1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58thermal expansion coefficientThe European Standard EN 14581:2004 has the status of a British Standa
2、rdICS 73.020; 91.100.15Natural stone test methods Determination of linear BRITISH STANDARDBS EN 14581:2004BS EN 14581:2004This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2005 BSI 29 September 2005ISBN 0 580 46616 7Cross-reference
3、sThe British Standards which implement international or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Stan
4、dards 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 Standard does not of itself confer immunity from legal obligations.Summary of pagesThis document comprises a front cover,
5、an inside front cover, the EN title page, pages 2 to 13 and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd. No. Date CommentsA list of organizations represented on this committee can be obtained on r
6、equest to its secretary.enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK.National forewordThis British Standard is the official English language version of EN 14581:2004.The
7、 UK participation in its preparation was entrusted to Technical Committee B/545, Natural stone, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14581December 2004I
8、CS 73.020; 91.100.15English versionNatural stone test methods - Determination of linear thermalexpansion coefficientMthodes dessai pour pierres naturelles - Dterminationdu coefficient linaire de dilatation thermiquePrfverfahren fr Naturstein - Bestimmung des linearenthermischen Ausdehnungskoeffizien
9、tenThis European Standard was approved by CEN on 12 November 2004.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 r
10、eferences concerning such nationalstandards may be obtained on application to the Central Secretariat 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 i
11、nto its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
12、Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, 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 2004 CEN All rights of e
13、xploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 14581:2004: EEN 14581:2004 (E) 2 Contents Page Foreword3 1 Scope 5 2 Normative references 5 3 Principle5 4 Symbols 5 5 Apparatus .6 6 Preparation of the specimens 8 7 Test procedure.10 8 Expression of res
14、ults 11 9 Test report 12 Bibliography 13 EN 14581:2004 (E) 3 Foreword This document (EN 14581:2004) 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 public
15、ation of an identical text or by endorsement, at the latest by June 2005, and conflicting national standards shall be withdrawn at the latest by June 2005. This final draft document is one of the series of documents for tests on natural stone. Test methods for natural stone consist of the following
16、parts: EN 1925, Natural stone test methods Determination of water absorption 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
17、12370, Natural stone test methods Determination of resistance to salt crystallisation 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 fl
18、exural strength under constant moment 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 at atmospheric p
19、ressure 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 14147, Natural stone test methods Determination of resistance to ageing by salt m
20、ist EN 14158, Natural stone test methods Determination of rupture energy EN 14205, Natural stone test methods Determination of Knoop hardness EN 14231, Natural stone test methods Determination of the slip resistance by means of the pendulum tester EN 14157, Natural stone test methods Determination o
21、f the abrasion resistance EN 14579, Natural stone test methods Determination of sound speed propagation prEN 14580, Natural stone test methods Determination of the static elastic modulus EN 14581, Natural stone test methods Determination of linear thermal expansion coefficient EN 14581:2004 (E) 4 Ac
22、cording to the CEN/CENELEC Internal Regulations, the national standards 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, Lith
23、uania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14581:2004 (E) 5 1 Scope This document specifies two methods to determine the linear thermal expansion coefficient of natural stone, respectively based on mechanical
24、 length-change measurements (Method A) or on the use of bonded electric strain gauges (Method B). 2 Normative references Not applicable. 3 Principle After drying to constant mass, the specimen is subjected to length measurement in a direction “i” whilst maintaining at least two different temperature
25、s. The linear coefficient of thermal expansion between the extreme temperatures is expressed as the unitary change in length for a change of temperature of 1 C. 4 Symbols s20l Initial length of the specimen at a temperature of (20 0,5) C in mm. s80l Final length of the specimen at a temperature of (
26、80 0,5) C in mm. ()s20s80slll = Change of length of the specimen in mm. If sl is positive, represents an expansion. If negative, a shrinkage (Note 1). r20l Initial length of the reference sample at a temperature of (20 0,5) C in mm. r80l Final length of the reference sample at a temperature of (80 0
27、,5) C in mm. ()r20r80rlll = Change of length of the reference sample in millimetres. T (60 1) C, the change in the temperature from (20 0,5) C to (80 0,5) C. r Unitary linear thermal expansion of the reference sample in 10-6(mm/mm). sis20sll= Unitary linear thermal expansion of the specimen in the d
28、irection “i” in 10-6(mm/mm). 3s2s1s, Unitary linear thermal expansion of the specimen along three orthogonal directions in 10-6(mm/mm). r Linear coefficient of thermal expansion of the reference sample in C-1. iLinear coefficient of thermal expansion of the specimen in the direction “i“ in C-1. 1,2,
29、 3Linear coefficients of thermal expansion of the specimen along three orthogonal directions, in C-1. EN 14581:2004 (E) 6 NOTE 1 Due to rock anisotropy, the coefficient of thermal expansion can change with the direction in which the measurement is carried out. In some cases the coefficient of therma
30、l expansion can be negative in some directions and positive in other ones. NOTE 2 The coefficient of thermal expansion is not linear with the temperatures. The temperature range in this document is (20 to 80) C, and it will be assumed that iis linear in this range. If the linearity of the thermal ex
31、pansion coefficient need to be evaluated, intermediate measurements at different temperature will need to be made and plotted on a graph. 5 Apparatus 5.1 A ventilated oven capable of raising the temperature from (20 0,2) C to (80 0,2) C at a rate of 0,5 C/min and maintaining temperatures within that
32、 range for at least two hours with an accuracy of at least 0,5 C. 5.2 (For Method A) A mechanical measuring device (dilatometer), with an accuracy of at least 1/100 000 of the measuring length (see Figure 1), any other device able to measure length-changes within the given accuracy (e.g. electronic
33、dilatometers). 5.3 (For Method B) A strain gauge measuring device, containing the following parts (see Figure 2): 5.3.1 Strain gauges suitable to be used within the foreseen temperature range. NOTE Strain gauges should be chosen according to their manufacturers specifications and test laboratory exp
34、erience. Strain gauge length should be at least 8 times the maximum grain size of the rock to be tested. In the case of exceptionally large grains, this length could be 3 times the maximum grain size. 5.3.2 A measuring device consisting of an electrical bridge (Wheatstone bridge) and a signal amplif
35、ier, with at least four measuring channels. The accuracy of the device shall be at least 510-6(mm/mm). Inner resistances in the electrical bridge shall be fixed to a granite rock or similar one for compensating temperatures. 5.4 A calibrated reference sample, with a known coefficient of thermal expa
36、nsion within test temperature range (20 to 80) C. A reference sample could be made of different materials with low thermal expansion coefficient (invar steel, etc). It shall have a length twice the length of strain gauges and a minimum cross section of 50 mm x 50 mm. 5.5 A temperature measuring devi
37、ce (e.g. a thermocouple) with an accuracy of at least 0,2 C. EN 14581:2004 (E) 7 Key 1 test specimen 2 rivets bonded on the test specimen 3 measuring tips of the device, one is mobile 4 mechanical measuring device 5 temperature measuring device Figure 1 Example of a mechanical measuring device EN 14
38、581:2004 (E) 8 Key 1 reference sample with a couple of bonded strain gauges 2 test specimen with three couples of bonded strain gauges 3 Wheatstone bridge control unit A heating unit control B data aquisition system C terminal box D fixed resistance E heating unit F temperature sensor Figure 2 Schem
39、atic test set-up of a strain-gauges measuring device 6 Preparation of the specimens 6.1 Sampling The sampling is not the responsibility of the test laboratory, except when specially requested. The position of any bedding or anisotropy shall be marked on the sample or on each specimen by means of at
40、least two parallel lines. For each direction, at least 2 specimens, shall be selected from an homogeneous batch. The number of test specimens may need to be increased if the stone being tested is heterogeneous. NOTE 1 The thermal expansion coefficient of many stone types is dependent on direction. T
41、herefore, thermal expansion should be measured in several directions in order to assess the degree of anisotropy. NOTE 2 Discontinuities in natural stone, such as joints, inclusions, veins, bedding, etc., may influence the thermal expansion. Production of microcraks during sampling or specimen prepa
42、ration should be avoided. EN 14581:2004 (E) 9 6.2 Test specimens 6.2.1 General The test can be carried out as an identification test or as a technological test. Identification tests are carried out when the use of the stone with respect to the position of the planes of anisotropy and the thickness a
43、nd the surface finish of the stone elements are not known. Technological tests are those carried out when the use of the stone with respect to the position of the planes of anisotropy and the thickness and surface finish of the stone elements are known. In this case, the length of the specimens shal
44、l have the same orientation as the most relevant directions of the largest plane. 6.2.2 Dimensions The dimension of the test specimen shall be in accordance with the minimum size of the measuring length, which is related to the accuracy of the measuring device, and to the maximum grain size of the r
45、ock. Using mechanical measuring devices, specimens for identification test shall be rectangular prisms, with minimum 50 mm width, 20 mm thickness and 250 mm length (length shall be at least 10 times the largest rock grain size). If strain gauge devices are used, specimens for identification test sha
46、ll be cubes or rectangular prisms with minimum 70 mm length, thickness and width. Each one of these dimensions shall be, at least, 10 times the largest rock grain size. For technological test, the thickness shall be equal to that of commercial units and, therefore, the specimen may be not thick enou
47、gh as to enable thermal expansion determinations according to this dimension. In this case, the test is carried out only along the width and the length of the specimen. 6.2.3 Fixing rivets or strain gauges Specimen faces, where the rivets or the strain gauges will be fixed, shall be finished with 60
48、0 (FEPA) grain-size sand paper. Fixing adhesive to be used shall be stable within the test temperature range (20 to 80) C. For identification tests using a mechanical device, two rivets are fixed at adequate distance (minimum 200 mm) along the longitudinal axe of each specimen. For identification te
49、sts using strain gauges, three pairs of gauges shall be fixed to each specimen, in three different perpendicular directions. Gauges in each pair shall be fixed in the same arrangement at opposite faces (see Figure 3). Another pair of gauges shall be fixed at opposite faces of the reference sample. For technological tests, rivets and gauges direction will be lined up with the manufacturing directions. EN 14581:
