TC-Hydraulics Workshop – Recent Advances in Geotextile Filtration Design: Pore Opening Size Measurement using a Porometer or an Optical Test
This 90-minute webinar will introduce techniques available to measure the opening size of a geotextile. This property has historically been measured using ASTM D4751, which involves dry sieving of glass beads through a dry geotextile. However, the opening size can also be measured using a capillary flow test, or, in the case of very thin geotextiles, by optical measurements. Both techniques provide a reliable AOS much quicker than the traditional dry sieving technique and are often used in Manufacturing Quality Control as a replacement to dry sieving.
Key limitations of the traditional, dry sieving technique will first be introduced, with an emphasis on the documented repeatability issues experienced with the test. The capillary flow test will then be discussed, as a means to determine the AOS, as well as the entire pore size distribution of a geotextile and it’s permeability. Finally, the optical technique used for knitted geotextiles and thin heat-bonded geotextiles will be introduced. In both cases, the results obtained with the innovative technique will be compared to the traditional AOS test.