This paper evaluates the effects on the Performance Grade (PG) of liquid asphalt and on the mechanical properties of hot mix asphalt concrete when using Hypertherm Warm Mix Asphalt (WMA) modifier in high volume Recycled Asphalt Pavement (RAP) mixtures. For a reconstruction project on New Brunswick Rte 10, asphalt binder characterization was performed in the mix design phase of the NBDOT HRB mix design, resulting in a required grade bump from PG 58-28 to PG 52-34 at a level of 30% RAP. During paving a 1 KM trial section of this project was paved with an identical mixture utilizing a PG 58- 28 as the virgin binder and including Hypertherm™, a warm mix additive. The WMAHRB was produced at 250◦ F (120◦ C), versus the 310◦ F (155◦ C) temperature of the conventional mixture. The binder characterization of liquid asphalt extracted from the plant produced asphalt concrete showed extremely encouraging results. The WMA-HRB graded to PG 67-27, while the conventional HRB mixture graded to PG 78-23. This indicates that applying WMA in this manner not only successfully reduced aging of the asphalt binder during production, reducing the need for the typical grade bump required, but produced superior low temperature results than the conventional HRB mixture. Data collected by fitting dynamic modulus master curves from the mixtures produced and rut information generated from plant mix produced samples seem to support the asphalt binder information very well. Further supporting performance testing of fatigue and low temperature cracking susceptibility will be performed to further investigate the relative performance of these mixtures.