Standard Method of Test for Determining the Indirect Tensile Nflex Factor to Assess the Cracking Resistance of Asphalt Mixtures

Abstract

This test method covers the determination of cracking resistance of asphalt mixtures using the indirect tensile (IDT) geometry at 25℃.

The Toughness (area beneath the stress-estimated strain data) and Brittleness Slope (post peak stress-estimated strain rate) are used to calculate a parameter referred to as the Nflex factor, which may be a useful indicator of load-related cracking of asphalt pavement layers.

This procedure applies to test specimens having a nominal maximum aggregate size (NMAS) of 19 mm or less.

Lab compacted specimens or field core specimens can be used.

This standard does not purport to address all of the safety concerns, if any, associated with its use.

It is the responsibility of the user of this standard to establish and follow appropriate health and safety practices and determine the applicability of regulatory limitations prior to use