Standard Test Method for Determination of External Loading Characteristics of Plastic Pipe by Parallel-Plate Loading
ASTM D2412 is used to determine pipe stiffness and to characterize the material behavior of plastics in pipe form. There are many different materials that are used to make pipes so it is important to define this test as only covering thermoplastic resin pipe, reinforced thermosetting resin pipe (RTRP), and reinforced polymer mortar pipe (RPMP). Any other type of pipe such as PVC is not specifically covered under this test, however ASTM D2412 is used as a stand-in procedure and is back-referenced in many similar ASTM tests for hollow tubes and pipes.
The pipe is compressed between two platens in order to gather load-deflection data. Load measurements are taken at constant intervals.
Pipes tested under ASTM D2412 must be smaller than the envelope of the two compression platens by at least a half an inch. Square or circular platens can be used, with most customers choosing a square platen. Care must be taken to account for the mid-section of the pipe which will expand slightly as the pipe is compressed.
Compression platens are used for D2412. A compression cage can be use for tension only testing machines in order to convert the tensile force into a compressive force.
A spherically seated compression platen can be used in order to normalize the vector of compression. The platen has a spherically seated joint that wobbles slightly and lines up the load force on the pipe specimen.
Calculations for ASTM D2412 include percentage load deflection, pipe stiffness, and the stiffness factor. These calculations are made by taking load measurements at certain percentage deflections (5%, 10%, 20% etc.) and dividing the numbers into each other using the mathematical formulas from the official publication.
ASTM D695 - Compression Properties of Rigid Plastics
ASTM F2435 - Steel Reinforced Polyethylene (PE) Corrugated
ASTM C497 - Concrete Pipe External Load Crushing Strength