Cost benefit analysis of anti-strip additives in hot mix asphalt with various aggregates.

PDFTech ReportFHWA-PA-2015-004-110204355I01 - 110204Benefit cost analysisAntistrip additivesHot mix paving mixturesAsphalt concreteLife cycle analysisMoisture contentAggregatesPennsylvaniaPennsylvania. Dept. of Transportation. Bureau of Planning and ResearchChristensen, DonaldMorian, DennisWang, WilliamAdvanced Asphalt Technologies, LLCUnited States. Federal Highway AdministrationUS Transportation CollectionThis report documents research on moisture sensitivity testing of hot-mix asphalt (HMA) mixes in Pennsylvania and theassociated use of antistrip. The primary objective of the research was to evaluate and compare benefit/cost ratios of mandatory useof antistrip, and of antistrip usage conditional on the results of moisture resistance testing, based upon life cycle cost analyses. Asecondary objective was to evaluate a unique version of the modified Lottman procedure used in Pennsylvania between 2003 andOctober 2014, which involved a relatively low level of saturation in specimen conditioning. This procedure (low-saturation method)typically results in saturation between about 30 % and 67 %, as compared to the 70 to 80 % required in the test version used byPennsylvania prior to 2003 and after October 2014 (high-saturation method). It was found that the low-saturation method passed allHMA mixes, even those with a documented history of high susceptibility to moisture damage. This procedure therefore had abenefit/cost ratio of zero. For the high-saturation method, it was found that both antistrip usage dependent on the results of testingand mandatory usage for all mixes had benefit/cost ratios that were greater than one and in general much greater than one. Thebenefit/cost ratios for mandatory antistrip usage were greater than those for conditional usage, because of the high cost associatedwith the failure of moisture resistance testing to identify all moisture susceptible mixes