In situ measurements of emulsion application rates

ABSTRACT

The emulsion application rate (EAR) is critical to the performance of tack coats and surface treatments. Current quality assurance and quality control measures for EARs are limited and fail to consider in situ measurements. This study evaluates in situ measures to address transverse and longitudinal variability in applied EARs and pavement emulsion absorption using field experiments. Results demonstrate that the Tack Lifter can be used effectively to measure pavement emulsion absorption rates and to capture longitudinal variability in the applied EAR. The Tack Lifter is a simple, weighted device that is placed on a super-absorbent sheet which absorbs emulsion applied to a pavement or plate. When applied directly to a pavement, the device measures the effective EAR on the pavement, neglecting emulsions absorbed into the paving surface. When applied to a plate placed on the pavement prior to emulsion application, the device measures the total applied EAR. Results indicate emulsion absorption should be quantified prior to construction to guide appropriate adjustment of the target EAR. Applied EARs can vary significantly along the length of paving. Limited results indicate transverse variability is relatively consistent along the length of paving and therefore, should be remedied prior to construction rather than using in situ measurements.

KEYWORDS:

• Asphalt emulsion
• quality control quality assurance
• in situ

Disclosure statement

No potential conflict of interest was reported by the authors.

Acknowledgements

The authors also acknowledge and thank Instrotek, Inc. for fabricating the Tack Lifter.

Additional information

Funding

This work was supported by the North Carolina Department of Transportation [grant number HWY-2014-03].