Experimental Procedure:

1. Selection and preparation of samples

According to the standard GB/T13760, when selecting samples, the first two layers of the roll should not be taken as samples. During and after sampling, it is important to ensure that the physical state of the sample has not changed prior to testing.

Cut 10 circular specimens with a diameter of 100mm uniformly from the selected samples in the length and width directions, ensuring a distance of at least 100mm from the edge of the sample. If the sample is not cut temporarily, it should be stored in a dry, clean, and dark place.

2. Humidity control of the sample

Dampen the sample and conduct the test under the conditions of relative humidity of 65% ± 5% and temperature of 20 ℃± 2 ℃. When the mass change of the sample during continuous weighing with an interval of at least 2 hours does not exceed 0.25% of the sample mass, it can be considered that the sample has been humidified.

It should be noted that if it can be demonstrated that the test results are not affected by relative humidity, humidity control and testing may not be carried out under the specified relative humidity conditions. The sample used for wet state testing should be immersed in water at a temperature of 20 ℃± 2 ℃ (or 27 ℃± 2 ℃) for at least 24 hours and sufficient to keep the sample moist. To keep the sample moist, a non-ionic neutral wetting agent not exceeding 0.05% can also be added to the water.

3. Installation fixture

Install the top rod and fixture base on the testing machine, ensuring that the fixture is on the axis of the top rod.

4. Set up the instrument

Select the range of the force so that the output value is between 10% and 90% of the full range. Set the operating speed of the testing machine to 300mm/min ± 10mm/min.

5. Clamp the sample

The sample is fixed on the ring fixture without tension or wrinkles, ensuring that the sample does not slip, and the ring fixture holding the sample is placed on the test bench. For wet samples, the test shall be conducted within 3 minutes after removal from water.

6. Determination of puncture strength

Start the testing instrument until the sample is punctured, and record the maximum value during the testing process as the puncture strength of the sample, measured in Newtons (N). For geotechnical composite materials, in the case of bimodal values, regardless of whether the second peak is greater than the first peak, the first peak is used as the puncture strength of the specimen. If the yarn slips out of the ring fixture or the sample slips during the test, the test data should be discarded and another sample needs to be taken for measurement.

7. Calculate

Calculate the average puncture strength of 10 samples, and the result needs to be rounded to three significant figures according to standard regulations. If the unevenness of the test results is large, the number of samples can be increased. If necessary, calculate the coefficient of variation of the puncture strength and round it to 0.1% according to the specified results.