TB/T 1878-2002Prestressed concrete sleeper fatigue test methods (English PDF)

2.1 The fatigue test of prestressed concrete sleepers (hereinafter referred to as sleepers)

shall use a fatigue testing machine, which has an accuracy level 1 and a loading vibration frequency between 4 Hz ~ 8 Hz.

2.2 Use a 20X reading magnifying glass, to observe the crack width. The reading accuracy is 0.01 mm; there is lighting equipment.

4.4 Characteristic value rho of fatigue load cycle

4.6 During the fatigue test, attention shall be paid to observe whether the loading meets the requirements of the test pattern; correct it if necessary.

4.7 The fatigue test shall be carried out continuously. If the test is stopped due to irresistible factors in the middle, it shall be subject to the 2 million accumulated fatigues;

it shall be indicated in the report.

4.8 Test results

4.8.1 After the sleeper is unloaded after 2 x 106 fatigue cycles, use a scale magnifying glass, to observe both sides of the test section, within 5 minutes after returning to zero.

The observed position is the position of the outer row of steel wires in the tension area, where the maximum residual crack width shall not exceed 0.05 mm.

4.8.2 After the sleeper has undergone 2 x 106 fatigue cycles, the failure test shall be carried out; its failure strength shall not be lower than 80% of the design failure strength;

the design failure strength shall be given by the design drawing. The sign of the failure state is that the crack width reaches 1.5 mm, OR where there are two or more cracks

AND the maximum crack width reaches 1.0 mm.

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