prEN 12390-4
(Main)Testing hardened concrete - Part 4: Compressive strength - Specification for testing machines
Testing hardened concrete - Part 4: Compressive strength - Specification for testing machines
This document specifies the requirements for the performance of compression testing machines for the measurement of the compressive strength of concrete.
Prüfung von Festbeton - Teil 4: Bestimmung der Druckfestigkeit - Anforderungen an Prüfmaschinen
Dieses Dokument legt die Anforderungen an die Leistung von Druckprüfmaschinen zur Messung der Druckfestigkeit von Beton fest.
Essais pour béton durci - Partie 4 : Résistance à la compression - Caractéristiques des machines d'essai
Le présent document spécifie les exigences relatives aux performances des machines d’essai pour la mesure de la résistance du béton à la compression.
Preskušanje strjenega betona - 4. del: Tlačna trdnost - Specifikacija za stiskalnice
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-januar-2024
Preskušanje strjenega betona - 4. del: Tlačna trdnost - Specifikacija za stiskalnice
Testing hardened concrete - Part 4: Compressive strength - Specification for testing
machines
Prüfung von Festbeton - Teil 4: Bestimmung der Druckfestigkeit - Anforderungen an
Prüfmaschinen
Essais pour béton durci - Partie 4 : Résistance à la compression - Caractéristiques des
machines d'essai
Ta slovenski standard je istoveten z: prEN 12390-4
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
November 2023
ICS 91.100.30 Will supersede EN 12390-4:2019
English Version
Testing hardened concrete - Part 4: Compressive strength -
Specification for testing machines
Essais pour béton durci - Partie 4 : Résistance à la Prüfung von Festbeton - Teil 4: Bestimmung der
compression - Caractéristiques des machines d¿'essai Druckfestigkeit - Anforderungen an Prüfmaschinen
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 104.
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 12390-4:2023 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Construction of machines . 6
5 Details to be provided . 10
Annex A (normative) Strain gauged column and proving procedure for compression testing
machines . 12
Bibliography . 17
European foreword
This document (prEN 12390-4:2023) has been prepared by Technical Committee CEN/TC 104 “Concrete
and related products”, the secretariat of which is held by SN.
This document will supersede EN 12390-4:2019.
This standard is one of a series on testing concrete.
EN 12390, Testing hardened concrete, consists of the following parts:
— Part 1: Shape, dimensions and other requirements for specimens and moulds;
— Part 2: Making and curing specimens for strength tests;
— Part 3: Compressive strength of test specimens;
— Part 4: Compressive strength – Specification for testing machines;
— Part 5: Flexural strength of test specimens;
— Part 6: Tensile splitting strength of test specimens;
— Part 7: Density of hardened concrete;
— Part 8: Depth of penetration of water under pressure;
— Part 10: Determination of the carbonation resistance of concrete at atmospheric levels of carbon
dioxide;
— Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion;
— Part 12: Determination of the potential carbonation resistance of concrete: Accelerated carbonation
method (in preparation);
— Part 13: Determination of secant modulus of elasticity in compression;
— Part 14: Semi-adiabatic method for the determination of heat released by concrete during its hardening
process;
— Part 15: Adiabatic method for the determination of heat released by concrete during its hardening
process;
— Part 16: Determination of the shrinkage of concrete;
— Part 17: Determination of creep of concrete in compression.
— Reference to compliance with EN ISO 7500-1
— insertion of Table 2 of EN ISO 7500-1
— creation of two classes of machines
Introduction
The requirements for testing machines set out in this document have been formulated to satisfy the needs
of those compressive tests on concrete specimens which are specified in EN 206:2013+A2:2021.
Machines conforming to this standard can be suitable for other uses, but this needs to be carefully
considered on an individual test basis. Particular care needs to be taken before using machines
conforming to this document for compressive tests on small specimens, e.g. those with lateral dimensions
significantly less than 100 mm. The main concern is that the ball-seating fitted to the upper platen can be
too large to align satisfactorily on the top of such small specimens and special adaptations can be
required. Another concern is the ability to accurately determine the failure load of small or low strength
specimens.
1 Scope
This document specifies the requirements for the performance of compression testing machines for the
measurement of the compressive strength of concrete.
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 ISO 6507-1, Metallic materials - Vickers hardness test - Part 1: Test method (ISO 6507-1)
EN ISO 7500-1:2018, Metallic materials - Calibration and verification of static uniaxial testing machines -
Part 1: Tension/compression testing machines - Calibration and verification of the force-measuring system
(ISO 7500-1:2018)
EN ISO 21920-2, Geometrical product specifications (GPS) - Surface texture: Profile -Part 2: Terms,
definitions and surface texture parameters (ISO 21920-2)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
• IEC Electropedia: available at https://www.electropedia.org/
• ISO Online browsing platform: available at https://www.iso.org/obp
3.1
auxiliary platen
separate platen usually of a size equal to the designated size of the specimen being tested
3.2
contact area
part of the platen that comes into contact with the specimen
3.3
indicated force
force indicated on the machine scale(s) or display
3.4
indication range
total force range, from zero to maximum, displayed on the machine
3.5
machine platens
lower platen and upper platen both centred on the central vertical axis of the machine and where the
upper platen is spherically seated
3.6
measuring range
part of an indication range over which the machine conforms with the accuracy values specified in
EN ISO 7500-1
3.7
spacing block
metal block to adjust the space available to test specimens
3.8
true force
force indicated on a calibrated force proving device
4 Construction of machines
4.1 General
Machines shall conform to EN ISO 7500-1:2018 with the following specifications:
4.2 Machine platens, auxiliary platens and spacing blocks
NOTE The use of auxiliary platens is optional.
4.2.1 Machine and auxiliary platens shall be made of a material which shall not deform irreversibly
when the machine is used.
4.2.2 Machine and auxiliary platens shall have a hardness value of at least 570HV30 (or 53HRC) when
tested in accordance with EN ISO 6507-1.
4.2.3 The flatness tolerance for machine platens and auxiliary platens shall be 0,03 mm for the area in
contact with the specimen.
NOTE For the purpose of this document, flatness can be assessed by the measurement of straightness in four
positions (see EN 12390-1:2012, Annex B).
4.2.4 The roughness value (R ) for the surface texture of machine and auxiliary platens shall be in the
a
range 0,4 μm to 3,2 μm, when assessed in accordance with EN ISO 21920-2 for the area in contact with
the specimens.
4.2.5 Platens are rectangular, square or circular. The dimensions of the surface of the machine platens
and auxiliary platens in contact with the specimen shall surpass the dimensions of the specimen as placed
in the machine'.
4.2.6 The two contact faces of an auxiliary platen shall be produced to be parallel to a tolerance of
0,05 mm.
4.2.7 Auxiliary platens shall be at least 23 mm thick.
4.2.8 Spacing blocks may be used if there is a requirement to reduce the distance between the machine
platens.
For stability reasons, the total number of spacing blocks shall not exceed four. Spacing blocks shall be
precisely centred along the machine axis.
4.2.9 A spacing block may be either circular or square in section and shall be rigidly supported from
below.
A minimum diameter or length of side of 200 mm is recommended for spacing blocks.
4.2.10 Spacing blocks shall comply with the flatness and parallelism tolerances required for auxiliary
platens (see 4.2.3 and 4.2.6).
4.2.11 Spacing blocks shall be positioned below the lower machine platen and not in contact with the
specimen.
4.2.12 Spacing blocks shall be precisely positioned centrally on the vertical machine axis.
4.3 Force measurement
4.3.1 Force indicator
The machine shall be provided with:
— dials or digital displays which allow the force to be read to the accuracy specified in 4.3.2;
— a system which allows the maximum force sustained to be read after completion of the test, until
reset;
— displays readable from the operating position.
The machine force indication system shall not be affected by explosive failure of the specimen.
The lowest verifiable value of each measuring range shall be less than or equal to 20 % of the maximum
value of the range. If the machine is equipped with several indication ranges, the above requirement shall
apply to each range.
4.3.2 Class of testing machine
Two classes of machines are defined: (see also 4.5.5)
Class A machines: Machines shall conform to class 1 of Table 1
Class B machines: Machines shall conform to class 2 of Table 1
a
Table 1 Characteristic values of the force-measuring system
Class of Maximum permissible value (%)
machine range
Relative error of Relative
resolution
a
Indication Repeatability Reversibility Zero
1 ± 1,0 1,0 ± 1,5 ± 0,1 0,5
2 ± 2,0 2,0 ± 3,0 ± 0,2 1,0
a
The relative reversibility error is only determined when required
4.4 Force control
4.4.1 The compression testing machine shall be provided with a control system. The control system
shall enable the machine to be verified and to allow force to be applied smoothly and without shock. It
shall also allow the force to be applied at constant rates prescribed in the relevant standard.
4.4.2 The control system may be operated either by manual or automatic means.
a
This table derives from EN ISO 7500-1: 2018.
4.4.3 A load rate indicator and/or a pacer shall be fitted on the machine. The pacer shall indicate a rate
within at least ± 5 % of the specified rate.
It is recommended that the machine is provided with digital or analogical recorder of the load rate.
4.5 Force transfer
4.5.1 The upper platen shall incorporate a ball-seating. The upper platen and the ball-seating may be
constructed separately or in one piece.
4.5.2 At the design stage, the manufacturer shall ensure that the centre of rotation of the ball-seating
shall coincide with the centre of the contact area of the machine platen and permit a rotation of at least
three degrees.
4.5.3 At the start of a test, the upper platen shall align itself with the surface of the specimen when the
initial con
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