Abstract
The federal highway administration's study to identify the changes in asphalts as it is mixed with aggregate during drum-dryer and batch mixing operations is reported. The details of the study are described and the results are tabulated and discussed. It was found that steam distillation of asphalts is not occurring in drum-dryer operations. The revolving forced air distillation- (rfad), thin film oven- (tfo), and rolling thin film oven (rtfo)-condiditoned asphalts appear to have the most properties similar to those of the recovered asphalts than those of the asphalts from steam distillation. These and other conclusions drawn from the tests are discussed.