00730.40 733 Section 00730 - Emulsified Asphalt Tack Coat
Description
00730.00Scope - This Work consists of furnishing and placing Emulsified Asphalt on a prepared
asphalt concrete, portland cement concrete, or other paved surface to ensure bond between Lifts as specified.
Materials
00730.11Emulsified Asphalt - Furnish CSS-1, CSS -1h, CMS -2, CMS -2S, CMS -2h, CRS -1, CRS -2,
HFRS -2, or HFMS -2 as selected by the Contractor. Furnish Emulsified Asphalt meeting the requirements of ODOT's publication Standard Specifications for Asphalt Materials . Copies of the publication are available from the ODOT Pavement Services Engineer. The applicable Specifications are those contained in the current publication on the date the Project is advertised. The materials may be conditionally accepted at the source or point of loading for transport to the Project.
Excessive delay in the use of the Emulsified Asphalt or exc essive pumping of the Emulsified Asphalt may significantly reduce the viscosity and may make the material unsuitable for tack coat use. For this reason limit pumping between the bulk storage tank, hauling transportation, field storage tanks and distributor to an absolute minimum to maintain proper viscosity. Final acceptance of Emulsified Asphalt will be at the point of application.
Dilution of the tack coat material may be allowed to a maximum 1:1 ratio. Determine the proportion of water to be added to the Emulsified Asphalt . Do not dilute the Emulsified Asphalt until the Engineer approves the dilution ratio. Add the water to the Emulsified Asphalt and mix according to the asphalt Supplier . Obtain samples according to AASHTO R 66 prior to dilution wi th water, if allowed, according to it is sampled.
Equipment
00730.22Asphalt Distributor - Provide an asphalt distributor designed, equipped, maintained and
operated so the Emulsified Asphalt Material may be applied uniformly at even heat. The distributor shall be capable of applying the asphalt on variable surface widths up to 16 feet, at readily determined and controlled rates from 0.05 to 2.0 gallons per square yard, and with uniform pressure. The variation allowed from any specified rate shall not exceed 0. 02 gallons per square yard. Provide distributor Equipment that includes a tachometer, pressure gauges, accurate volume measuring devices and a thermometer for measuring temperature of tank contents. Provide distributors equipped with a positive power unit for the asphalt pump, and full circulation spray bars adjustable both laterally and vertically. Set the bar height for triple lap coverage.
Construction
00730.40Temperature Limitations - Apply tack coat only when the surface temperature in the
shade is not less than the appropriate minimum surface temperature according to 00735.40,
00744.40, and 00745.40, as applicable
00730.41 734 00730.41 Traffic Control - Do not apply the tack to more than one-half the width of the travel way at one time. The remaining widt h shall remain open to traffic. Do not close the open lane until traffic controlled by pilot car is operating on the new surface.
00730.42Preparation of Underlying Surfaces - Immediately before applying the tack coat, the
surface to be tacked shall be clean and dry. Clean all loose material by brooming, flushing with water or other approved methods.
00730.44Applying Tack Coat - Apply the Emulsified Asphalt with a pressure distributor conforming
to 00730.22, unless otherwise allowed. Apply the Emulsified Asphalt to the prepared surface at a rate between 0.05 and 0.20 gallons per square yard as directed and with the Emulsified Asphalt temperature between 140 °F and 185 °F as recommended by the manufacturer. Application rates for tack coat diluted according to 00730.11 will be increased as necessary to provide the same amount of residual asphalt as the application rates specified above. Do not place hot mixed asphalt concrete Pavement or Emulsified Asphalt Concrete Pavement on the tack coat until the Emulsified Asphalt separates from the water (breaks), but before it loses its tackiness.
Measurement
00730.80Measurement - The quantities of Emulsified Asph alt cement used as tack will be
measured on the weight basis.
Payment
00730.90Payment - The accepted quantities of Emulsified Asphalt cement used as tack coat will be
paid for at the Contract unit price, per T on, for the item "Emulsified Asphalt for T ack Coat".
Payment will be payment in full for furnishing, mixing with water, and placing the Materials, and for furnishing all Equipment , labor, and Incidentals necessary to complete the Work as specified.
No separate or additional payment will be made for water added to dilute the Emulsified Asphalt used for tack coat after delivery from the asphalt Supplier .