ASTM D7228-06a (R2020) PDF Download

ASTM D7228-06a (R2020) is a standard test method that provides a means of predicting temperatures within the asphalt-bound layer(s) of a flexible pavement section. The test method is based on temperature relationships developed as part of the Federal Highway Administration (FHWA) Long Term Pavement Performance (LTPP) Seasonal Monitoring Program.

The standard addresses the need to adjust deflection data from asphalt pavements for the effects of pavement surface course temperature. Traditionally, measuring the temperature at depth required drilling holes into the pavement and using handheld devices or permanently installed temperature instrumentation. However, this test method offers an alternative approach that estimates the temperature at depth from the pavement surface temperature, the time of day, the previous day's high and low air temperatures, and the desired depth.

By utilizing this test method, time and resources are saved compared to the conventional practice of manually drilling holes into the pavement. Additionally, it provides a significant increase in the volume of temperature data collected, as it allows for recording temperature variations between test points.