Asphalt Tack Coat Best Practices

STORAGE

• Store emulsion in vertical tanks. for long-term storage.
• Store at a temperature between 50°F and 180°F  (10°C and 83°C).
• Don’t let the emulsion freeze.
• Don’t allow emulsion temperatures to exceed 212°F (100°C) or water boiling point.
• Don’t allow emulsion to free-fall into vessel from loading line or recirculation line.
• Do bottom load.
• Circulate material every two weeks.
• Protect pump, valves and lines from freezing.

HANDLING

• Don’t mix anionic and cationic emulsions.
• Don’t load elevated temperature material above 212°F (100°C) on top of asphalt emulsion.
• Circulate vessel while heating with direct fire tubes. (Low fire on heating tubes).
• Dilute emulsion by adding warm water to the emulsion.
• Check with the emulsion manufacturer for guidance on dilution of emulsion.
• Wear proper personal protective equipment (PPE) to safely handle the emulsion.
• Asphalt emulsions are nonhazardous materials.
• Asphalt emulsions do not require placards.

NAPA's Emulsion Bond Coat Best Practices Checklist

1. Clean the pavement
2. Maintain emulsion at proper temperature
3. Determine residual asphalt content required
4. Calculate application rate
5. Set spray-bar height for triple overlap of spray
6. Ensure nozzles are correct size
7. Ensure all nozzles are same size
8. Set spray nozzles at same angle
9. Ensure all nozzles are clean and functioning properly
10. Ensure distributor is calibrated
11. Ensure uniform application of tack coat
12. Prevent tracking and pickup of the emulsion

Other Best Practices References:

1. Tack Coat Best Practices, NAPA QIP-128 (2013)
2. Tack Coats: How and what to apply! Colorado Asphalt Pavement Association (CAPA)(2011)
3. Tack Coat Guidelines, Caltrans (2009)
4. Hot Mix Asphalt Paving, US Army Corp of Engineers (2000)
5. FHWA Technical Bulletin on Tack Coat Best Practices (2016)