Assessment of Emulsified RAP Cold Mixes via Non-Destructive Testing

摘要

Curing of emulsion in cold recycling process is one of the important factors affecting performance of the recycled mix. In the study here, the effect of curing time and temperature on emulsified RAP cold mixes is evaluated using ultrasonic pulse velocity (UPV) test. The UPV test was also employed to evaluate its effectiveness in discerning rutting potential of the mixes. A series of 100% cold milled RAP mixes were prepared with conventional emulsion and polymer modified emulsion, with and without treatment with 1% cement. The specimens were tested with UPV at curing temperatures at a defined set time intervals, up to 14 days after compaction. The rutting potential of the specimens cured for three days was evaluated using the Superpave Shear Tester. Results indicate that the UPV test is able to discern and capture expected stiffness trend among the mixes with variations in temperature and curing time. Results also indicate that the UPV test, as a simple and quick method, has the ability to properly rank the rutting potential of cold mixes.