TY - JOUR
T1 - Comparisons between geotextile pore sizes obtained from capillary flow and dry sieving tests
AU - Fatema, Nuzhath
AU - Bhatia, Shobha K.
N1 - Publisher Copyright:
Copyright © 2019 by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959
PY - 2019/7/12
Y1 - 2019/7/12
N2 - In the United States of America, two standard methods of measuring the largest pore size of a geotextile have been accepted: Dry Sieving Test (ASTM D4751, Standard Test Methods for Determining Apparent Opening Size of a Geotextile) and Capillary Flow Test (ASTM D6767, Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test). Despite several drawbacks of Dry Sieving Tests, such as the amount of time required; tendency of glass beads to become trapped, including trapping of glass beads inside the geotextiles; likelihood of imprecise preparation of glass beads; and potential electrostatic effects, the largest pore size (apparent opening size [AOS], O95) results obtained from Dry Sieving Test still determines many filtration criteria. Although the Capillary Flow Test was approved in 2002, it is still not widely adopted, despite the fact that it provides the largest pore size (Bubble Point, O98) and a complete pore size distribution of a geotextile. Decades of analyses searched for a correlation between the Dry Sieving and Capillary Flow Test results; however, none of them have been widely accepted because of the limited number of geotextiles used and a lack of proper calibration. The current study investigates a possible correlation between the Dry Sieving and Capillary Flow Test results with 51 woven, nonwoven, and composite geotextiles. The Capillary Flow Porometer was calibrated using four thin metal plates with known pore openings and two membranes. This study describes the challenges experienced during the Capillary Flow Test and factors affecting the test results. One finding is that the cleaning of calibration materials and equipment with Methanol plays an important role in the Capillary Flow Test results. The use of different shape factors, contact angles, and wetting liquids in the analyses are also considered. The outliers of Capillary Flow Test results were removed from the analysis using a box plot and whisker diagram, and a good correlation between AOS and Bubble Point (R2 = 0.78) was established.
AB - In the United States of America, two standard methods of measuring the largest pore size of a geotextile have been accepted: Dry Sieving Test (ASTM D4751, Standard Test Methods for Determining Apparent Opening Size of a Geotextile) and Capillary Flow Test (ASTM D6767, Standard Test Method for Pore Size Characteristics of Geotextiles by Capillary Flow Test). Despite several drawbacks of Dry Sieving Tests, such as the amount of time required; tendency of glass beads to become trapped, including trapping of glass beads inside the geotextiles; likelihood of imprecise preparation of glass beads; and potential electrostatic effects, the largest pore size (apparent opening size [AOS], O95) results obtained from Dry Sieving Test still determines many filtration criteria. Although the Capillary Flow Test was approved in 2002, it is still not widely adopted, despite the fact that it provides the largest pore size (Bubble Point, O98) and a complete pore size distribution of a geotextile. Decades of analyses searched for a correlation between the Dry Sieving and Capillary Flow Test results; however, none of them have been widely accepted because of the limited number of geotextiles used and a lack of proper calibration. The current study investigates a possible correlation between the Dry Sieving and Capillary Flow Test results with 51 woven, nonwoven, and composite geotextiles. The Capillary Flow Porometer was calibrated using four thin metal plates with known pore openings and two membranes. This study describes the challenges experienced during the Capillary Flow Test and factors affecting the test results. One finding is that the cleaning of calibration materials and equipment with Methanol plays an important role in the Capillary Flow Test results. The use of different shape factors, contact angles, and wetting liquids in the analyses are also considered. The outliers of Capillary Flow Test results were removed from the analysis using a box plot and whisker diagram, and a good correlation between AOS and Bubble Point (R2 = 0.78) was established.
KW - Apparent opening size
KW - Bubble Point
KW - Capillary Flow Porometer
KW - Capillary Flow Test
KW - Dry Sieving Test
KW - Geotextiles
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U2 - 10.1520/GTJ20180203
DO - 10.1520/GTJ20180203
M3 - Article
AN - SCOPUS:85071306703
SN - 0149-6115
VL - 43
JO - Geotechnical Testing Journal
JF - Geotechnical Testing Journal
IS - 4
ER -