Two data bases provided the statistical information necessary todetermine the precision of individual methods of extraction testingwith various solvents. Results of this investigation showed no statistical difference between either centrifuge, reflux, or vacuum extraction methods, regardless of the type of solvent used for the test.This precision corroborated the statistics reported in astm d2172. Data bases for determining the precision of nuclear asphalt content gauges were created through extensive testing by the university of nevada-reno and round robin testing by eight state laboratories. Results from this testing developed a precision statement for astm d4125(nuclear asphalt content gauges). A coparison between the statistics from traditional extraction methods and the nuclear gauges showedthat when determining the asphalt content of mixtures with absorptive aggregates (absorption capacity greater than 2.5%) The nuclear gauges appear to be significantly more accurate. Further testing with the nuclear gauges indicated three conclusions. First, the sample temperature did not influence test results when included in the software of the gauges. Second, asphalt content could be determined when mixtures contained latex and polyolefin additives. Third, changes in the gauge environment influenced test results. This paper appears intransportation research record no. 1228, Asphalt mixtures and asphalt chemistry.
Abstract