Historical Development of Asphalt Content Determination by the Ignition Method

Abstract

This study was conducted to develop a reliable, detailed test procedure for determining asphalt cement (AC) content by the ignition method. The goal was to minimize the overall test time as well as technician time, and to produce a test method with acceptable accuracy. A detailed test procedure for the ignition method was developed based upon previous laboratory studies at the National Center for Asphalt Technology. Using the developed test procedure, an extensive evaluation of the ignition method was performed in the laboratory on mixtures with differing mixture properties (i.e. aggregate type, gradation, and AC content). The purpose of the laboratory investigations was to determine the accuracy of this test method for AC content and gradation determinations. The ignition method, centrifuge extraction method, and nuclear asphalt content (NAC) gauge were evaluated on five construction projects within the state of Alabama. The test procedure was modified based on this study to improve the accuracy and to reduce test time.