1、BRITISH STANDARDBS EN 13161:2008Natural stone test methods Determination of flexural strength under constant momentICS 73.020; 91.100.15g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g3
2、8g50g51g60g53g44g42g43g55g3g47g36g58BS EN 13161:2008This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 August 2008 BSI 2008ISBN 978 0 580 58536 4National forewordThis British Standard is the UK implementation of EN 13161:2008. It supersedes B
3、S EN 13161:2001 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee B/545, Natural stone.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provis
4、ions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments/corrigenda issued since publicationDate CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 13161April 2008ICS 73.020; 91.100.15 Sup
5、ersedes EN 13161:2001 English VersionNatural stone test methods - Determination of flexural strengthunder constant momentMthodes dessai pour pierres naturelles - Dterminationde la rsistance en flexion sous moment constantPrfverfahren fr Naturstein - Bestimmung derBiegefestigkeit unter Drittellinienl
6、astThis European Standard was approved by CEN on 28 March 2008.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical refe
7、rences concerning such nationalstandards may be obtained on application to the CEN 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 translationunder the responsibility of a CEN member in
8、to its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
9、Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2008
10、 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 13161:2008: EEN 13161:2008 (E) 2 Contents Page Foreword3 1 Scope 5 2 Normative references 5 3 Principle5 4 Symbols 5 5 Apparatus .5 6 Preparation of specimens.6 6.1 Sampling.6 6.2 Test
11、 specimens6 6.2.1 Surface finish .6 6.2.2 Dimensions.7 6.2.3 Limit deviations7 6.2.4 Planes of anisotropy .7 6.2.5 Conditioning before testing9 7 Test procedure.9 8 Expression of results 10 9 Test report 10 Annex A (normative) Statistical evaluation of the test results.12 A.1 Scope 12 A.2 Symbols an
12、d definitions .12 A.3 Statistical evaluation of test results 12 Bibliography 15 BS EN 13161:2008EN 13161:2008 (E) 3 Foreword This document (EN 13161:2008) has been prepared by Technical Committee CEN/TC 246 “Natural stones”, the secretariat of which is held by UNI. This European Standard shall be gi
13、ven the status of a national standard, either by publication of an identical text or by endorsement, at the latest by October 2008, and conflicting national standards shall be withdrawn at the latest by October 2008. Attention is drawn to the possibility that some of the elements of this document ma
14、y be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 13161:2001. This European Standard is one of the series of European Standards for tests on natural stone. Test methods for natural stone cons
15、ist of the following parts: EN 1925, Natural stone test methods Determination of water absorption coefficient by capillarity EN 1926, Natural stone test methods Determination of uniaxial compressive strength EN 1936, Natural stone test methods Determination of real density and apparent density and o
16、f total porosity and open porosity EN 12370, Natural stone test methods Determination of resistance to salt crystallisation EN 12371, Natural stone test methods Determination of frost resistance EN 12372, Natural stone test methods Determination of flexural strength under concentrated load EN 12407,
17、 Natural stone test methods Petrographic examination EN 13364, Natural stone test methods 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 a
18、t atmospheric pressure EN 13919, Natural stone test methods Determination of resistance to ageing by SO2action in the presence of humidity EN 14066, Natural stone test methods Determination of resistance to ageing by thermal shock EN 14146, Natural stone test methods Determination of the dynamic mod
19、ulus of elasticity (by measuring the fundamental resonance frequency) EN 14147, Natural stone test methods Determination of resistance to ageing by salt mist EN 14157, Natural stone test methods Determination of abrasion resistance EN 14158, Natural stone test methods Determination of rupture energy
20、 EN 14205, Natural stone test methods Determination of Knoop hardness BS EN 13161:2008EN 13161:2008 (E) 4 EN 14231, Natural stone test methods Determination of the slip resistance by means of the pendulum tester EN 14579, Natural stone test methods Determination of sound speed propagation EN 14580,
21、Natural stone test methods Determination of static elastic modulus EN 14581, Natural stone test methods Determination of linear thermal expansion coefficient According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this
22、 European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the U
23、nited Kingdom. BS EN 13161:2008EN 13161:2008 (E) 5 1 Scope This European Standard specifies a method to determine the flexural strength of natural stones under constant moment. This European Standard contains provision for both an identification test and for a technological test. 2 Normative referen
24、ces The following referenced documents are indispensable for the application 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 12390-4, Testing hardened concrete Part 4:
25、 Compressive strength Specification for testing machines EN 12390-5, Testing hardened concrete Part 5: Flexural strength of test specimens 3 Principle After appropriate preparation a specimen of the rock to be tested is laid and centred between two supports. Thereafter the specimen is subjected to a
26、 load using two parallel rollers acting on the top surface of the specimen. These loading rollers are centred and located a distance of one third of the length of span. The loads are steadily increased until failure. 4 Symbols Rtc flexural strength at constant moment, in Megapascals; F load at failu
27、re in Newtons; b specimen width in millimetres; h specimen thickness in millimetres; L specimen length in millimetres; l distance between the supporting rollers, in millimetres. 5 Apparatus 5.1 A balance capable of weighing the specimen with a reading up to 0,01 % of the mass to be weighed. 5.2 A ve
28、ntilated oven capable of maintaining a temperature of (70 5) C. 5.3 A linear measuring device with a reading up to 0,05 mm. 5.4 A test machine of appropriate force, in accordance with EN 12390-4 and calibrated according to this European Standard. 5.5 A device for applying loads on the specimen by a
29、two-points load, in accordance with EN 12390-5. It consists of two upper rollers (load-applying rollers) and two lower rollers (supporting rollers): see Figure 1. The distance between the two supporting rollers shall be reported as requested in 6.2.2. BS EN 13161:2008EN 13161:2008 (E) 6 5.6 A room w
30、hich can be maintained at a temperature of (20 10) C. Key 1 load applying rollers 2, 3 supporting rollers Figure 1 Arrangement of loading of a test specimen (two point loading) 6 Preparation of specimens 6.1 Sampling The sampling is not the responsibility of the testing laboratory except when it is
31、especially requested. At least 10 specimens shall be selected from a homogeneous batch (see also 6.2.4). 6.2 Test specimens 6.2.1 Surface finish As a standard reference, the surface finish of the faces of the specimens shall be sawn, honed or polished (identification test). When it is necessary to c
32、arry out the test on final products (technological test) the surface finish of the specimens may be flamed, sandblasted etc., depending on the final use. For the technological test the specimens may be final products or sawn from final products. The surface intended for use shall be in BS EN 13161:2
33、008EN 13161:2008 (E) 7 contact with the two supporting rollers (facing downwards). However the kind of surface finish shall be stated in the report. 6.2.2 Dimensions The dimensions of the specimens are determined by their thickness h: the thickness h shall be between 25 mm and 100 mm and shall be gr
34、eater than twice the size of the largest crystal in the stone; the total length L shall be equal to six times the thickness; the distance between the supporting rollers l shall be equal to five times the thickness; the width b shall be between 50 mm and three times the thickness (50 mm b 3h), and in
35、 no case it shall be less than the thickness. 6.2.3 Limit deviations The limit deviation on the dimensions h, b, L and l shall be 1 mm of the nominal dimensions. In the case of identification test the faces shall not depart from perpendicularity to the axis of the specimen by more than 2 % with a ma
36、ximum of 2 mm difference, when measured in any direction. 6.2.4 Planes of anisotropy 6.2.4.1 Identification test If the stone shows planes of anisotropy (e.g. bedding, foliation), the direction of the planes of anisotropy is to be marked on each specimen by at least two parallel lines. If the use of
37、 the stone in respect of the position of the planes of anisotropy is known, the test shall be carried out with the force applied to the face that will be loaded during use. If the way of use of the stone is not known but the position of the planes of anisotropy is indicated on the specimens, the tes
38、t shall be carried out on each of the three arrangements shown in Figures from 2 to 4; the total number of specimens will then be 3 times 10. 6.2.4.2 Technological test The specimens shall be tested only for the relevant product direction that is, with the force applied to the face which will be loa
39、ded during use. BS EN 13161:2008EN 13161:2008 (E) 8 Figure 2 Test arrangement for a specimen with the load applied perpendicular to the planes of anisotropy Figure 3 Test arrangement for a specimen with the load applied parallel to the planes of anisotropy BS EN 13161:2008EN 13161:2008 (E) 9 Figure
40、4 Test arrangement for a specimen with the load applied perpendicular to the edges of the planes of anisotropy 6.2.5 Conditioning before testing The specimens shall be dried at (70 5) C to constant mass. Constant mass shall be considered to have been reached when the difference between two weighings
41、 made at an interval of (24 2) h is not greater than 0,1 % of the previous mass measurement. After drying and before testing the specimens shall be stored at (20 10) C for thermal equilibrium to be reached, and the test shall be performed within 24 h after removal from the oven. 7 Test procedure Wip
42、e the surfaces of the rollers clean and remove any loose grits from the faces of the specimen which will be in contact with the rollers. Align the specimen carefully and centrally between the supports and the loading cylinders such to gain uniform setting as shown in Figure 1. Specimen position rega
43、rding anisotropy directions is visualized in Figures 2, 3 and 4. The load is increased uniformly at a rate equivalent to (0,25 0,05) MPa/s until failure. The maximum load on the specimens shall be recorded to the nearest 10 N and the place and mode of the fracture shall be recorded if the failure ha
44、s occurred outside the two line loads. NOTE Where the loading rate (V, in N/s) is needed, the following equation can be used to determine the required rate: BS EN 13161:2008EN 13161:2008 (E) 10 labhV322= (N/s) 8 Expression of results For each specimen the flexural strength at constant moment Rtcis c
45、alculated by the Equation (1): 2tchblFR= (1) The result shall be expressed in Megapascals to the nearest 0,1 MPa. 9 Test report The test report shall contain the following information: a) unique identification number of the report; b) the name, number, and date of issue of this European Standard, i.
46、e. EN 13161:2008; c) the name and address of the test laboratory and the address where the test was carried out if different from the testing laboratory; d) the name and the address of the client; e) it is the responsibility of the client to supply the following information: the petrographic name of
47、 the stone; the commercial name of the stone; the country and region of extraction; the name of the supplier; the direction of any existing plane of anisotropy (if relevant to the test) to be clearly indicated on the sample or on each specimen by means of two parallel lines; the name of the person o
48、r organization which carried out the sampling; f) the date of delivery of the sample or of the specimens; g) the date when the specimens were prepared (if relevant) and the date of testing; h) the number of specimens in the sample; i) the surface finish of the specimens; j) the perpendicularity to t
49、he axis of the specimens; k) for each specimen: width (b) and thickness (h) to the nearest 0,1 mm; BS EN 13161:2008EN 13161:2008 (E) 11 length (L) and the length of span (l) to the nearest 1 mm; failure load to the nearest 10 N; flexural strength (Rtc) in MPa to the nearest 0,1 MPa; loading direction in relation to any anisotropy; mode and place of the fracture when outside the two line loads; l) for each relevant direction of loading the mean value tcR of the f
