AASHTO M 190:04(2017) Standard Specification for Asphalt-Coated Corrugated Metal Culvert Pipe and Pipe-Arches.
7.3. Physical requirements of the coating.
7.3.1. Shock Test—The apparatus for making the test consists of a rigid metal anvil or base plate not less than 12.7 mm thick resting on a solid foundation; a 2000-g hammer arranged to fall freely in suitable guides against a 1000-g plunger sliding freely in a vertical sleeve; the lower end of the plunger being spherical in shape with a radius of 12.7 mm; means for raising the hammer and dropping it through a distance of 130 mm upon the head of the plunger. Four test specimens shall be prepared in the form of disks 44.5 mm in diameter and 9.5 mm thick. Approximately 110 g of the asphalt sample shall be heated over a low flame until it becomes fluid and then poured into a brass mold or molds. Care must be exercised to melt the sample at the lowest possible temperature and to stir thoroughly until it is homogeneous and free from air bubbles. The test specimens may be molded separately or the material may be poured in one cylinder 44.5 mm in diameter and of such length that the four specimens may be cut from it with a wire cutter.
Split brass molds, coated with a suitable release agent (Note 1) having an inside diameter of 44.5 mm. slightly tapered outside surfaces, and held together by slip rings will be found suitable for molding the test specimens. If disk molds are used to prepare the specimens. they shall be removed after the asphalt has cooled to room temperature. The four specimens shall be cooled for a period of at least 1 h in a bath of ice and salt brine at a temperature of —1°C. The specimens shall then be removed from the bath one at a time and quickly placed on the anvil of the test apparatus and centered under the plunger. the hammer tripped to fall through a height of 130 mm upon the head of the plunger. AASHTO M 190 pdf download.