Evaluation of Asphalt Cement Characteristics and Field and LaboratoryPerformance of High RAP Warm Mix Asphalt Using Hypertherm? WMA Technology

摘要

During a reconstruction project on New Brunswick Rte 10, a 1-km trial section was paved with a 30rnpercent RAP mixture utilizing a PG 58-28 asphalt cement and Hypertherm? Warm Mix Asphalt (WMA)rnadditive, while the remaining project length was paved with hot mix asphalt incorporating virgin PG 52-rn34 binder and 30 percent RAP.rnCharacterization of asphalt cement extracted from the two plant-produced mixes showed extremelyrnencouraging results. The WMA asphalt cement graded to PG 67-27, while the conventional mixturerngraded to PG 78-23. The addition of Hypertherm reduced the aging of the asphalt binder duringrnproduction, thereby reducing the need for the typical grade bump and producing superior low temperaturernresults than the conventional mixture.rnComparison of dynamic modulus master curves and resilient modulus tests on the mixtures showed littlerndifference. Rut testing and indirect tensile data, further support the binder conclusions performing as wellrnor better than the conventional mixture. Preliminary Fracture Life analysis in indirect tensile fatigue showsrna contrastingly inferior relationship to the conventional mixture. Further testing of low temperaturerncracking susceptibility will be performed to further investigate the relative performance of these mixtures.