kSIST FprEN 12504-4:2021

Testing concrete in structures - Part 4: Determination of ultrasonic pulse velocity

This document specifies a method for the determination of the velocity of propagation of pulses of ultrasonic longitudinal waves or ultrasonic transverse waves in hardened concrete, which is used for a number of applications.

Prüfung von Beton in Bauwerken - Teil 4: Bestimmung der Ultraschall-Impulsgeschwindigkeit

Dieses Dokument legt ein Verfahren zur Bestimmung der Ausbreitungsgeschwindigkeit von Ultraschall-Longitudinalwellen oder Ultraschall-Transversalwellen aus der Laufzeit von Schallimpulsen in Festbeton für eine Anzahl von Anwendungsfällen fest.

Essais pour béton dans les structures - Partie 4 : Détermination de la vitesse de propagation des ultrasons

Le présent document spécifie une méthode de détermination de la vitesse de propagation des ondes ultrasonores longitudinales ou des ondes ultrasonores transversales dans le béton durci utilisée pour un certain nombre d’applications.

Preskušanje betona - 4. del: Določevanje hitrosti prehoda ultrazvoka

General Information

• Status: Not Published
• Public Enquiry End Date: 14-Nov-2019
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: BBB - Concrete, reinforced concrete and prestressed concrete
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 11-Mar-2021
• Due Date: 29-Apr-2021
• Completion Date: 12-Mar-2021
• 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
• Ref Project: EN 12504-4:2021 - Testing concrete in structures - Part 4: Determination of ultrasonic pulse velocity

RELATIONS

• Revised: SIST EN 12504-4:2004 - Testing concrete - Part 4: Determination of ultrasonic pulse velocity
• Effective Date: 01-Nov-2019
• Replaces: SIST EN 12504-4:2004 - Testing concrete - Part 4: Determination of ultrasonic pulse velocity
• Effective Date: 14-Jul-2021

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 12504-4:2019
01-november-2019
Preskušanje betona - 4. del: Določevanje hitrosti prehoda ultrazvoka
Testing concrete in structures - Part 4: Determination of ultrasonic pulse

Prüfung von Beton in Bauwerken - Teil 4: Bestimmung der Ultraschallgeschwindigkeit

Essais pour béton dans les structures - Partie 4 : Détermination de la vitesse de

propagation des ultrasons
Ta slovenski standard je istoveten z: prEN 12504-4
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
oSIST prEN 12504-4:2019 en,fr,de

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

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oSIST prEN 12504-4:2019
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oSIST prEN 12504-4:2019
DRAFT
EUROPEAN STANDARD
prEN 12504-4
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2019
ICS 91.100.30 Will supersede EN 12504-4:2004
English Version
Testing concrete in structures - Part 4: Determination of
ultrasonic pulse

Essais pour béton dans les structures - Partie 4: Prüfung von Beton in Bauwerken - Teil 4: Bestimmung

Determination de la vitesse de propagation du son der Ultraschallgeschwindigkeit

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, Turkey 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

© 2019 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12504-4:2019 E

worldwide for CEN national Members.
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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

1 Scope .................................................................................................................................................................... 4

2 Normative references .................................................................................................................................... 4

3 Terms and definitions ................................................................................................................................... 4

4 Principle ............................................................................................................................................................. 4

5 Apparatus ........................................................................................................................................................... 5

5.1 General ................................................................................................................................................................ 5

5.2 Performance requirements ......................................................................................................................... 5

5.3 Transducers ...................................................................................................................................................... 5

5.4 Apparatus for determination of arrival time of the pulse ................................................................ 5

6 Procedures......................................................................................................................................................... 6

6.1 Determination of Pulse Velocity ................................................................................................................ 6

6.1.1 Factors influencing pulse velocity measurements .............................................................................. 6

6.1.2 Transducer arrangement ............................................................................................................................. 6

6.1.3 Path length measurement ............................................................................................................................ 7

6.1.4 Coupling the transducer onto the concrete ........................................................................................... 8

6.1.5 Measurement of transit time ...................................................................................................................... 8

7 Expression of result ........................................................................................................................................ 8

8 Test report ......................................................................................................................................................... 8

9 Precision ............................................................................................................................................................. 9

Annex A (informative) Determination of pulse velocity - indirect transmission .............................. 10

Annex B (informative) Factors influencing pulse velocity measurements .......................................... 12

B.1 General ............................................................................................................................................................. 12

B.2 Moisture content .......................................................................................................................................... 12

B.3 Temperature of the concrete ................................................................................................................... 12

B.4 Path length ...................................................................................................................................................... 12

B.5 Shape and size of specimen ...................................................................................................................... 13

B.6 Effect of reinforcing bars ........................................................................................................................... 13

B.7 Cracks and voids ........................................................................................................................................... 13

Annex C (informative) Correlation of pulse velocity and strength ......................................................... 15

C.1 General ............................................................................................................................................................. 15

C.2 Correlation using moulded specimens ................................................................................................. 15

C.3 Correlation by tests on cores ................................................................................................................... 15

C.4 Correlation with the strength of precast units .................................................................................. 16

Bibliography ................................................................................................................................................................. 17

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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
European foreword

This document (prEN 12504-4:2019) has been prepared by Technical Committee CEN/TC 104 “Concrete

and related products”, the secretariat of which is held by SN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12504-4:2004.
This standard is one of a series on testing concrete.
EN 12504, Testing concrete in structures, consists of the following parts:
— Part 1: Cored specimens — Taking, examining and testing in compression;
— Part 2: Non-destructive testing — Determination of rebound number;
— Part 3: Determination of pull-out force;
— Part 4: Determination of ultrasonic pulse velocity.

This document is based on the International Standard ISO 1920-7, Testing of concrete — Part 7: Non-

destructive tests on hardened concrete. It is recognized that the ultrasonic pulse velocity determined using

this document is a convention in as much that the path length over which the pulse travels is not always

strictly known.

The measurement of pulse velocity can be used for the determination of the uniformity of concrete, the

presence of cracks or voids, changes in properties with time and in the determination of dynamic physical

properties. These subjects were considered to be outside the scope of this document, but some

information is given in Annex B and more information can be found in the technical literature. The

measurement can also be used to estimate the strength of in situ concrete elements or specimens given

in EN 13791, Assessment of in situ compressive strength in structures and precast concrete components.

However, it is not intended as an alternative to the direct measurement of the compressive strength of

concrete.
The following amendments have been made to the former edition:
— option to use equipment utilizing transverse waves.
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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
1 Scope

This document specifies a method for the determination of the velocity of propagation of pulses of

ultrasonic longitudinal waves or ultrasonic transverse waves in hardened concrete, which is used for a

number of applications.
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 206, Concrete — Specification, performance, production and conformity
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 206 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
3.1
transit time

time taken for an ultrasonic pulse to travel from the transmitting transducer to the receiving transducer,

passing through the interposed concrete
3.2
onset
leading edge of the pulse detected by the measuring apparatus
3.3
rise time

time for the leading edge of the first pulse to rise from 10% to 90% of its maximum amplitude

4 Principle

A pulse of longitudinal or transverse vibrations is produced by an electro-acoustical transducer held in

contact with one surface of the concrete under test. After traversing a known path length in the concrete,

the pulse of vibrations is converted into an electrical signal by a second transducer and electronic timing

circuits enable the transit time of the pulse to be measured.
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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
5 Apparatus
5.1 General

The apparatus consists of an electrical pulse generator, a pair of transducers, an amplifier and an

electronic timing device for measuring the time interval elapsing between the onset of a pulse generated

at the transmitting transducer and the onset of its arrival at the receiving transducer. A reference bar or

prism is used to zero the instrument or to provide a datum for the velocity measurement.

NOTE 1 This is typically necessary when the user changes the length of the cables being used.

Three forms of the electronic timing apparatus are available:

a) an oscilloscope on which the first front of the pulse is displayed in relation to a suitable time scale;

b) an interval timer with a direct reading digital display;
c) an A-scan display built directly into the instrument.

NOTE 2 An oscilloscope or integrated A-scan display provides the facility for monitoring the wave form of the

pulse, which can be advantageous in complex testing situations or in automatic system measurements.

5.2 Performance requirements
The apparatus shall conform to the following performance requirements:

— It shall be capable of measuring transit times in the reference bar or prism to a limit deviation

of ± 0,1 µs and an accuracy of 2 %.

— The electronic excitation pulse applied to the transmitting transducer shall have a rise time of not

greater than one-quarter of its natural period. This is to ensure a sharp pulse onset.

— The pulse repetition frequency shall be low enough to ensure that the onset of the received signal is

free from interference by reverberations.

The apparatus shall be used within the operating conditions stated by the manufacturer.

5.3 Transducers

The natural frequency of the transducers should normally be within the range 20 kHz to 150 kHz.

NOTE For longitudinal waves, frequencies as low as 10 kHz and as high as 200 kHz can sometimes be used.

High frequency pulses have a well defined onset, but, as they pass through the concrete, they become attenuated

more rapidly than pulses of lower frequency. It is, therefore, preferable to use high frequency transducers (60 kHz

to 200 kHz) for short path lengths (down to 50 mm) and low frequency transducers (10 kHz to 40 kHz) for long

path lengths (up to a maximum of 15 m). Transducers with a frequency of 40 kHz to 60 kHz are found to be useful

for most applications. For ultrasonic pulse echo measurements using transverse waves the transducer frequency of

40 kHz to 60 kHz is also typical, but the in this case the path length is limited to a maximum of approximately 2,5 m.

5.4 Apparatus for determination of arrival time of the pulse

The apparatus shall be capable of determining the time of arrival of the first front of the pulse with the

lowest possible threshold, even though this may be of small amplitude compared with that of the first

half wave of the pulse.
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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
6 Procedures
6.1 Determination of Pulse Velocity
6.1.1 Factors influencing pulse velocity measurements

In order to provide a measurement of pulse velocity, which is reproducible, it is necessary to take into

account various factors which can influence the measurements. These are set out in Annex B.

6.1.2 Transducer arrangement

Although the direction in which the maximum energy is propagated is at right angles to the face of the

transmitting transducer, it is possible to detect pulses which have travelled through the concrete in some

other direction. It is therefore possible to make measurements of pulse velocity by placing the two

transducers on opposite faces (direct transmission), or on adjacent faces (semi-direct transmission), or

the same face (indirect or surface transmission; pulse echo transmission) (see Figure 1) of a concrete

structure or specimen. In the case of pulse echo transmission, the receiver detects pulses which have

travelled through the concrete to the opposite face and have been reflected back to the first face.

Where it is necessary to place the transducers on opposite faces but not directly opposite each other such

arrangement shall be regarded as a semi-direct transmission (see Figure 1.b).

NOTE 1 The indirect transmission arrangement is the least sensitive and is used when only one face of the

concrete is accessible or when the quality of the surface concrete relative to the overall quality is of interest.

NOTE 2 The semi-direct transmission arrangement is used when the direct arrangement cannot be used, for

example at the corners of structures.

NOTE 3 Pulse echo transmission is an alternative to indirect transmission when only one face of the concrete is

accessible. The sensitivity is comparable with direct transmission.
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oSIST prEN 12504-4:2019
prEN 12504-4:2019 (E)
Key
R is the receiver transducer
T is the transmitter transducer
Figure 1 — Transducer positioning
6.1.3 Path length measurement

For direct transmission, the path length is the shortest distance between the transducers. The accuracy

of measurement of the path length shall be recorded to an accuracy of ± 1 %.

For semi-direct transmission, it is generally found to be sufficiently accurate to take the path length as

the distance measured from centre to centre of the transducer faces. The accuracy of path length is

dependent upon the size of the transducer compared with the centre to centre distance.

With indirect
...