Field test of a polyphosphoric acid (PPA) modified asphalt binder on Rt. 1 in Perry : [second interim report, April 2012].

PDFTech Report42960Phosphoric acidAsphalt pavementsBindersField testsSuperpaveHot mix paving mixturesPavement performanceRuttingCrackingMaineMaine. Dept. of TransportationThompson, BillMaine. Dept. of Transportation. Transportation Research DivisionUS Transportation CollectionThe Maine Department of Transportation (MaineDOT) uses the Superpave hot mix asphalt process andspecifies asphalt binder grades using the Performance Grade criteria. The Department mainly uses asphaltbinder grade PG64-28. This is an asphalt binder material that passes the performance tests for hightemperatures (rutting potential) at 64 degrees Celsius and passes tests for low temperatures (thermalcracking) at 28 degrees Celsius. It is widely recognized in the industry that the addition of polyphosphoricacid to asphalt can increase the high temperature PG grade to the next higher grade. However, there areconcerns among transportation agencies that this PPA could alter the long term performance of the asphaltbinder. One of the major asphalt suppliers to MaineDOT paving projects uses PPA to alter their PG58-28neat asphalt binder into a PG64-28.This experimental construction study was established to field test the long term performance of the PPAmodified PG64-28 and compare it to the PG58-28 neat asphalt binder.A highway reconstruction project, NH-1000(800)E, along Rt. 1 in Perry, Maine was selected as a suitablesite for this comparison