GRI Test Method GM 13 Revision

The latest version of GRI Test Method GM 13 incudes Revision 7, made on February 20, 2006. It added Note 6 on Asperity Height clarification
with respect to shear strength. Note 6 is as follows: The minimum average value of asperity height does not represent
an expected value of interface shear strength. Shear strength
associated with geomembranes is both site-specific and productspecific
and should be determined by direct shear testing using
ASTM D5321/ASTM D6243 as prescribed. This testing should be
included in the particular site’s CQA conformance testing protocol
for the geosynthetic materials involved, or formally waived by the
Design Engineer, with concurrence from the Owner prior to the
deployment of the geosynthetic materials. For the full text of GRI Test Method GM 13, please go to the “continued” link below.