Vietnamese standard 165 1-3:2008 Part 3: Welded fabric 1. Scope of application Applied to sheet or roll wire mesh with steel’s diameter from 4mm to 16mm for reinforcement of concrete. 2. Reference: TCVN 197:2002 (ISO 6892:1998): medal material- traction test TCVN 1651-1:2008: Steel for reinforcement of concrete. Part 1: mild steel round bar TCVN 1651-2: 2008: Steel for reinforcement of concrete. Part 2: deformed steel bar TCVN 4399:2008 (ISO 404:1992): steel and products from steel- Common spec for supply TCVN 6287:1997 (ISO 10065:1990): steel for reinforcement of concrete- bend test and uncompleted bend retest TCVN 6288:1997 (ISO 10544:1992): wire for reinforcement for concrete and producing wire of concrete ISO 10287:1992: Steel for reinforcement of concrete- determination of strength of joints in welded fabric ISO 11082:1992: Certification scheme for welded fabric for reinforcement of concrete structures. 3. Definition This standard uses following definitions 3.1 Test unit Number or amount of products are accepted or rejected based on testing on samples which meet the requirement of standards or orders ( TCVN 4399)
Transcript
Vietnamese standard 165 1-3:2008
Part 3: Welded fabric
1. Scope of application
Applied to sheet or roll wire mesh with steel’s diameter from 4mm to 16mm for reinforcement of concrete.
2. Reference:
TCVN 197:2002 (ISO 6892:1998): medal material- traction test
TCVN 1651-1:2008: Steel for reinforcement of concrete. Part 1: mild steel round bar
TCVN 1651-2: 2008: Steel for reinforcement of concrete. Part 2: deformed steel bar
TCVN 4399:2008 (ISO 404:1992): steel and products from steel- Common spec for supply
TCVN 6287:1997 (ISO 10065:1990): steel for reinforcement of concrete- bend test and uncompleted bend retest
TCVN 6288:1997 (ISO 10544:1992): wire for reinforcement for concrete and producing wire of concrete
ISO 10287:1992: Steel for reinforcement of concrete- determination of strength of joints in welded fabric
ISO 11082:1992: Certification scheme for welded fabric for reinforcement of concrete structures.
3. Definition
This standard uses following definitions
3.1 Test unit
Number or amount of products are accepted or rejected based on testing on samples which meet the requirement of standards or orders ( TCVN 4399)
3.2 Certification scheme
Certification scheme is involved to products, producing technique, services which meet the requirement of standards, specific rules and having the same process ( TCVN 6450)
3.3 Characteristic value
Based on ISO 8930
3.4 Fabric
A geometric shape of longitudinal and transverse wire to make a suitable angle and to be welded at all intersection points
3.5 Inspection
Including measuring, inspecting, testing and judging one or many characteristics of a product or a service and comparing them with defined requirements to consider if the product or service is adequate or not (TCVN ISO 9000).
3.6 Length of fabric
The longest dimension of fabric
3.7 Longitudinal wire
Wire is in manufacturing direction
3.8 Nominal cross- sectional area
Nominal cross sectional area is equivalent with area of a round wire and nominal diameter
3.9 Overhang (u)
Length of a longitudinal wire or transverse wire which overhangs the core of farthest transverse wire of the fabric.
For twin wire structure, overhang is measure from tangential line of contiguous wires
3.10 Spacing (b)
Distance between cores of contiguous wires for single wire mesh, and between tangential lines of contiguous wires for twin wire mesh.
3.11 Transverse wire
Wire which is perpendicular to manufacturing direction.
3.12 Twin wire
Two wires with same type and dimension, being placed next to each other and contacting as a couple
3.13 Width of fabric
The shortest direction of the fabric
3.14 Wire
Material to make fabric
4. Shape and dimension
This standard includes common wire mesh (4.2) and designed wire mesh (4.3)
4.1 General requirements
4.1.1 Fabric is made from:
Cool- drawn wire with diameter from 4mm to 16mm ( 5mm,6mm,7mm,8mm,9mm,10mm, 12mm are recommended), weight and shape based on TCVN 6288; or
Mild round steel bar with d=6mm,8mm,10mm,12mm or 16mm ( 6mm,8mm,10mm, 12mm are recommended), weight based on TCVN1651-1; or
Deformed steel bar with d=6mm,8mm,10mm,12mm or 16mm ( 6mm,8mm,10mm, 12mm are recommended), weight based on TCVN1651-2.
4.1.2 The whole wire fabric has to be made by machine and all intersection points have to be welded by electric welding according to Article 6
4.1.3 Every fabric has to have an amount of wire which has suitable for given length, width, spacing and dimension of overhang
Amount of unqualified joint is not higher than 1% the total of joints in the mesh or half of joints along any wire.
4.1.4 The fabric do not have any defects which have bad impact on mechanic characteristic of steel.
Joint which obeys Article 7 is not considered as defect.
4.1.5 Longitudinal wire is single wire or twin wire. The other wire must be single wire
4.1.6 Diameter of wire in single wire fabric must be: dmin ≥ 0.6 dmax
With:
dmax: nominal diameter of biggest wire
dmin: nominal diameter of intersection wire
Diameter of twin wire mesh: 0.7 dT ≤dL≤1.25dT
With:
dT nominal diameter of transverse wire.
dL nominal diameter of a wire of twin wire
4.1.7 Dimension of fabric is length in both direction.
4.1.8 Acceptable geometric deviation for fabric is:
Length and width: ±25mm or ±0.5% bigger number
Distance of wire: ±10mm or ±7.5% bigger number
4.1.9 Recommended longitudinal spacing is multiple of 50mm and should not be smaller than 100mm
Recommended transverse spacing is multiple of 25mm and should not be smaller than 100mm
4.2 Geometric shape of common fabric
Wire of common fabric have same nominal diameter , same spacing. Diameter and spacing in 2 direction can be different.
All wires in a same direction have a same length.
Overhang is not smaller than 25mm
4.3 Geometric shape of designed fabric
Common designed fabric is described in 4.2
Geometric shape and dimension of designed fabric must be due to a agreement of manufacturer and buyer and be shown in drawing
Overhang part, u, is not smaller than 25mm
5. Chemical composition
Based on:
TCVN 6288 for cool-drawn wire
TCVN 1651-1 for mild round steel bar
TCVN1651-2 for deformed steel bar
6. Mechanic characteristic
Traction test and bend test must meet the requirement of these below standards:
TCVN 6288 for cool- drawn wire
TCVN 1651-1 for mild round steel bar
TCVN 1651-2 for deformed steel bar
Strength of joint, (N), equals at least 30% yield stress x cross sectional area of the largest wire
7. Mechanic test
Test is made on wire from mesh’s structure at given condition.
Sample can be heat up to 100oC and then cool down to test temperature.
7.1 Traction test
Based on TCVN197. Calculated length of sample is 5 times of nominal diameter and having at least one long wire. Distance between 2 terminal points is at least 20 times of nominal diameter and not smaller than 180mm
The un-test wire is cut 20mm from joint for twin wire mesh
Use cross sectional area for calculating yield stress and untimate tension
7.2 Bend test
Based on TCVN 6287
Sample must be taken from the biggest single wire from both direction for single wire mesh and from twin wire for twin wire mesh.
Length of sample is at least 200mm and has no long wire.
Sample is bent with a angle from 160o to 180o based on:
TCVN 6288 for cool-drawn wire
TCVN 1651-1 for mild round steel bar
TCVN 1651-2 for deformed steel bar
Bending angle must be measured before discharging
7.3 Strength of joint
Based on ISO 10287
Recommended tested joints with smallest dimension is as picture . For more joints tested, the sample can have one or more joints, depending on distance between wires.
For single wire mesh in both direction, bigger wire is pulling one
For twin wire mesh, one wire is pulling one. The other is cut and not impacting on the joint.
Tested sample passed the traction test can be used for this test unless a defective point is in welding area.
8. Notation
8.1 Common fabric
Common fabric is noticed as followed rank:
Wire mesh TCVN 1651-3
Distance between wires in longitudinal direction and transversal direction: (mm)
Length x Width: (m)
Label of wire in longitudinal and transversal directions according to current national standard.
8.2 Designed wire mesh
Designed wire mesh in this standard is noticed as followed rank:
Wire mesh 1651-3
D ( for designed)
Length x Width (m)
Number of drawing
Position *
Label of wire according to current national standard.
9. Label
Every package has to be labeled by manufacturer, number of this standard and number of test certificate. For designed wire mesh, add position *
10. Certificate and Inspection
Made by a third party, based on ISO 11082
Followed a test method for special supply
10.1 Certificate system
Based on ISO 11082
10.2 Test of special supply
Rules of characteristics, scope and judgment of acceptable test on supplying wire mesh which is not mentioned in certificate system will be mentioned in article 10.3 and 10.4
Test for special supply must be obeyed article 10.3
If there is an agreement between seller and buyer, can use 10.4
10.3 Inspection for adequacy
10.3.1 Organization
Based on agreement between buyer and seller, considering rule of import country
10.3.2 Scale of samples and test
10.3.2.1 Test on quantitative sign
For specific characteristic:
All separate value, Xi of 15 samples ( n=15)
Average value m15 ( for n-15)
Standard deviation, S15 ( for n=15). Sample will meet the requirement if :
M15-2.33x S15≥fk
With:
Fk: required special value
2.33: value of acceptable value k with n=15 and defective ratio is 5% (p=0.95), probability 90%
If it does not meet the above, index k’= (m15-fk)/s15 is calculated from available result. If k’≥2, the test can be continued. This requires 45 another samples from different wire meshes. Total samples are 60
Test unit is passed if: m60-1.93x s60 >fk
10.3.2.2 Test on eliminated sign
When characteristics is considered as the biggest or smallest value, all results taken from 15 samples must obeyed this standard, in case of the results meet all requirements.
Test can be continued when there are 2 results, as maximum, not meeting the requirement. In this case, test 45 next samples from different wire meshes. The test unit will be passed if 02 of 60, as maximum, don’t meet the requirements.
10.4 Test on secured smallest value
Products have to be devised into test unit which has maximum weight as 50 tons, or a part of it. Each test unit includes products with same nominal diameter and producing package.
Each unit is tested for one mechanic characteristic. Each separated result must meet the requirement in article 6
If any result don’t meet the requirement, test again, based on TCVN4399
Manufacturer must submit a report which shows products meeting the mechanic characteristic in articale 6 and confirming that other requirements are met.
