| Mechanical Properties Tensile
Strength - The tensile strength of wire used for double-twisted
mesh, lacing wire and stiffeners, when tested in accordance with ASTM A
370, shall be in accordance with the requirements of ASTM A 641, A 809,
and A 856/A 856M for soft-temper wire.
Fasteners - The tensile strength of zinc-coated steel wire,
Zinc-5% Aluminum-Mischmetal Alloy-coated steel wire and aluminum-coated
steel wire used for fasteners shall be in accordance with the
requirements for ASTM A 764, Type A, B or C. The tensile strength of
stainless steel wire used for fasteners shall be in accordance with the
requirements of ASTM A 313, Type 302. Any fastener system shall give the
number of fasteners required to comply with minimum strength
requirements for fasteners in accordance with the Pull-Apart Resistance
Test . The manufacturer or supplier shall state the number of fasteners
required for all vertical and horizontal connections for single and
multiple basket joining and shall include a description of a properly
installed fastener including drawings or photographs.
Mesh and Panel to Panel Joint Strength - The minimum strength
requirements of the mesh, selvedge wire to mesh connection, panel to
panel connection and punch test.
Physical Properties Metallic Coating - The coating
weights shall conform to the requirements of ASTM A 641, Class 3 for
zinc coating, or ASTM A 856/A 856M, Class 3 for Zn - 5Al - MM coating,
or ASTM A 609 for aluminum coating.
PVC for Coating - The initial properties of PVC coating
material shall have a demonstrated ability to conform to the following
requirements:
1. Specific Gravity - In the range of 1.30 to 1.35 when
tested according to Test Method ASTM D 792.
2. Tensile Strength - Not less than 20.6 MPa when tested
according to Test Method ASTM D 412.
3. Modulus of Elasticity - Not less than 18.6 MPa when
tested according to Test Method ASTM D 412.
4. Hardness - Shore "D" between 50 and 60, when tested
according to Test Method ASTM D 2240.
5. Brittleness Temperature - Not higher than -9°C or
lower temperature when specified by the purchaser, when tested according
to Test Method ASTM D 746,. The maximum brittleness temperature should
be at least 8°C below the minimum temperature at which gabions will be
filled.
6. Resistance to Abrasion - The percentage of the weight
loss shall be less than 12%, when tested according to Test Method ASTM D
1242.
7. Salt Spray Exposure and Ultraviolet Light Exposure:
- The PVC shall show no effect after 3,000 hours
of salt spray exposure according to Test Method ASTM B 117.
- The PVC shall show no effect of exposure to
ultraviolet light with test exposure of 3,000 hours, using apparatus
Type E and 63° , when tested according to Practice ASTM D 1499 and
Practice ASTM G 23.
- Evaluation of Coating after Salt Spray and Ultraviolet
Exposure Test - After the Salt Spray Test and exposure to
ultraviolet light as specified above, PVC coating shall not show cracks,
blister, split nor noticeable change of color. In addition, the specific
gravity, tensile strength, hardness and resistance to abrasion shall not
change more than 6%, 25%, 10% and 10% respectively from their initial
values.
8. PVC coating shall not show cracks
or breaks after the wires are twisted in the fabrication of the mesh.
9. Salt Spray Resistance for Fastener
- After testing the fasteners, the selvedge or mesh wire confined by the
fasteners shall show no rusty spots on any part of the surface excluding
the cut ends.
Dimensions and Tolerances
1. The diameter of metallic-coated wire shall conform to
ASTM A 641, A 356/A 256M and A 809 as applicable.
2. The diameter of metallic-coated wire and stainless steel
wire used in the fabrication of fasteners shall conform to Table 7
plus or minus the tolerances shown in ASTM A 764.
3. The minimum and nominal thickness of PVC coating
uniformly applied in a quality workmanlike manner.
4. Gabions shall be manufactured with a 8 x 10 mesh type
having a nominal mesh opening of 83mm x 114mm . Dimensions are measured
at right angles to the center axis of the opening (D = 83mm) and
parallel to the twist along the same axis.
5. Revet mattresses shall be manufactured with a 6 x 8
mesh type having a nominal mesh opening of 64mm x 83mm. Dimensions are
measured at right angles to the center axis of the opening (D = 64) and
parallel to the twist along the same axis.
6. The width, height and length of the gabions as manufactured
shall not differ more than ± 5% from the ordered size prior to filling
7. The width and length of the revet mattress as manufactured
shall not differ more than ± 5%, and the height shall not differ more
than ± 10% from the ordered size prior to filling. Mesh opening
tolerances - Tolerances on the hexagonal, double-twisted wire mesh
opening shall not exceed ± 10% on the nominal dimension D values. |