Attachment_3_-_Tack_Coat_Specifications.pdf

SECTION TABLE OF CONTENTS

SECTION 32 12 13

BITUMINOUS TACK COAT

PART 1 - GENERAL

1.1 NOT USED

1.2 REFERENCES

1.3 SUBMITTALS

1.4 DELIVERY, STORAGE, AND HANDLING

1.5 EQUIPMENT, TOOLS AND MACHINES

1.5.1 General Requirements

1.5.2 Bituminous Distributor

1.5.3 Heating Equipment for Storage Tanks

1.5.4 Power Brooms and Power Blowers

1.6 ENVIRONMENTAL REQUIREMENTS

PART 2 - PRODUCTS

2.1 TACK COAT

2.1.1 Emulsified Asphalt

PART 3 - EXECUTION

3.1 PREPARATION OF SURFACE

3.2 APPLICATION RATE

3.3 APPLICATION TEMPERATURE

3.3.1 Temperature Ranges

3.4 APPLICATION

3.4.1 Tack Coat

3.5 CURING PERIOD

3.6 TESTING

3.6.1 Calibration Test

3.6.2 Trial Applications

3.6.2.1 Tack Coat Trial Application Rate

-- End of Section Table of Contents --

5 April 2018

SECTION 32 12 13

BITUMINOUS TACK COAT

PART 1 - GENERAL

1.1 NOT USED

1.2 REFERENCES

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN ASSOCIATION OF STATE HIGHWAY AND TRANSPORTATION OFFICIALS (AASHTO)

AASHTO T 102 (2009; R 2013) Standard Method of Test for Spot Test of Asphaltic Materials

ASTM INTERNATIONAL (ASTM)

ASTM D1250 (2008) Standard Guide for Use of the Petroleum Measurement Tables

ASTM D140/D140M (2016) Standard Practice for

Sampling Asphalt Materials

ASTM D2026/D2026M (2015) Cutback Asphalt (Slow-Curing Type)

ASTM D2027/D2027M (2013) Cutback Asphalt (Medium-Curing Type)

ASTM D2028/D2028M (2015) Cutback Asphalt (Rapid-Curing Type)

ASTM D2397/D2397M (2017) Standard Specification for Cationic Emulsified Asphalt

ASTM D2995 (1999; R 2009) Determining

Application Rate of Bituminous Distributors

ASTM D6373 (2016) Standard Specification for Performance Graded Asphalt Binder

ASTM D946/D946M (2015) Penetration-Graded Asphalt

Cement for Use in Pavement Construction

ASTM D977 (2017) Standard Specification for Emulsified Asphalt

1.3 SUBMITTALS

Submit a Certificate of Compliance for the tack coat material for approval.

1.4 DELIVERY, STORAGE, AND HANDLING

Inspect the materials delivered to the site for contamination and damage.

Unload and store the materials with a minimum of handling.

1.5 EQUIPMENT, TOOLS AND MACHINES

1.6.1 General Requirements

Maintain all equipment in a satisfactory working condition at all times.

Calibrate equipment as required.

1.6.2 Bituminous Distributor

Provide a self-propelled distributor with pneumatic tires of such size and number to prevent rutting, shoving or otherwise damaging the surface being sprayed. Calibrate the distributer in accordance with ASTM D2995. Design and equip the distributor to spray the bituminous material in a uniform coverage at the specified temperature, at readily determined and controlled total liquid rates from 0.03 to 1.0 gallons per square yard, with a pressure range of 25 to 75 psi, and with an allowable variation from the specified rate of not more than plus or minus 5 percent, and at variable widths. Include with the distributor equipment a separate power unit for the bitumen pump, full-circulation spray bars, tachometer, pressure gauges, volume-measuring devices, adequate heaters for heating of materials to the proper application temperature, a thermometer for reading the temperature of tank contents, and a hand hose attachment suitable for applying bituminous material manually to areas inaccessible to the distributor. The distributor will be capable of circulating and agitating the bituminous material during the heating process.

1.6.3 Heating Equipment for Storage Tanks

Use steam, electric, or hot oil heaters for heating the bituminous material. Provide steam heaters consisting of steam coils and equipment for producing steam, so designed that the steam cannot come in contact with the bituminous material. Fix an armored thermometer to the tank with a temperature range from 40 to 400 degrees F so that the temperature of the bituminous material may be determined at all times.

1.6.4 Power Brooms and Power Blowers

Use power brooms and power blowers suitable for cleaning the milled surface.

1.7 ENVIRONMENTAL REQUIREMENTS

Apply the tack coat only when the milled surface is dry. Apply the tack coat only when the atmospheric temperature in the shade is 50 degrees F or above, and when the temperature has not been below 35 degrees F for the 12 hours prior to application.

PART 2 - PRODUCTS

2.1 TACK COAT

2.1.1 Emulsified Asphalt

Provide emulsified asphalt conforming to ASTM D977, Type SS1h. No dilution is allowed for tack coat applications.

PART 3 - EXECUTION

3.1 PREPARATION OF SURFACE

Immediately before applying the tack coat, remove all loose material, dirt, clay, or other objectionable material from the milled surface by means of a power broom or blower supplemented with hand brooms. Apply tack coat only when the surface is dry and clean.

3.2 APPLICATION RATE

Apply the tack coat in quantities of not less than 0.03 gallons, nor more than 0.10 gallons per square yard of residual asphalt onto the milled surface. Do not dilute asphalt emulsion when used as a tack coat.

3.3 APPLICATION TEMPERATURE

3.3.1 Temperature Ranges

The viscosity requirements determine the application temperature to be used. The following is a normal range of application temperatures:

Asphalt Emulsion

All Grades 70-160 degrees F

3.4 APPLICATION

3.4.1 Tack Coat

Apply the tack coat over the entire milled surface, and at transverse and longitudinal joints. Apply the tack coat when the milled surface is clean and dry. Immediately following the preparation of the milled surface, apply the tack coat by means of the bituminous distributor, within the limits of temperature specified herein, and at a rate as specified above in the paragraph APPLICATION RATE. Apply the tack coat so that uniform distribution is obtained over the entire milled surface. Treat lightly coated areas and spots missed by the distributor by spraying with a hand wand or using other approved method. Following the application of the tack coat, allow the surface to cure without being disturbed for period of time necessary to permit setting of the tack coat. Apply the tack coat only as far in advance of the placing of the overlying layer as required for that day's operation. Maintain and protect the treated surface from damage until the new pavement is placed.

3.5 CURING PERIOD

Following the application of the tack coat, and prior to installing the new pavement, allow the tack coat to properly cure. Maintain the tacked surface in good condition until the new pavement is placed.

3.6 TESTING

3.6.1 Calibration Test

Furnish all equipment, materials, and labor necessary to calibrate the bituminous distributor. Calibrate using the approved job material and prior to applying the tack coat material to the prepared surface.

Calibrate the bituminous distributor in accordance with ASTM D2995.

3.6.2 Trial Applications

Before applying the spray application of tack coat, apply three lengths of at least 100 feet for the full width of the distributor bar to evaluate the amount of bituminous material that can be satisfactorily applied.

3.6.2.1 Tack Coat Trial Application Rate

Apply the trial application rate of the tack coat in the amount of 0.05 gallons per square yard. Make other trial applications using various amounts of material as may be deemed necessary.

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