ASTM D4595 – Standard Test Method for Tensile Properties of Geotextiles by the Wide-Width Strip Method

Wide-Width GeoTextiles

ASTM D4595 – This test method covers the measurement of tensile properties of geotextiles using a wide-width strip specimen tensile method.

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 application.

This test method covers the measurement of tensile strength and elongation of geotextiles and includes directions for the calculation of initial modulus,

offset modulus, secant modulus, and breaking toughness.

Procedures for measuring the tensile properties of both conditioned and wet geotextiles by the wide-width strip method are included.

The basic distinction between this test method and other methods for measuring strip tensile properties is the width of the specimen.

This width, by contrast, is greater than the length of the specimen.

Some fabrics used in geotextile applications have a tendency to contract (neck down) under a force in the gage length area.

The greater width of the specimen specified in this test method minimizes the contraction effect of those fabrics and provides a closer relationship to expected

geotextile behavior in the field and a standard comparison

ASTM D4595 – Geometry

The specimen for this test is 8×8 and the procedure necessitates that the entire textile strip be secured within the grips.

ASTM D4595 – Significance and Use

The determination of the wide-width strip force − elongation properties of geotextiles provides design parameters for reinforcement type applications, for example design of reinforced

embankments over soft subgrades, reinforced soil retaining walls, and reinforcement of slopes.

When strength is not necessarily a design consideration, an alternative test method may be used for acceptance testing. T

est Method D 4595 for the determination of the wide-width strip tensile properties of geotextiles may be used for the acceptance testing of commercial shipments of geotextiles

but caution is advised since information about between-laboratory precision is incomplete

ASTM D4595 – Solution

Extra wide grip faces are required for this test.

The standard specification requires the whole 8×8 strip to be fixtured within the workholding jig.

A set of 8×3 grip faces are shown in the video which are used in conjunction with a hydraulic grip setup.

Analysis

Sample calculations for ASTM D4595 are typically specified by the percent strain and pulled at 25mm/min.

Strain is another term for elongation and standard delineations occur at 1, 2, 5, and 10%.

Most fabrics have a bit of slack within the weaving and therefore do not experience full tensile stress until about 5% total elongation.