EN 846-14-2012 en Methods of test for ancillary components for masonry - Part 14 Determination of the initial shear strength between the prefabricated part of a composite lintel an.pdf

1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN 846-14:2012Methods of test for ancillarycomponents for masonryPart 14: Determination of the initial shearstrength between the prefabricated part ofa composite lintel and th

2、e masonry above itBS EN 846-14:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 846-14:2012. The UK participation in its preparation was entrusted to T e c h n i c a l Committee B/519/3, Ancillary components.A list of organizations represented on this commit

3、tee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2012. Published by BSI Standards Limited 2012.ISBN 978 0 580 69588 9 ICS 91.08

4、0.30 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 September 2012.Amendments issued since publicationDate T e x t a f f e c t e dBS EN 846-14:2012EUROPEAN S

5、TANDARD NORME EUROPENNE EUROPISCHE NORM EN 846-14 September 2012 ICS 91.080.30 English Version Methods of test for ancillary components for masonry - Part 14: Determination of the initial shear strength between the prefabricated part of a composite lintel and the masonry above itMthodes dessai des c

6、omposants accessoires de maonnerie - Partie 14: Dtermination de la rsistance initiale au cisaillement entre la partie prfabrique dun linteau composite et de la maonnerie place au-dessus Prfverfahren fr Ergnzungsbauteile fr Mauerwerk - Teil 14: Bestimmung der Anfangsscherfestigkeit des Verbunds zwisc

7、hen dem vorgefertigten Teil eines teilweise vorgefertigten, bauseits ergnzten Sturzes und dem ber dem Sturz befindlichen Mauerwerk This European Standard was approved by CEN on 11 February 2012. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions

8、for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in th

9、ree 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 b

10、odies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,

11、 Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserved worldwide for CE

12、N national Members. Ref. No. EN 846-14:2012: EBS EN 846-14:2012 EN 846-14:2012 (E) 2 Contents Page Foreword . . 31 Scope. 42 Normative references . . 43 Principle . . 44 Terms, definitions and symbols . 54.1 Terms and definitions . . 54.2 Symbols . . 55 Materials . . 65.1 Masonry units . 65.1.1 Cond

13、itioning of the units . 65.1.2 Testing. 65.2 Mortar . . 65.3 Prefabricated part of the composite lintel . 66 Apparatus . . 67 Preparation and curing of specimens . . 77.1 Preparation of masonry specimen . 77.2 Curing and conditioning of the specimens . 88 Procedure . 88.1 Placing the specimens in th

14、e testing machine . . 88.2 Loading . 108.2.1 Procedure A . . 108.2.2 Procedure B . . 108.2.3 Loading rate . . 108.3 Measurements and observations . 118.4 Replications . . 119 Calculations . . 1110 Evaluation of results . . 1210.1 Procedure A . . 1210.2 Procedure B . . 1210.2.1 General . . 1210.2.2 S

15、imple method . 1210.2.3 Statistical method . . 1311 Test report . . 14Annex A (informative) Types of failure . . 15Bibliography . . 17BS EN 846-14:2012 EN 846-14:2012 (E) 3 Foreword This document (EN 846-14:2012) has been prepared by Technical Committee CEN/TC 125 “Masonry”, the secretariat of which

16、 is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by March 2013, and conflicting national standards shall be withdrawn at the latest by March 2013. Attention is drawn to the possibilit

17、y that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organisations of the following countries are bou

18、nd to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portuga

19、l, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 846-14:2012 EN 846-14:2012 (E) 4 1 Scope This European Standard specifies a method for determining the in plane initial shear strength of the horizontal bed joint between the prefabricated part of a comp

20、osite lintel and the masonry above it, using a specimen tested in shear. Guidance is given on the preparation of the specimens, the conditioning required before testing, the testing machine, the method of test, the method of calculation and the contents of the test report. The method corresponds wit

21、h the method described in EN 1052-3:2003+A1:2006. Guidance is given where the method deviates from EN 1052-3. Therefore, each section of EN 1052-3 is repeated given the necessary changes. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document

22、 and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 772-1, Methods of test for masonry units Part 1: Determination of compressive strength EN 772

23、-10, Methods of test for masonry units Part 10: Determination of moisture content of calcium silicate and autoclaved aerated concrete units EN 772-16, Methods of test for masonry units Part 16: Determination of dimensions EN 998-2, Specification for mortar for masonry Part 2: Masonry mortar EN 1015-

24、3, Methods of test for mortar for masonry Part 3: Determination of consistence of fresh mortars (by flow table) EN 1015-7, Methods of test for mortar for masonry Part 7: Determination of air content of fresh mortar EN 1015-11, Methods of test for mortar for masonry Part 11: Determination of flexural

25、 and compressive strength of hardened mortar 3 Principle The initial shear strength of the horizontal bed joint between the prefabricated part of a composite lintel and the masonry above it is derived from the strength of small specimens tested to destruction. The specimens are tested in shear under

26、 four-point load. Four different failure modes are considered to give valid results. Two procedures, A and B are included. Procedure A involves testing specimens at different precompressions and the initial shear strength is defined by a linear regression curve to zero prestress. Procedure B involve

27、s testing specimens at zero precompression and determining a characteristic initial shear strength from a simple or a statistical consideration of the results. BS EN 846-14:2012 EN 846-14:2012 (E) 5 4 Terms, definitions and symbols 4.1 Terms and definitions For the purpose of this European Standard,

28、 the following terms and definitions apply. 4.1.1 masonry assemblage of masonry units laid in a specified pattern and jointed together with mortar 4.1.2 shear strength of masonry strength of masonry subjected to shear forces 4.2 Symbols Aiis the gross cross-sectional area of a specimen parallel to t

29、he bed joints, in mm2 E distance between centre lines of the mortar bed and the loading roller, in mm fv0iis the shear strength of an individual sample, in N/mm2 fpiis the precompressive stress of an individual sample, in N/mm2fv0is the mean initial shear strength, in N/mm2 fvk0,clis the characteris

30、tic initial shear strength, in N/mm2 F is the representation of the force applied to the specimen, in N Fi,maxis the maximum shear load, in N Fpiis the precompressive force, in N h1and h2are the heights of cut units, in mm huis the height of the units according to EN 772-16, in mm hppclis the height

31、 of the part of the prefabricated composite lintel according to EN 772-16, in mm k is a function of n given in Table 3 lsis the length of specimen, in mm luis the length of the units according to EN 772-16, in mm n is the number of samples s is the standard deviation of the n log values tbjis the th

32、ickness of the bed joint, in mm tsis the thickness of the steel loading plates, in mm Y is log10of the initial shear strength, fv0Ycis the characteristic value of the log10 of the individual samples Yiis log10of the shear strength of the individual samples Ymeanis the mean of the log10of the shear s

33、trength of the individual samples BS EN 846-14:2012 EN 846-14:2012 (E) 6 5 Materials 5.1 Masonry units 5.1.1 Conditioning of the units The conditioning of masonry units shall be as specified: Record the method of conditioning the masonry units prior to laying. Measure the moisture content by mass of

34、 autoclaved aerated concrete and calcium silicate units in accordance with EN 772-10. Record the age of non-autoclaved concrete units at the time of testing the masonry specimens. 5.1.2 Testing Determine the compressive strength of a sample of masonry units, using the test method given in EN 772-1.

35、For non-autoclaved concrete units determine the compressive strength at the time of testing the masonry specimens. 5.2 Mortar The mortar, its mixing procedure and its flow value shall conform with the requirements of EN 998-2, unless otherwise specified, and these shall be reported in the test repor

36、t. Take representative samples of fresh mortar from the masons board to make mortar prism specimens, to determine the flow value in accordance with EN 1015-3 and to determine the air content in accordance with EN 1015-7. Use the prism specimens to determine the mean compressive strength at the time

37、of testing the masonry specimens in accordance with EN 1015-11. 5.3 Prefabricated part of the composite lintel Conditioning of the prefabricated part of the composite lintels The conditioning of the lintel shall be as specified after cutting. Record the method of conditioning the prefabricated part

38、of the composite lintels prior to laying. 6 Apparatus The testing machines used to apply the shear loads and precompression shall comply with the requirements given in Table 1. The testing machine to apply the shear loads shall have adequate capacity but the scale used shall be such that the ultimat

39、e load on the specimen exceeds one fifth of the full scale reading. The machine shall be provided with a load pacer or equivalent means to enable the load to be applied at the rate specified. Table 1 Requirements for testing machines Maximum permissible repeatability of forces as percentage of indic

40、ated force Maximum permissible mean error of forces as percentage of indicated force Maximum permissible error of zero force as percentage of maximum force of range 2,0 2,0 0,4 BS EN 846-14:2012 EN 846-14:2012 (E) 7 6.1 Apparatus capable of measuring the cross sectional area of the specimens to an a

41、ccuracy of 1 %. 7 Preparation and curing of specimens 7.1 Preparation of masonry specimen Prepare specimens, according Table 2 and Figure 1. If hu 200 mm, type II specimens may be used. The bottom parts consist of a piece of the prefabricated part of the composite lintels with the intended upper bed

42、 face towards the mortar joints. Where for practical purposes it is necessary to cut units, ensure that the faces of the unit to be mortared are representative of the unit as a whole. The length ls of the piece of the prefabricated part of the composite lintel shall correspond with the length of the

43、 masonry unit lu 300 mm. Type I Type II Key 1 Piece of prefabricated part of composite lintel 2 Masonry unit Possible saw cuts Figure 1 Dimensions of shear test specimens BS EN 846-14:2012 EN 846-14:2012 (E) 8 Table 2 Dimensions and type of shear test specimens Unit length Specimen type and dimensio

44、ns luType according to Figure 1 Dimensions mm mm 300 I ls = lu 300 I 300 300 II hu 200 300 ls 350 Record the method of conditioning the prefabricated part of the composite lintels prior to laying. Build the specimens within 30 min after completion of the conditioning of the units. Use mortar mixed n

45、ot more than 1 h beforehand unless it is designed to be used over a more prolonged period. The bearing surfaces of the masonry units shall be wiped clean of any adherent dust. The lower piece of the prefabricated part of the composite lintel shall be laid on a clean level surface. The masonry unit s

46、hall be laid so that a final mortar joint thickness of 8 mm to 15 mm, representative of masonry with conventional mortar joints, or of 1 mm to 3 mm, representative of masonry with thin layer mortar joints, is attained. The masonry unit shall be checked for linear alignment and level using a set-squa

47、re and spirit level. Excess mortar shall then be struck off with a trowel. The procedure for the masonry unit shall be repeated for the top piece of the prefabricated part of the composite lintel. The intended bonding faces of the pieces of the prefabricated part of the composite lintel shall be in

48、contact with the mortar (the faces that are normally visible shall stay visible). 7.2 Curing and conditioning of the specimens Immediately after building, pre-compress each specimen by an uniformly distributed mass to give a vertical stress between 2,0 N/mm2 10-3N/mm2 and 5,0 N/mm2 10-3N/mm2. Then c

49、ure the specimens and maintain them undisturbed until testing. For other than lime based mortars, prevent the test specimens from drying out during the curing period by close covering with polyethylene sheet, and maintain the specimens undisturbed until testing, unless otherwise specified. Test each specimen at an age of 28 days 1, unless otherwise specified for lime based mortars, and determine the compressive strength of the mortar at the same