prEN 10138-3

Prestressing steels - Part 3: Bars

This document specifies the requirements and definitions for the essential characteristics of prestressing bars, which are used for the prestressing of concrete and which are delivered as finished products in the form of:
-   hot rolled and processed bars;
-   plain and threaded bars.
NOTE 1   The specification of manufacturing processes related to the finished product is required to ensure that the essential characteristics can be tested properly and that test results are valid. It is not possible to anticipate that any other manufacturing process leads to products which can be tested properly with the specified test methods. Thus, a conclusion to the safe application in building construction would not any longer be possible for those products.
This document does not apply to:
-   galvanized steel;
-   epoxy coated steel;
-   reinforcing steel (see EN 10080);
-   further processing.
NOTE 2   Example for further processing: Plain bars are also applied in systems for the prestressing of concrete with threaded ends. The threaded ends depend in length and type on the intended use of the system and are manufactured downstream in the supply chain.

Spannstähle - Teil 3: Stäbe

Diese Europäische Norm legt allgemeine Anforderungen und Definitionen für die Leistungsmerkmale von Spannstäben fest, die für das Vorspannen von Betonbauwerken verwendet und als Fertigerzeugnis geliefert wird in Form von:
-   warmgewalzten und verarbeiteten Stäben;
-   glatten oder gerippten Stäben
ANMERKUNG 1   Die Spezifikation des Herstellungsverfahrens ist erforderlich, um sicherzustellen, dass die wesentlichen Merkmale ordnungsgemäß getestet werden können und dass die Prüfergebnisse gültig sind. Es ist nicht vorhersehbar, dass ein weiterer Herstellungsprozess zu Erzeugnissen führt, die mit den angegebenen Prüfmethoden ordnungsgemäß getestet werden können. Als Schlussfolgerung: eine sichere Anwendung wäre im Hochbau für diese Produkte nicht mehr möglich.
Diese Europäische Norm gilt nicht für
-   verzinkten Betonstahl;
-   epoxibeschichteten Betonstahl;
-   Betonstahl (siehe EN 10080);
-   Weiterverarbeitung.
ANMERKUNG 2   Beispiel für die Weiterverarbeitung: Glatte Stäbe sind auch als Gewindestäbe zum Vorspannen von Beton eingesetzt. Die Gewindelänge an den Stabenden hängt von dem Bautyp ab und wird nachträglich in der Lieferkette hergestellt.

Armatures de précontrainte en acier - Partie 3 : Barres

Le présent document spécifie les prescriptions et les définitions des caractéristiques essentielles des barres de précontrainte utilisées pour la précontrainte du béton et livrées en tant que produits finis sous forme de :
-   barres laminées à chaud et traitées ;
-   barres lisses et filetées.
NOTE 1   La spécification des procédés de fabrication relatifs au produit fini est requise pour assurer que les caractéristiques essentielles peuvent être soumises à essai correctement et que les résultats d’essais sont valides. Il n'est pas possible de prévoir qu'un autre procédé de fabrication conduise à des produits pouvant être soumis à essai correctement avec les méthodes d'essai spécifiées. Il ne serait donc plus possible de conclure à une application sûre dans la construction de bâtiments pour ces produits.
Le présent document ne s'applique pas à :
-   l'acier galvanisé ;
-   l'acier avec revêtement époxy ;
-   l'acier pour béton armé (voir EN 10080) ;
-   au traitement ultérieur.
NOTE 2   Exemple de traitement ultérieur : Les barres lisses sont également utilisées dans les systèmes de précontrainte du béton avec des extrémités filetées. Les extrémités filetées dépendent, pour leur longueur et leur type, de l'utilisation prévue du système et sont fabriquées en aval de la chaîne d'approvisionnement.

Prednapeta jekla - 3. del: Palice

General Information

• Status: Not Published
• Publication Date: 13-May-2024
• ICS: 77.140.15 - Steels for reinforcement of concrete
• Technical Committee: ECISS/TC 104 - Concrete reinforcing and prestressing steels
• Drafting Committee: CEN/TC 459/SC 4/WG 4 - Pre-stressing steels
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 10-Aug-2023
• Due Date: 21-Mar-2023
• Completion Date: 10-Aug-2023
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Mandate: M/115 REV - Revised mandate M/115 to CEN/CENELEC concerning the execution of standardisation work for harmonized standards on reinforcing and prestressing steel (for concrete)
• Ref Project: oSIST prEN 10138-3:2023 - Prestressing steels - Part 3: Bars

Overview

The prEN 10138-3:2023 standard, developed by CEN, specifies the requirements and definitions for prestressing bars used in concrete reinforcement. These bars are delivered as finished products and include hot rolled and processed bars, both plain and threaded types. The standard ensures that these prestressing steels meet essential mechanical and physical characteristics crucial for safe and reliable use in construction.

This document is part of the broader standardization framework for prestressing steels, focusing exclusively on bars. It excludes galvanized steel, epoxy coated steel, reinforcing steel (covered by EN 10080), and further processing activities such as adding threaded ends after delivery.

Key Topics

prEN 10138-3 covers diverse and practical aspects critical to the quality and performance of prestressing bars:

• Material Specifications
  Defines hot rolled bars and processed bars (treated via accelerated cooling, cold stretching, or tempering), and their suitability as plain or threaded prestressing bars.

• Essential Mechanical Characteristics
  Detailed parameters such as tensile strength, tensile yield strength, stress ratios, modulus of elasticity, elongation at maximum load, relaxation, and fatigue strength are specified to guarantee robust performance in prestressing applications.

• Surface Geometry and Threading
  Differentiates between plain bars and threaded bars, including specifications for thread patterns, rib height, rib spacing, and rib inclination to ensure optimal stress distribution and anchorage in concrete.

• Testing and Quality Control
  Covers assessment and verification of constancy of performance, encompassing factory production controls, product type testing, sampling methods, compliance criteria, retesting protocols, and test reporting.

• Durability and Environmental Resistance
  Includes testing for stress corrosion resistance and conditions for transport, storage, and handling to maintain product integrity from factory to construction site.

• Manufacturing Process Requirements
  Stipulates that only specific manufacturing methods ensure product testability and reliability. This reinforces traceability and validates that prestressing bars safely conform to building construction standards.

Applications

The prEN 10138-3 standard is essential for manufacturers, suppliers, and engineers involved in:

• Prestressed Concrete Construction
  Ensuring bars used in bridges, buildings, and infrastructure projects meet stringent strength and durability requirements.

• Quality Assurance in Steel Production
  Facilitating consistent production of prestressing bars with guaranteed performance through defined processes and testing.

• Safe Design and Engineering
  Enabling design engineers to specify prestressing bars confidently, knowing they comply with standardized essential characteristics and testing protocols.

• Supply Chain Management
  Allowing clear product identification and evaluation based on defined heats, batches, and production runs, minimizing risks during procurement and installation.

Related Standards

prEN 10138-3 complements and references several key standards:

• EN 10020:2000 - Definition and classification of steel grades
• EN 10079:2007 - Definition of steel products
• EN ISO 15630-3:2019 - Test methods for prestressing steels
• EN 10080 - Reinforcing steel (not applicable within prEN 10138-3’s scope)

These referenced standards ensure cohesive terminology, testing methodologies, and product classifications aligned with European steel standards and EU regulations.

---

By adhering to prEN 10138-3, stakeholders in the prestressed concrete industry gain access to a comprehensive framework for producing and utilizing prestressing bars that meet rigorous safety, mechanical, and durability requirements-ensuring structural integrity and long-term performance in demanding construction environments.

Standards Content (Sample)

SLOVENSKI STANDARD
01-julij-2023
Prednapeta jekla - 3. del: Palice
Prestressing steels - Part 3: Bars
Spannstähle - Teil 3: Stäbe
Armatures de précontrainte en acier - Partie 3 : Barres
Ta slovenski standard je istoveten z: prEN 10138-3
ICS:
77.140.15 Jekla za armiranje betona Steels for reinforcement of
concrete
77.140.60 Jeklene palice in drogovi Steel bars and rods
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
May 2023
ICS 77.140.15
English Version
Prestressing steels - Part 3: Bars
Armatures de précontrainte en acier - Partie 3 : Barres Spannstähle - Teil 3: Stäbe
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 459/SC 4.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 10138-3:2023 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols . 8
5 Essential characteristics . 10
5.1 Tensile strength, tensile yield strength, stress ratio (ult. tensile strength/tens. yield
strength), modulus of elasticity and elongation at maximum load . 10
5.2 Relaxation . 10
5.3 Fatigue strength . 11
5.4 Durability . 11
5.5 Surface geometry . 11
5.5.1 Plain bar surface . 11
5.5.2 Thread bar surface for threads over the entire circumference . 11
5.5.3 Thread bar surface for threads over parts of the circumference (two rib rows) . 12
5.6 Section and tolerances . 13
5.6.1 Mass per meter and tolerances . 13
5.6.2 Length of bars . 14
5.6.3 Straightness . 14
6 Assessment and verification of constancy of performance . 17
6.1 General . 17
6.2 Product type testing . 17
6.2.1 General . 17
6.2.2 Test samples and testing . 18
6.2.3 Compliance criteria . 23
6.2.4 Re-testing . 24
6.2.5 Test report . 24
6.3 Factory production control (FPC) . 24
6.3.1 General . 24
6.3.2 Requirements . 24
6.4 Initial inspection of factory and of FPC . 32
6.5 Continuous surveillance of FPC . 32
6.5.1 General . 32
6.5.2 Audit testing of samples taken from the factory . 33
6.5.3 Procedure for modifications . 36
7 Test methods . 36
8 Delivery conditions . 36
8.1 General . 36
8.2 Packaging and handling . 36
8.3 Transport and storage . 37
8.4 Freedom from defects. 37
8.5 Welds . 37
Annex A (normative) Prestressing bars - Stress corrosion test in distilled water . 38
A.1 Scope . 38
A.2 Principle of the test . 38
A.3 Specimen . 38
A.4 Test device . 38
A.5 Test conditions . 39
A.6 Procedure . 40
A.7 Measurements . 40
A.8 Expression of results . 41
A.9 Test report . 41
Annex ZA (informative) Relationship of this European Standard with Regulation (EU)
No.305/2011 . 42
Bibliography . 46
European foreword
This document (prEN 10138-3:2023) has been prepared by Technical Committee CEN/TC 459/SC4
“Concrete reinforcing and prestressing steels”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document has been prepared under a Standardization Request given to CEN by the European
Commission and the European Free Trade Association, and supports essential requirements of EU
Directive(s) / Regulation(s).
For relationship with EU Directive(s) / Regulation(s), see informative Annex ZA, which is an integral part
of this document.
1 Scope
This document specifies the requirements and definitions for the essential characteristics of prestressing
bars, which are used for the prestressing of concrete and which are delivered as finished products in the
form of:
— hot rolled and processed bars;
— plain and threaded bars.
NOTE 1 The specification of manufacturing processes related to the finished product is required to ensure that
the essential characteristics can be tested properly and that test results are valid. It is not possible to anticipate that
any other manufacturing process leads to products which can be tested properly with the specified test methods.
Thus, a conclusion to the safe application in building construction would not any longer be possible for those
products.
This document does not apply to:
— galvanized steel;
— epoxy coated steel;
— reinforcing steel (see EN 10080);
— further processing.
NOTE 2 Example for further processing: Plain bars are also applied in systems for the prestressing of concrete
with threaded ends. The threaded ends depend in length and type on the intended use of the system and are
manufactured downstream in the supply chain.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 10020:2000, Definition and classification of grades of steel
EN 10079:2007, Definition of steel products
EN ISO 15630-3:2019, Steel for the reinforcement and prestressing of concrete — Test methods — Part 3:
Prestressing steels (EN ISO 15630-3:2019, Corrected version 2019-10)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 10020:2000 and
EN 10079:2007 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
3.1
prestressing steel
steel product with a circular or practically circular cross-section which is suitable for the prestressing of
concrete
3.2
hot rolled bar
product manufactured in straight lengths in a hot rolling mill
NOTE 1 to entry: It may be plain or present threads.
3.3
processed bar
hot rolled bar treated after production by accelerated cooling (including quenching), cold stretching or
additional tempering, either singly or in combination
NOTE 1 to entry: It may be plain or present threads.
3.4
threaded prestressing bar
bar with up to two rows of transverse ribs arranged helically or circumferential, which are uniformly
distributed over the entire length and which are screwable
3.5
plain prestressing bar
bar with a smooth surface
3.6
heat
quantity of steel corresponding to the same casting operation identified by a single number so designated
by the steel manufacturer
3.7
rib height
distance from the highest point of the thread to the surface of the core, to be measured normal to the axis
of the bar
3.8
rib spacing
distance between the centres of two consecutive threads measured parallel to the axis of the bar
3.9
rib inclination
angle between the axis of the transverse thread or indentation and the longitudinal axis of the bar
3.10
specified value
value which is defined in a standard and has not been measured or calculated with measured values. A
specified value can be a characteristic, a minimum, a maximum or any testing value
NOTE 1 to entry: The specified value may be declared by the manufacturer in his declaration of performance.
3.11
testing value
value which defines testing conditions such as e.g. testing temperature, specified maximum stress in the
fatigue test or bending diameter in the bend test
3.12
characteristic value
value of a material or product property having a prescribed probability of not being attained in a
hypothetical unlimited test series
NOTE 1 to entry: This value generally corresponds to a specific fractile of the assumed statistical distribution of
the particular property of the material or product.
3.13
minimum value
value below which no test result shall fall
3.14
maximum value
value which no test result shall exceed
3.15
median value
value separating the higher half from the lower half of a data sample
3.16
product type
set of representative performance levels or classes of a construction product, in relation to its essential
characteristics, produced using a given combination of raw materials or other elements in a specific
production process (see CPR – Regulation No 305/2011, Article 2. 9)
NOTE 1 to entry: A set of different diameters of the same mechanical properties and same surface geometry of
bars tested on the same cross-section type.
3.17
test unit
number of pieces or the tonnage of products to accept or reject together, on the basis of the verification
tests carried out on sample products in accordance with the requirements of the product standard or
order
3.18
sample product
item (e.g. bar, sheet, coil) selected for inspection or testing
3.19
sample
sufficient quantity of material taken from the sample product for the purpose of producing one or more
test pieces
3.20
test piece
part of a sample, with specified dimensions, machined or unmachined, brought to a required condition
for submission to a given verification test
NOTE 1 to entry: Example for the application of the terms test piece, sample, sample product, test unit and product
type:
The product type consist of prestressing bars in the diameter range of 18 mm to 47 mm, manufactured as hot rolled
bars with a set of mainly same declared performance level for the essential characteristics. (e.g. for mainly: Same
declared performance level each for tensile strength, tensile yield strength etc. independent on diameter but with
different performance levels for fatigue strength, relaxation).
The test unit for the product type testing of e.g. the essential characteristic tensile yield strength is specified as
lower, intermediate and upper diameter of the diameter range of the product type each manufactured out of 3
different heats. This test unit is composed of in total 9 sample products (each a combination of heat and diameter).
For each sample product a specified number of test pieces is to be taken. This specified number of test pieces per
sample product is called sample.
4 Symbols
The symbols used in this document and the corresponding designations are given in Table 1.
Table 1 — Symbols and corresponding designations
Symbol Unit Designation
A % Characteristic value of percentage total elongation at maximum force
gt
A % Elongation under maximum force after test for durability testing
gtr
according to Annex A
a mm Rib height for threaded bar
b mm Rib top width of a threaded bar
K
b mm Rib bottom width of a threaded bar
F
C kN, %,- Specified characteristic value for essential characteristics
v
c mm Rib space for a threaded bar
d mm Nominal diameter
d mm Horizontal core diameter of a threaded bar
h
d mm Major diameter of a threaded bar
ma
d mm Minor diameter of a threaded bar
mi
d mm Vertical core diameter of a threaded bar
v
E GPa Characteristic value of modulus of elasticity
F kN Initial force in relaxation and durability test, based on actual force
kN Mean value of maximum force in durability testing according to
F
m
EN ISO 15630-3
F kN Maximum force after test for durability testing according to Annex A
mr
F kN Force at the conventional yield point at 0,1 % after test for durability
p0,1r
testing according to Annex A
Symbol Unit Designation
F kN Force range in the axial force fatigue test
r
F kN Upper force in the axial force fatigue test
up
h mm/m Deviation from straightness
b
k — Coefficient as a function of the number of test results
L mm Length of the test piece for durability testing according to Annex A
L mm Length of the test piece immersed in distilled water for durability
testing according to Annex A
m g/m Nominal mass per meter
N - Number of load cycles in fatigue test
n — Number of test pieces
P - Surface geometry – plain bar
P mm Pitch of a threaded bar
th
p -, % Reliable failure rate
q I/min Flow rate of water circulation for durability testing according to
Annex A
R ° Radius of the transition from rib to core for a threaded bar
R kN Characteristic value of tensile strength
m
R kN Characteristic value of 0,1 % yield strength
p0,1
R /R - Characteristic value of stress ratio
m p0,1
s kN, %,- Estimated standard deviation of the test results for essential
characteristics
S 2 Nominal cross-sectional area
n mm
T °C Test temperature for durability testing according to Annex A
t h Minimum time without fracture in durability test
a
t h Median time to fracture in durability test
f,m
t h Time to fracture for durability testing according to Annex A
fr
x kN, %- Estimated average value of test results for essential characteristics

Z % Stress coefficient after test for durability testing according to Annex A
r
α ° Rib flank angle of a threaded bar
(1-α) — Statistically reliable failure rate
β ° Rib inclination of a threaded bar
ΔF % Percentage loss of initial force F in relaxation test
rt 0
Δl mm Deviation from the nominal length
Symbol Unit Designation
Δm % Deviation from the nominal mass per meter

5 Essential characteristics
5.1 Tensile strength, tensile yield strength, stress ratio (ult. tensile strength/tens. yield
strength), modulus of elasticity and elongation at maximum load
a) In the context of this document the characteristic value C is the lower or upper limit (fractile p) of
v
the confidence interval at which there is a 95 % probability (1 - α = 0,95) that 95 % (p = 0,95) or 90 %
(p = 0,90) of the individual measured values are at or above this lower limit, and/or are at or below
this upper limit respectively (see Table 5 and Table 6). This definition refers to the long-term quality
level of production (see 6.3.2.5.4).
b) The essential characteristics tensile strength (R ), tensile yield strength (R ), stress ratio
m p0,1,
(R /R ), modulus of elasticity (E) and elongation at maximum load (A ) of prestressing bars are
m p0,1 gt
determined in tensile tests in accordance with EN ISO 15630-3 with the specified number of test
pieces according to Clause 6.
c) The determined characteristic values C for tensile strength, tensile yield strength, stress ratio,
v
modulus of elasticity and elongation at maximum load (R , R , R /R , E and A .) shall be at
m p0,1 m p0,1 gt
least the corresponding specified characteristic values C with:
v
— R : p = 0,05 at 1- α = 0,95 (95 %) and p = 0,95 at 1- α = 0,95 (95 %);
m
— R : p = 0,05 at 1- α = 0,95 (95 %);
p0,1
— R /R : p=0,10 at 1- α = 0,95 (95 %);
m p0,1
— A : p=0,10 at 1- α = 0,95 (95 %);
gt
— E: p=0,10 at 1- α = 0,95 (95 %) and p = 0,90 at 1- α = 0,95 (95 %).
The declared performance is the corresponding specified characteristic value C .
v
d) The values E, R and R shall be calculated using the nominal cross-sectional area S of the
p0,1 m n
product.
5.2 Relaxation
a) Relaxation of a prestressing bar is specified as the percentage loss of initial force F determined in
an isothermal relaxation test in accordance with EN ISO 15630-3 with the number of test pieces
according to Clause 6.
b) The declared performance for relaxation is the percentage loss ΔF of initial force F . Different
rt 0
relaxations may be declared for one product or the product type. This applies as well for different
diameter ranges within one product type.
5.3 Fatigue strength
a) Fatigue strength is specified as a number of force cycles N at a force range F and a maximum force
r
F and shall be determined by an axial force controlled fatigue test in accordance with
up
EN ISO 15630-3 with the number of test pieces according to Clause 6. For the force range F and the
r
maximum force F nominal values apply.
up
b) The declared performance is the number of force cycles N fulfilled for the specified number of
individual tests at a force range F and a maximum force F . Different fatigue strengths may be
r up
declared for one product or the product type. This applies as well for different diameter ranges
within one product type.
It is recommended that the declared number of force cycles N fulfilled for the specified number of
individual tests at a force range F and a maximum force F corresponds to the design specification for
r up
N* and Δσ of EN 1992-1-1.
Rsk
5.4 Durability
a) Durability is specified as the resistance of prestressing bar against hydrogen induced stress
corrosion cracking in thiocyanate solutions A and/or B and/or distilled water (solution C)
determined in accordance with EN ISO 15630-3 and/or Annex A with the number of test pieces
according to Clause 6.
b) The declared performance is the minimum time in hours t without fracture and/or, where
a
applicable, the median time in hours t until fracture in the used test solution (A or B according to
f,m
EN ISO 15630-3 or distilled water C according to Annex A) at an initial force F declared as
percentage of (mean value according to EN ISO 15630-3) for the specified number of individual
F
m
tests. Different durability’s may be declared for one product or the product type. This applies as well
for different diameter ranges within one product type.
According to EN ISO 15630-3, F = 80 % of F is recommended.
0 m
5.5 Surface geometry
5.5.1 Plain bar surface
For plain bars no parameters and measurements apply and the declaration of performance is P for plain
bar.
5.5.2 Thread bar surface for threads over the entire circumference
Surface geometry is declared as a full set of the following thread parameters (see Figure 1):
Major diameter d
ma
Minor diameter d
mi
Pitch P
th
Rib flank angle α
Figure 1 — Example for threaded bar geometry - threads over the entire circumference
Each thread parameter shall be declared as a range between minimum and maximum value. The thread
parameters shall be determined with an accuracy in accordance with EN ISO 15630-3 with the number
of test pieces according to Clause 6.
5.5.3 Thread bar surface for threads over parts of the circumference (two rib rows)
Surface geometry is declared as a full set of the following thread parameters (see Figure 2):
— core diameter d
v
— core diameter d
h
— rib hight a
— rib spacing c
— rib inclination β
— rib top width b and rib bottom width b
K F
Each thread parameter shall be declared as a range in between a minimum value and a maximum value.
The thread parameters shall be determined in accordance with EN ISO 15630-3 with the number of test
pieces according to Clause 6.
The declared thread parameters should not be outside the thresholds shown in the following Table 2.
Table 2 — Ranges for the thread parameters
Core diameter Rib height Rib spacing Rib Rib top Rib bottom
inclination width width
d d a c β b b
h v k F
0,95d- 0,92d- 0,025d- 0,30d-0,60d 75°-85° 0,05d- 0,10d-0,50d
1,02d 1,02d 0,10d 0,20d
Figure 2 — Example for threaded bar geometry - threads over parts of the circumference
5.6 Section and tolerances
5.6.1 Mass per meter and tolerances
The values for the nominal mass per meter m are calculated for each nominal diameter d with the values
of the nominal cross-sectional area S using a density value of 7,85 kg/dm (see Table 3).
n
Table 3 — Preferred nominal diameters, cross-sectional areas and masses per meter
Nominal cross Nominal mass per
Nominal Nominal mass per
sectional area meter Plain
diameter meter Thread
S m
d n m
kg/m
mm 2 kg/m
mm
15,0 173 - 1,41
17,5 241 - 1,96
20,0 309 - 2,51
26,0 531 4,17 -
26,5 552 - 4,48
32,0 804 6,31 6,53
36,0 1018 7,99 8,27
40,0 1257 9,87 10,21
47,0 1735 - 14,10
57,0 2581 - 20,95
65,0 3331 - 27,10
75,0 4418 - 35,90
The declared performance is the deviation from the nominal mass per meter Δm in percent. The
permissible deviation from the nominal mass per meter Δm should not be more than −2 %, + 6 % for
d ≤ 47 mm and −5 %, + 6 % for d > 47 mm. Measurements of mass per meter and tolerances shall be
performed according to EN ISO 15630-3 with the number of test pieces according to Clause 6.
5.6.2 Length of bars
The nominal length of bars shall be agreed at the time of enquiry and order. The permissible deviation
from the nominal length Δl should not be more than −0 mm and +100 mm. The declared performance is
the deviation from nominal length Δl in mm. Measurements of length shall be performed according to
EN ISO 15630-3 with the number of test pieces according to Clause 6.
5.6.3 Straightness
Straightness shall be determined in accordance with EN ISO 15630-3 with the number of test pieces
according to Clause 6. The deviation from straightness Δh for any length of bar should not exceed
b
4 mm/m. The declared performance is the deviation from straightness h in mm/m length.
b
NOTE The grades of prestressing bars applied in European countries are specified in national designation or
application documents. Preferred grades of prestressing bars are given in the following Table N1. This NOTE applies
to the whole Clause 5.
Table N1 — Preferred grades of prestressing bars
Essential Steel grades (designation according to EN 10027-1:2016 and
EN 10027-2:2015)
characteristics
Y1030H Y1050H Y1100H Y1230H
1.1380 1.1383 1.1381 1.1382
Surface geometry Plain (P), Plain (P), Plain (P), Plain (P),
Thread (T) Thread (T) Thread (T) Thread (T)
Nominal diameter [mm] P: 26,0-32,0- P: 26,0-32,0- P: 26,0-32,0- P: 26,0-32,0-
36,0-40,0 36,0-40,0 36,0-40,0 36,0-40,0
T: 57,0-65,0- T: 17,5-26,5- T: 15,0-20,0- T: 18,0-26,5-
75,0 32,0-36,0-40,0- 26,5 32,0-36,0-40,0-
47,0 47,0
Section and tolerances
— deviation from −2 %; +6 % for d ≤ 47 mm and −5 %, + 6 % for d > 47 mm
nominal mass per
meter Δm [%]
— deviation from −0 mm and +100 mm
nominal length Δ l
[mm]
— deviation from ≤4 mm/m
straightness h in
b
mm/m length
Yield strength R 835 950 900 1 080
p0,1
[MPa]
Tensile strength R 1 030 1 050 1 100 1 230
m
[MPa]
Upper tensile strength 1 180 1 210 1 260 1 370
[MPa]
Stress ratio (ult. tensile
A: 1,08 / A: 1,08 / A: 1,08 / A: 1,08 /
strength/tens. yield
strength) R /R [-]
m p0,1
B: 1,10 B: 1,10 B: 1,10 B: 1,10
Class A / B
Modulus of elasticity E 205 205 205 205
c
[GPa]
Elongation at maximum 3,5 / 5 3,5 / 5 3,5 / 5 3,5 / 5
load A [%]
gt
Relaxation
ΔF [%] of initial force
rt
a
≤ 4
b
F (70 % F )
0 m
Essential Steel grades (designation according to EN 10027-1:2016 and
characteristics EN 10027-2:2015)
Y1030H Y1050H Y1100H Y1230H
1.1380 1.1383 1.1381 1.1382
Fatigue strength plain
bars
— number of force 6
2×10
cycles N [-] at
— force range F [kN] d ≤ 40 mm: 200 × S ; d > 40 mm: 150 × S
r n n
and
— maximum force F b
up 70 % F
m
[kN]
Fatigue strength
threaded bars
— number of force 6
2×10
cycles N [-] at
— force range F [kN] d ≤ 40 mm: 180 × S ; d > 40 mm: 120 × S
r n n
and
— maximum force F
b
up 70 % F
m
[kN]
Durability
— minimum time in d = 15 mm 15 < d ≤ 25 mm d > 25 mm
hours t [h] for test
a
A: 20 h / A: 60 h / A:100 h /
solution A/B/C
B: 2 000 h / B: 2 000 h / B: 2 000 h /
C: 2 160 h C: 2 160 h C: 2 160 h
— median time in d = 15 mm 15 < d ≤ 25 mm d > 25 mm
hours [h] for test
t
fm,
A: 50 h / A: 250 h / A: 400 h /
solution A/B/C
B: - / C: - B: - / C: - B: - / C: -
Initial force as 80 %
b
percentage of F [%]
m
for test solution A/B/C
Essential Steel grades (designation according to EN 10027-1:2016 and
characteristics EN 10027-2:2015)
Y1030H Y1050H Y1100H Y1230H
1.1380 1.1383 1.1381 1.1382
a
After 1 000 h (may be extrapolated from at least 240 h)
b
Actual value
c
Mean value
6 Assessment and verification of constancy of performance
6.1 General
The compliance of prestressing bars with the requirements of this standard and with the performances
declared by the manufacturer in the DoP shall be demonstrated by:
— determination of the product type (see 6.2);
— factory production control by the manufacturer (see 6.3), including product assessment (see 6.4 and
6.5).
The manufacturer shall always retain the overall control and shall have the necessary means to take
responsibility for the product.
NOTE Details for declaration of performance (DoP) are given in the Annex ZA.
6.2 Product type testing
6.2.1 General
All the performances related to the essential characteristics included in this standard shall be determined
when the manufacturer intends to declare the respective performances.
Assessment previously performed for the manufacturer in accordance with the provisions of this
standard, may be taken into account provided that they were made to the same or a more rigorous test
method, under the same AVCP system on the same product or products of similar design, construction
and functionality, such that the results are applicable to the product in question.
NOTE Same AVCP system means testing by an independent third party, under the responsibility of a notified
product certification body.
Reference to the assessment method standards should be made to allow the selection of a suitable
representative sample.
In addition, the determination of the product type shall be performed for all essential characteristics
included in the standard for which the manufacturer declares the performance:
— at the beginning of the production of a new or modified prestressing bar (unless a member of the
same product range), or
— at the beginning of a new or modified method of production (where this may affect the stated
properties), or
— it shall be repeated for the appropriate essential characteristic(s), whenever a change occurs in the
prestressing bar design, in the raw material, or in the production (subject to the definition of a
family). This is only required if the changes would affect significantly one or more of the essential
characteristics.
Products bearing regulatory marking in accordance with appropriate harmonised European
specifications may be presumed to have the performances declared in the DoP, although this does not
replace the responsibility on the prestressing bar manufacturer to ensure that the prestressing bar as a
whole is correctly manufactured.
6.2.2 Test samples and testing
The test pieces shall be taken as random samples from the production material presented for testing.
Care shall be taken to ensure that the samples genuinely reflect the properties of the material to be tested.
Tests shall be carried out on the full cross-section of the product. The testing schedule is given in Table 4.
Table 4 — Testing schedule for essential characteristics of prestressing bars
Essential characteristic Clause Test No. of test Compliance
method a criteria
pieces
Tensile strength (R ) 5.1 7 10 6.2.3 and 6.2.4
m
Yield strength (R ) 5.1 7 10 6.2.3 and 6.2.4
p0,1
Stress ratio (R /R ) 5.1 7 10 6.2.3 and 6.2.4
m p0,1
Modulus of elasticity (E) 5.1 7 10 6.2.3 and 6.2.4
Elongation at maximum load (A ) 5.1 7 10 6.2.3 and 6.2.4
gt
Relaxation (ΔF ) 5.2 7 2 6.2.3 and 6.2.4
rt
Fatigue strength (N) 5.3 7 5 6.2.3 and 6.2.4
5.4 7 6 6.2.3 and 6.2.4
b
Durability (t and/or t t )
a f,m
f ,m
Surface geometry 5.5 7 3 6.2.3 and 6.2.4
Section and tolerances 5.6 7 3 6.2.3 and 6.2.4
— Mass per meter and tolerances
(Δm)
— Length of bars (Δl)
— Straightness (h )
b
a
Total number of test pieces e.g. for R : n = 10×3ø×3 heats = 90 for the product type
m
b
For test solution C (distilled water) the number of test pieces n = 2

In the case that the product type consists of single products with a small range of diameters, the number
of sample products may be reduced.
Recommended is for:
— a diameter range with a maximum diameter of ≤47 mm and the difference between largest and
smallest diameter ≤ 11 mm
and for
— a diameter range with a maximum diameter > 47 mm and the difference between largest and
smallest diameter ≤ 20 mm,
that the number of sample products may be reduced to the smallest and largest diameter instead of the
smallest, intermediate and largest diameter of the product type.
6.2.2.1 Tensile strength, tensile yield strength, stress ratio (ult. tensile strength/tens. yield
strength), modulus of elasticity, elongation at maximum load, surface geometry, mass per meter
and tolerances, length of bars and straightness
For each product type, the test unit consists of 9 sample products which shall be selected as follows:
— three sample products are selected as combinations of the smallest diameter of the diameter range
manufactured out of 3 different heats;
— three sample products are selected as combinations of the intermediate diameter of the diameter
range manufactured out of 3 different heats;
— three sample products are selected as combinations of the largest diameter of the diameter range
manufactured out of 3 different heats.
For each sample product, samples shall be taken consisting of the number of test pieces given in Table 4.
NOTE Example for test unit: Prestressing bars with same declared performance for the essential characteristics
in the diameter range from 18 mm to 47 mm form the product type. The diameters 18 mm (smallest), 32 mm
(intermediate) and 47 mm (largest) may represent the product type. For each selected diameter, the sample
product consists of 10 test pieces (number of test pieces depend on the essential characteristic) taken from 1 heat
for R , in total 10 test pieces per sample product of one diameter. For each diameter, three sample products have
m
to be selected from 3 heats, in total 30 test pieces per diameter. The test unit consist of 9 sample products, in total
90 test pieces for the product type.
6.2.2.2 Fatigue
In the case that same performance level of fatigue strength is declared for all single products of the
product type, the test unit consists of 9 sample products which shall be selected as follows:
— three sample products shall be selected as combinations of the smallest diameter of the diameter
range manufactured out of 3 different heats;
— three sample products shall be selected as combinations of the intermediate diameter of the diameter
range manufactured out of 3 different heats;
— three sample products shall be selected as combinations of the largest diameter of the diameter range
manufactured out of 3 different heats.
For each sample product, samples shall be taken consisting of the number of test pieces given in Table 4.
For every additional performance level of fatigue strength declared for the product type, the test unit
consists of 3 sample products which shall be selected as follows:
— one sample product shall be selected as combination of the smallest diameter of the diameter range
manufactured out of 1 heat;
— one sample product shall be selected as combination of the intermediate diameter of the diameter
range manufactured out of 1 heat;
— one sample product shall be selected as combination of the largest diameter of the diameter range
manufactured out of 1 heat.
For each sample product, samples shall be taken consisting of the number of test pieces given in Table 4.
NOTE 1 Example: Prestressing bars with the declared performance for the essential characteristic fatigue
(N = 1 million load cycles for F = 96,5 kN at maximum force F = 611 kN) in the diameter range from 18 mm to
1 r up
47 mm form the product type. The diameters 18 mm (smallest), 32 mm (intermediate) and 47 mm (largest) may
represent the product type. For each selected diameter, the sample product consists of 5 test pieces taken from 1
heat for N , in total 5 test pieces per sample product of one diameter. For each diameter, three sample products
have to be selected from 3 heats, in total 15 test pieces per diameter. The test unit consist of 9 sample products, in
total 45 test pieces for the product type. For an additional performance level for the essential characteristic fatigue
(N = 0,5 million load cycles for F = 115 kN at maximum force F = 611 kN) in the same diameter range from
2 r up
18 mm to 47 mm, the sample product consist of 5 test pieces taken from 1 heat for N , in total 5 test pieces per
sample product of one diameter. The test unit consist of 3 sample products, in total 15 test pieces for the product
type.
In the case that different performance levels for fatigue strength are declared for single products out of
the product type, the test unit shall be as follows:
For each single product three sample products shall be selected as combinations of the diameter of the
single product manufactured out of three different heats. This applies for the first performance level of
declared fatigue strength. For each sample product, samples shall be taken consisting of the number of
test pieces given in Table 4. For every additional performance level of declared fatigue strength, one
sample product shall be selected as a combination of the diameter of the single product manufactured
out of 1 heat. For each sample product, samples shall be taken consisting of the number of test pieces
given in Table 4.
NOTE 2 Example: The product type of prestressing bars consists of the diameter range from 18 mm to 47 mm.
For diameter 18 mm, the declared performance for the essential characteristic fatigue is:
N = 1 million load cycles for F = 96,5 kN at maximum force F = 611 kN and
1 r up
N = 0,5 million load cycles for F = 115 kN at maximum force F = 611 kN
2 r up
Three sample products each with 5 test pieces have to be selected for N from 3 heats, in total 15 test
pieces for the test unit for N . For N one sample product with 5 test pieces out of one heat, in total 5 test
1 2
pieces for the test unit for N .
In the case that different performance levels for fatigue strength are declared for groups of products with
less than 3 single diameters out of the product type, the test unit shall be as follows:
For each group of products, three sample products shall be selected from the largest diameter of the
group manufactured out of 3 heats for the first performance level of declared fatigue strength.
For each sample product, samples shall be taken consisting of the number of test pieces given in Table 4.
For every additional performance level of declared fatigue strength of the group of products, one sample
product shall be selected from the largest diameter of the group manufactured out of 1 heat. For each
sample product, samples shall be taken consisting of the number of test pieces given in Table 4.
NOTE 3
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