1. Test equipment and sample preparation
First, suitable testing equipment is required, and a universal material testing machine is usually used to conduct compressive strength testing. In terms of sample preparation, cutting should be carried out according to relevant standards. The sample of EPS molded polystyrene insulation board should be square or circular, with a side length or diameter of generally 50mm or 100mm, and a thickness equal to the original thickness of the insulation board, and the two pressure surfaces of the sample should be flat and parallel. For specimens cut from large insulation boards, ensure that the cutting process does not cause damage to the internal structure of the specimen to ensure the accuracy of the test results.
2. Test environmental conditions
Test environmental conditions have a significant impact on measurement results. It is generally required to conduct testing in a standard laboratory environment, with the temperature usually controlled at (23±2)°C and the relative humidity at (50±5)%. This is because the performance of EPS molded polystyrene insulation board will change with changes in temperature and humidity. Testing under specified environmental conditions can make the results comparable and repeatable.
3. Loading speed and testing process
Loading speed is an important parameter for measuring compressive strength. For EPS molded polystyrene insulation board, the loading speed is usually set to a relatively slow speed, such as 10% ± 5% of the sample thickness per minute. During the test, place the sample between the upper and lower pressure plates of the universal material testing machine, ensure that the center of the sample is aligned with the center of the pressure plate, and apply pressure to the sample at a uniform loading speed until the sample is destroyed. The testing machine can record the applied pressure and the deformation of the specimen in real time.
4. Calculation of compressive strength
The compressive strength is calculated based on the data obtained during the test. The compressive strength is equal to the maximum pressure endured by the specimen when it fails divided by the stress area of the specimen. The force-bearing area is calculated according to the corresponding geometric formula according to the shape of the specimen (square or circle). Through multiple measurements (generally no less than 5 samples), the average value is taken as the compressive strength value of EPS molded polystyrene insulation board, which can reduce test errors and improve the accuracy of the results.
5. Consideration of influencing factors
When measuring compressive strength, there are some influencing factors that need to be considered. For example, the density of EPS molded polystyrene insulation board has a greater impact on its compressive strength. The higher the density, the higher the compressive strength is usually. In addition, factors such as the production process of the insulation board, the quality of the raw materials, and whether there are defects will also affect the measurement results of the compressive strength to a certain extent. Therefore, during the test process, these factors must be comprehensively considered to comprehensively and accurately measure the compressive strength of EPS molded polystyrene insulation board.
