Tensile Testing Machine Trapezoid Tearing Strength of Geotextiles
ASTM D4533 ETM304C
Description: Special grips for geotextiles tensile test
Standard: ASTM D4533
Standard Test Method for Trapezoid Tearing Strength of Geotextiles
- This test method is an index test used to measure the force
required to continue or propagate a tear in woven or non-woven
geotextiles by the trapezoid method. While useful for quality
control and acceptance testing, the trapezoid tear test does not
provide all the information needed for all design applications and
other test methods should be used.
- This test method is applicable to most geotextiles that include
woven fabrics, nonwoven fabrics, layered fabrics, knit fabrics, and
felts that are used for geotextile applications.
- The values stated in SI units are to be regarded as the standard.
- This standard does not purport to address all of the safety
concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and
health practices and determine the applicability of regulatory
limitations prior to use.
Summary of Test Method
An outline of an isosceles trapezoid is marked on a rectangular
specimen cut for the determination of tearing strength, and the
nonparallel sides of the trapezoid marked on the specimen are
clamped in parallel jaws of a tensile testing machine. The
separation of the jaws is continuously increased so the tear
propagates across the specimen. At the same time, the force
developed is recorded. The tearing strength, which is the maximum
value of the tearing force, is obtained from the autographic force
– extension curve.
Report the following:
1. State that the tests were performed as directed in this test
method. Describe the material(s) or product(s) sampled and the
method of sampling used.
2 Report the following information for each swatch in the
2.1 Average of the maximum tearing strengths in newtons (1bf) for
2.2 Number of specimens tested for each direction.
2.3 Coefficient of variation of the observed tearin strength of
individual specimens, if required.
2.4 Condition of the specimens
|Load Accuracy||Better than ±1% of reading|
|Load Resolution||1/350000 of capacity, stepless|
|Extension Measurement Range||0.02%-100%FS|
|Extension Measurement Accuracy||Better than ±1% of reading|
|Extension Resolution||1/500000 of capacity|
|Displacement Measurement Accuracy||Better than ±1% of reading|
|Speed Accuracy||Better than ±1% of setting speed|
|Max. Test Speed||500mm/min|
|Min. Test Speed||0.001mm/min|
|Crosshead Speed Accuracy|
.01mm/min, better than ±0.2% of setting
|Total Crosshead Travel (without grips)||1100mm|
|Effective Test Width||420mm|
|Power Supply||Single phase 220V±10%, 50Hz|