MEDC 02 ( 1932 ) DTZS  
 
ICS: 77.140.65; 93.020  
1 
           
 
 
 
DRAFT TANZANIA STANDARD  
Gabions and revet mattresses — Specification  
 
 
 
 
 
 
 
  
 
 
 
 
 
 
 
 
TANZANIA BUREAU OF STANDARDS  
 
 
 
©TBS 2023                                                                                                                                   First Edition  
MEDC 02 ( 1932 ) DTZS  
 
ICS: 77.140.65; 93.020  
2 
 This Tanzania Standard  was published under the authority of the Board of Directors  of Tanzania Bureau 
of Standards on 2023 -XX-XX.  
  
 
The Tanzania Bureau of Standards (TBS) is the statutory national standards body for Tanzania 
established under the Standards Act No. 3 of 1975 , amended by Act No. 1 of 1977  and revised by 
Standards Act No. 02 of 2009 .  
 
 
The Mechanical Engineering Divisional Standards Committee (MEDC) under whose supervision, this 
Tanzania Standard  was prepared, consists of representatives from the following organizations:  
 
*University of Dar es Salaam, College of Engin eering and Technology  
*National Development Corporation (NDC)  
*Dar es salaam Institute of Technology (DIT)  
Weights and Measures Agency (WMA)  
Tanzania Industrial Research Development Organization (TIRDO)  
*Aluminium Africa  
National Institute of Transport (NIT)  
Ministry of Works  
 
 
The organizations marked with an asterisk (*) in the above list, together with the following, were directly 
represented on the Technical Committee entrusted with the preparation of this Tanzania St andard :  
 
Tanzania Automotive Technology Centre  (TATC)    
M.M. Int egrated  Steel Mills Limited  
Trans Auto Parts Company Limited (TAPCO)  
 
 
 
 
 
 
Tanzania Bureau of Standards  
P O Box 9524  
Dar es Salaam  
Phone: 022 2450206/2450949/2450298  
Fax: 022 2450959  
Email: info@tbs.go.tz   
 
 
 
 
ISBN 9976 -64-663-1MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
3 
 0 Foreword  
This Tanzania Standard has been prepared by Metals and Structures Technical Committee (MEDC 02) 
under the supervision of Mechanical En gineering Standards Divisional C ommittee  (MEDC) . 
The role of gabions and revet mattresses is to  provide a highly versatile solution of earth retention and 
erosion pr otection  hence, control land sliding on road sides, erosion and scouring on the rivers banks 
during flood and high velocity river streams and prevent the water logged areas from further damaging . 
Therefore, the main objective this Tanzania Standard is  to protect the environment through soil retention 
(preventing soil erosion) by ensuring the  quality  requirements of gabion and revet mattresses are in place 
and adhered to . 
In the preparation of this  Tanzania Standard, assistance was drawn from the followi ng publications:  
 
SABS 1580 :2010 , Hexagonal steel wire mesh gabions and revet mattresses . 
 
ASTM A975 – 20, Standard Specification for  Double -Twisted Hexagonal Mesh Gabions and Revet  
Mattresses (Metallic -Coated Steel Wire or Metallic -Coated  Steel Wire With Poly (Vinyl Chloride) (PVC) 
Coating)  
 
For the purpose of deciding whether a particular requirement of this Tanzania Standard  is complied with, 
the final value observed or calculated, expressing the result of a test or analysis  shall be rounded off in 
accordance with TZS 4 (see clause 2).  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
4 
 Gabion s and revet mattresses — Specification  
 
 
1 Scope  
This Tanzania Standard specifies materials,  dimensions,  construction and testing  of gabion s and revet 
mattresses . It also specifies the characteristics of  metallic -coated steel wire applied in producing gabion s 
and revet mattresses . 
 
This standard cover  gabions  and revet  mattresses produced from double -twisted  metallic -coated wire 
mesh, and metallic -coated wire for lacing wire, stiffeners, and fasteners used for manufacturing, 
asse mbling, and installation of the product. These specifications also cover  gabions and revet  mattresses 
in which the wire me sh, lacing wire, and stiffeners are poly  (vinyl chloride) (PVC) coated after the metallic 
coating.  
 
 
2 References  
For the purpose of this Draft Tanzania Standard , the foll owing references shall apply:  
 
TZS 4 , Rounding off numerical values  
TZS 1795/EAS 135, Steel wire and steel wire products for  fencing — Specification  
ISO 37 , Rubber, vulcanized or thermoplastic — Determination of tensile stress -strain properties  
ISO 868 , Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore 
hardness)  
ISO 974 , Plastics — Determination of the brittleness temperature by impact  
ISO 1183 -1, Plastics — Methods for determining the density of non -cellular plastics — Part 1: Immersion 
method, liquid pycnometer method and titration method  
ISO 6892 -1, Metallic materials — Tensile testing — Part 1: Method of test at room temperature  
ISO 6931 -1, Stainless steels for springs — Part 1: Wire  
ISO 7989 -1, Steel wire and wire products — Non-ferrous metallic coatings on steel wire — Part 1: 
General principles  
ISO 7989 -2, Steel wire and wire  products — Non-ferrous metallic coatings on steel wire — Part 2: Zinc or  
zinc-alloy coating  
ISO 9227, Corrosion tests in artificial atmospheres — Salt spray tests  
ISO 22034 -1, Steel wire and wire products — Part 1: General test methods  
ISO 22034 -2, Steel wire and wire products — Part 2: Tolerances on wire dimensions  
ISO 22779, Metallic coatings — Physical vapour -deposited coatings of aluminium — Specification and 
test methods  
ASTM A809 , Standard specification for aluminum -coated (aluminized) carbon steel w ire 
ASTM D1499, Standard practice for filtered open -flame carbon -arc exposures of plastics  
ASTM G152 , Standard practice for operating open flame carbon arc light apparatus for exposure of 
nonmetallic materials  
ASTM D7014 , Standard Practice for  installation  of double -twisted wire mesh gabions and revet 
mattresses  
 
 
 
 
 
 
 
 
 
 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
5 
 3 Definitions  
For the purpose of this Tanzania Standard  the following definitions shall apply:  
 
3.1 gabion  
A double -twisted metallic -coated  wire mesh container  (with or without PVC coating)  of variable sizes, 
uniformly partitioned into  internal cells, interconnected with other similar unit s, and filled with stone at the 
project site to form flexible, p ermeable, monolithic structures such as retaining walls, sea wal l, channel 
linings,  revetments, and weirs for erosion control projects  and material -retaining structures  in civil 
engineering works . 
 
3.2 revet mattress  
a double twisted metallic -coated  wire mesh container (with or without PVC coating)  uniformly partitioned 
into internal cells relatively small height in relation to other dimensions, having smaller mesh openings 
than the mesh used for gabions generally used for river bank protection and channel linings  in civil 
engineering  works . 
 
3.3 double -twisted wire mesh  
a nonraveling  mesh made by twisting continuo us pairs of wires through three one-half turns (commonly  
called double -twisted) to form hexagonal -shaped openings w hich are then interconnected to adjacent 
wires to form hexagonal openings.  
  
3.4 diaphragm  
an internal divisio n of a gabion cage that is attached  to the bottom, the sides, and, after the gabion cage 
is packed with stones, to the lid of the cage.  
 
3.5 edge wire  
a term inal wire used to edge the wire mesh parallel to the double t wist by continuously weaving it into the 
wire mesh.  
 
3.6 lacing wire  
a metallic -coated steel wire or metallic -coated steel wire (with or without PVC coating ) used to assemble 
and interconnect empty units, to close and secure stone -filled units, and for internal stiffeners.  
 
3.7 selvedge wire  
a terminal wire used to edge the wire mesh perpendicular to t he double twist by mechanically wrapping 
the mesh wires aro und it at least 2.5 times or by inserting it throughout the twists and folding one mesh 
length , intended to strengthen and facilitate co nnections between panels . 
 
3.8 fastener  
an alter nate method to lacing wire used for binding operations for gabions and revet mattresses.  
 
3.9 stiffener  
a length of metallic -coated steel w ire (with or without PVC coating)  used for support of facing by 
connect ing the front panel to the back panel of a gabion using wire having the same diameter as fo r the 
lacing wire or across the corners of a gabion cell  
 
 
4 Classifications   
Double -twisted wire g abions and revet mattresses are classified according to coating, as follows:  
 
4.1 Style 1  
It consists o f double -twisted wire mesh made from wire which is zinc coated before being double -twisted  
into mesh. Fasteners, lacing wire, an d stiffeners are produced from zinc -coated wire.   
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
6 
 4.2 Style 2  
It consists o f double -twisted wire mesh made from wire which is coa ted with Zn95AI5  before being 
double -twisted into mesh. Fastene rs, lacing wire, and stiffeners are also produced from Zn95AI5  coated 
wire.   
 
4.3 Style 3  
It consists of do uble-twisted mesh, lacing wire, and stiffeners as Style 1  or Style 2  and over coated  with 
PVC. Fasteners shall be of stainless steel wire.  
 
4.4 Style 4  
It consists o f double -twisted mesh made from wire which is aluminum -coated before being double -twisted 
into mesh. Fasteners, lacin g wire, and stiffeners are also produced from aluminum -coated wire . 
 
 
5 Material s and Manufacture   
5.1 The wire used in th e manufacture of double -twisted mesh for use in gabions and revet mat tresses 
shall conform to the coating specifications shown in 5.1.1, 5. 1.2, 5. 1.3, or 5. 1.4 as appropriate for the 
style ordered, except that the  wire strength shall conform to 6.1.  
 
5.1.1 Style 1 double -twisted mesh shall be manufactured from  zinc-coated steel wire conforming to  ISO 
7989 -2, Class A  as shown in Table 1 .  
 
Table 1: Coating mass per unit area  for zinc-coated steel wire  
 
Nominal diameter of wire, d (mm)  Minimum mass of zinc coating per unit area (g/m)  
1,85 ≤ d < 2,15  215 
2,15 ≤ d < 2,50  230 
2,50 ≤ d < 2,80  245 
2,80 ≤ d < 3,20  255 
3,20 ≤ d < 3,80  265 
3,80 ≤ d < 4,40  275 
4,40 ≤ d < 5,20  280 
5,20 ≤ d < 8,20  290 
8,20 ≤ d ≤ 10,00  300 
 
5.1.2 Style 2 double -twisted mesh shall be manufactured from  zinc-aluminium coatings of type  Zn95AI5  
steel wire  conforming to  ISO 7989 -2, Class A as shown in Table 2. 
 
Table 2: Coating mass per unit area for zinc -aluminium coated steel wire of type Zn95AI5  
 
Nominal diameter of wire, d (mm)  Minimum mass of zinc-aluminium  coating per unit 
area (g/m)  
1,85 ≤ d < 2,15  215 
2,15 ≤ d < 2,50  230 
2,50 ≤ d < 2,80  245 
2,80 ≤ d < 3,20 255 
3,20 ≤ d < 3,80  265 
3,80 ≤ d < 4,40  275 
4,40 ≤ d < 5,20  280 
5,20 ≤ d < 8,20  290 
8,20 ≤ d ≤ 10,00  300 
 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
7 
 5.1.3 Style 3 double -twisted mesh shall be manufactured from the same type of metallic -coated steel wire 
as Style 1  or Style 2  with an additional PVC coating ex truded onto the metallic -coated steel wire. The 
PVC coating sha ll conform to the properties in 7.2. 
 
5.1.3.1 Original or modifi ed thermoplastic polymers along with their application methods can b e permitted 
as a substitute for PVC coatings, as long as the ir performance is equivalent to the performance 
requirements of the PVC coating.  
 
5.1.4  Style 4 double -twisted mesh shall be manufactured from aluminum -coated steel w ire conforming to 
ISO 22779  or ASTM A809 . 
 
5.2 Lacing wire and stiffene rs shall be made of wire having the same coating material as the double -
twisted wire mes h furnished on the order and conforming to either ISO 7989 -2 (as shown in Table 1 or 
Table 2 ), ISO 22779 or ASTM A809 , with a tensile strength in accordance with 6.1 
 
5.3 Fasteners made from zinc -coated steel wire, zinc-aluminium coatings of type Zn95AI5  steel wire, and 
aluminum  coated  steel wire shall conform to either  ISO 7989 -2 (as shown in Table 1 or Table 2 ), ISO 
22779 or ASTM A809 , with a tensi le strength in accordance with 6.1. Fasteners made from stainless steel 
wire shall conform to  ISO 6931 -1, with a tensile strength  in accordance with 6.1 . 
 
5.4 Gabions and revet mattresses shall be manufactured  with all components mechanically connecte d at 
the production  facility with the exception of the mattress lid which is produced  separately from the base 
(see Fig. 1, Fig. 2, and Fig. 3). All  gabions (Fig. 1 and Fig. 2) and revet mattresses (Fig. 3) shall  be 
supplied in the collapsed form, either f olded and bundled or  rolled, for shipping.  
 
 
 
Figure 1: Gabion  
 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
8 
  
 
Figure 2: Mechanically Manufactured Gabion  
 
 
 
Figure 3: Revet Mattress  
 
 
 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
9 
 6 Mechanical Properties  
 
6.1 Tensile Strength  
The te nsile strength of wire used for double -twisted mesh, selvedge wire, lacing wire , and stiffener, when 
tested in accordance with test m ethods  specified in  ISO 6892 -1 or ISO 22034 -1, shall be in accordance 
with the requi rements of TZS 1795/EAS 135  or ISO 6931 -1. 
 
6.2 Fasteners  
The tensil e strength of zinc -coated steel wire, zinc-aluminium coatings of type Zn95AI5  steel wire, and 
aluminum -coated steel wire  used for fasteners shall be in accordance with the requireme nts of TZS 
1795/EAS 135 . The tensile strength of stainless steel wire used for fasteners shall be in accordance with 
the requirements of ISO 6931 -1. Any fastener system sha ll give the number of fasteners required to 
comply with  Table 2 in accordance with the pull-part resistance test (see 12.1.2). The manufacturer  or 
supplier shall state the number of faste ners required for all vertical and horizontal connections for single - 
and multiple  basket joinings and shall incl ude a description of a properly installed fastener including 
drawings or photographs.  
 
6.3 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, when tested in accordance with 12.1, shall be as shown in Table 3 . 
 
Table 3 : Minimum strength requirements of mesh and connections  
 
Test description  Gabions, metallic  
Coated (kN/m)  Gabion, PVC coated 
(kN/m)  
 Revet m attress 
metallic coated and 
PVC coated  (kN/m)  
Parallel to twist 51.1 42.3 33.6 
Perpendicular to twist  26.3 20.4 13.1 
Connection to selvedges  20.4 17.5 10.2 
Panel to panel  connection 
using lacing wire or  fasteners  20.4 17.5 10.2 
 (kN) (kN)  (kN)  
Punch Test  26.7 23.6 17.8 
 
 
7. Physical Properties  
 
7.1 Metallic Coating  
The c oating weights shall conform to the requirements of ISO 7989 -2 (see Table 1 ) for zinc coating or  
ISO 7989 -2 (see Table 2 ) for zinc-aluminium coatings of type Zn95AI5 , or ISO 22779 /ASTM A809 for 
aluminum coating.  
 
7.2 PVC for Coating  
Where poly  vinyl chloride (PVC) coated wire is required the wire shall have a zinc coating as specified in 
Table 1 , and shall in addition be coated wit h PVC by means of an acceptable extrusion process.  The 
initial properties of PVC coating material shall have a demonst rated ability to conform to the following 
requirements:  
 
7.2.1 Specific Gravity  
It shall  range from 1.30 to 1.35 when tested in accordance with Test Method  ISO 1183 -1. 
 
7.2.2 Tensile Strength  
Not less than 20.6 MPa when tested in accordance with Test Methods ISO 37 . 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
10 
 7.2.3 Modulus of Elasticity  
Not less than 18.6 MPa  when tested in accordance with Test Methods ISO 37 . 
 
7.2.4 Hardness  
Shore ― D‖ between 50 and 60, when tested in accordance with Test Method ISO 868 . 
 
7.2.5 Brittleness Temperature  
Not higher than −9 °C, or lower temperature w hen specified by the purchaser, when tested in accordance 
with Test Method ISO 974  (see Note 2). 
 
NOTE 2: The maximum brittleness temperature should be at least  −9°C (15 °F) below the minimum 
temperature at which the gabions will  be filled.  
 
7.2.6  Salt Spray Exposure and Ultraviolet Light Exposure:  
7.2.6.1 The PVC shall show  no effect after 3000 h of salt spray exposure in accordance with Test Method 
ISO 9227 . 
7.2.6.2 The PVC shal l show no effect of exposure to ultraviolet light with test expo sure of 3000 h, using 
apparatus Type E and 63 °C,  when tested in accordance with Practices ASTM D1499 and ASTM G152 . 
 
7.2.6.3 Evaluation of Coating After Salt Spray and Ultraviolet Exposure Test   
After the salt spray test and exposure to ultraviolet light as specified in 7.2.6 .1 and 7.2.6 .2, the PVC 
coating shall not show cracks nor  noticeable change of color, or blisters or splits. In addition , the specific 
gravity, tensile strength  and hardness  shall not change more than 6%, 25%  and 10%,  respectively, from  
their initial values.  
 
7.2.7 The PVC coating shall not show cracks or breaks after the wires are twisted in the fabrication of the 
mesh.  
 
7.2.8 Salt Spray Resistance for Fastener  
After testing in accordance with 12 .1.3, 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.  
 
 
8. Dimensions and Tolerances  
 
8.1 The minimum diameter of metall ic coated wire shall conform to Table 3  with tolerances according to  
ISO 22034 -2. 
 
8.2 The diameter of metallic -coated wire and stainless steel wire used in the fabrication of f asteners shall 
conform to Table 1 with tolerances according to ISO 22034 -2. The minimum and n ominal thickness of 
PVC coating uniformly applied in a quality  workmanlike manner shall be as shown in Table 4 . 
 
8.3 Gabions shall be ma nufactured with an 8 by 10 mesh type having a nominal mesh o pening of 83 by 
114 mm . Dimensions are measure d at right ang les to the center axis of the opening (D = 83 mm, see Fig. 
4) and parallel to the twist along the same axis.  The mesh tolerances are given in Table 7 of clause 8.8.  
 
8.4 Revet mattresses sh all be manufactured with a 6 by 8 mesh type having a nomi nal mesh opening of 
64 by 83 mm . Dimensions are measured at right angles to the center axis of the open ing (D = 64 mm, see 
Fig. 4) and parallel to the twist along the same axis.  The mesh tolerances are given in Table 7 of clause 
8.8. 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
11 
  
Figure 4: Wire mesh opening nominal dimension D 
 
8.5 The width, height, and length of the gabion as  manufactured shall not differ more than ± 5 % from the 
ordered size prior to filling. (Typical gabion sizes are shown in Tables 5). 
 
8.6 The width and length of the  revet mattress as manufactured shall not dif fer more than ± 5 %, and the 
height shall not  differ more than ± 10 % from the  ordered size prior to filling. (Typical revet mattress s izes 
are shown in Tables 6 ). 
 
Table 4 : Mesh Characteristics  a 
 
Characteristics  
 Gabion  Revet Mattresses  
Metallic Coated  PVC Coated  Metallic Coated  PVC Coated  
Mesh Type  8 by 10  6 by 8  
Mesh Opening (mm)  83 by 114  83 by 114  64 by 83  64 by 83  
Mesh wire (mm)  3.05 2.7 2.2 2.2 
Selvedge wire (mm)  3.8 3.4 2.7 2.7 
Lacing wire (mm)  2.2 2.2 2.2 2.2 
Fasteners (mm)  3.0 3.0 3.0 3.0 
Stiffeners:      
- Using lacing  
Wire (mm)  2.2 2.2 2.2 2.2 
- Preformed 
(mm)  3.8 3.4 N/A N/A 
PVC coating  
thickness:      
- Nominal (mm)  N/A 0.50 N/A 0.50 
- Minimum  N/A 0.45 N/A 0.45 
a All dimensions and wire diameters are minimum nominal values.  
 
 
 
 
 
 
 
 
 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
12 
 Table 5 : Typical Gabion Sizes  
 
Length (m)  Width (m)  Height  (m) Number of c ells, 
Each Volume, m3 
2.0 1.0 1.0 2.0 2.0 
3.0 1.0 1.0 3.0 3.0 
4.0  1.0  1.0  4.0  4.0 
2.0  1.0  0.5  2.0  1.0 
3.0  1.0  0.5  3.0  1.5 
4.0  1.0  0.5  4.0  2.0 
2.0  1.0  0.3  2.0  0.6 
3.0  1.0  0.3  3.0  0.9 
4.0  1.0  0.3  4.0  1.2 
6.0 2.0 0.5 6.0 6.0 
N.B:  
Other dimensions of gabions may be produced as per agreement between purchaser and manufacturer.  
 
 
Table 6: Typical Revet Mattress Sizes  
 
Length (m)  Width (m)  Height (m)  Number of c ells, 
Each Area , m2 
3.0 2.0 0.17 3.0 6.0 
4.0  2.0 0.17 4.0  8.0 
3.0  2.0 0.23  3.0 6.0 
4.0  2.0 0.23 4.0  8.0 
3.0  2.0 0.30  3.0 6.0 
4.0  2.0 0.30  4.0  8.0 
6.0 2.0 0.17 6.0 12.0 
6.0 2.0 0.23 6.0 12.0 
6.0 2.0 0.30 6.0 12.0 
N.B:  
Other dimensions of revet mattresses may be produced as per agreement between purchaser and 
manufacturer.  
 
 
8.8 Mesh Opening Tolerances  
Tolerances on the  hexagonal, double -twisted wire mesh opening shall not exceed  ±10 % on the nominal 
dimension D values, as follows (see Fig. 4):  
 
Table 7:  Mesh Opening Tolerances  
 
S/No.  Mesh Type  Nominal Dimension D Values  Tolerances  
1 6 by 8  64 mm  ±10 %  
2 8 by 10  83 mm  ±10 %  
       
 
9. Workmanship  
9.1 Wire of proper grade and quality, when fabricated in the manner herein required, shall result in a 
strong, serviceable mesh -type product having sub stantially uniform openings. It shall be fabricated and 
finished in a workmanlike manner, as determined by visual inspec tion, and shall conform to this 
specification.  MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
13 
  
9.2 Installation of double -twisted wire mesh gabions and revet m attresses  for various  applications such as  
erosion control, soil retention or freestanding structures  should be done according to ASTM D7014 . 
 
 
10. Sampling  
10.1 Samples for determining the mechanical and ph ysical properties of double -twisted w ire mesh shall 
be in accordance with the samples, dimensions , and requirements described in clause  12. 
 
10.2 Samples for determin ing the mechanical and physical properties of coated steel wire used for mesh, 
lacing wire, and stiffeners shall be selected at random from wire coils used for manufacturing.  
 
 
11. Number of Tests  
11.1 A minimum of thre e tests each for conformance to strength of metallic -coated steel wire mesh 
parallel to twist, perpendicular to twists, conn ection of metallic -coated steel wire mesh to selvedge, and 
punch test shall be performed. A minimum of five tests for the c onformance of the fastener test shall be 
performed. A retest for conformance with the aforementioned  strength and connecti on tests shall be 
required when changes of the physical chara cteristics  of the mesh products occur. For metallic -coated 
steel wire with PVC coating, follow the same requirements as for the metallic -coated steel wir e mesh. The 
results of all three t ests must meet the requirements of Table 2. 
 
11.2 The tensile strength, m etallic coating weight, and PVC coating thickness of the metallic steel wire 
used in the fabrication of mesh, lacing wire,  stiffeners, and fasteners must be certified by the steel wire 
producers for conformance to the requirements of Sections 6 , 7 and 8 , and Table 1  or Table 2  for each lot 
shipment to the manufacturer’s facility.  
 
 
12. Test Methods  
12.1 Mechanical Property Tests:  
12.1.1 Tensile Strength Test  
The wire mes h specimens shall be representative of proper field construction and be taken randomly from 
a production l ot or material delivered to the jobsite, and shall be as large as p ractical to minimize the 
effect of variations. The wire mesh specimen shall be rect angular in shape with minimum 25 cm  in load 
direction (L) and 80 cm in the cross di rection (W).Wire mesh specimens shall be selvedged on both c ross 
ends by either manually or mechanically inserting a selv edge wire with a diameter shown in Table 1 and 
securely twisti ng the wire mesh around it with minimum 2.5 turns before testi ng. The tes ts shall be run 
with the load applied parallel to the axis of twist and repeated on a separate test specimen with th e load 
applied perpendicular to the axis of twist.  
 
12.1.1.1  The apparatus shall  grip the wire in such a manner as to allow the wire failures to occur at least 
one mesh pattern away from the gripping points . If a failure occurs in a wire leading directly to a gripping 
point, that specimen shall be rejected and not included among the tests reported.  
 
12.1.1.2  To pret ension an d remove the wire mesh slack, a preload of approximately 4000 N shall be 
applied.  
Once the preloading is reached, the load is then applied at a  uniform strain rate of 6 mm/min  until first 
fracture of an individual w ire in the mesh occurs. Tensile strength of the mesh is a rati o of breaking load 
to effective width of the specimen. Fai lure is defined when no further increment in the tensile strength  is 
observed. The machine head travel at each load increment  or sequential incident of wire failure may  be 
stopped for recording pertinent information such as load, fracture ty pe, resulting mesh geometry and 
elongation, and resulting reduction in wire gaug e. The distortion of the mesh or changes in  gauge length 
shall be measured to accuracy consistent with reporting the percent elongation to the nearest 0.5 %. The 
results of the tests shall be in accordance with the requirements shown in Table 2.  MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
14 
  
12.1.2 P ull-Apart Resistance Test  
A set of the jointed panels, which are prepared by the same method as specified in the salt spray test but 
without  being subject to the 48 h salt spray test, shall be mounted on a loading machine with grips or 
clamps such that the panels are uniformly secured along the full width. The grips or c lamps shall  be 
designed to only transmit tension forces. The  load will then be applied at a uniform rate not to exceed 220 
N/s until failure occurs. The failure is defi ned as when the maximum load is reached and a drop of 
stren gth is observed with subsequent loading or alternatively the opening between any two closest 
selvedge wires, applicable to a fastener confining two selvedge wires, becomes greater than t he wire 
mesh opening (D) at any place along the panel width. T he strength requirements of the jointed panels a t 
failure shall be as shown in Table 2.  
 
12.1.2.1 Fastener Test  
The pull-apart test on the fastener shall be done in conjunction with the pull -apart test on panel to panel 
connection. The test co nsists of measuring the maximum opening resistance of single fastener used to 
connect the wire mesh panels together for the pull-apart resistance test. The fasteners used for this test 
shall be obtained from the same  manufacturer production batch as the fasteners used during the  panel to 
panel connection te st. The t esting tension machine used for the test shall be able to register the 
maximum tensile strength achieved during the test. The clampi ng system used shall not interfere with the 
radius of the fastener when closed. The loads applied to the speci men shall be d one perpendicular to the 
closing axe (see Fig . 5). The load shall be applied without interruption at a speed of 5 mm per m inute. 
The test shall be done on five specimens to determine the average maximum resistance of each type of 
fastener tested.  
 
 
Figure  5: Single fastener test with load applied perpendicular to the closing axe  
 
12.1.2.2 Report  
The repo rt shall include the pull -apart resistance test and the fasten er test, and have the following 
information:  
 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
15 
 (1) Type of fastener  tested (manufacturer, material composition, coating, and dimension).  
(2) Description of the testing  apparatus used for both tests, if different.  
(3) Table showing the re sults obtained for the panel to panel connection and the single fastener tests.  
(4) Name of the laboratory where the test  was done, date of test, and name of the test supervisor.  
 
12.1.3 Salt Spray Test  
A set of two identical rectangular gabion panels, each with a width about 10 .5 mesh openings along a 
selvedge wire, shall be jointed by p roperly installed  wire fasteners along the two selvedge wires so that 
each fastener confines two selv edge and two mesh wires. If the fasteners are also to be us ed to join two 
individual empty gabion baskets, two addition al selvedge wires that are each mech anically wrapped with 
mesh wires shall be included so that each fastener confines fou r selvedge and four mesh wires. A 
properly installed fastener shall meet the following requirements:  
 
12.1.3.1  Each fastener type s hall be in a closed position. Each fastener type shall be closed and the free 
ends of the fastener shall overlap a minimum of 25.4mm. The set of the jointed panels shall be subject to 
Salt Spray Test according to  ISO 9227  for a period not less than 48 ± 1 h cycle length.  
 
12.1.4 Punch Test 
The wire mesh specimens shall be representative of proper field con struction and be taken randomly from 
a production lot or from materials delivered to the jobsite. The punch test could be done using two 
different apparatus.  
 
12.1.4.1 Pre -Tensioned Pu nch Test  
An uncut section of 1.82 m in length (unselv edged) and not less than 0.91 m in width shall have the e nds 
securely clamped for 0.91 m along the width of the sample. W hen the width of the section under test 
exceeds 0.9 1 m, the clamps shall be center ed along the width and t he excess width will be allowed to fall 
free on each side of the clamped section. The sample shall then be subjected to tension sufficient to 
cause 10 % elongation of the sample se ction between the clamps. After elongation and while  clamped as  
described above (and otherwise unsupported), the section shall be subjected to a load of 960 cm2 applied 
to the a pproximate center of the sample section between the clamps and in a direction perpendicular to 
the direction of the tension force.  
 
12.1.4.2 Secured Punch Test  
The specimen shall be rectangular in shape with 1.0 m  side length (L). The tolerance on specimen size 
shall not exceed 620  %. The wire mesh specimen shall be securel y connected to the perimeter of a rigid 
square test frame usi ng constraining devices such as grips or links as schematical ly shown in Fig. 6. After 
being secured to the test frame, the specimen shall be subjected to a loading disc with a contact are a of 
960 cm2 applied to the approximate center of  the sample section between the clamps and in a direction 
perpen dicular to the direction of the tension force. To remove th e wire mesh slack, the specimen shall be 
preloaded until the maximum vertical deformation at the center is less than 20  % of the side length. Once 
the preloading is reached, the lo ad is then applied at a uniform strain rate of 10 mm/min  until the 
specimen no longer supports any increase in the applied load. During the test, the applied load and 
vertic al deformation at the center of the wire mesh specimen  shall be continuously measured and  load 
versus deformation curve shall be plotted. Failure is  determined when no further in crement of punching 
load to the specimen is observed.  
 
 
 
 
 
 
 
 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
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Figure 6: Secured punch test with every mesh clamped  
 
12.1.4.3  The sample shall wi thstand, without rupture of any strand or opening of any mesh fa stening, an 
actual load applied by means of a circular ram a t a rate as indicated in 12.1.2 equaling or exceeding the 
values shown in Table 2. The ram head used in the test  shall be ci rcular with a 350 mm diameter and 
have its edge s beveled or rounded to prevent cutting of the wire strands.  
 
12.1.5 Abrasion Resistance Test  
This test method covers the determination of the resistan ce of polymer coated steel wire to abrasion 
caused by a linear rubbing action. A n abrading wire reciprocates back and forth along a linear path, until it 
abrades through the polymer coatin g and the test is automatically stopped. Abrasion is pro minent where 
there is scuffing, scratching, or wearing a ction caused by actions such as glaciation, movement of soli d 
objects, or waves breaking on coastlines.  
 
12.1.5.1  The polymer coa ted wire specimens used in this test shall be taken random ly from production 
lot. A small segment of polymer coating shal l be s tripped from both ends of the wire specimen before 
securing in place.  A total vertical load of 2400 g ± 50 g shall be applied to the abrading wire of 0.5 mm ± 
0.05 mm diameter as shown in Figure  7. Subject the test specimen to abrasion at a speed of 55 ± 5 
cycles per minute for a stroke length of 12.7 mm. Th e test shall stop automatically when the polymer 
coating is worn through to the metal wire.  
Record the number of cycles.  A total of four tests shall be performed on each specimen.  For each 
subsequent test, move the specimen 25 mm and ro tate 90°. Replace abradant wire before each test.  
 
12.1.5.2  The final result shall be calculated as the average of 4 tests performed.  
 
12.1.6 Corrosion S pread Test for Polymer Coatings  
The corrosion spread test is relevant for polymer coatings to assess, in the event of a loca l damage to an 
over-sheath, any consequential corrosion of the outer surface of the steel wire core and ensure that the 
corrosion effect will remain confined  to the dam aged area of the cove ring. The procedure consists of 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
17 
 immersing wire samples of 2 50 mm long in a 5 % solution of HCl by weight. Samples ar e removed from 
the solution and analyzed after 100, 500 , 1000, 1500, and 2500 hours of immersion. The polymer coating 
shall be removed, and the length of the corroded wire meas ured. The part of the wire with reduced 
diameter is cons idered as corroded. The average corrosion lengths measured versus time plot shall show 
the maximum length after which there is no more increase  in length with time. This m aximum length 
measured shall be always less than a mesh repetition.  
 
12.2 Metallic Coating Weight  
Perform coating weight tests as prescribed in  Test Methods ISO 7989 -1 or ISO 22779  as applicable.  
 
12.3 Polymer Coating Thickness:  
12.3.1 The thickness of the poly mer coating shall be determined on a randomly chosen i ndividual piece of 
wire removed from the mesh.  
 
12.3.2 Measure with a  micrometer the diameter of the metallic coated steel wire with  polymer coating. 
Determine the thickness of the polymer c oating by stripping the polymer coating from the wire and 
measure the reduced diameter with a micrometer. The thickness o f the coating is the difference between 
the diameter of the metallic -coated steel wire with  polymer coating a nd the measured diameter of the 
metallic  coated wire divided by two. Th is value shall be in accordance with Table 1. When removing the 
polymer coating by stripping, take care not to remove any of the metallic surfaces.  
 
 
13. Inspection  
13.1 Unless otherwise specified in the contract or pur chase order, the producer is respons ible for the 
performance of all inspection and test requirem ents of this specification. The producer shall use his /her 
own or an y other suitable facilities for the perfor mance of the inspectio n and test requirements, at his 
option, unless disapproved b y the purchaser at the time the order is placed. The purchaser at their own 
expense shall have the right to perform any of the ins pections and tests set forth in this specifi cation 
when suc h tests are deemed necessary to ensure that the material conforms to the prescribed 
requirements.  
 
13.2 When requested by owner or purchaser, fastener s used for assembly and installation of the units on 
the field shall be tested for compliance with the pull -apart resistance certification provided by the producer  
or supplier in accordance with 12.1.2.2 . When tested in accord ance with 12.1.2.1 , the average maximum 
resistance of the fasten ers from the field shall not be lower than 90 % o f the resistance provided in the 
certification.  
 
 
 
 
 
 
 
 
 
 MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
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Figure  7: Linear abrader  
 
 
14. Marking  
The following information shall be legibly impressed on a corrosion -resistant metal tag that is securely  
attached to the longest side wall of a gabion or revet mattress : 
a) The manufacturer's name or trade name or trade mark;  
b) the date of manufacture; and  
c) the size of the gabion or revet mattress.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
MEDC 02 (1932) DTZS  
ICS: 77.140.65; 93.020                                                                                                                  
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