Precision and Accuracy of the Ignition Method for Determining Asphalt Content: Florida Round-Robin Study

Abstract

To implement the ignition method for both quality control and acceptance purposes in Florida, the State Materials Office of the Florida Department of Transportation (FDOT) carried out a round-robin study to determine the precision and accuracy of this procedure for local conditions. Twelve materials laboratories, including both public and private sectors throughout Florida, participated in the investigation. Each of the 12 participant laboratories received a total of 36 hot-mix asphalt (HMA) mixture samples for asphalt content determination and gradation analysis. Samples were prepared in accordance with FDOT specifications with six different types of aggregate and one type of asphalt cement. Six laboratories used one ignition tester brand and the remainder used a tester from a different manufacturer. The testers, similar in nature, both include an internally mounted load cell and an automated system for data collection and processing. The interlaboratory test data were collected and analyzed at the FDOT State Materials Office. The round-robin test program is described and the accuracy and precision of the ignition method on materials commonly used in HMA construction in the state of Florida are discussed.