Small-width tensile test

For soil reinforcement, the prime role of the GTX is to provide structural integrity through its tensile behavior. Thus the load—extension characteristics of the GTX are of paramount importance to soil reinforcement apphcations. Three types of tests used to assess the tensile characteristics of GTX are the small-width tensile test (see Section 7.5.2), the grab test (see Section 7.5.1), and the wide-width tensile test (see Section 7.3.1). 

Wide-width tensile tests provide a better measure of tme tensile strength than small-width tensile tests. The test data are presented in a load per unit width versus strain curve from which the modulus values (Eq. [7.1]) can be calculated. The specimens tested are not confined, as it would be in its end use this test does not result in a tme design value, especially for GTX-N. Nevertheless it is the index test for GTXs (Fig. 7.5). 

This tensile test is used as a control test for the evaluation of durability tests because of the small size of the specimens. The test result as maximum force of the exposed/ immersed specimens is only used relative to the maximum force of the control specimen. There is no simple relationship between small-width tensile tests of fabrics and wide-width tensile tests of GTXs (Table 7.7 and Fig. 7.9). 

Figure 7.9 Small-width tensile test on a nonwoven geotextile. Courtesy SKZ.

Tensile force EN 29073-3 ISO 13934-1 Small-width test Used for durability test ... 

Tensile stress-strain tests give another elastic constant, called Poisson s ratio, v. Poisson s ratio is defined for very small elongations as the decrease in width of the specimen per unit initial width divided by the increase in. length per unit initial length on the application of a tensile load ... 

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