EN 13230-6:2020

Railway applications - Track - Concrete sleepers and bearers - Part 6: Design

This document provides particular design guidance in the following areas:
-   derivation of characteristic loads and test loads;
-   calculation of characteristic and test bending moments.
The aim of this document is to give guidance for the preparation of all data to be given by the purchaser to the supplier in accordance with Parts 1 to 5 of EN 13230. It applies to gauges 1 000 mm, 1 435 mm, 1 668 mm as well as to all lengths of sleepers and bearers.
This standard gives special criteria for the design of concrete sleepers and bearers as track components. The design methods in the Eurocode do not apply to these concrete elements.
All track parameters to be taken into account for the design of sleepers and bearers are detailed in this standard. Information is given on these parameters so that they can be used as inputs for the design calculation process. It is the responsibility of the purchaser to calculate or determine all track parameters used in this standard.
This standard gives guidance for the design calculation process. It explains how experience and calculation can be combined to use design parameters.
This standard gives examples of numerical data that can be used when applying Clauses 4 to 6 according to the state of the art.

Bahnanwendungen - Oberbau - Gleis- und Weichenschwellen aus Beton - Teil 6: Bemessung

Dieses Dokument enthält einschlägige Entwurfsrichtlinien für die folgenden Bereiche:
- die Herleitung von charakteristischen Lasten und Prüflasten;
- die Berechnung von charakteristischen Biegemomenten und Prüfbiegemomenten.
Ziel dieses Dokuments ist die Bereitstellung einer Anleitung zur Vorbereitung aller Daten, die der Kunde dem Lieferanten in Übereinstimmung mit EN 13230, Teil 1 bis Teil 5, zur Verfügung stellen muss. Sie gilt sowohl für die Spurweiten 1 000 mm, 1 435 mm und 1 668 mm als auch für alle Längen von Gleis  und Weichenschwellen.
Dieses Dokument enthält besondere Kriterien für die Bemessung von Gleis  und Weichenschwellen aus Beton als Gleiskomponenten. Die im Eurocode beschriebenen Bemessungsverfahren gelten nicht für diese Betonelemente.
Alle Gleisparameter, die bei der Bemessung von Gleis  und Weichenschwellen berücksichtigt werden müssen, sind in diesem Dokument im Einzelnen beschrieben. Es werden die erforderlichen Informationen zu diesen Parametern gegeben, sodass diese als Eingangswerte für das Bemessungsverfahren verwendet werden können. Es liegt in der Verantwortung des Kunden, alle in dieser Norm verwendeten Gleisparameter zu berechnen oder festzulegen.
Dieses Dokument enthält eine Anleitung für das Bemessungsverfahren. Sie legt dar, wie Betriebserfahrung und Rechenmodelle zur Festlegung von Bemessungskennwerten kombiniert werden können.
Dieses Dokument enthält Beispiele für Zahlenwerte, die bei Anwendung der Abschnitte 4 bis 6 in Übereinstimmung mit dem aktuellen Stand der Technik verwendet werden können.

Applications ferroviaires - Voie - Traverses et supports en béton - Partie 6 : Conception

Le présent document donne des recommandations de conception particulières dans les domaines suivants :
- la répartition des charges caractéristiques et des charges d'essai ;
- le calcul des moments de flexion caractéristiques et des moments de flexion d'essai.
L'objet du présent document est de formuler des recommandations pour la préparation de l'ensemble des données que l'acheteur doit remettre au fournisseur conformément aux Parties 1 à 5 de la série EN 13230. Il s'applique aux écartements de 1 000 mm, 1 435 mm et 1 668 mm, ainsi qu'à toutes les longueurs de traverses et supports.
Le présent document établit des critères spéciaux pour la conception de traverses et supports en béton en tant qu'éléments de voie. Les méthodes de conception figurant dans l'Eurocode ne s'appliquent pas à ces éléments en béton.
Tous les paramètres de voie à prendre en compte pour la conception des traverses et supports sont décrits dans le présent document. Le présent document fournit des informations concernant ces paramètres de sorte qu'ils puissent être utilisés comme données d'entrée pour le processus du calcul de conception. Il relève de la responsabilité de l'acheteur de calculer ou de déterminer tous les paramètres de voie utilisés dans le présent document.
Le présent document donne des recommandations pour le processus de calcul de conception. Elle explique comment les données empiriques et de calcul peuvent être combinées afin d'utiliser des paramètres de conception.
Le présent document donne des exemples de données numériques qui peuvent être utilisées lors de l'application des Articles 4 à 6 conformément à l'état de l'art.

Železniške naprave - Zgornji ustroj proge - Betonski pragi in kretniški betonski pragi - 6. del: Načrtovanje

General Information

• Status: Published
• Publication Date: 30-Jul-2020
• Withdrawal Date: 30-Oct-2020
• ICS: 91.100.30 - Concrete and concrete products
• ICS: 93.100 - Construction of railways
• Technical Committee: CEN/TC 256 - Railway applications
• Drafting Committee: CEN/TC 256/SC 1/WG 16 - Sleepers and bearers
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 29-Apr-2020
• Due Date: 30-Jan-2016
• Completion Date: 29-Apr-2020
• Directive: 2008/57/EC - Directive 2008/57/EC of the European Parliament and of the Council of 17 June 2008 on the interoperability of the rail system within the Community (Recast)
• Directive: 2016/797/EU - Directive (EU) 2016/797 of the European Parliament and of the Council of 11 May 2016 on the interoperability of the rail system within the European Union (Text with EEA relevance)
• Mandate: M/483 - Mandate for programming and standardisation addressed to the European standardisation bodies under directive 2008/57/EC in the field of the interoperability of the rail system within the European Union
• Ref Project: SIST EN 13230-6:2020 - Railway applications - Track - Concrete sleepers and bearers - Part 6: Design

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 13230-6:2020
01-julij-2020
Železniške naprave - Zgornji ustroj proge - Betonski pragi in kretniški betonski
pragi - 6. del: Načrtovanje
Railway applications - Track - Concrete sleepers and bearers - Part 6: Design
Bahnanwendungen - Oberbau - Gleis- und Weichenschwellen aus Beton - Teil 6:
Entwurf

Applications ferroviaires - Voie - Traverses et supports en béton - Partie 6 : Conception

Ta slovenski standard je istoveten z: EN 13230-6:2020
ICS:
45.080 Tračnice in železniški deli Rails and railway
components
91.100.30 Beton in betonski izdelki Concrete and concrete
products
SIST EN 13230-6:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 13230-6:2020
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SIST EN 13230-6:2020
EN 13230-6
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2020
EUROPÄISCHE NORM
ICS 91.100.30; 93.100
English Version
Railway applications - Track - Concrete sleepers and
bearers - Part 6: Design

Applications ferroviaires - Voie - Traverses et supports Bahnanwendungen - Oberbau - Gleis- und

en béton - Partie 6 : Conception Weichenschwellen aus Beton - Teil 6: Bemessung
This European Standard was approved by CEN on 8 April 2019.

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. Up-to-date lists and bibliographical references

concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN

member.

This European Standard exists 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, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13230-6:2020 E

worldwide for CEN national Members.
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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

Introduction .................................................................................................................................................................... 5

1 Scope .................................................................................................................................................................... 6

2 Normative references .................................................................................................................................... 6

3 Terms, definitions and symbols ................................................................................................................. 6

4 General requirements ................................................................................................................................... 9

4.1 General process for determination of bending moments ................................................................ 9

4.1.1 General ................................................................................................................................................................ 9

4.1.2 Empirical method ............................................................................................................................................ 9

4.1.3 Theoretical method ..................................................................................................................................... 10

4.1.4 Combined method ........................................................................................................................................ 11

4.2 Crack formation in concrete sleepers or bearers ............................................................................. 11

4.2.1 Cracks under rail seat ................................................................................................................................. 11

4.2.2 Cracks at centre part (prestressed monoblock sleepers or bearers) ....................................... 12

4.2.3 Cracks for tests for negative bending under rail seat or positive bending at centre

part .................................................................................................................................................................... 12

4.3 Section design of sleeper ........................................................................................................................... 12

4.4 Durability of sleeper ................................................................................................................................... 12

5 Design parameters ....................................................................................................................................... 12

5.1 Maintenance ................................................................................................................................................... 12

5.1.1 Track and rolling stock quality ............................................................................................................... 12

5.1.2 Distribution of the vertical load in the longitudinal direction .................................................... 13

5.1.3 Distribution of ballast reaction along the length of the sleeper ................................................. 13

5.2 Track laying conditions ............................................................................................................................. 13

5.2.1 Mass of sleeper .............................................................................................................................................. 13

5.2.2 Length of sleeper .......................................................................................................................................... 13

5.2.3 Depth of sleeper ............................................................................................................................................ 13

5.2.4 Track installation methods ...................................................................................................................... 13

5.3 Track components design ......................................................................................................................... 14

5.3.1 Rail profile and sleeper spacing ............................................................................................................. 14

5.3.2 Fastening system .......................................................................................................................................... 14

5.3.3 Track stability ............................................................................................................................................... 14

5.4 Impact of traffic characteristics and track alignment .................................................................... 15

5.4.1 Axle load .......................................................................................................................................................... 15

5.4.2 Maximum speed ............................................................................................................................................ 15

5.4.3 Curving load ................................................................................................................................................... 15

6 Design method .............................................................................................................................................. 15

6.1 Specific aspects for design and testing ................................................................................................. 15

6.1.1 Railway experience for exceptional or accidental impact loads................................................. 15

6.1.2 Flexural tensile strength of concrete .................................................................................................... 15

6.1.3 Losses of prestressing ................................................................................................................................ 16

6.1.4 Experience for track work ........................................................................................................................ 16

6.2 Design calculation ........................................................................................................................................ 16

6.2.1 General ............................................................................................................................................................. 16

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EN 13230-6:2020 (E)

6.2.2 Calculation of dynamic rail seat load P under normal service conditions ............................. 16

6.2.3 Calculation of the characteristic bending moments for rail seat of sleepers ......................... 16

6.2.4 Calculation of the characteristic bending moments for centre part of sleepers ................... 17

6.2.5 Calculation of the characteristic bending moments for bearers ................................................. 18

6.2.6 Checking of stresses in concrete ............................................................................................................. 18

6.2.7 Determination of test bending moments for first crack formation............................................ 18

Annex A (informative) Design methods and factors for sleepers ............................................................ 20

A.1 General ............................................................................................................................................................. 20

A.1.1 Introduction ................................................................................................................................................... 20

A.1.2 Determination of characteristic bending moments ......................................................................... 20

A.1.3 Load levels and corresponding bending moments .......................................................................... 21

A.2 Rail seat load .................................................................................................................................................. 22

A.2.1 Normal service increment for the dynamic wheel load .................................................................. 22

A.2.2 Distribution of vertical loads in longitudinal direction .................................................................. 22

A.2.3 Effects of elastic rail pads .......................................................................................................................... 25

A.2.4 Calculation of dynamic rail seat load .................................................................................................... 25

A.3 Characteristic bending moments ............................................................................................................ 25

A.3.1 General ............................................................................................................................................................. 25

A.3.2 Rail seat section............................................................................................................................................. 26

A.3.3 Sleeper centre section ................................................................................................................................. 27

A.4 Factors for test loads and acceptance criteria ................................................................................... 33

A.4.1 General ............................................................................................................................................................. 33

A.4.2 Factor for first crack formation ............................................................................................................... 33

A.4.3 Factors for exceptional loads ................................................................................................................... 34

A.4.4 Factors for accidental loads ...................................................................................................................... 35

A.4.5 Factor for fatigue test .................................................................................................................................. 35

A.5 Checking of stresses for Serviceability Limit State (for prestressed sleepers only) ............ 35

A.6 Design examples ........................................................................................................................................... 36

A.6.1 General ............................................................................................................................................................. 36

A.6.2 Example 1: 1 435 mm gauge waisted sleeper with elastic beam on elastic foundation

calculation ....................................................................................................................................................... 38

A.6.3 Example 2: 1 435 mm gauge rectangular sleeper using simplified method ........................... 46

A.6.4 Example 3: 1 668 mm gauge waisted sleeper ..................................................................................... 52

Annex B (informative) Design methods and factors for turnout bearers ............................................. 56

Annex ZA (informative) Relationship between this European standard and the Essential

Requirements of EU Directive 2008/57/EC aimed to be covered .............................................. 59

Bibliography ................................................................................................................................................................. 61

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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
European foreword

This document (EN 13230-6:2020) has been prepared by Technical Committee CEN/TC 256 “Railway

applications”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by October 2020, and conflicting national standards shall

be withdrawn at the latest by October 2020.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document has been prepared under a mandate given to CEN by the European Commission and the

European Free Trade Association, and supports essential requirements of EU Directive 2008/57/EC.

For relationship with EU Directive 2008/57/EC, see informative Annex ZA, which is an integral part of

this document.

This European Standard is one of the EN 13230 series, Railway applications – Track – Concrete sleepers

and bearers, which consist of the following parts:
— Part 1: General requirements;
— Part 2: Prestressed monoblock sleepers;
— Part 3: Twin-block reinforced sleepers;
— Part 4: Prestressed bearers for switches and crossings;
— Part 5: Special elements;
— Part 6: Design.

This European Standard can be used as a technical basis between contracting parties (purchaser –

supplier).

Annexes A and B are informative; they can be used as normative requirements by completion of a

contract, if agreed by the contracting parties.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,

France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,

Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.
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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
Introduction

This document covers the design of concrete sleepers and bearers and is used in conjunction with the

following parts:
— Part 1: General requirements;
— Part 2: Prestressed monoblock sleepers;
— Part 3: Twin-block reinforced sleepers;
— Part 4: Prestressed bearers for switches and crossings;
— Part 5: Special elements.

Concrete sleepers and bearers are safety critical components for railway applications. They are not

covered by any other European Standard.

As safety critical components, an agreement is needed between purchaser and supplier to operate a

factory Quality System.
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EN 13230-6:2020 (E)
1 Scope
This document provides particular design guidance in the following areas:
— derivation of characteristic loads and test loads;
— calculation of characteristic and test bending moments.

The aim of this document is to give guidance for the preparation of all data to be given by the purchaser

to the supplier in accordance with Parts 1 to 5 of EN 13230. It applies to gauges 1 000 mm, 1 435 mm,

1 668 mm as well as to all lengths of sleepers and bearers.

This document gives special criteria for the design of concrete sleepers and bearers as track

components. The design methods in the Eurocode do not apply to these concrete elements.

All track parameters to be taken into account for the design of sleepers and bearers are detailed in this

document. Information is given on these parameters so that they can be used as inputs for the design

calculation process. It is the responsibility of the purchaser to calculate or determine all track

parameters used in this document.

This document gives guidance for the design calculation process. It explains how experience and

calculation can be combined to use design parameters.

This document gives examples of numerical data that can be used when applying Clauses 4 to 6

according to the state of the art.
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 13146-3, Railway applications – Track – Test methods for fastening systems – Part 3: Determination of

attenuation of impact loads

EN 13146-5, Railway applications – Track – Test methods for fastening systems – Part 5: Determination of

electrical resistance

EN 13146-10, Railway applications – Track – Test methods for fastening systems – Part 10: Proof load test

for pull-out resistance

EN 13230-1:2016, Railway applications – Track – Concrete sleepers and bearers – Part 1: General

requirements
3 Terms, definitions and symbols

For the purposes of this document, the terms and definitions given in EN 13230-1:2016 and the

following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
3.1
nominal axle load
nom
axle load from nominal weight of rolling stock
3.2
nominal wheel load
nom
static vertical wheel load resulting from nominal axle load
3.3
characteristic wheel load
characteristic value of the vertical wheel load
3.4
factor k
factor used for rail pad attenuation
3.5
factor kv
factor used for the effect of speed
3.6
factor k
factor used for longitudinal distribution of vertical load between sleepers
3.7
factor k

factor used for variations of the longitudinal load distribution between sleepers due to support faults

3.8
factor k
i,r

factor used for calculation of characteristic bending moments at rail seat due to irregularities in the

support along the length of the sleeper
3.9
factor k
i,c

factor used for calculation of characteristic bending moments at centre section due to irregularities in

the support along the length of the sleeper
3.10
internal lever arm

internal lever arm of the forces and ballast reaction acting on the sleeper at the rail seat section

3.11
exceptional load
load that occurs only a few times in the life of sleeper
3.12
accidental load
load that occurs only once in the life of a sleeper
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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
3.13
factor k

factor used for the calculation of acceptance criteria for first crack formation in static tests

3.14
dynamic rail seat load

characteristic load on a rail seat of the sleeper for normal service dynamic loading

3.15
characteristic bending moment
bending moment from dynamic rail seat load P
3.16
characteristic positive bending moment for rail seat section
k,r,pos
positive bending moment at rail seat from dynamic rail seat load P
3.17
characteristic negative bending moment for rail seat section
k,r,neg
negative bending moment at rail seat from dynamic rail seat load P
3.18
characteristic negative bending moment for centre section
k,c,neg
negative bending moment at centre section from dynamic rail seat load P
3.19
characteristic positive bending moment for centre section
k,c,pos
positive bending moment at centre section from dynamic rail seat load P
3.20
test bending moment

test bending moment for first crack formation derived from characteristic bending moment

3.21
positive test bending moment for rail seat section
t,r,pos

positive test bending moment for first crack formation at rail seat derived from the characteristic

bending moment
3.22
negative test bending moment for rail seat section
t,r,neg

negative test bending moment for first crack formation at rail seat derived from the characteristic

bending moment
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SIST EN 13230-6:2020
EN 13230-6:2020 (E)
3.23
negative test bending moment for centre section
t,c,neg

negative test bending moment for first crack formation at centre section derived from the characteristic

bending moment
3.24
positive test bending moment for centre section
t,c,pos

positive test bending moment for first crack formation at centre section derived from the characteristic

bending moment
3.25
factor k

factor used for calculation of test bending moments which is due to exceptional and random impact

load, which is applied to characteristic bending moments and which is k for dynamic test and k for

1d 1s
static test
3.26
factor k2

factor which is used for calculation of test bending moments due to accidental impact load, which is

applied to characteristic bending moments and which is k for dynamic test and k for static test

2d 2s
3.27
factor k

factor which is used for calculation of fatigue test bending moments and which is applied to

characteristic bending moments
4 General requirements
4.1 General process for determination of bending moments
4.1.1 General

The track is an assembly of transverse concrete sleepers or bearers secured to the rails by means of a

fastening system and supported by ballast or other support. It is characterized by the gauge of the track,

the rail profile, the inclination of the rails and the spacing of the concrete sleepers and bearers. The

assembly including the rail, the fastening system and concrete sleepers or bearers on ballast or other

support may be considered as a beam on an elastic foundation.

The determination of bending moments in sleepers and bearers laid on ballast for the service

conditions may be obtained using the three following different approaches.
4.1.2 Empirical method

In the empirical method appropriate sleepers or bearers are tested in track under service conditions.

Deficiency from tested sleepers/bearers can lead to step wise improvement of the sleeper/bearer

design. The results shall be confirmed by permanent observation during at least five years. The

characteristic bending moments shall be determined by measurements in track. The number of the test

samples shall be sufficient to give statistically reliable results.

The characteristic bending moment may also be determined by means of bending tests according to the

EN 13230 series using sleepers that have been in service for five years at least. The test bending

moment that produces the first crack formation shall be in accordance with EN 13230-1:2016, 7.2.

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EN 13230-6:2020 (E)

Figure 1 details steps for the determination of characteristic bending moments for prestressed concrete

sleepers. In this figure, new sleeper means a sleeper with geometry similar to the existing one.

For twin block concrete sleepers and bearers the same methodology shall be used.
Figure 1 — Empirical method for design of prestressed concrete sleepers

NOTE Taking the test loads Fr , Fc and Fc of the existing sleeper as initial reference test loads for a new

r r rn

sleeper normally will lead to characteristic bending moments lying on the safe side. The assumption that all losses

of prestress and strength have taken place may be correct for an exposition to traffic loads for at least 5 years.

In order to get more information about the load carrying capacity of the existing sleeper, additional

tests for inverse bending moments at the rail seat and dynamic tests at sleeper centre may be carried

out.
4.1.3 Theoretical method

The theoretical method shall be based on design procedures considering the dynamic load, the elastic

behaviour of all track components including all types of elastic pads, the variable ballast-subsoil

elasticity and the different ballast consolidation phases.
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Figure 2 details steps for the determination of bending moments for prestressed concrete sleepers. For

twin block concrete sleepers and bearers the same methodology shall be used.
Figure 2 — Theoretical method for design of prestressed concrete sleepers
4.1.4 Combined method

The combined method includes empirical and theoretical elements leading to a shorter product

development time.
4.2 Crack formation in concrete sleepers or bearers
4.2.1 Cracks under rail seat
Wheel loads generate positive and negative bending moments under the rail seat.
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EN 13230-6:2020 (E)

The bending resistance at the end of the required service life time under the rail seat is determined by

the characteristic bending moment.

When subjected to the static test bending moment, there shall be no first crack at the tensile face of the

prestressed concrete sleeper or bearer, see EN 13230-1:2016, 7.2.

The second stage of the test bending moment to be defined is the bending moment due to exceptional

and random impact loads. It is calculated by multiplying the positive characteristic bending moment

M by coefficient k . Any crack produced by this bending moment shall close (crack width below

k,r,pos 1

0,05 mm) upon removal of the bending moment. Exceptional bending moments occur only a few times

in the lifetime of a concrete sleeper and bearer.

The third stage of the test bending moment is the ultimate bending moment due to accidental impacts,

calculated by multiplying the positive characteristic bending moment M by coefficient k .

k,r,pos 2
4.2.2 Cracks at centre part (prestressed monoblock sleepers or bearers)

Wheel loads generate positive and negative bending over the central length of the sleeper.

The required flexural strength over the central part of the sleeper is determined from the bending

moment induced by the dynamic rail seat load and depends on the distribution of the ballast reaction.

When subjected to the negative static test bending moment, there shall be no first crack at the tensile

face of the concrete sleeper or bearer as required in EN 13230-1:2016, 7.2.

If permitted by the purchaser, controlled cracking of sleepers or bearers in track can be accepted. In

that case, residual crack opening and fatigue shall be checked according to method agreed by the

purchaser.

4.2.3 Cracks for tests for negative bending under rail seat or positive bending at centre part

Addit
...