BS EN 772-4-1998 Methods of test for masonry units - Determination of real and bulk density and of total and open porosity for natural stone masonry units《砖石结构体的试验方法 天然石头砖砌结构体的实际密度.pdf

《BS EN 772-4-1998 Methods of test for masonry units - Determination of real and bulk density and of total and open porosity for natural stone masonry units《砖石结构体的试验方法 天然石头砖砌结构体的实际密度.pdf》由会员分享，可在线阅读，更多相关《BS EN 772-4-1998 Methods of test for masonry units - Determination of real and bulk density and of total and open porosity for natural stone masonry units《砖石结构体的试验方法 天然石头砖砌结构体的实际密度.pdf（8页珍藏版）》请在麦多课文档分享上搜索。

1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 772-4:1998 The Euro

2、pean Standard EN 772-4:1998 has the status of a British Standard ICS 91.100.20 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Methods of test for masonry units Part 4: Determination of real and bulk density and of total and open porosity for natural stone masonry unitsBS EN 7

3、72-4:1998 This British Standard, having been prepared under the direction of the Sector Committee for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 December 1998 BSI 1998 ISBN 0 580 30697 6 Amendments issued since publication

4、 Amd. No. Date Text affected National foreword This British Standard is the English language version of EN 772-4:1998. No existing British Standard is superseded. The UK participation in its preparation was entrusted by Technical Committee B/519, Masonry and associated testing, to Subcommittee B/519

5、/1, Masonry units, which has the responsibility to: aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promul

6、gate them in the UK. A list of organizations represented on this subcommittee 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 Standards Catalogue under the

7、section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicat

8、ion. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 5 and a back cover.CEN European Committee for Standardization Comite Europe en de Normalisat

9、ion Europa isches Komitee fu r Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1998 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 772-4:1998 E EUROPEAN STANDARD EN 772-4 NORME EUROPE ENNE EUROPA ISCHE NORM August

10、 1998 ICS 91.100.20 Descriptors: construction, masonry units, natural stone, tests, determination, real density, bulk density, open porosity, total porosity English version Methods of test for masonry units Part 4: Determination of real and bulk density and of total and open porosity for natural sto

11、ne masonry units Me thodes dessai des e le ments de maonnerie Partie 4: De termination des masses volumiques re elle et apparente et des porosite s ouverte et totale pour des e le ments de maonnerie en pierre naturelle Pru fverfahren fu r Mauersteine Teil 4: Bestimmung der Dichte und der Rohdichte s

12、owie der Gesamtporosita t und der offenen Porosita t von Mauersteinen aus Naturstein This European Standard was approved by CEN on 2 July 1998. 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 n

13、ational standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards 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

14、 any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Ge

15、rmany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.Page 2 EN 772-4:1998 BSI 1998 Foreword This European Standard has been prepared by Technical Committee CEN/TC 125, Masonry, the Secretariat of which is held by BSI. This E

16、uropean Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 1999, and conflicting national standards shall be withdrawn at the latest by February 1999. According to the CEN/CENELEC Internal Regulations, th

17、e national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United King

18、dom. Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Principle 3 4 Symbols 3 5 Materials 3 6 Apparatus 3 7 Preparation of the specimens 3 8 Procedure 3 9 Calculation and expression of results 4 10 Evaluation of test results 4 11 Test report 4Page 3 EN 772-4:1998 BSI 1998 1 Scope This E

19、uropean Standard specifies a method of determining the real density and the bulk density and the open and total porosity of natural stone masonry units. 2 Normative references This European Standard incorporates by dated or undated reference, provision from other publications. These normative refere

20、nces are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to this European Standard only when incorporated in it by amendment or revision. For undated references, the

21、latest edition of the publication referred to applies. prEN 771-6, Specification for masonry units Part 6: Natural stone masonry units. 3 Principle After drying to constant mass and calculating the bulk and impermeable volume, the bulk and real density of the units are calculated. 4 Symbols m sat,s

22、is the mass of the saturated specimen (g). m dry,s is the mass of the dry specimen (g). m w,s is the apparent mass of the specimen immersed in water (g). V b is the bulk volume (mm 3 ). V p is the volume of open pores (mm 3 ). V i is the impermeable volume (mm 3 ). r r,s is the real density of the s

23、pecimen (kg/m 3 ). r b,s is the bulk density of the specimen (kg/m 3 ). m c,s is the mass of the crushed portion (g). V c,s is the volume of liquid displaced by the crushed portion (ml). P o is the open porosity (%). P is the total porosity (%). r w is the density of water (kg/m 3 ). 5 Materials Dei

24、onized water 6 Apparatus 6.1 Ventilated oven, capable of maintaining a temperature of 708C 58C. 6.2 Evacuation vessel, capable of maintaining a pressure of 2,0 kPa 0,7 kPa. 6.3 Weighing instrument, capable of weighing the specimens to an accuracy of at least 0,01 % of their mass. 6.4 Linear measurin

25、g device, with an accuracy of 0,1 mm. 6.5 Le Chatelier type flask, consisting of a flat-bottomed flask with a tube graduated from 0 ml to 24 ml in 0,1 ml graduations. 6.6 Sieve, with a 0,1 mm mesh. 7 Preparation of the specimens 7.1 Sampling The method of sampling shall be in accordance with prEN 77

26、1-6. The minimum number of specimens shall be five, but a larger minimum number may be specified in the product specification, in which case that larger number shall be used. 7.2 Test specimen The test specimens may have the form of a cylinder, cube or prism and shall be obtained by diamond sawing o

27、r coring. Their volume shall be at least 25 cm 3 . In addition, the surface area to volume ratio shall be between 0,1 mm 21 and 0,2 mm 21 . 7.3 Preparation of specimens Dry the specimens at a temperature of 708C 58Ct o constant mass (6.1). Constant mass is reached if, during the drying process in su

28、bsequent weighings with not less than a 24 h interval, the loss in mass between two determinations is less than 0,1 % of the mass. 8 Procedure 8.1 Open porosity and bulk (apparent) density Weigh the specimens (m d ), then place them in an evacuation vessel (6.2) and lower the pressure gradually to 2

29、,0 kPa 0,7 kPa = (15 5) mm Hg. Maintain this pressure constant for 24 h in order to eliminate the air contained in the open pores of the specimens. Introduce deionized water at 208C 58C slowly into the vessel. The rate at which the water rises shall be such that the samples are completely immersed i

30、n not less than 15 min. Maintain the pressure of 2,0 kPa 0,7 kPa during introduction of the water and for 24 h afterwards.Page 4 EN 772-4:1998 BSI 1998 At the end of this period return the vessel to atmospheric pressure and leave the specimens under water for another 24 h at atmospheric pressure. Re

31、cord the apparent mass in water (m w,s ) for each specimen and quickly wipe with a damp cloth and determine the mass (m sat,s ) of the specimen saturated with water. In the case of natural stones with visible cavities (e.g. travertine) the apparent volume is determined by measuring their dimensions

32、to the nearest 1 mm. 8.2 Real density Having determined the apparent density and the open porosity, crush each specimen separately until the particles pass through the sieve (6.6). Dry the crushed specimen to a constant mass and set apart a portion (m c,s ) of approximately 50 g (weighed to an accur

33、acy of 0,1 g). Introduce deionized water into the Le Chatelier flask (6.5) until the level is up to the zero graduation. Then add the weighed portion of each specimen into the flask in five fractions each of approximately 10 g, ensuring that all of each fraction falls into the liquid. After the intr

34、oduction of each fraction, agitate the liquid to disperse the crushed specimen. Read the graduation to determine the volume (V c,s ) (in ml to the nearest 0,1 ml) of liquid displaced by the mass (m c,s )o f crushed portion. Before taking the initial and final volume readings make sure that the ambie

35、nt air temperature is 208C 58C. 9 Calculation and expression of results 9.1 General The volume of the open pores (in mm 3 ) is expressed to the nearest 1 mm 3 by equation (1): V p = (1) m sat,s 2 m dry,s r w The bulk volume (in mm 3 ) is expressed to the nearest 1m m 3 by equation (2): V b = (2) m s

36、at,s 2 m w,s r w which can alternatively be calculated on the basis of the dimensions of the specimen. NOTE The value of the density of water (r w )a t2 08 C is 0,998 g/ml. 9.2 Bulk (apparent) density The bulk density is expressed to the nearest 10 kg/m 3 by the ratio of the mass of the dry specimen

37、 and its bulk volume, by equation (3): r b,s = (3) m dry,s 3 r w 3 1 000 m sat,s 2 m w,s 9.3 Open porosity The open porosity is expressed by the ratio to the nearest 0,1 % of the volume of open pores and its bulk volume, by equation (4): P o = 3 100 (4) V p V b 9.4 Real density The real density (in

38、kg/m 3 ) is expressed by the ratio of the mass of the crushed dry specimen (m c,s ) to the volume of liquid displaced by the mass (V c,s )b y equation (5): r r,s = (5) m c,s 3 1 000 V c,s 9.5 Total porosity The total porosity (P) is expressed by the ratio (as a percentage) of the volume of pores (op

39、en and closed) and the bulk volume of the specimen, by equation (6): P = 3 100 (6) 12 r b,s r r,s 10 Evaluation of test results Calculate the mean value for bulk (apparent density) to the nearest 10 kg/m 3 and for the total porosity to the nearest 0,1 %. 11 Test report The test report shall contain

40、the following information: a) the number, title and date of issue of this European Standard; b) a description of the specimens to prEN 771-6, the name and address of the client, and: the type of stone; the commercial name of the stone; the country and region of extraction; the name of the supplier;

41、c) the method of sampling and by which organization; d) the direction of any bedding or anisotropic features, to be clearly indicated on the samples by means of two parallel lines; e) the date of delivery of the specimens; f) the date of testing; g) the number of specimens in the sample; h) for each

42、 sample: the real density and the bulk (apparent) density to the nearest 10 kg/m 3 , the open porosity and the total porosity to the nearest 0,1 %; i) the arithmetic mean of the individual values for the real density and for the bulk (apparent) density (to the nearest 10 kg/m 3 ), for the open poros

43、ity and for the total porosity (to the nearest 0,1 %); j) remarks, if any.Page 5 EN 772-4:1998 BSI 1998 Dimensions in millimetres 1 2 3 Ground glass stopper Have two 0,1 ml graduations extend above 1 and below 0 mark Capacity of bulk approx 250 ml 4 5 6 6 ml capacity at 20 C 17 ml capacity at 20 C 1

44、 ml capacity at 20 C NOTE Variations of a few millimetres in such dimensions as total height of flask, diameter of base, etc., are to be expected and should not be considered sufficient cause for rejection. Figure 1 Le Chatelier flask for measurement of real densityBSI 389 Chiswick High Road London

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