3.5
other defects shall extend a minimum of 6 inches beyond the edges of the defect.
All corners of patches shall be rounded with a radius of at least 3 inches.
TRIAL SEAM TESTING
A.
Trial seams shall be performed with each seam welder at the beginning (start of
shift) of each day, and at the beginning of each period after which the welder has
been turned off or disconnected from its power supply, or has been idle for 30
minutes (extrusion welder) or 60 minutes (hot wedge welder), and after any
change in operator personnel on a welder, after 5 hours of continuous seaming,
or at any other time deemed necessary by the CQA Consultant.
The Installation Contractor is responsible for providing and operating an on-site
tensiometer and corresponding sample cutting equipment to perform all trial
and field seam testing.
Trial seams shall be produced under the same physical conditions as production
seaming.
Trial seam sample testing:
1. Trial seams shall be a minimum of 5 feet long and 12 inches wide
(perpendicular to the seam).
2. One-inch wide samples shall be cut perpendicular to the seam and tested
according to ASTM D6392 in a tensiometer for bonded seam strength
(shear) and peel adhesion.
3. Two (2) samples will be tested for shear and peel (4 peel tests total for
fusion welds as both edges of the weld must be tested). All tests must pass
for an acceptable trial seam.
4. Each sample failure must consist ofa ductile break that is film tearing bond
and must meet the strength requirements of the following table:
Property Test Method Minimum Value
Peel Strength Fusion ASTM D6392 60 lb/in
Peel Strength Extrusion ASTM D6392 52 lb/in
Shear ASTM D6392 80 Ib/in
If a trial seam test fails, then another trial seam shall be performed and tested.
If the second trial seam fails, then the seam welder shall not be used until it is
repaired or faulty conditions are corrected, and two trial seams pass the
destructive tests.
A record of the date, time, ambient weather conditions, test results, operator,
and equipment number shall be kept by the Installation Contractor, and
submitted to the CQA Consultant.
File No. 3066.21 Geomembrane 02550 - 8 of 10 January 2021
