Tack Lifter for In Situ Measurement of Effective Emulsion Application Rates

Emulsion application rates are critically important to the performance of pavement surface treatments and tack coats. In this study, the tack lifter was introduced as a means to measure in situ effective emulsion application rates at specific locations along the length of paving. The tack lifter is a simple, weighted device that is placed on top of a superabsorbent foam sheet applied to a paving surface. The absorbent sheet soaks up emulsion from the roadway surface to get a spot check of the amount of emulsion on the surface. The device measures the effective emulsion application rate on the paving surface, neglecting emulsions absorbed into the paving surface. Laboratory studies of emulsion application onto chip seal and hot-mix asphalt concrete surfaces demonstrate the ability of the tack lifter to capture the sensitivity of emulsion absorption to pavement surface texture. In addition, preliminary tack lifter field trial results are presented to demonstrate its use as a quality control field test.