Determination of crushing strength of a compressed duct

A compressed length of 100 mm is cut from a new compressed duct. This test specimen is placed in a suitable testing device to restrain the two extremities and subjected to a constantly increasing test load perpendicular to the axial direction and evenly distributed along its entire length, until the deformation in the direction of the load is equal to 10 % of the external diameter.

The rate of increase of deformation during the test shall not exceed 50 mm/min.

The crushing strength shall be determined from the maximum test load F, that has been reached.