1、December 2007DEUTSCHE NORM English price group 6No part of this standard may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 91.100.30!$Jw“1398490w
2、ww.din.deDDIN EN 14721Test method for metallic fibre concrete Measuring the fibre content in fresh and hardened concreteEnglish version of DIN EN 14721:2007-12Bestimmung des Fasergehalts in Frisch- und FestbetonEnglische Fassung DIN EN 14721:2007-12SupersedesDIN EN 14721:2005-10www.beuth.deDocument
3、comprises 9 pages(includes Amendment A1:2007)Prfverfahren fr Beton mit metallischen Fasern (enthlt nderung A1:2007)DIN EN 14721:2007-12 2 National foreword This standard has been prepared by Technical Committee CEN/TC 229 “Precast concrete products” (Secretariat: AFNOR, France). The responsible Germ
4、an body involved in its preparation was the Normenausschuss Bauwesen (Building and Civil Engineering Standards Committee), Technical Committee NA 005-07-08 AA Betonfertigteile. Amendments This standard differs from DIN EN 14721:2005-10 as follows: a) The scope has been described in more detail. b) C
5、lause 8 “Test report” has been amended. Previous editions DIN EN 14721: 2005-10 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 14721:2005+A1 September 2007 ICS 91.100.30 Supersedes EN 14721:2005 English Version Test method for metallic fibre concrete - Measuring the fibre content in fresh and
6、hardened concrete Mthode dessai du bton de fibres mtalliques - Mesurage de la teneur en fibres du bton frais ou durci Prfverfahren fr Beton mit metallischen Fasern - Bestimmung des Fasergehalts in Frisch- und Festbeton This European Standard was approved by CEN on 27 June 2005 and includes Amendment
7、 1 approved by CEN on 16 August 2007. 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 national standard without any alteration. Up-to-date lists and bibliographical references concerning such n
8、ational standards may be obtained on application to the CEN Management Centre 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 a
9、nd notified to the CEN Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembo
10、urg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All righ
11、ts of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 14721:2005+A1:2007: EEN 14721:2005+A1:2007 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references 4 3 Principle4 4 Apparatus .4 5 Test specimens5 6 Testing procedures5 7 Expression of res
12、ults 7 8 Test report 7 9 Precision.7 EN 14721:2005+A1:2007 (E) 3 Foreword This European Standard (EN 14721:2005+A1:2007) has been prepared by Technical Committee CEN/TC 229 “Precast concrete products”, the secretariat of which is held by AFNOR. This document shall be given the status of a national s
13、tandard, either by publication of an identical text or by endorsement, at the latest by March 2008 and conflicting national standards shall be withdrawn at the latest by March 2008. This document includes Amendment 1, approved by CEN on 2007-08-16. This document supersedes EN 14721:2005. The start a
14、nd finish of text introduced or altered by amendment is indicated in the text by tags ! “. 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, Cyprus, Czech Repub
15、lic, Denmark, Estonia, 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 14721:2005+A1:2007 (E) 4 1 Scope This European Standa
16、rd specifies two methods of measuring the fibre content of metallic fibre concrete. Method A measures the fibre content of a hardened concrete specimen. Method B measures the fibre content of a fresh concrete specimen. !This European Standard does not apply to sprayed concrete.“ 2 Normative referenc
17、es 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 referenced document (including any amendments) applies. EN 12350-6, Testing fresh concrete Part 6: Den
18、sity EN 12390-7, Testing hardened concrete Part 7: Density of hardened concrete 3 Principle Fibres are extracted from a hardened (Method A) or fresh (Method B) concrete sample and the fibre content is determined from the mass of fibre and the volume of the concrete sample. 4 Apparatus 4.1 Method A 4
19、.1.1 Core drill equipment, capable of extracting test cores from the hardened concrete to the volume set out in 5.1. 4.1.2 Callipers and/or rules, capable of measuring the dimensions of test cores to an accuracy of 0,5 mm. 4.1.3 Balance, equipped with a stirrup for weighing the test core in both air
20、 and water to an accuracy of 10 g. 4.1.4 Water tank, fitted with a device to maintain water at a constant level and of sufficient size to allow the test core on the stirrup to be fully immersed to a constant depth. 4.1.5 Balance or scales, capable of determining the mass of the extracted metallic fi
21、bres to an accuracy of 0,5 g. 4.2 Method B 4.2.1 Container, watertight, of sufficient rigidity to retain its shape, made of metal not readily attacked by cement paste, having a smooth internal face, with the rim machined to a plane surface. The rim and base shall be parallel. The smallest dimension
22、of the container shall be at least four times the maximum nominal size of the coarse aggregate in the concrete, but shall be not less than 150 mm. The volume of the container shall be not less than 3 . 4.2.2 Scoop, or similar sampling device, made from non-absorbent material not readily attacked by
23、cement paste, suitable for taking increments of concrete. EN 14721:2005+A1:2007 (E) 5 4.2.3 Means of compacting the concrete, which may be one of the following: internal (poker) vibrator with a minimum frequency of approximately 120 Hz, the diameter of the internal vibrator not exceeding approximate
24、ly one-quarter of the smallest dimension of the container; vibrating table with a minimum frequency of approximately 40 Hz. 4.2.4 Steel trowel or float. 4.2.5 Balance or scales, capable of determining the mass of the extracted metallic fibres to an accuracy of 0,5 g. 4.2.6 Sieve or filter equipment,
25、 suitable for washing out cement and other fine materials from fresh concrete. 5 Test specimens 5.1 Method A - Hardened specimen The hardened test specimen shall consist of 3 or more test cores obtained in accordance with 6.1.1. The volume of a test core shall be 1 or more. The volume of the test sp
26、ecimen shall be 5 or more. 5.2 Method B - Fresh specimen The fresh test specimen shall consist of 3 or more test samples obtained in accordance with 6.1.2. The volume of each test sample shall be 3 or more. 6 Testing procedures 6.1 Sampling 6.1.1 Method A 6.1.1.1 Drilling cores The cores shall be dr
27、illed perpendicular to the product surface. The drill shall be kept positioned rigidly during coring. 6.1.2 Method B 6.1.2.1 Filling the container Clean all the apparatus to use. Using the scoop take the required number of increments from the discharging stream of concrete from the mixer, disregardi
28、ng the very first part and the very last part. When sampling from a falling stream, take the increments in such a way as to represent the whole width and thickness of the stream. Deposit the increments into the container. 6.1.2.2 Compacting the concrete Immediately after placing in the container, th
29、e concrete shall be compacted, if necessary, in a manner comparable to that used in the application. EN 14721:2005+A1:2007 (E) 6 6.2 Volume of sample 6.2.1 Method A - Hardened sample The volume of each test core shall be determined by calculation using measured values of actual dimensions or by wate
30、r displacement in compliance with EN 12390-7. The volume V of the test core shall be expressed to the nearest 0,02 . 6.2.2 Method B - Fresh sample The volume of the container shall be obtained by calibration in compliance with EN 12350-6. The volume of each test sample shall be determined by one of
31、either following methods. In case the container is completely filled after compaction, the concrete shall be levelled off, using the steel trowel or float. Then the volume of the fresh sample is equal to the volume of the container. In case the container is not completely filled after compacting the
32、 concrete, the container shall be placed on a horizontal surface and the volume of water required to fill the container shall be measured. Then the volume of the fresh sample is equal to the volume of the container less the volume of the water added. The volume V of the test sample shall be expresse
33、d to the nearest 0,02 . 6.3 Mass of fibre 6.3.1 Method A - Hardened sample Each test core shall be crushed in a compression testing machine, or other suitable device, so that all the fibres can be separated from the concrete. Magnetic fibres may be collected by using a magnet. The collected fibres s
34、hall be thoroughly cleaned and then weighed. The mass m of the fibres shall be expressed to the nearest 0,5 g. 6.3.2 Method B - Fresh sample Each test sample shall be placed in a sieve or filter equipment where the cement and other fine materials can be washed out so that the fibres can be separated
35、 from the mass. Magnetic fibres may be collected directly or after washing out by using a magnet. The collected fibres shall be cleaned, dried and then weighed. The mass m of the fibres shall be expressed to the nearest 0,5 g. EN 14721:2005+A1:2007 (E) 7 7 Expression of results The fibre content sha
36、ll be calculated from the determined fibre mass and sample volume, using the formula: VmC f=where Cfis the fibre content, in kg/m3; m is the mass of fibre extracted from the sample, in g; V is the volume of the sample, in . 8 Test report The test report shall include: a) identification of the test s
37、pecimen; b) description of the method (A or B) and in case of method B the placing and compacting procedure used; c) volume of each sample to the nearest 0,02 ; d) mass of the fibres in each sample to the nearest 0,5 g; e) the calculated fibre content of each sample to the nearest kg/m3; f) the aver
38、age value of the fibre content to the nearest kg/m3; g) reference to this European Standard; h) any deviation from the standard testing method; i) !place and date of testing, testing institute and person responsible for testing;“ j) a declaration from the person technically responsible for the test
39、that the testing was carried out in accordance with this standard, except for the indicated deviation(s). The test report may include the identification and/or description of the fibre type. 9 Precision Beside the following indicative data, no precision data in terms of repeatability or reproducibility are available. In case of method A a loss up to 5 % of the mass of fibres may occur in the process of crushing and collecting. In case of method B no fibre loss occurs.
