Sigma 50/3.2
Area of Application
Sigma 50/50/3.2 is a single twisted mesh product made from high tensile wire and used for high strength slope stabilization solutions. Like other rectangular mesh, it conforms to slopes better than hexagonal mesh, yielding maximum surface contact for better control of erosion. Both draped and anchored mesh systems are common applications.
High Strength
The strength of a mesh product is most often characterized by its tensile strength and puncture strength. For pinned or anchored mesh systems, the characterization of how the mesh performs in association with the specific anchor plate is of critical importance. In this case, puncture strength should always be carried out using the actual anchor plate as well as in open-air/unsupported conditions. HPN, HPN+ and Sigma Netting are the highest tensile strength single-twisted wire mesh products on the market having symmetrical strength parameters. Other products have significantly reduced tensile strengths perpendicular to their weave.
Draped Mesh System
Draped mesh systems allow material behind the mesh to move down slope in a controlled manner. These systems are normally secured along the top of the system with a suspension cable, with few or no anchors below. A major consideration for draped mesh systems is not only the strength but the unit weight of the material. The higher the weight, the better the system will resist impacts. HPN and HPN+ are used where dynamic loading of the draped mesh system require greater mechanical impedance than standard double-twist.
Anchored Mesh System
To prevent the movement of small material down a slope, the mesh may be pinned using a matrix of soil or rock anchors, possible with the combination of steel ropes and anchor plates. Such systems are termed slope retention or anchored mesh systems. The anchor spacing, depth and type must be designed by a geotechnical engineer to properly accommodate the expected forces and to reduce maintenance.
Revegetation Mats
A common practice for anchored mesh systems is to apply geotextile or fiber mats beneath the system to reduce the lost of fine material and encourage revegetation.
Alternate Solutions Using Flexible Facing
HPN, HPN+ and Sigma Netting are versatile products that can be used in a variety of applications where high strength is required such as: shoring, tunnel and shaft linings, wall reinforcement, bank stabilization, and sink hole mitigation.
Mesh Characteristics
| Mesh Size (a x a) [mm (inch)] | 50 x 50 (1.97 x 1.97) |
| Opening Angle (?) | 90° |
| Wire Diameter [mm (inch)] | 3.2 (0.13) |
| Construction | Single Twist |
| Number of Mesh Openings, Length [per m (per ft)] | 13 (4) |
| Number of Mesh Openings, Width [per m (per ft)] | 13 (4) |
| Sewing Rope Diameter [mm (inch)] | 4 (0.16) |
Wire Properties
| Tensile Strength [N/mm2 (ksi)] | min. 1770 (257) |
| Corrosion Protection | Zn-Al Galvanized |
| Min. Mass of Coating [g/m2 (oz/ft2)] | 150 (0.49) |
| Coating Class | Class B |
Mesh Strength Properties
| Tensile Strength, Lengthwise [kN/m (lbf/ft)] | >150 (>10.278) |
| Tensile Strength, Crosswise [kN/m (lbf/ft)] | >150 (>10.278) |
| Puncture Strength, Free-air [kN (lbf)] | 100 (22,481) |
| Puncture Strength, Supported [kN (lbf)] | 410 (92,172) |
| Puncture Strength, ASTM [kN (lbf)] | 150 (33,721) |
| Shear Resistance [kN (lbf)] | 205 (46,086) |
| Shear-puncture Resistance [kN (lbf)] | 45 (10,116) |
Standard Roll Sizes
| Length (L) [m (ft)] | 15 - 25 (49 - 82) |
| Width (W) [m (ft)] | 3.0 - 4.0 (9.9 - 13.1) |
| Unit Weight [kg/m2 (lb/ft2)] | 2.75 (0.56) |
| Roll Weight [kg (lbs)] | 120 - 265 (265 - 584) |
Mesh Dimensions
Panel Dimensions
Seam Connection
*Connection details according to state of the art practice. Actual seam connection to be determined by a qualified engineer in accordance with local regulations.