This report examines the use of the asphalt ignition oven temperature-time series generated
during the asphalt content by ignition test method in identifying erroneous test results. The study
was undertaken to provide an empirical tool for asphalt laboratory staff in troubleshooting and
validating asphalt content test results.
Results of the data analysis show that some variations in testing procedure can be identified
through the temperature-time series. In particular, the first tests performed each day are readily
discernable from subsequent tests, even after allowing significant oven warm-up time.
Variations in sample size or asphalt content are also shown to create differing temperature-time
series; however, the difference is not significant enough to identify errors on individual tests, it is
only demonstrable across the group averages. Despite the differences in temperature-time data,
no conclusive difference in the accuracy of the test results was found.
It is concluded that the monitoring of the temperature-time series may be a valuable tool in
identifying systematic and gross errors introduced during the asphalt content by ignition test
method. However, while the preliminary results of this study demonstrate that differences do
exist, additional testing should be undertaken to assess the reliability of the proposed method
under real-world scenarios. Additional trials will also be required to identify any other procedural
variations which result in differences in the temperature-time trend.
