1、BRITISH STANDARD BS EN 14579:2004 Natural stone test methods Determination of sound speed propagation The European Standard EN 14579:2004 has the status of a British Standard ICS 73.020; 91.100.15 BS EN 14579:2004 This British Standard was published under the authority of the Standards Policy and St
2、rategy Committee on 17 January 2005 BSI 17 January 2005 ISBN 0 580 45268 9 National foreword This British Standard is the official English language version of EN 14579:2004. The UK participation in its preparation was entrusted to Technical Committee B/545, Natural stone, which has the responsibilit
3、y to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “Internatio
4、nal Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British
5、 Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and E
6、uropean developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.
7、 Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14579 October2004 ICS73.020;91.100.15 Englishversion NaturalstonetestmethodsDeterminationofsoundspeed propagation MthodesdessaipourpierresnaturellesDtermination delavitessedepropagationduson P
8、rfverfahrenfrNatursteinBestimmungder GeschwindigkeitderSchallausbreitung ThisEuropeanStandardwasapprovedbyCENon23August2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptod
9、atelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownla
10、nguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Port
11、ugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers.
12、Ref.No.EN14579:2004:EEN 14579:2004 (E) 2 Contents Page Foreword3 1 Scope 4 2 Principle4 3 Symbols and abbreviations 4 4 Apparatus .4 4.1 General4 4.2 Performance requirements .4 4.3 Transducers .5 4.4 Apparatus for the determination of the arrival time of the pulse .5 4.5 Other apparatus .5 5 Prepar
13、ation of the specimens 5 5.1 Sampling.5 5.2 Test specimens5 5.2.1 General5 5.2.2 Dimensions.5 5.2.3 The test specimens shall be prisms of 300 mm x 75 mm x 50 mm with a tolerance of 2mm. Planes of anisotropy .5 5.2.4 Drying the specimens .5 6 Test procedure.6 6.1 General6 6.2 Determination of Pulse V
14、elocity.6 6.2.1 Factors influencing pulse velocity measurements 6 6.2.2 Transducer arrangement 6 6.2.3 Path length measurement.7 6.2.4 Coupling the transducer onto the stone .7 6.2.5 Measurement of the transit time 7 7 Expression of the results7 8 Test report 8 Annex A (normative) Determination of p
15、ulse velocity in the case of indirect transmission .9 Annex B (informative) Factors influencing the measurement of the velocity of sound 10 B.1 General Points10 B.2 Water Content 10 B.3 Path Length 10 B.4 Shape and sizes of the test specimens.11 B.5 Fissures and voids 11 Bibliography 12 EN 14579:200
16、4 (E) 3 Foreword This document (EN 14579:2004) has been prepared by Technical Committee CEN/TC 246 “Natural stones”, the secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the
17、latest by April 2005, and conflicting national standards shall be withdrawn at the latest by April 2005. This standard is one of the series for tests on natural stone. Test methods for natural stone consist of the following parts: EN 1925, Natural stone test methods Determination of water absorption
18、 coefficient by capillarity EN 1926, Natural stone test methods Determination of compressive strength EN 1936, Natural stone test methods Determination of real density and apparent density, and of total and open porosity EN 12370, Natural stone test methods Determination of resistance to salt crysta
19、llisation EN 12372, Natural stone test methods Determination of flexural strength under concentrated load EN 12407, Natural stone test methods Petrographic examination EN 13161, Natural stone test methods Determination of flexural strength under constant moment EN 13364, Natural stone test methods -
20、 Determination of the breaking load at dowel hole EN 13373, Natural stone test methods Determination of geometric characteristics on units EN 13755, Natural stone test methods Determination of water absorption at atmospheric pressure EN 13919, Natural stone test methods Determination of resistance t
21、o ageing by SO 2action in the presence of humidity EN 14066, Natural stone test methods Determination of resistance to ageing by thermal shock EN 14147, Natural stone test methods Determination of resistance to ageing by salt mist EN 14205, Natural stone test methods - Determination of Knoop hardnes
22、s EN 14231, Natural stone test methods Determination of the slip resistance by means of the pendulum tester EN 14157:2004, Natural stone test methods Determination of abrasion resistance EN 14158:2004, Natural stone test methods Determination of rupture energy EN 14579:2004, Natural stone test metho
23、ds Determination of sound speed propagation prEN 14580:2002, Natural stone test methods Determination of the static elastic modulus prEN 14581:2002, Natural stone test methods Determination of linear thermal expansion coefficient According to the CEN/CENELEC Internal Regulations, the national standa
24、rds organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slo
25、vakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EN 14579:2004 (E) 4 1 Scope This document specifies a method for the determination of the velocity of propagation of pulses of ultrasonic longitudinal waves in natural stone, both in laboratory and in situ. 2 Principle A pulse of longitu
26、dinal vibrations is produced by an electro-acoustical transducer held in contact with one surface of the stone under test. After traversing a known path length in the stone, the pulse of vibrations is converted into an electrical signal by a second transducer and electronic timing circuits enable th
27、e transit time of the pulse to be measured. 3 Symbols and abbreviations V pulse velocity, in km/s L path length, in mm T time taken by the pulse to transverse the length, in s 4 Apparatus 4.1 General 4.1.1 The apparatus consists essentially of an electrical pulse generator, a pair of transducers, an
28、 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. 4.1.2 Two forms of electronic timing apparatus are available: a) an oscilloscope on whic
29、h 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. NOTE An oscilloscope provides the facility for examining the wave form, which can be advantageous in complex situations. 4.2 Performance requirements The appa
30、ratus shall comply with the following performance requirements: - to measure transit times in the calibration bar to an accuracy of 0,1 s; - to ensure a sharp pulse onset, that is the electronic excitation pulse applied to the transmitting transducer shall have a rise time of not greater than one-qu
31、arter of its natural period; - the pulse repetition frequency shall be low enough to ensure that the onset of the received signal is free from interference by reverberations. EN 14579:2004 (E) 5 4.3 Transducers The natural frequency of the transducers shall be within the range 20 to 150 kHz. NOTE Fr
32、equencies as low as 10 kHz and as high as 200 kHz may sometimes be used. High frequency pulses have a well defined onset, but, as they pass through the natural stone, they become attenuated more rapidly than pulses of lower frequency. It is therefore preferable to use high frequency transducers (82
33、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 82 kHz are found to be useful for most applications. 4.4 Apparatus for the determination of the arrival t
34、ime of the pulse The apparatus shall be capable of determining the time of arrival of the first front of the pulse, even though this may be of small amplitude compared with that of the first half wave of the pulse. 4.5 Other apparatus A weighing instrument with an accuracy of 0,01 % of the mass to b
35、e weighed. A ventilated oven capable of maintaining a temperature of (70 5) C. 5 Preparation of the specimens 5.1 Sampling The sampling is not the responsibility of the test laboratory except where specially requested. At least 6 specimens shall be selected from a homogeneous batch (see also 5.2.3)
36、5.2 Test specimens 5.2.1 General As a standard reference the surface finish of the faces of the specimens shall be sawn or honed. 5.2.2 Dimensions 5.2.3 The test specimens shall be prisms of 300 mm x 75 mm x 50 mm with a tolerance of 2mm. Planes of anisotropy If the stone shows planes of anisotropy
37、(e.g. bedding, foliation) the specimens shall be prepared with the long axis either parallel or perpendicular to these planes. 5.2.4 Drying the specimens The specimens shall be dried at a temperature of (70 5) C to constant mass. This is assumed to have been attained when the difference between two
38、weighings at an interval of (24 2) h is not greater than 0,1 % of the first of these two masses. EN 14579:2004 (E) 6 6 Test procedure 6.1 General The apparatus shall be used within the operating conditions stated by the manufacturer. 6.2 Determination of Pulse Velocity 6.2.1 Factors influencing puls
39、e 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 informative Annex B. 6.2.2 Transducer arrangement Although the direction in which the max
40、imum 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 natural stone in some other direction. It is therefore possible to make measurements of pulse velocity by placing the two transducers either on op
41、posite face (direct transmission), or on adjacent faces (semi-direct transmission), or on the same face (indirect or surface transmission). (see Figure 1). T = transmitter R = receiver a) direct transmission b) semi-direct transmission c) indirect or surface transmission Figure 1 Different transduce
42、r arrangements for the determination of pulse velocity NOTE 1 It may be 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 2 The indirect transmission arrangement is the l
43、east sensitive and should only be used, for in situ measurements when only a single face of the natural stone is accessible, or when it is more important to determine the strength of the layer near the surface than that of the body of the stone itself. NOTE 3 The semi-direct transmission arrangement
44、 has a sensitivity intermediate between the other two arrangements and should only be used when the direct arrangement cannot be used. EN 14579:2004 (E) 7 6.2.3 Path length measurement For direct transmission, the path length is the distance between the transducers measured with an accuracy of 1 %.
45、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 transducers faces. The accuracy of the measurement of the path length is dependent upon the size of the transducers compared with the centre t
46、o centre distance and it shall be estimated. With indirect transmission, the path length is not measured, but a series of measurements is made with the transducers at different distances apart. 6.2.4 Coupling the transducer onto the stone There shall be adequate acoustical coupling between the stone
47、 and the face of each transducer. For sufficiently smooth surface finishes a good acoustical contact is ensured by the use of a coupling medium such as petroleum jelly, grease, soft soap and kaolin/glycerol paste and by pressing the transducer against the stone surface. Repeated readings of the tran
48、sit time shall be made until a minimum value is obtained, so as to allow the layer of couplant to become thinly spread. When the surface finish is very rough and uneven, the surface area shall be smoothed and levelled by grinding, or by the use of a quick-setting epoxy resin. NOTE Special transducers are available for use on very rough surfaces 6.2.5 Measurement of the transit time Using the electronic device the time interval indicated shall be recorded. 7 Expression of the results For direct and semi-direct trans
