Gabion Mats shall be made of hexagonal double-twisted mild steel wire mesh. For tolerances, see Table I.Gabion Mats shall be supplied in various lengths, widths and heights. The tolerances of mattress dimensions are 3% in length, 3% in width and 2.5cm in height acc.to elated standards. In order to strengthen the mattresses, all the edges of the structure has a wire of greater diameter. (See fig.II) Usually the mattresses having bigger length than 2meter is divided into compartments by panels (called diaphgram)positioned per 1(one) meter. If diaphgrams not requested, it should be clearly stated by client. The mesh used in mattresses strictly conforms to EN10223-3 and ASTM A975-97. All the wires used in gabion mattresses and lacing wire have the tensile strength, that is, 38-48kg/mm (54,000-70,000psi) according to BS1052/80 and ASTM A641-97. (The figures above are of wire prior to manufacturing mesh).
The tolerances on diameter of zinc coated wire are in Table II. The elongation at break is min.12% and tested to be carried out on a sample of minimum 30cm (12 in.) long, before manufacturing the mesh. (In acc.with ASTM A370-92) Galvanisation strictly conforms to ASTM A641-97 Class III Soft Temper Coating. Zinc adherence has to be such that when the wire is wrapped around a cylindrical mandrel having 4 times the diameter of the wire, the zinc shall not flake or crack to such an extent that any flake or crack can be removed by simply rubbing with bare fingers.
The advantages of Gabion Mats
1. Flexible:
The double twisted hexagonal wire mesh structure tolerates against huge forces without breaking or cracking. It adapts itself to some degree of movement.
2. Durable:
Even if the wire mesh is necessary for the first few years of the life of structure, the galvanised wire mesh has a very long life. If the galvanised wire coated with PVC, the life of the structure gets longer. (Better for hydraulic works)
3. Permeable:
The hexagonal wire mesh structure filled with stones provide an effective permeability throughout the structure, they are self-draining. This is very beneficial in hydraulic works.
4. Economy:
Mattresses are very economical when compared to the conventional structures especially when the stones to fill the structure are close to the work area. Low maintenance is required for
construction works (Life Time Economy)
5. Strength:
It can absorb the huge amount of energy and very strong under tension generated by the nature. Well-made gabion structures can exist in perfect condition for many decades.
The advantages of Mattress Structures
1.Opening out and unfold Mattress Base Panel.
2.Lifting up side panels and diaphgrams to become in vertical position with the base. Then lace the adjacent edges to each other with lacing wire. We should also lace one edge of lid to base.
3.Placing mattress to its final position. It is important that diaphgarms run along slope and side panels are paralel to slope. Please bring the lid nearby the formed base for next process.
4.Assembling several mattresses in line and lacing adjacent edges together with lacing wire as double loop then singular loop per 100mm in turn. Then we should stake them out.
5.Starting filling mattresses from bottom to up with stones not smaller than mesh opening and not bigger than 2/3 of the depth of mattresses. Then we should slightly overfill the mattresses to allow for settlement.
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