1、BSI Standards PublicationBS EN 1052-2:2016Methods of test for masonryPart 2: Determination of flexural strengthBS EN 1052-2:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 1052-2:2016. It supersedes BS EN 1052-2:1999 which is withdrawn.The UK participation
2、in its preparation was entrusted to Technical Committee B/519, Masonry and associated testing.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 provisions of a contract. Users are responsib
3、le for its correct application. The British Standards Institution 2016.Published by BSI Standards Limited 2016ISBN 978 0 580 87726 1 ICS 91.080.30 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards
4、 Policy and Strategy Committee on 31 March 2016.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS EN 1052-2:2016EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 1052-2 March 2016 ICS 91.080.30 Supersedes EN 1052-2:1999English Version Methods of test for masonry - Part
5、2: Determination of flexural strength Mthodes dessai de la maonnerie - Partie 2: Dtermination de la rsistance la flexion Prfverfahren fr Mauerwerk - Teil 2: Bestimmung der Biegezugfestigkeit This European Standard was approved by CEN on 3 January 2016. CEN members are bound to comply with the CEN/CE
6、NELEC Internal Regulations which stipulate the conditions 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
7、 or to any CEN member. This European Standard exists in three 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 o
8、fficial versions. CEN members are the national standards bodies 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, Netherlan
9、ds, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2016 CEN All rights
10、of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 1052-2:2016 EBS EN 1052-2:2016EN 1052-2:2016(E) 2 Contents Page European foreword 3 1 Scope 4 2 Normative references 4 3 Principle . 4 4 Terms, definitions and symbols 4 4.1 Terms and definitions .
11、4 4.2 Symbols 5 5 Materials 5 5.1 Masonry units . 5 5.1.1 Conditioning of the units 5 5.1.2 Testing 5 5.2 Mortar . 5 6 Apparatus 6 7 Preparation of specimens 6 7.1 Masonry specimens 6 7.2 Construction and curing of the specimens 6 8 Procedure 7 8.1 Placing the specimens in the testing equipment . 7
12、8.2 Loading . 7 8.3 Measurements and observations 9 8.4 Replications 10 9 Calculations . 10 10 Evaluation of results 10 11 Test report . 11 BS EN 1052-2:2016EN 1052-2:2016(E) 3 European foreword This document (EN 1052-2:2016) has been prepared by Technical Committee CEN/TC 125 “Masonry”, the secreta
13、riat of which 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 September 2016, and conflicting national standards shall be withdrawn at the latest by September 2016. Attention is dr
14、awn to the possibility 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. This document supersedes EN 1052-2:1999. This document has been prepared under a mandate given to CEN
15、 by the European Commission and the European Free Trade Association. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark,
16、 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, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 1052-2:2016E
17、N 1052-2:2016(E) 4 1 Scope This European standard specifies a method for determining the flexural strength of small masonry specimens for the two principal axes of loading. Guidance is given on the preparation of the specimens, the conditioning required before testing, the testing machine, the metho
18、d of test, the method of calculation and the contents of the test report. 2 Normative references 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 referenc
19、ed document (including any amendments) applies. EN 772-1, Methods of test for masonry units Part 1: Determination of compressive strength EN 772-10, Methods of test for masonry units Part 10: Determination of moisture content of calcium silicate and autoclaved aerated concrete units EN 998-2, Specif
20、ication for mortar for masonry Part 2: Masonry mortar EN 1015-3, Methods of test for mortar for masonry Part 3: Determination of consistence of fresh mortar (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 t
21、est for mortar for masonary Part 11: Determination of flexural and compressive strength of hardened mortar 3 Principle The flexural strength of masonry is derived from the strength of small specimens tested to destruction under four point loading. The maximum load achieved is recorded. The character
22、istic value, calculated from the maximum stresses achieved by the samples is considered to be the flexural strength of the masonry. 4 Terms, definitions and symbols 4.1 Terms and definitions For the purposes of this document, the following terms and definitions apply. 4.1.1 masonry assemblage of mas
23、onry units laid in a specified pattern and jointed together with mortar 4.1.2 flexural strength of masonry strength of masonry in pure bending assuming a linear stress distribution of internal stresses BS EN 1052-2:2016EN 1052-2:2016(E) 5 4.2 Symbols For the purposes of this document, the following
24、symbols apply. b is the height or width of a masonry specimen perpendicular to the direction of span, (mm) Fi, maxis the maximum load applied to an individual masonry specimen, (N) fmean is the mean flexural strength of the masonry specimens, (N/mm2) fxiis the flexural strength of an individual maso
25、nry specimen, (N/mm2) fxkis the characteristic flexural strength of masonry, (N/mm2) huis the height of masonry unit, (mm) k is the numerical factor lsis the length of a masonry specimen in the direction of span, (mm) luis the length of masonry unit, (mm) l1is the spacing of the outer bearings, (mm)
26、 l2is the spacing of the inner bearings, (mm) l3is the length of specimen outside the outer support (1/2(lsl1), (mm) m is the mass of the sample, (kg) n is the number of specimens s is the standard deviation of the log values tuis the width of masonry unit, (mm) x is the distance between the flexura
27、l crack in the specimen after testing and the nearer of the outer supports, (mm) 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 units prior to laying. Measure the moisture content by mass of
28、 autoclaved aerated concrete and calcium silicate masonry 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 method given in EN 772-
29、1. 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 to the requirements of EN 998-2, unless otherwise specified, and these shall be reported in the test repo
30、rt. Take representative samples of fresh mortar from the masons board to make mortar prisms, to determine the flow value in accordance with EN 1015-3, and to determine the air content in accordance BS EN 1052-2:2016EN 1052-2:2016(E) 6 with EN 1015-7. Use the prism specimens to determine the mean com
31、pressive strength at the time of testing of the masonry specimens in accordance with EN 1015-11. 6 Apparatus A testing machine complying with the requirements given in Table 1, and accommodating variations of plane. The testing machine shall have adequate capacity but the scale used shall be such th
32、at the ultimate 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. The bearings shall be designed to ensure that contact is provided over the full width of the m
33、asonry, for example by using a hollow rubber bolster of at least 7 mm wall thickness and a 10 mm bore containing an 8 mm diameter steel rod. Table 1 Requirements for testing machines Maximum permissible repeatability of forces as percentage of indicated force Maximum permissible mean error of forces
34、 as percentage of indicated force Maximum permissible error of zero force as percentage of maximum force of range 2,0 2,0 0,4 7 Preparation of specimens 7.1 Masonry specimens For each of the two principal axes of loading use at least five specimens according to Figure 1 having the sizes given in Tab
35、le 2. The size of the masonry specimens shall be chosen so that the distance between the inner and outer bearings shall be not less than the thickness of the masonry specimen. The thickness of the specimen shall be equal to tuunless otherwise specified. Table 2 Specimen sizes for testing the flexura
36、l strength of masonry Direction humm b mm Additional conditions Flexural strength for a plane of failure parallel to the bed joints any 400 and 1,5 luminimum 2 bed joints within l2Flexural strength for a plane of failure perpendicular to the bed joints 250 240 and 3huminimum 1 head joint every cours
37、e within l2 250 1000 minimum 1 bed joint and minimum 1 head joint every course within l27.2 Construction and curing of the specimens Build the specimens within 30 min after completion of the conditioning of the units, using mortar mixed not more than one hour beforehand unless the mortar is designed
38、 to be used over a more prolonged period. Construct the specimens to the bond specified. Do not allow the work to be interrupted before completion. Immediately after building, pre-compress each specimen using a uniformly distributed mass to give a vertical stress between 2,5 103N/mm2and 5,0 103N/mm2
39、; then cure the specimens, and maintain them undisturbed until testing. For other than lime-based mortar 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. Tes
40、t each specimen at an age of BS EN 1052-2:2016EN 1052-2:2016(E) 7 28 days 1 day, unless otherwise specified, and determine the compressive strength of the mortar at the same age, following EN 1015-11. For lime-based mortars an alternative curing regime and period may be necessary and this should be
41、specified. 8 Procedure 8.1 Placing the specimens in the testing equipment Test the masonry specimen in the vertical attitude under four-point loading (see Figure 1). As an alternative, the specimen can be tested in a horizontal position. If the specimens are to be tested horizontally, weigh the mass
42、 m of each specimen to 0,1 kg. The distance between the outer bearings and the end of the specimen shall be greater than or equal to 15 mm. The distance between the inner bearings may be varied to suit the format of the masonry but shall be 0,4 times to 0,6 times the spacing of the outer bearings. T
43、he inner bearings shall be located so that they are, as far as practicable, midway between the nearest mortar joints which are parallel to the bearings. When testing in the vertical attitude ensure that the base of each masonry specimen is free from frictional restraint, for example by setting it on
44、 two layers of polytetrafluoroethylene with grease between them or on ball, needle or roller bearings. When testing in the horizontal attitude care is needed, especially with masonry of low flexural strength, to avoid failures in handling and placing in the test machine. It may be necessary to build
45、 extra test specimens to ensure that five valid results can be achieved. 8.2 Loading Increase the flexural stress at a rate between 0,03 N/mm2/min and 0,3 N/mm2/min. BS EN 1052-2:2016EN 1052-2:2016(E) 8 Dimensions in mm Key b2luand b 400 mm and hu 250 mm and more than two bed joints in l2b4huand b 2
46、40 mm and hu 250 mm and a minimum of one head joint in l2Flexural strength for a plane of failure parallel to the bed joints Flexural strength for a plane of failure perpendicular to the bed joints Key b1,5luand b 400 mm and hu 250 mm and two bed joints in l2b4huand b 240 mm and hu 250 mm and a mini
47、mum of one head joint in l2BS EN 1052-2:2016EN 1052-2:2016(E) 9 Flexural strength for a plane of failure parallel to the bed joints Flexural strength for a plane of failure perpendicular to the bed joints Key b1,5luand b 400 mm and two bed joints in l2b 1000 mm and h 250 mm and one head joint and on
48、e bed joint in l2Flexural strength for a plane of failure parallel to the bed joints Flexural strength for a plane of failure perpendicular to the bed joints Figure 1 Typical examples of masonry test specimens meeting the requirements of Table 2 8.3 Measurements and observations Record the following
49、: a) age of non-autoclaved concrete units; b) the dimensions of the cross-section of the specimen parallel to the bearings, to the nearest 1 mm; c) the spacing of the outer and of the inner bearings, in mm; d) the maximum load Fi,maxto the nearest 10 N. Discard any result where failure does not occur between the inner bearings; e) the length of time from the start of loading until the maximum load is achieved; f) crack patterns; g) the distance x between the flexural crack and nearer of the outer bearings as
