Standard Test Method for Index Puncture Resistance of Geomembranes and Related Products

 

Theory:

ASTM D4833 is used for evaluating the puncture strength of sharp objects such as rocks and stones that rest within soil. This test is typically conducted on geo-textiles which are used in the agriculture industry. Geo-textiles are also used in land reclamation projects as well as for highway and road construction. The material is used to maintain a barrier and prevent the soil from washing away during torrential rain.

 

There is some minor variability in this test based on where exactly the chamfered probe contacts the fabric. Therefore ASTM D6241 is commonly used as a replacement and involves a wider 50mm round puncture implement. Other puncture tests that seek to characterize similar properties are the ball burst test under either ASTM D3787 or ASTM D6797. 

Geometry:

There are two key elements to this procedure. The first is the geometry of the puncture implement which is 8mm in diamater with a 45 degree beveled or chamfered edge.  The second is the size of the open hole in the clamping jig.  Please see our literature below for more info on the exact construction of the fixture.

Solution:

The clamping jig and puncture implement are available as a package. They use a standard 1.25 inch or 5/8" adapter to attach to the top and bottom of the testing machine. It is vitally important that the user pre-specifies enough capacity so that the test actually achieves full puncture and the proper calculations can be made. 

Analysis:

There are several calculations that are common across most puncture tests. They include the average puncture stength which is an average of the peak load across multiple specimens of the same type of sample. An average must be taken because textiles are non uniform based on their woven stricture. Other calculations are centered around the variability and deviation between tests.