This test method outlines the procedure for measuring the apparent viscosity of hot-poured asphalt crack sealant at elevated temperature from 150° to 200°C using a rotational viscometer as specified by AASHTO MP 25 and PP 85.

The rotational viscometer is a rotating spindle-type viscometer that meets the requirements of AASHTO T 316. This test method can be used for general specification and is especially convenient for use in a field laboratory or a plant site.

Viscosity data obtained with this test method are used to ensure that the hot-poured asphalt crack sealant’s apparent viscosity is low enough to fill cracks and, at the same time, high enough not to flow out of the crack. Ideally, the shear rates during the test should match the shear rates the hot-poured asphalt crack sealant experiences during installation. The rotational speed of the spindle was selected at 60 rpm to resemble field pouring conditions. Changing spindle sizes and rotational speeds affect both the shear rate and the measured apparent viscosity.

This standard was formerly designated as provisional standard TP 85.