406.04 Open -Graded Friction Surface Course
405.06 Basis of Payment
The Department will pay for each pay i tem at the contract unit price per the specified pay unit as follows: Pay Item: Pay Unit: PERMEABLE FRICTION 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. ” OPEN -GRADED FRICTION SURFACE COURSE
406.01 Description
This work consists of mixing aggregate and bituminous material in a central plant, then spreading and compacting the mixed material on a prepared roadbed.
406.02 Materials
Provide materials in accordance with Section 708, “Plant Mix Bituminous Bases and Surfaces.”
406.03 Equipment
Provide equipment in accordance with Subsection 411.03, “Equipment.”
406.04 Construct Ion Methods
A.Stockpiling Materials Stockpile aggregate in accordance with Subsection 106.08, “Storage and Handling of Materials.”
B.Preparation of Materials Dry and heat the aggregate to a temperature no greater than 260 °F [127 °C]. Collect resulting dust, and remove or return it to the mixture required to meet the Job -Mix Formula (JMF). Ensure the aggregate used in the Open -Graded Friction Surface Course (OGFSC) is free of oily or carbonaceous coatings. Ensure the temperature of bituminous material does not exceed 350 °F [177 °C] before and during mixing.
C.Mixing Mix the aggregate and bituminous material in accordance with Subsection 411.04.E, “Mixing.” OPEN -GRADED FRICTION SURFACE COURSE 406.04
D.Loading and Hauling Coordinate loading and hauling the OGFSC with laydown operations to: Ensure OGFSC placement within the temperature range in accordance with Subsection 406.04.G., “Spreading and Finishing,” and Prevent separation of t he asphalt and aggregate in the OGFSC.
E.Tack Apply a tack coat or NT tack material in accordance with Section 407, “Fog Seal and Tack Coat.”
F.Weather and Seasonal Limitations Place OGFSC on a dry surface. Ensure the prepar ed roadbed surface is at least 60 °F [15 °C] measured away from artificial heat sources. Ensure the weather conditions allow proper leveling and consolidation of the OGFSC. Place OGFSC between April 1 and October 31, unless otherwise approved by the Resid ent Engineer.
G.Spreading and Finishing Before placing OGFSC, remove foreign material from the prepared roadbed. Ensure the temperature of the OGFSC at the time of placement is in accordance with the temperature required by the JMF 25 °F [14°C]. Ensure the paver moves continuously during paving. If paving stops, remove all material from the paver and restart the paving operation.
H.Joints Place the longitudinal OGFSC joint at the lane lines, and offset this joint from the underlying joint by at least 3 in [75 mm]. Ensure that the joints are tight, smooth, butt -type joints.
I.Compaction Roll the surface with two or three passes with a non -vibratory, steel -wheeled, self -propelled roller immediately after placing OGFSC. Construct a smooth finished surfa ce in accordance with Subsection 401.04.A(1), “Surface Elevation and Smoothness,” and Subsection 401.04.A(2), “Width .” Restrict traffic from the finished OGFSC pavement until the surface temperature is within 10°F [6°C] of the ambient temperature, or 2 hr after the final rolling.
J.Tolerance Ensure the finished OGFSC is at least as thick as the thickness shown on the Plans, but no thicker than the thickness shown on the Plans plus ¼ in [6.4 mm]. Remove and replace defective areas immediately, at no additional cost to the Department.
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.” SECTION 407 FOG SEAL AND TACK COAT
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.”
Source: Oklahoma Standard Specifications for Highway Construction, 2019 Edition. Pages 238–239 of 935.