The Terra Aqua PVC coated Reno mattress is a mattress shaped container manufactured from heavily galvanized steel wire with an additional PVC coated jacket to form a flexible and effective surface protection to defend against erosion and scouring. The flexible wire mesh will accommodate significant deformation without failure. The base and sides of the Reno Mattress are made of a single sheet of wire mesh (main panel). Partition panels (diaphragms) are made of the same wire mesh as the main panel and are attached to the base of the main panel dividing the Reno Mattress into 3 foot cells. The lid is formed either by a single sheet or in rolls of a specified length from the same wire as is in the main panel.
The mesh shall be woven into a hexagonal pattern with the joints formed by twisting each pair of wires through three and a half turns or a complete double twist. Because of this appearance, the joints are often double twisted. The size of the mesh conforms to the specification issued by the manufacturing facility and shall be uniform in opening size where the smallest dimension shall be 6cm minimum but not larger than 8 cm.
All wire used in the fabrication of the Reno Mattress and in the lacing operations shall conform to Federal Specification QQ-W-461H, Class 3, Finish 5, soft, and have an average tensile strength in accordance with the current ASTM A 641, Table 2, before PVC coating and fabrication of the netting. The nominal diameter of the wire used in the fabrication of the netting shall be 0.0866 inches minimum, subject to diameter tolerance in accordance with the current ASTM A 641, Table 3.
Tests shall be conducted on the wire before coating with PVC and fabrication on the mattresses on a sample 12 inches long. Elongation shall not be less than 12%.
All wire used in the fabricating and construction of the gabions shall be galvanized according to ASTM A 641, Table 1. The minimum weight of the zinc coating shall be according to the table following when tested in accordance with ASTM A 90. Adhesion of the zinc coating to the wire shall be capable of being wrapped in a close helix at a rate not exceeding 15 turns per minute around a cylindrical steel mandrel having a diameter 3 times the nominal wire diameter being tested. After the wrap test is completed, the wire shall not exhibit any cracking or flaking of the zinc coating to such an extent that any zinc can be removed by rubbing with bare fingers.
All edges of the Reno Mattress including end panels and the diaphragms, shall be mechanically selvedged in such a way as to prevent unraveling of the mesh and to develop the full strength of the mesh. The wire used for the selvedge shall have a diameter greater than that of the wire used to form the mesh.
Sufficient lacing and connecting wire shall be supplied with the mattress for all wiring operations. The nominal diameter of lacing wire shall be 0.0866 inches minimum. Alternative wire fasteners shall be ASTM approved wire fasteners used in lieu of lacing wire.
PVC (Poly Vinyl Chloride) Coating. The coating shall be gray in color and shall have a nominal thickness of 0.0216 inches but not less than 0.015 inches in thickness. The protective PVC plastic shall be suitable to resist deleterious effects from exposure to light, immersion in salt or polluted water and shall not show any material difference in its initial compound properties. The PVC compound shall also be resistant to attack from acids and resistant to abrasion.
According to engineering requirements the Terra Aqua Reno Mattress is designed to incorporate internal diaphragms to form cells having a nominal length of three feet. The internal diaphragms will prevent stone fill migration within the reno mattress.
A tolerance of +5% on the width and on the length of the Reno Mattress and a tolerance of +10% on the height within the manufacturers stated dimensions shall be permitted.
The Terra Aqua Heavy Duty Reno Mattress was designed specifically to accommodate stone size of 3 to 6 inches (75-105mm) allowing for two layers of stone fill. Only hard durable stone shall be used as mattress fill.
On channel slopes, the mattress shall be placed perpendicular to the flow of the channel with the length dimension of the reno mattress going up and down the slope. On the channel bed, the length dimension of the reno mattress shall be placed parallel to the flow, while the width of the reno mattress runs across the channel bed. An approved corner closure tool shall be used to adjoin adjacent mattresses to insure a tight, neat seam and minimize mattress wire joint deformation.