BS 6906-2 Geotextile Apparent Pore Size Distribution Test apparatus, Dry sieving method

BSI - BS 6906-2 Methods of Test for Geotextiles Part 2: Determination of the Apparent Pore Size Distribution by Dry Sieving

1, What's apparent opening size (Apparent Pore Size Distribution)?  

The apparent opening size refers to the size of openings in geotextiles that allow water to pass through. It affects the rate of water flow, the effectiveness of filtration, and the stability of soil. The smaller the effective aperture, the better the filtration effect, but water permeability may decrease; conversely, if the effective aperture is too large, it may lead to the loss of soil particles. Therefore, a reasonable effective aperture value is crucial for the selection and application of geotextiles.

2. The Principle and Process of Dry Sieving Method

The dry sieving method is a commonly used technique for determining the opening size of geotextiles. It involves screening standard particles of different sizes to observe the flow of water through the geotextile and thus determine its opening size. 

The specific steps are as follows: 

2.1. Prepare the sample: Choose the geotextile sample to be tested, cut it into a standard size, typically 200mm x 200mm.

2.2. Select standard particles: Based on the characteristics of the geotextile, select standard particles of different size ranges (such as quartz sand), ensuring these particles are evenly distributed and have suitable shape and density.

2.3. Dry sieving experiment:- Place the geotextile sample on the screen of the dry sieve machine, ensuring the sample is fully spread out and free of wrinkles.- Evenly sprinkle the standard particles on the geotextile and start vibrating the sieve machine to allow particles to be screened through the geotextile.- Record the number of particles passing through the geotextile according to a preset time, and analyze the quantity and distribution of particles that remain after passing through.

2.4. Data analysis: Based on the screening results, use formulas to calculate the effective aperture and compare it with the standard values to assess the testing result of the geotextile.

3. Advantages of the Dry Sieving Method

As an important method for determining the effective aperture of geotextiles, the dry sieving method has several notable advantages:- Simplicity: The dry sieving method is easy to operate, requires low equipment standards, and is easy for users to master.- Intuitive and reliable: Through visual observation and data recording, the dry sieving method can intuitively derive the filtration performance of geotextiles.- Wide applicability: The dry sieving method is suitable for various types of geotextiles, particularly non-woven fabrics and woven geotextiles.

Beijing United Test Co.,Ltd. export@unitedtest.com offer the Dry sieving method geotextile fabric apparent Opening Size Test. Contact us now : export@unitedtest.com, unitedtest@hotmail.com