilution. The Resident Engineer will measure bituminous material by the gallon [liter] or ton [metric ton].
407.06 Basis of Payment
The Department will pay for each pay item at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit:
A.FOG SEAL Gallon [Liter]
B.TACK COAT Gallon [Liter]
C.NT TACK MATERIAL Gallon [Liter] The Department considers the cost of water for dilution to be included in the contract unit price for Fog Seal and Tack Coat . SECTION 408 PRIME COAT
408.01 Description
This work consists of preparing and treating a surface with bituminous and blotter material. Cutback. A mixture of asphalt and petroleum solvent. Residual Asphalt Content. The amount of asphalt remaining on the pavement surface after the petroleum solvent evaporates. MC-30 and MC -70. Cutbacks with resi dual asphalt contents of at least 50 percent and 55 percent, respectively.
408.02 Materials
Provide materials in accordance with Subsection 708.03, “Asphalt Materials,” for MC -30 and MC -70. In ODEQ designated non -attain ment air quality counties, an emulsion may be used at the same percent residual application rate.
408.03 Equipment
Provide distributors, heating equipment, and supply tanks in accordance with Subsection 401.03, “Equipment.”
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 240–241 of 935.