PD 6533:1993

Describes both index and performance tests, that are currently available or under development, for the principal forms of degradation of geotextiles.

This document describes tests for the principal forms of degradation. The long-term effect of mechanical load on its own, i.e. creep and creep-rupture, is excluded and the reader is referred to BS 6906 : Part 5. In each case, an index and a performance test are defined. The index test is intended as a short, tightly defined, hopefully cheap test that can be applied to all types of geotextiles for screening, ranking and classification. In order to achieve this end, the method may differ considerably from real service conditions. In many cases, however, it will be necessary to carry out further tests more closely related to service conditions using, for example, soil extracted directly from site. Such ‘performance’ tests are only described in outline and may be more complex and expensive.

NOTE. Many of the test methods described are currently under discussion in both European and International Standards Committees. It is anticipated that the tests, once agreed, will be used for interlaboratory trials and for comparison with service conditions. As a result of these trials, modifications to the tests are expected, together with improved guidelines for interpretation. As in other fields of engineering, confidence in the durability of geotextiles can only be expected to develop gradually as the technology matures and the results of long-term service experience accumulate.