the panels to be seamed shall not damage the Geomembrane or adversely
affect the seaming operation. The top Geomembrane of the seam overlap shall
be beveled and the extrusion apparatus shall be purged of heat-degraded
extrudite before seaming.
Should wrinkles occur, a cut shall be made along the ridge of the wrinkle and
laid flat so the edges of the material overlap. The overlap shall be extrusion-
seamed and any portion of the seam with less than 3 inches of overlap shall be
patched with a circular or oval patch extending a minimum of 6 inches beyond
the cut in all directions.
All T-seams and air testing needle holes are to be capped with a circular or oval
patch extending a minimum of 6 inches beyond the spot weld in all directions.
The Installation Contractor shall log the ambient air temperature 6 inches
above the Geomembrane elevation, extruded temperatures in extrusion
equipment barrels and nozzles, and operating temperatures of hot wedge
seamers at intervals specified by the CQA Consultant.
The Installation Contractor shall visually inspect seams and panels for holes,
crimps, abrasions, or defects, and shall mark each suspect location. All repair
locations shall be assigned an appropriate identifying label that shall be clearly
marked on the panel adjacent to the repair location and shall be shown on the
as-built drawings. Each marked location shall be repaired, non-destructively
tested, and recorded on the as-built drawings. No repairs shall be covered
until passing results of non-destructive tests are achieved and accepted by the
CQA Consultant.
Methods of repair shall consist of spot welding small tears or over-abraded
areas where thickness of the Geomembrane was reduced by more than 6 mils
(0.006 inches) abrading and re-welding small sections of defective extrusion
welds and removing a defective seam and replacing with a new strip of
material. The surface of the Gcomembrane in the seam/repair area shall be
abraded no more than one hour before the repair is made. All GGomembrane
surfaces shall be cleaned and dried at the time of the repair. Patches over
larger holes and 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.
3.5 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.
File No. 3066.09.00 Geomembrane 02550 - 10 of 14 December 2017
