AASHTO PP 113-21 PDF Download

AASHTO PP 113-21 is a standard practice that outlines a method for characterizing the relaxation behavior of asphalt binders using the Delta Tc parameter. The standard specifies the use of results from the Bending Beam Rheometer (BBR) test, specifically the stiffness and m-value, to calculate the Delta Tc value. This parameter is used to assess the relaxation properties of the asphalt binder at low temperatures.

The practice is primarily intended for use with asphalt binder residue that has undergone long-term conditioning with T 240 (Rolling Thin-Film Oven) and R 28 (Pressurized Aging Vessel). However, it can also be used with recovered asphalt binder from asphalt mixtures, reclaimed asphalt pavement (RAP), and reclaimed asphalt shingles (RAS).

The main purpose of this practice is to provide insight into the behavior of asphalt binders at low temperatures. By assessing the relaxation properties of the binder, it helps determine to what extent the binder can contribute to non-load related cracking in asphalt pavements. The standard can be used in conjunction with other specifications such as M 320 or M 332, which specify performance-graded asphalt binders and the Multiple Stress Creep Recovery (MSCR) test, respectively.