02340.30 1085 Section 02340 - Rock Gabion Baskets
Description
02340.00Scope - This Section includes the requirements for Rock gabion baskets of twisted or
welded wire mesh.
Materials
02340.10General - Provide wire mesh Material free of breaks in the wire, breaks at w eld points or
other deficiencies. Individual wires of either style mesh shall meet the following minimum requirements:
Galvanizing ............................................................. 0.80 oz. per sq. ft. minimum Tensile strength * ................................................................. 60,000 psi minimum Wire diameter tolerance limit ................................................................. ± 0.004"
* Tensile area includes galvanizing
Welded wire shall also conform to AASHTO M 55 (ASTM A185) except that the weld shears shall be 600 pounds for 11 gauge, and 800 pounds for 9 gauge wires. All wire sizes are after galvanizing. Tie wires and internal connecting wires shall be galvanized and no smaller than 13 1/2 gauge. Spiral binders may be used as an alternate to tie wire for basket assembly and basket -to-basket connections. Spiral binders shall be 9 gauge, galvanized, and have a 3 inch pitch. High tensile fasteners of the locking spring steel clip or clamp-on ring type may be used as alternates to tie wire for basket assembly only. High tensile fasteners shall be fabricated from 11 gauge steel wire with a minimum tensile strength of 240,000 psi. Provide a Class 3 zinc coating according to ASTM A764. High tensile fasteners shall provide a closed position tensile strength of 600 pounds.
All wire shall be galvanized according to ASTM A641.
02340.12Twisted Wire Mesh Gabion Baskets - Furnish gabion panels of the twisted mesh style
manufactured from 11 gauge with 9 gauge selvage wires. The mesh shall form a uniform hexagonal pattern and shall be formed with a non -raveling twist. The major axis (maximum line dimensions) of any hexagonal opening shall not exceed 4.75 inches. The area of the hexagonal opening, approximately 3.2 inches by 4.5 inches, shall not exceed 9.5 square inches.
02340.20Welded Wire Mesh Gabion Baskets - Furnish gabion panels of the welded mesh style
manufactured from 11 gauge or 9 gauge wire. The mesh shall form a nominal 3 inch by 3 inch grid pattern and conform to AASHTO M 55 (ASTM A185). The maximum line dimension of any opening shall not exceed 4.75 inches. The 12 inch and 18 inch high mattresses shall be made from 11 gauge panels. Gabions of square Cross Section (cubical -celled units) may be made with either 9 gauge or 11 gauge panels, except that within the same unit, panels of dissimilar wire sizes may not be mixed.
Galvanized 9 gauge stiffeners, placed diagonally i n the baskets at the vertical one -third points, as shown or as recommended by the manufacturer, may be used instead of perpendicular cross ties.
02340.30PVC Coated Wire Mesh Gabion Baskets - The wire type used for PVC coated wire mesh
gabions shall be either twisted wire mesh or welded wire mesh and shall conform to 02340.00 and
or 02340.20
The PVC coating for twisted wire mesh gabions shall be extruded onto the wire core before weaving the coated wire into a double twisted hexagonal mesh. The use and minimum diameter of the various wires is as follows: 02340.40 1086 • Gabion Panel wire core shall be manufactured from galvanized 12 gauge wire core. The overall minimum diameter of the galvanized wire core plus PVC coating shall be 0.136 inch. • Selva ge and reinforcing wire shall be of heavily galvanized 10 gauge wire core coated with PVC and having an overall minimum diameter (galvanized wire core plus PVC coating) of 0.165 inch. • Lacing and connecting wire shall be of heavily galvanized 13 1/2 gauge w ire core coated with PVC and having an overall minimum diameter (galvanized wire core plus PVC coating) of 0.120 inch.
02340.40Fabrication - Fabricate gabions so that the sides, ends, lid and diaphragms can be
assembled at the construction site into rectangular baskets of the specified sizes. Dimensions for heights, lengths and widths of gabion baskets shall be as indicated on the Plans with a tolerance of plus or minus 3 percent. Gabions shall be of single unit construction. Either connect the base, lid, ends and sides into a single unit or connect one edge of these members to the base section of the gabion in such a manner that strength and flexibility at the point of connection are at least equal to those of the mesh.
If the length of the gabion exceeds its horizontal width, equally divide the gabion by diaphragms into cells whose length does not exceed the horizontal width. The diaphr agm Material shall be of the same mesh and size as the body of the gabions. Furnish the gabion with the necessary diaphragms secured in proper position on the base in such manner that no additional tying at this juncture will be necessary.
Assemble the w ire mesh panels (base, ends, sides, diaphragms and lid) so strength and flexibility at connections are at least equal to those of a single panel.
02340.50Acceptance - Provide a quality compliance certificate for gabion baskets according
to 00165.35.