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DRAFT UGANDA STANDARD

DUS DEAS 412-3

First Edition 2018-mm-dd

Reference number DUS DEAS 412-3: 2018

© UNBS 2018

Steel for the reinforcement of concrete — Part 3: Welded fabric

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DUS DEAS 412-3: 2018

ii © UNBS 2018 - All rights reserved

Compliance with this standard does not, of itself confer immunity from legal obligations

A Uganda Standard does not purport to include all necessary provisions of a contract. Users are responsible for its correct application

© UNBS 2018

All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any form or by any means, electronic or mechanical, including photocopying and microfilm, without prior written permission from UNBS.

Requests for permission to reproduce this document should be addressed to

The Executive Director Uganda National Bureau of Standards P.O. Box 6329 Kampala Uganda Tel: +256 417 333 250/1/2 Fax: +256 414 286 123 E-mail: info@unbs.go.ug Web: www.unbs.go.ug

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DUS DEAS 412-3: 2018

© UNBS 2018 - All rights reserved iii

National foreword

Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry of Trade, Industry and Cooperatives established under Cap 327, of the Laws of Uganda, as amended. UNBS is mandated to co-ordinate the elaboration of standards and is

(a) a member of International Organisation for Standardisation (ISO) and

(b) a contact point for the WHO/FAO Codex Alimentarius Commission on Food Standards, and

(c) the National Enquiry Point on TBT Agreement of the World Trade Organisation (WTO).

The work of preparing Uganda Standards is carried out through Technical Committees. A Technical Committee is established to deliberate on standards in a given field or area and consists of representatives of consumers, traders, academicians, manufacturers, government and other stakeholders.

Draft Uganda Standards adopted by the Technical Committee are widely circulated to stakeholders and the general public for comments. The committee reviews the comments before recommending the draft standards for approval and declaration as Uganda Standards by the National Standards Council.

This Draft Uganda Standard, DUS DEAS 412-3:2018, Steel for the reinforcement of concrete — Part 3: Welded bars, is identical with and has been reproduced from an East African Standard, EAS 412-3:2018, Steel for the reinforcement of concrete — Part 3: Welded bars, and is being proposed for adoption as a Uganda Standard.

This standard was developed by Mechanical engineering and metallurgy Standards Technical Committee (UNBS/TC 4).

This second edition cancels and replaces the first edition (US EAS 412-3:2013), which has been technically revised.

Wherever the words, “East African Standard " appear, they should be replaced by "Uganda Standard."

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DEAS 412-3

DRAFT EAST AFRICAN STANDARD DEAS 412-3:2018 - Steel for the reinforcement of concrete —Part 3: Welded Fabric

EAST AFRICAN COMMUNITY

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DEAS 412-3

Copyright notice

This EAC document is copyright-protected by EAC. While the reproduction of this document by participants in the EAC standards development process is permitted without prior permission from EAC, neither this document nor any extract from it may be reproduced, stored or transmitted in any form for any other purpose without prior written permission from EAC.

Requests for permission to reproduce this document for the purpose of selling it should be addressed as shown below or to EAC’s member body in the country of the requester:

© East African Community 2016 — All rights reserved East African Community P.O. Box 1096 Arusha Tanzania Tel: 255 27 2504253/8 Fax: 255 27 2504481/2504255 E-mail: eac@eachq.org

Web: www.eac-quality.net

Reproduction for sales purposes may be subject to royalty payments or a licensing agreement. Violators may be prosecuted.

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DEAS 412-3

Foreword Development of the East African Standards has been necessitated by the need for harmonizing requirements governing quality of products and services in the East African Community. It is envisaged that through harmonized standardization, trade barriers that are encountered when goods and services are exchanged within the Community will be removed.

In order to achieve this objective, the Community established an East African Standards Committee mandated to develop and issue East African Standards.

The Committee is composed of representatives of the National Standards Bodies in Partner States, together with the representatives from the private sectors and consumer organizations. Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the Partner States. The comments received are discussed and incorporated before finalization of standards, in accordance with the procedures of the Community.

East African Standards are subject to review, to keep pace with technological advances. Users of the East African Standards are therefore expected to ensure that they always have the latest versions of the standards they are implementing.

CD/TZ/6:2016 was prepared by Technical Committee EASC/TC 035 Steel and Steel Products

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DEAS 412-3

EAST AFRICA DRAFT STANDARD

Steel for the reinforcement of concrete —

Part 3: Welded Fabric

1 Scope

This part of East Africa Draft Standard specifies technical requirements for factory made sheets or rolls of welded fabric, manufactured from steel wires or bars with diameters from 2.5 mm to 16 mm and designed for the reinforcement of concrete structures and the ordinary reinforcement of pre stressed concrete structures. For the purpose of this part of DEAS 412-3 the term “wire” also includes bars.

2 Normative references

The following East Africa Draft Standard contain provisions which, through reference in this text, constitute provisions of this part of East Africa Draft Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of IS0 6935 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and IS0 maintain registers of currently valid International Standards. IS0 404:1992, Steel and steel products – General technical delivery requirements. IS0 6892:1984, Metallic materials - tensile testing.

DEAS 412-1:2018, Steel for the reinforcement of concrete- Part 1: Plain bars.

DEAS 412-2:2018, Steel for the reinforcement of concrete - Part 2: Ribbed bars.

IS0 10065:1990, Steel bars for reinforcement of concrete - Bend and rebend tests. IS0 10287: --1), Steel for the reinforcement of concrete - Determination of strength of joints in welded fabric.

IS0 10544: -1), Cold-reduced steel wire for the reinforcement of concrete and the manufacture of welded fabric. IS0 11082: --1), Certification scheme for -welded fabric for the reinforcement of concrete structures

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3 Definition

For the purposes of this part of East Africa Draft Standard, the following definitions apply. 3.1 test unit: The number of pieces or the tonnage of products to be accepted or rejected together, on the basis of the tests to be carried out on sample products in accordance with the requirements of the product standard or order. [ISO 4041 3.2 certification scheme: Certification system as related to specified products, processes or services to which the same particular standards and rules, and the same procedure, apply. (ISO/IEC Guide 21) 3.3 characteristic value: Value having a prescribed probability of not being attained in a hypothetical unlimited test series. [ISO 89301 NOTE 1 Equivalent to fractile, which is defined in IS0 3534.

3.4 fabric: A geometrical arrangement of longitudinal and transverse wires that are arranged substantially at right angles to each other and welded together at all points of intersection.

3.5 inspection: Activities such as measuring, examining, testing, gauging one or more characteristics of a product or service and comparing these with specified requirements to determine conformity. [ISO 8402) 3.6 length of fabric: The longest side of the fabric, irrespective of the manufacturing direction.

3.7 longitudinal wire: Wire in the manufacturing direction of the fabric.

3.8 nominal cross-sectional area: The cross-sectional area equivalent to the area of a circular plain wire of nominal diameter.

3.9 overhang: The length of longitudinal or transverse wires beyond the centre of the outer crossing wire in a fabric. For twin wire fabric, the overhang is measured from the tangent line of the adjacent wires. (See figure I.)

3.10 spacing: The centre-to-centre distance of wires in a fabric. For twin wire fabric, the spacing is measured between tangents of the adjacent wires. (See figure I.)

3.11 transverse wire: Wire perpendicular to the manufacturing direction of the fabric. 3.12 twin wires: Two wires of the same type and size placed adjacently and in contact with each other as a pair. 3.13 width of fabric: The shortest side of the fabric irrespective of the manufacturing direction. 3.14 wire: The material from which the fabric is welded.

NOTE 2 For the purposes of this part of IS0 6935, the term “wire” also includes bars within the size range specified in 4.1 .l.

4 Form and dimensions This part of East Africa Draft Standard covers regular fabric (4.2) and designed fabric (4.3

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4.1 General requirements 4.1.1 The fabric shall be made of either - cold-reduced wires with nominal diameters in the range from 2 .5 mm to 16 mm (recommended:2.5, 3, 4, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm and 12 mm) and with mass and geometry complying with IS0 10544; Or

- plain bars with nominal diameters of 6 mm,8 mm, 10 mm, 12 mm or 16 mm (recommended: 6 mm, 8 mm, 10 mm and 12 mm) and with mass complying withDEAS 412-1;

Or

- ribbed bars with nominal diameters of 6 mm, 8 mm, 10 mm, 12 mm or 16 mm (recommended: 6 mm, 8 mm, 10 mm and 12 mm) and with mass and geometry complying withDEAS 412-2.

4.1.2 All fabric shall be machine made, and the joints at the intersections of the longitudinal ‘and transverse wires shall be made by electrical resistance welding to provide shear resistant connections complying with clause 6 4.1.3 Each sheet of fabric shall contain the number of wires appropriate to its specified length, width, spacing and overhang dimensions as in annex 1 The number of broken welds shall not exceed either 1 % of the total number of cross-welded joints in the sheet or half the number of cross-welded joints along any one wire.

4.1.4 Fabric shall be free from any defect which can be shown to affect adversely the mechanical properties of the steel. Fabric including butt-welded wires shall be permitted and missing wires resulting from test sampling in accordance with clause 7 shall not be considered as defects. 4.1.5 The longitudinal wires may be single or twin wires. The transverse wires shall be single wire 4.1.6 The diameters of crossing wires in single wire fabric shall meet the following requirement: d min ≥0.36 d max where

d max is the nominal diameter of the thickest wire; d min is the nominal diameter of the wire. For twin-wire fabric, the wire diameters shall meet the following requirement: 0.7dT < d L < 1.25 d T, where

d T is the nominal diameter of the transverse wire;

d L is the nominal diameter of one of the twin wires. 4.1.7 The dimensions of the fabric shall be specified as gross length in both directions.

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The preferred sheet sizes, to be 4.2 m x 2.1 m and 4.8 m x 2.4 m. The preferred roll sizes, to be 30m x 2.1 m, 30 m x 2.4 m, 48 m x 2.1 m, and 48 m x 2.4 m. The length and width of the sheet or roll to be measured from the tips of the overhangs 4.1.8 The permitted are geometric deviations for fabric are: The tolerance on the cold reduced wire diameter of the welded fabric shall be ± 2.5 % of the nominal diameter and for hot rolled wires the mass per metre length tolerances in respective material standards shall apply Wire Spacing: ± 10mm or ± 7.5% whichever is greater Deviations on the dimensions of the sheet or roll shall be + 25 mm for lengths of up to 5m, and +0.5% for lengths exceeding 5m. Tolerance on the mass of fabric shall be +6% or -4%. 4.1.9 The recommended spacing of longitudinal wires is a multiple of 50 mm and preferably not less than 100 mm. The recommended spacing of transverse wires is a multiple of 25 mm and preferably not less than 100 mm. 4.2 Geometry of regular fabric Regular fabric is characterized by having wires of equal nominal diameter across the length and width of the fabric. The spacing is also constant in each direction. The wire diameters and spacing may differ for the two directions. All the wires in one direction shall be of equal length. The recommended overhang, u, is not less than 25 mm. The preferred mesh sizes, wire sizes and mass per square metre shall be as given in Tables 2, 3, 4 and 5 on Annex K 4.3 Geometry of designed fabric Designed fabric differs from regular fabric, which is described in 4.2. The geometry and dimensions of designed fabric shall be agreed between the manufacturer and purchaser, and shall be specified on a-drawing. The recommended overhang, U, is not less than 25 mm 5 Chemical composition The chemical composition of the welded fabric shall comply with the product analysis requirements of - IS0 10544 for cold-reduced wires; DEAS 412-1 for plain bars; - DEAS 412-2 for ribbed bars. 6 Mechanical properties The tensile and bending properties of the welded fabric shall comply with the requirements of - IS0 10544 for cold-reduced wires; - DEAS 412-1 for plain bars; - DEAS 412-2 for ribbed bars. The strength of the welded joints, in newtons, shall be at least 30 % of the specified characteristic yield or proof stress multiplied by the nominal cross-sectional area of the thickest wire.

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7 Testing of mechanical properties

The testing shall be done on wires taken from the fabric in the delivery condition. The test piece shall not be worked before testing but it may be heated to 100 “C and then cooled freely in air to the test temperature. 7.1 Tensile test The tensile properties shall be determined according to IS0 6892. The test piece shall have an original gauge length of five times the nominal diameter and shall have at least one crossing wire. The free distance between the grips shall be at least 20 times the nominal diameter, and not less than 180 mm. In fabric with twin wires, the wire which is not under test shall be cut off approximately 20 mm from the joints. For calculation of yield or proof stress and tensile strength, the nominal cross-sectional area of the wire shall be used. 7.2 Bend test The bend test shall be carried out according to IS0 10065 The test piece shall be taken from the thickest wire in fabric with single wires in both directions. In the case of twin-wire fabric, the test piece shall be taken from the twin wire. The length of the test piece shall be at least 200 mm, and it shall be free from crossing wires in the length subject to bending. The test piece shall be bent to an angle between 160” and 180’ over a mandrel of the diameter specified in - IS0 10544 for cold-reduced wires; - DEAS 412-1 for plain bars; - DEAS 412-2 for ribbed bars.

The angle of bend shall be measured before unloading.

Figure 2

7.3 Strength of welded joints

The joints shall be tested according to IS0 10287. A test piece with the recommended minimum dimensions

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shown in figure2 shall be cut from the fabric. In addition to the weld to be tested, the test piece may have one or more welds, depending on the spacing. For fabric with single wires in both directions, the thicker wire shall be used as the pulling wire. For fabric with twin wires, one of the twin wires shall be the pulling wire. The other twin wire is cut off from the crossing wire without affecting the weld under test. Test pieces previously subjected to tensile testing -may be used for the weld shear test, provided that the necking at the fracture is clear of the weld zone

8 Designation

8.1 Regular fabric

Regular fabric shall be designated in the following order: - welded fabric DEAS 412-3 - spacing in the direction of length and width respectively, in millimetres; - length x width, in metres; - designation of the wires in the direction of length and width respectively, according to the International Standard whose requirements shall apply

Example of designation of regular fabric:

Welded fabric DEAS 412-3 - 150 mm x 200 mm -5 m x 2 m, reinforcing steel IS0 10544, 8 mm indented,

Reinforcing steel IS0 10544 6 mm indented.

8.2 Designed fabric

Designed fabric according to this part of IS0 6935 should be designated in the following order:

- welded fabric DEAS 412-3;

- D (for designed);

- length x width, in metres;

- drwg. No. (for drawing);

- pos. No. (for position);

- designation of the wires according to the International Standard whose requirements shall apply.

Example of designation of designed fabric:

Welded fabric DEAS 412-3-D 6,2 m x 3,4 m, drwg. No. 318 - pos. No. 3, Reinforcing steel IS0 693592- 16 RB 5OOW, Reinforcing steel IS0 6935-l -10 PB 300

9 Marking Each bundle of welded fabric shall have a label stating the manufacturer, the number of this part of East Africa Draft Standard (DEAS 412-3 ) and a reference number related to the test certificate. For designed fabric, the position number shall be included.

Each sheet and each bundle shall be legibly and indelibly marked as follows;

Each sheet shall be marked with manufacturers name or logo, steel grade and nominal diameter

Each bundle shall be marked with manufacturers name or logo, steel grade, nominal diameter and batch / cast

number

Roll and sheet of width 2.1m shall in addition be marked with a strip of paint of color code RAL 1003 YELLOW along the length atleast 200mm deep

10 Certification and inspection Certification and inspection of reinforcement shall be performed

- in accordance with a certification scheme monitored by an external body, see IS0 11082; - according to testing of a specific delivery.

10.1 Certification scheme In the case of certification scheme, certification and inspection shall be performed in accordance with IS0 11082.

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10.2 Testing of a specific delivery Provisions regarding the nature, extent and evaluation of acceptance tests on deliveries of welded fabric not subject to a certification scheme are given in 10.3 and 10.4. Testing of a specific delivery shall be performed according to 10.3. By agreement between manufacturer and purchaser, 10.4 may be used. 10.3 Verification of conformity 10.3.1 Organization The tests shall be organized and carried out according to an agreement between purchaser and manufacturer, taking into consideration the national rules of the receiving country.

10.3.2 Extent of sampling and testing

For the purpose of testing, the delivery shall be subdivided into test units with a maximum mass of 25 t or a

fraction thereof. Each test unit shall consist of products of the same fabric type and from the same production

lot.

Fifteen test pieces (if appropriate 60 test pieces; see10.3.3.1) from various fabrics shall be taken from each test unit

10.3.3 Evaluation of the results 10.3.3.1 Inspection by variables For properties, which are specified as characteristic values, the following shall be determined:

a) all individual values, xi, of the 15 test pieces (n = 15);

b) the mean value m15 (for n = 15);

c) the standard deviation s15, (for n = 15).

The test unit corresponds to the requirements if the condition stated below is fulfilled for all properties:

M15 – 2.33 x s15 ≥ f k where

f k is the required characteristic value;

2,33 is the value for the acceptability index k for n = 15 for a failure rate of 5 %A0

ρ, = 095) at a probability of 90 % (1 - α = 0.90). If the condition stated above is not fulfilled, the index

is determined from the test results available. Where k’ > 2, testing can be continued. In this case 45 additional

test pieces shall be taken and tested from various fabrics, so that a total of 60 test results are available (n=60). The test unit shall be considered to comply with the requirements if the condition stated below is fulfilled for all properties.

M60 - 1393 x S60) > fk

where I.93 is the value for the acceptability index k for n = 60 for a failure rate of 5 % (p = 0,95) at a probability of 90 % (1 - α = 0,90).

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10.3.3.2 Inspection by attributes When testing properties specified as maximum or minimum values, all results determined on the 15 test pieces shall comply with the requirements of this part of East Africa Draft Standard. In this case the test unit shall be considered to comply with the requirements. The tests can be continued when at most 2 results not conforming to conditions occur. In this case 45 further test pieces from various fabrics in the test unit shall be tested, so that a total of 60 test results are available’. The test unit complies with the requirements if at most 2 of the 60 results do not conform to the conditions. 10.4 Verification of guaranteed minimum values Tests shall be carried out according to the following. Tests shall be carried out according to the following. - For the purpose of testing, the delivery shall be subdivided into test units with a maximum mass of 50 t or a fraction thereof. Each test unit shall consist of products of the same nominal diameter from the same production lot. -For each mechanical property’ specified, one test shall be carried out for each-test unit. Each individual test result shall meet the requirements specified in clause 6. - If any test result does not meet the requirements, retests may be carried out, according to IS0 404 -the manufacturer shall submit a test report stating that products of the delivery satisfy the mechanical properties specified in clause 6 and a confirmation that the other requirements of this part of IS0 6935 are fulfilled.

11 Test report The test report shall contain the following information:

a) works producing the welded fabric;

b) designation of the fabric according to clause 8;

c) number on the bundle;

d) name of the organization carrying out the test, if appropriate;

e) date of testing;

f) mass of the test unit;

g) test results.

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Weld mesh dimensions

Mesh Reference

Size

Box Size (Pitch of wires, mm)

Wire Diameter (mm) Sheet Size (mm) Overhang

Number of wires nominally

Mass Per Sheet (kg)

Main Cross Main Cross Lengt

h Width Main Cross

Length

Width Nomin

al Cross Main

WM 5030 50 x 50 x 3 50 50 3.0 3.0 2440 1220 25.0 25.0 49 24 6.6

WM 5035 50 x 50 x 3.5 50 50 3.5 3.5 2440 1220 25.0 25.0 49 24 8.9

WM 5040 50 x 50 x 4 50 50 4.0 4.0 2440 1220 25.0 25.0 49 24 11.7

WM 6030 60 x 60 x 3 60 60 3.0 3.0 2440 1220 30.0 30.0 41 20 5.5

WM 6040 60 x 60 x 4 60 60 4.0 4.0 2440 1220 30.0 30.0 41 20 9.7

WM 6530 65 x 65 x 3 65 65 3.0 3.0 2440 1220 32.5 32.5 38 19 5.1

WM 6535 65 x 65 x 3.5 65 65 3.5 3.5 2440 1220 32.5 32.5 38 19 7.0

WM 6540 65 x 65 x 4 65 65 4.0 4.0 2440 1220 32.5 32.5 38 19 9.1

WM 7525 75 x 75 x 2.5 75 75 2.5 2.5 2440 1220 37.5 37.5 33 16 3.1

WM 7530 75 x 75 x 3 75 75 3.0 3.0 2440 1220 37.5 37.5 33 16 4.4

WM 7535 75 x 75 x 3.5 75 75 3.5 3.5 2440 1220 37.5 37.5 33 16 6.0

WM 7540 75 x 75 x 4 75 75 4.0 4.0 2440 1220 37.5 37.5 33 16 7.8

WM 7540 75 x 75 x 5 75 75 5.0 5.0 2440 1220 37.5 37.5 33 16 12.2

BM 5030 50 x 50 x 3 50 50 3.0 3.0 1830 915 25.0 25.0 37 18 3.7

BM 5035 50 x 50 x 3.5 50 50 3.5 3.5 1830 915 25.0 25.0 37 18 5.0

BM 5040 50 x 50 x 4 50 50 4.0 4.0 1830 915 25.0 25.0 37 18 6.6

BM 6530 65 x 65 x 3 65 65 3.0 3.0 1830 915 32.5 32.5 28 14 2.8

BM 6535 65 x 65 x 3.5 65 65 3.5 3.5 1830 915 32.5 32.5 28 14 3.9

BM 6540 65 x 65 x 4 65 65 4.0 4.0 1830 915 32.5 32.5 28 14 5.1

BK 5030 50 x 50 x 3 50 50 3.0 3.0 1830 760 25.0 25.0 37 15 3.1

BK 5035 50 x 50 x 3.5 50 50 3.5 3.5 1830 760 25.0 25.0 37 15 4.2

BK 5040 50 x 50 x 4 50 50 4.0 4.0 1830 760 25.0 25.0 37 15 5.5

BK 6530 65 x 65 x 3 65 65 3.0 3.0 1830 760 32.5 32.5 28 12 2.4

BK 6535 65 x 65 x 3.5 65 65 3.5 3.5 1830 760 32.5 32.5 28 12 3.3

BK 6540 65 x 65 x 4 65 65 4.0 4.0 1830 760 32.5 32.5 28 12 4.3

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Rectangular Mesh

50 x 25 x 2.5 50 25 2.5 2.5 2440 1220 25.0 12.5 98 24 6.9

50 x 25 x 3 50 25 3.0 3.0 2440 1220 25.0 12.5 98 24 9.9

50 x 25 x 4 50 25 4.0 4.0 2440 1220 25.0 12.5 98 24 17.6

75 x 25 x 2.5 75 25 2.5 2.5 2440 1220 37.5 12.5 98 16 6.1

75 x 25 x 3 75 25 3.0 3.0 2440 1220 37.5 12.5 98 16 8.8

75 x 25 x 4 75 25 4.0 4.0 2440 1220 37.5 12.5 98 16 15.6

75 x 30 x 3 75 30 3.0 3.0 2440 1220 37.5 15.0 81 16 7.6

75 x 30 x 4 75 30 4.0 4.0 2440 1220 37.5 15.0 81 16 13.6

a) WM denotes weld mesh. b) BM and BK denote bed mesh