Bentonite waterproof blanket permeability tester

The bentonite waterproof blanket permeability tester measures the permeability coefficient of these impermeable mats under set pressure and time. Under a certain pressure difference, the mat allows minor seepage. By gauging the seepage flow and sample thickness within a specified time under given pressure, the permeability coefficient can be calculated.

Application:

Used to determine the permeability coefficient of bentonite waterproof blanket under specified pressure and time conditions. The bentonite waterproof blanket will produce small seepage under a certain pressure difference, and the permeability coefficient can be calculated by measuring the seepage flow and the thickness of the sample within a certain time under the specified hydraulic pressure difference.

Standard:

SL/T 235-30-2012: Specification for test and measurement of geosynthetics

JG/T 193- Appendix A-2006: Appendix A: Test method for water permeability of sodium bentonite geosynthetic clay liner (equivalent to ASTM D5084-1990)

GB/T 35470- Appendix B-2017: Appendix B: [Specific test method or additional requirements for rail transportation applications]

JC/T 2054- Appendix A-2020: Appendix A: [Specific test method or additional requirements for natural sodium bentonite impermeable liner]

ASTM D5887-1999: Standard Test Method for Measurement of Index Flux Through Saturated Geosynthetic Clay Liner Specimens Using a Flexible Wall Permeameter

Features:

Using 1+2 mode, it can provide a single station machine and a 2 station auxiliary machine;

The table is made of stainless steel, clean appearance, good water resistance, no rust;

Test through pressure loading, no need to connect to electricity, safe and reliable;

Adopt imported high-precision pressure regulator, the pressure regulation is accurate and stable, to ensure the experimental requirements;

The loading circuit design is reasonable, and the valve switch adjustment is simple;

The measurement accuracy was improved to 0.05m1.

The integrated vacuum device makes it easier to vacuum during sample preparation and testing;

Add negative pressure degassing device, so that the water entering the sample is degassing water, the test result is more accurate; :

The test chamber can be moved to make the operation more flexible;

The main use of two-position valve, instrument operation is simpler;

The automatic test interface is reserved, which can be more convenient to obtain pressure reading and automatic measurement by adding an automatic test device.

Parameters:

Accessoriess

Main unit: 1 set

Packing list: 1 copy

Product manual: 1 copy

Product certificate of conformity: 1 copy

Test Procedures

Sample Preparation: Cut a sample with a diameter of 70 mm ± 2 mm.  Place filter paper, the sample, and another piece of filter paper sequentially on a permeable stone. Then place another permeable stone on top and install the top cover. Place a flexible film around the sample and install an "O" ring seal.

System Filling and Degassing: Fill the permeation chamber with water, connect the water supply chamber and the permeation chamber with tubing, and apply a pressure of 7 KPa to 35 KPa to the permeation chamber to allow water flow. Open the vent valve to release any visible air bubbles.

Saturation Treatment: Adjust the initial pressure in the permeation chamber to 35 KPa, and the initial back pressure at the top and bottom of the sample to 15 kPa. Slowly increase the pressure and maintain it for 48 hours to saturate the sample.

Permeation Test: Increase the pressure at the bottom of the sample to 30 KPa. After the pressure stabilizes, measure the flow rate through the sample and the water pressure difference across the sample every hour.

Termination Conditions: The experiment is terminated when the number of tests within 8 hours is ≥ 3. and the ratio of inlet flow to outlet flow in the last three consecutive tests is between 0.75 and 1.25. with no significant upward or downward trend in flow values.

Data Recording: Remove the sample, measure and record its height and diameter, and calculate the permeability coefficient.