AASHTO T 305-14 (2018) PDF Download

The AASHTO T 305-14 (2018) standard outlines a procedure for measuring the amount of draindown in an uncompacted asphalt mixture sample. Draindown refers to the separation of asphalt binder from the aggregate particles in the mixture, which can result in reduced performance and durability.

The test method involves subjecting the asphalt mixture sample to elevated temperatures that simulate the conditions encountered during production, storage, transport, and placement of the mixture. This is important because these conditions can influence the degree of draindown that occurs in the mixture. The standard is particularly applicable to porous asphalt and Stone Matrix Asphalt (SMA), which are types of mixtures prone to draindown issues.

By quantifying the amount of draindown in the asphalt mixture, this standard provides a means for evaluating the material's performance and determining the need for adjustments in the mixture design or construction process. This information can be valuable in ensuring the long-term durability and functionality of the asphalt pavement.