SIST-TP CEN/TR 15481:2007

Welding of reinforcing steel - Tack weldability - Test methods and performance requirements

This Technical Report presents a method to verify the  tack weldability of reinforcing steel. The purpose is to ensure that sufficient strength and ductility will remain in the welded material when short welding times are applied. This Technical Report does not cover the welded joint itself.

Schweißen von Betonstahl - Heftschweißeignung - Prüfverfahren und Anforderungen bei der Durchführung der Prüfung

Soudage des aciers pour armature - Soudabilité au pointage - Méthodes d'essai et exigences de performances

Le présent Rapport technique présente une méthode permettant de vérifier la soudabilité au pointage des aciers pour armature. Le but est de s'assurer que le matériau présente encore une résistance et une ductilité suffisantes après avoir été soudé avec un temps de soudage court. Le présent Rapport technique ne couvre pas le joint soudé proprement dit.

Varjenje betonskega jekla – Varivost spenjalnih varkov – Preskusne metode in zahteve za izvedbo

General Information

• Status: Published
• Publication Date: 31-Mar-2007
• ICS: 25.160.10 - Welding processes
• Technical Committee: VAR - Welding
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2007
• Due Date: 01-Apr-2007
• Completion Date: 01-Apr-2007
• Ref Project: CEN/TR 15481:2006 - Welding of reinforcing steel - Tack weldability - Test methods and performance requirements

Overview

SIST-TP CEN/TR 15481:2007 is a European Technical Report established by CEN/TC 121 focused on the tack weldability of reinforcing steel. It provides standardized test methods and performance requirements to assess the suitability of reinforcing steel for tack welding processes. The primary goal is to ensure that the steel retains sufficient strength and ductility after tack welding, particularly when short welding times are employed.

This standard does not cover the welded joint itself but concentrates on the material's behavior under tack welding conditions, thereby supporting quality control in welding reinforcing steel for concrete structures.

Key Topics

• Test Methods: Detailed procedures for performing tack weldability tests using welding process 135 (metal active gas welding). Verification also applies to processes 111, 114, 136, 21, and 23 down to 0 °C.

• Test Piece Preparation: Specifications for welding a row of at least ten tack welds on straight reinforcing steel bars, with focus on tack placement to minimize interference with ribs.

• Chemical Composition: Requirements are aligned with relevant standards for weldable reinforcing steels, ensuring material compatibility.

• Testing Procedures:

  • Tensile Testing: Conducted in accordance with EN ISO 15630-1 to verify yield strength, tensile strength, and elongation in the welded material.
  • Bend Testing: Performed to evaluate ductility, requiring a minimum bend angle of 90° around mandrels sized according to bar diameter.

• Performance Requirements:

  • Welded samples must meet or exceed mechanical properties stipulated in the steel’s product specification.
  • Average reduction in yield strength must not exceed 5% compared to unwelded samples.
  • Visual inspection post-bend test to ensure no cracks visible to the naked eye.

• Extent and Validity of Testing: At least two batches per steel grade and delivery condition, with multiple tests per batch to ensure consistency. Validity depends on consistent steel grade, production route, carbon equivalent, and bar diameter.

• Evaluation Criteria: Test results are evaluated per steel grade and size, with allowance for limited statistical analysis due to sample size constraints. Re-tests are permissible under certain failure conditions.

• Identification: Steels passing the tack weldability tests should be marked as compliant according to this Technical Report.

Applications

The methods and requirements set out in SIST-TP CEN/TR 15481:2007 are crucial for:

• Quality Assurance in Welding Reinforcement Bars: Ensuring welds formed by tack welding during rebar assembly retain necessary mechanical properties.
• Structural Engineering: Enhancing reliability of reinforced concrete by verifying steel compatibility with welding processes commonly used in construction and prefabrication.
• Construction Standards Compliance: Meeting regulatory and project-specific welding quality criteria for infrastructure, buildings, and civil engineering works.
• Material Procurement and Certification: Assisting manufacturers and suppliers in certifying reinforcing steel that meets tack weldability standards to optimize downstream usage.
• Testing Laboratories: Providing clear, harmonized procedures for laboratories conducting tack weldability assessments.

Related Standards and References

• EN ISO 15630-1: Steel for reinforcement and prestressing - Test methods for reinforcing bars, wire rod, and wire.
• EN ISO 4063: Welding and allied processes - Nomenclature and reference numbers relevant to welding methods cited.
• EN 439: Welding consumables - Shielding gases for arc welding and cutting.
• EN 440: Welding consumables - Wire electrodes and deposits for gas-shielded metal arc welding.

These related standards complement CEN/TR 15481 by providing foundational guidance on welding processes, consumables, and mechanical testing protocols applicable to reinforcing steel.

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Keywords: tack weldability, reinforcing steel, welding test methods, performance requirements, tack welding, tensile test, bend test, steel quality, welded reinforcing bars, EN ISO 15630-1, CEN technical report, welding standards, reinforcing steel welding.

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-2007
Varjenje betonskega jekla – Varivost spenjalnih varkov – Preskusne metode in
zahteve za izvedbo
Welding of reinforcing steel - Tack weldability - Test methods and performance
requirements
Schweißen von Betonstahl - Heftschweißeignung - Prüfverfahren und Anforderungen bei
der Durchführung der Prüfung
Soudage des aciers pour armature - Soudabilité au pointage - Méthodes d'essai et
exigences de performances
Ta slovenski standard je istoveten z: CEN/TR 15481:2006
ICS:
25.160.10 Varilni postopki in varjenje Welding processes
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

TECHNICAL REPORT
CEN/TR 15481
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
December 2006
ICS 25.160.01
English Version
Welding of reinforcing steel - Tack weldability - Test methods
and performance requirements
Soudage des aciers pour armature - Soudabilité au Schweißen von Betonstahl - Heftschweißeignung -
frointage - Méthodes d'essai et exigences de performances Prüfverfahren und Anforderungen bei der Durchführung der
Prüfung
This Technical Report was approved by CEN on 27 July 2006. It has been drawn up by the Technical Committee CEN/TC 121.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 15481:2006: E
worldwide for CEN national Members.

Contents Page
Foreword.3
1 Scope .4
2 Normative references .4
3 Chemical composition .4
4 Welding processes .4
5 Test piece .4
6 Testing and performance requirements.5
7 Extent of testing.6
8 Evaluation of test results .7
9 Identification.7
Bibliography .8

Foreword
This document (CEN/TR 15481:2006) has been prepared by Technical Committee CEN/TC 121 “Welding”,
the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
1 Scope
This Technical Report presents a method to verify the tack weldability of reinforcing steel. The purpose is to
ensure that sufficient strength and ductility will remain in the welded material when short welding times are
applied. This Technical Report does not cover the welded joint itself.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
EN ISO 4063, Welding and allied processes - Nomenclature of processes and reference numbers (ISO
4063:1998)
EN ISO 15630-1, Steel for the reinforcement and prestressing of concrete — Test methods — Part 1:
Reinforcing bars, wire rod and wire (ISO 15630-1:2002)
3 Chemical composition
The restrictions to the chemical composition should be in accordance with the relevant standard for the
weldable reinforcing steel concerned.
4 Welding processes
The tack weldability test is carried out by welding process 135 (see EN ISO 4063). Tack weldability is also
considered verified for the welding processes 111, 114, 136, 21 and 23 down to 0 °C.
5 Test piece
The test piece is made by welding a straight row of tacks in accordance with Table 1 and Figure 1 on straight
pieces of the reinforcing steel bar with a length suitable for tensile and bending t
...