1、BRITISH STANDARDBS EN14488-3:2006Testing sprayed concrete Part 3: Flexural strengths (first peak, ultimate and residual) of fibre reinforced beam specimensThe European Standard EN 14488-3:2006 has the status of a British StandardICS 91.100.30g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g
2、54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 14488-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 May 2006 BSI 2006ISBN 0 580 483
3、98 3National forewordThis British Standard is the official English language version of EN 14488-3:2006.The UK participation in its preparation was entrusted by Technical Committee B/517, Concrete, to Subcommittee B/517/10, Sprayed concrete, which has the responsibility to: A list of organizations re
4、presented on this subcommittee can be obtained on request to its secretary.Cross-referencesThe 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 In
5、dex”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards 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 con
6、fer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate
7、them in the UK.Summary of pagesThis document comprises a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover.The BSI copyright notice displayed in this document indicates when the document was last issued.Amendments issued since publicationAmd.
8、 No. Date CommentsEUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 14488-3April 2006ICS 91.100.30English VersionTesting sprayed concrete - Part 3: Flexural strengths (first peak,ultimate and residual) of fibre reinforced beam specimensEssais pour bton projet - Partie 3 : Rsistances laflexion (au pr
9、emier pic, ultime et rsiduelle) dprouvettesparalllpipdiques en bton renforc par des fibresPrfung von Spritzbeton - Teil 3: Biegefestigkeiten(Erstriss-, Biegezug- und Restfestigkeit) faserverstrktenbalkenfrmigen BetonprfkrpernThis European Standard was approved by CEN on 27 February 2006.CEN members
10、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 references concerning such nationalstandards may be obtained on application to
11、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 into its own language and notified to the Central Secretariat has the same stat
12、us 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, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Sl
13、ovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN na
14、tional Members.Ref. No. EN 14488-3:2006: EEN 14488-3:2006 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Principle4 4 Apparatus .4 4.1 Testing machine.4 4.2 Force application .5 4.3 Deflection measurement and control 6 5 Test specimen7 5.1 General7 5.2 Adjustment of test specimen
15、s7 6 Procedures .8 6.1 Preparation and positioning of specimens.8 6.2 Loading .8 7 Expression of results 8 7.1 First peak and ultimate flexural strengths 8 7.2 Residual flexural strengths.10 8 Test report 10 9 Accuracy.11 Bibliography 12 EN 14488-3:2006 (E) 3 Foreword This European Standard (EN 1448
16、8-3:2006) has been prepared by Technical Committee CEN/TC 104 “Concrete and related products”, the secretariat of which is held by DIN. 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 October 2006
17、, and conflicting national standards shall be withdrawn at the latest by December 2007. This European Standard is part of a series concerned with testing sprayed concrete. This series EN 14488 Testing sprayed concrete includes the following parts: Part 1: Sampling fresh and hardened concrete Part 2:
18、 Compressive strength of young sprayed concrete Part 3: Flexural strengths (first peak, ultimate and residual) of fibre reinforced beam specimens Part 4: Bond strength of cores by direct tension Part 5: Determination of energy absorption capacity of fibre reinforced slab specimens Part 6: Thickness
19、of concrete on a substrate Part 7: Fibre content of fibre reinforced concrete According 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,
20、Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14488-3:2006 (E) 4 1 Scope This part of European Standard specifies a method
21、 for the determination of the flexural (first peak, ultimate and residual) strength of beam specimens of hardened sprayed concrete. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies.
22、For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12390-1:2000, Testing hardened concrete Part 1: Shape, dimensions and other requirements for specimens and moulds EN 12390-4:2000, Testing hardened concrete Part 4: Compressive strength Speci
23、fication for testing machines EN 14487-1, Sprayed concrete Part 1: Definitions, specifications and conformity EN 14488-1, Testing sprayed concrete Part 1: Sampling fresh and hardened concrete 3 Principle Prismatic beam specimens are subject to a bending moment by the application of load through uppe
24、r and lower rollers. The first peak, maximum and residual loads sustained are recorded and the corresponding flexural strengths calculated. A fibre reinforced prism specimen, sawn from a test panel in accordance with EN 14488-1 is subject to a bending moment by the application of load through upper
25、and lower rollers under deflection control to obtain its load/deflection response (the latter exclusive of non-bending deformations). The first peak, ultimate and residual flexural strengths are determined from the load/deflection curve. 4 Apparatus 4.1 Testing machine The test shall be carried out
26、using a testing machine conforming to 4.2 and 4.3 of EN 12390-4:2000. The stiffness and control system of the testing machine shall be such that the test can be deflection controlled. The stiffness of the load system (including frame, load cell, loading block and support frame) shall be at least 200
27、 kN/mm. A steel or aluminium yoke (Figure 1). A calibrated electronic transducer with a resolution of at least 0,02 mm. An electronic data logger or XY plotter. EN 14488-3:2006 (E) 5 Key 1 Cramp 2 Reference bar (clamped or glued) 3 Loading roller 4 Yoke 5 Transducer 6 Locating screw NOTE A yoke/tran
28、sducer may be fixed at each side of the beam, instead of at only one as it is represented in the section of the beam. Figure 1 Arrangement of yoke for bending deflection measurement 4.2 Force application The device for applying loads (see Figure 2) shall consist of: two supporting rollers; two upper
29、 rollers carried by an articulated cross member, which divides the load applied by the machine equally between the two rollers. All rollers shall be manufactured from steel and shall have a circular cross-section with a diameter of 20 mm to 40 mm. They shall be at least 10 mm longer than the width o
30、f the test specimen. Three rollers, including the two upper ones, shall be capable of rotating freely around their axes and of being inclined in a plane normal to the longitudinal axis of the test specimen. The distance, l, between the outer rollers (i.e. the span) shall be equal to 3 d, where d is
31、150 mm. The distance between the inner rollers shall be equal to d. The inner rollers shall be equally spaced between the outer rollers as shown in Figure 2. All rollers shall be adjusted to the positions illustrated in Figure 2 to an accuracy of 2,0 mm. EN 14488-3:2006 (E) 6 Dimensions in millimetr
32、es Key 1 Loading roller (capable of rotation and of being inclined) 2 Supporting roller 3 Supporting roller (capable of rotation and of being inclined) F is the load (Pfpor Pult) defined above in newtons l is the span w is the average beam width d is the beam height L is the beam length Figure 2 Arr
33、angement of loading of test specimen 4.3 Deflection measurement and control Bending deflection, excluding any support deformations and twist, shall be measured by means of an electronic transducer mounted at mid-span to a yoke that is held to the beam at mid-height of the beam (the neutral axis) and
34、 directly over the supports. A suitable yoke arrangement is shown in Figure 1. It is preferable to use two transducers, one mounted on each side of the beam. The testing machine shall be controlled from the transducer in order to load the specimen at a constant rate of deflection at the midspan of t
35、he beam. The load-deflection curve shall be continuously recorded or logged. Where two transducers are used the average midspan deflection shall be determined. EN 14488-3:2006 (E) 7 5 Test specimen 5.1 General Each test specimen shall be a sawn prism with dimensions of 75 mm depth 125 mm width and a
36、 length of at least 500 mm length cut from a sprayed panel as shown in Figure 3 and prepared to meet the requirements of EN 12390-1. The bottom uncut mould face shall be identified on the specimen (indicating the direction of spraying). Beams shall be tested with the bottom uncut moulded face in ten
37、sion, unless otherwise specified. If the top face of the beam is to be put in tension it shall not be sawn (to avoid cutting end anchorages of the steel fibres). The prisms should be stored in water at (20 +/- 2)C for a minimum of 3 days after sawing until no more than 3 hours before testing (leavin
38、g sufficient time for preparation including the attachment of any location devices for the yoke or transducer). Testing shall normally be performed at 28 days. The specimens shall be examined and any abnormalities observed shall be reported. Key 1 Top of beam Figure 3 Cutting arrangement for beams 5
39、.2 Adjustment of test specimens Where the dimensions or shapes of test specimens do not conform to 4.3 of EN 12390-1:2000 because they exceed the respective tolerances, they shall be rejected or adjusted as follows: uneven surfaces shall be levelled by grinding; the deviation of angles shall be corr
40、ected by cutting and/or grinding. NOTE The tolerances specified in EN 12390-3 will usually be too demanding for specimens sawn from sprayed concrete test panels and should normally be relaxed by prior agreement of the parties. EN 14488-3:2006 (E) 8 6 Procedures 6.1 Preparation and positioning of spe
41、cimens For specimens stored in water, wipe excess moisture from the surface of the specimen before placing in the testing machine. Wipe clean all testing machine bearing surfaces and remove any loose grit or other extraneous material from the surfaces of the specimen that will be in contact with the
42、 rollers. Mount the yoke and transducer(s) on the specimen, ensuring the yoke is held directly over the supporting rollers and at mid-depth of the specimen and that the transducer(s) are located at midspan and bear against a reference plate attached or clamped to the beam. Place the test specimen in
43、 the machine, correctly centred and orientated (uncut mould face normally in tension) and with the longitudinal axis of the specimen at right angles to the longitudinal axis of the upper and lower rollers. NOTE The test result may be affected by the direction of loading with respect to the direction
44、 of spraying. 6.2 Loading Do not apply the load until all loading and supporting rollers are resting evenly against the test specimen. The testing machine shall be controlled from the transducer in order to load the specimen at a constant rate of deflection at the mid-span of the beam of (0,25 0,05)
45、 mm per minute until a deflection of 0,5 mm. After this point the rate of deflection may be increased to 1,0 mm/min. The test shall be finished when the mid-span deformation exceeds 4 mm or the specimen fractures. Record the load and deflection continuously with the data logger or XY plotter, and al
46、so record the maximum load and corresponding deflection indicated. Measure the distance from the centre of the crack on the tensile face to the nearest support and report a fracture outside the loading rollers (see Figure 2). 7 Expression of results 7.1 First peak and ultimate flexural strengths The
47、 first peak flexural strength shall be calculated from the load-deflection curve (Figure 4) as follows. The initial straight line portion of the curve shall be determined, based on data up to 50 % of the peak load, and a line drawn parallel at a horizontal offset of 0,1 mm mid-span beam defection. T
48、he first peak flexural strength (ffp) shall be calculated from the first peak load (Pfp) achieved up to and including the point at which the 0,1 mm offset line intercepts the load/deflection curve (see Figure 4). The ultimate flexural strength (fult) shall be calculated from the maximum load (Pult)
49、recorded. Two measurements shall be made of the beam width and depth at the fracture plane, to the nearest 0,1 mm and the average calculated to the nearest 1 mm. A note shall be made if the fracture plane is outside loading rollers and the results discarded. EN 14488-3:2006 (E) 9 Each flexural strength shall be calculated as an equivalent elastic tensile strength: flexural strength in MPa = P l /( w d2) (1) where P is the load (Pfpor Pult) defined above in newtons l is the span (450 mm) w is the average beam width
