The sodium bentonite components shall be 90 percent montmorillonite (from
Wyoming) and shall be applied to the base carrier sheet at no less than 1
pound/square foot.
Carrier sheets shall be woven polypropylene (3.1 0z/yd? minimum), and
nonwoven polypropylene (6 oz/yd2 minimum).
The sodium bentonite shall have a permeability no greater than 5x10-? cm/sec
at 5 psi confining pressure and 2 psi head.
PART 3 - EXECUTION
3.1
INSTALLATION
A.
GCL shall be installed in accordance with the manufacturer's
recommendations, and as shown on the Drawings and specified herein.
GCL shall be deployed over prepared and approved subgrade as soon as
practicable after completion of subgrade preparation. The material shall be
placed so as not to cause subgrade disturbance with the carrier side in contact
with the Drainage Sand. GCL shall not be deployed through standing water or
during rainfall. Care shall be exercised to ensure that no large stones or foreign
objects are trapped beneath the GCL.
CONTRACTOR shall only deploy GCL in an area that can be completed in one
day. Completion includes deploying, seaming, and covering with
Geomembrane. If inclement weather is approaching or is present, no
additional GCL shall be placed until the previously placed GCL is covered with
Geomembrane and seamed. GCL that becomes wet and hydrates shall be
removed and replaced at the discretion of ENGINEER at no additional cost to
OWNER.
Adjacent sheets of GCL shall be overlapped a minimum of 6 inches. A
continuous bead of granular sodium bentonite shall be applied between all
overlapping edges of material. On sideslopes, seams shall be perpendicular to
the contours. Seams shall be made in accordance with the manufacturer's
recommendations. Wrinkles and creases shall be removed from a sheet prior
to deploying and overlapping the adjacent sheet. CONTRACTOR shall clean all
dirt and debris from contacting surfaces.
Where cuts are required during installation, the exposed surfaces shall receive
powdered bentonite and be slightly hydrated.
All holes, tears, and cuts in the GCL shall be recorded and repaired in
accordance with the manufacturer's recommendations or as specified by
ENGINEER.
[END OF SECTION 02530]
P:\3000s\3066.09\Source Files\Type II App\Specifications\ Division 2 Specifications\02530 GCL.docx
Filo Na 2N6A NG Gensunthetir Clay Liner A292N — 2 af? Neremher 7117
