ISO 22074-3:2021 Railway infrastructure — Rail fastening systems — Part 3: Proof load test method for pull-out resistance

ISO 22074-3:2021 Railway infrastructure — Rail fastening systems — Part 3: Proof load test method for pull-out resistance. 5 Apparatus 5.1 Actuator, capable of applying an upward force of at least 25 % more than the specified proof load to an insert. A linkage shall he provided between the actuator and the fastening component which ensures that the vertical force is applied directly above the part of the component which is anchored to the sleeper or support without applying unrepresentative flexural or torsional moments to any component. 5.2 Force measuring instruments, which shall conform to ISO 7500-1:2018, class 2 over the required range of force. 6 Test specimens 6.1 Rail support For sleepers or bearers, the test specimen shall consist of a sleeper or half sleeper (or bearer) with cast- in or glued-in fastening components or holes and rail seats as made without modification for this test. For applications in ballastless track where sleepers are not used, a representative section of the support (e.g a concrete block) shall be used which has a depth equal to the depth of the proposed supporting element. If that dimension is not known, the block shall have a depth: — great enough to avoid a bending failure of the concrete during the test; and — not less than the embedded length of the insert plus 15 mm. In plan view, the support used in the test may be of any shape but it shall: — extend at least 150mm from the centre line of the insert in all directions; or — replicate the distance from the insert to the edge of the supporting element in track if that is less than 150 mm. If a concrete block is used, it shall have a cube strength not greater than the cube strength of the concrete specified for application in the track. It shall also not contain steel reinforcing elements close to the fastening unless they are present in the application in the track. If it does contain steel reinforcing. there shall be at least 15 mm of concrete covering the steel. 6.2 Fastening components The test specimen shall consist of an insert as made and without modification for the test. For inserts intended to receive a screw, the load shall be applied to the insert through a screw from the fastening system, inserted to the design depth. For fastening systems in which the design depth...