ASTM D8237-21 PDF Download

ASTM D8237-21 is a standard test method that provides a procedure for determining the fatigue failure of asphalt-aggregate mixtures using the four-point beam fatigue device. The test results obtained from this standard can be used to estimate the fatigue life of asphalt mixture pavement layers under repeated traffic loading.

The standard specifies that laboratory properties of the asphalt mixtures, along with an estimation of the strain level induced at the layer depth by traffic wheel loads, are necessary for accurately predicting the field performance of asphalt mixtures. It is important to note that field performance is impacted by various factors such as traffic variation, loading rate, climate variation, rest periods between loads, and aging.

The quality of the results produced by this standard is dependent on the competence of the personnel performing the procedure and the calibration and maintenance of the equipment used. Compliance with a specification such as D3666 is recommended to ensure reliable results, but it does not guarantee complete reliability. Following the suggestions of such specifications provides a means of evaluating and controlling some of the factors that affect the reliability of the test results.

The standard outlines the procedure for determining a fatigue curve using three or more strain levels. The resulting data can be used in fatigue models for mechanistic-empirical pavement design. Failure points are determined for estimating the fatigue life of asphalt mixture beam specimens that are 380 mm long, 50 mm thick, and 63 mm in breadth. The standard recommends an optimal nominal maximum aggregate size (NMAS) of 19 mm for beams that are 50 mm thick. Beams made with an NMAS greater than 19 mm may interfere with the material response and affect the repeatability of the test.

Note that the standard includes references to additional notes and footnotes that provide explanatory material. These notes and footnotes, excluding those in tables and figures, are not considered requirements of the standard.