BS-EN-12350-7-2000.pdf
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1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS EN 12350-7:2000 The Eu
2、ropean Standard EN 12350-7:2000 has the status of a British Standard ICS 91.100.30 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Testing fresh concrete Part 7: Air content Pressure methods This British Standard, having been prepared under the direction of the Sector Committe
3、e for Building and Civil Engineering, was published under the authority of the Standards Committee and comes into effect on 15 July 2000 BSI 07-2000 ISBN 0 580 35401 6 BS EN 12350-7:2000 Amendments issued since publication Amd. No.DateComments National foreword This British Standard is the official
4、English language version of EN 12350-7:2000. It will supersede BS 1881-106:1983 which will be withdrawn in 2003 when the full package of the related concrete package is available. The UK participation in its preparation was entrusted by Technical Committee B/517, Concrete, to Subcommittee B/517/1, P
5、roduction and testing, 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 pr
6、omulgate 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
7、the 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 16, an inside back cover and a back cover. The BSI copyright notice displayed in this docume
9、nt indicates when the document was last issued. (8523($1?67$1$5 1250(?(8523e(11( (8523b,6?$?QRUPDWLYH?$JJUHJDWH?FRUUHFWLRQ?IDFWRU?ZDWHU?FROXPQ?PHWKRG? $11(;?%?QRUPDWLYH?$JJUHJDWH?FRUUHFWLRQ?IDFWRU?SUHVVXUH?JDXJH?PHWKRG? $11(;?QRUPDWLYH? -?Testing hardened concrete (EN 12390); -?Testing concrete in s
10、tructures (EN 12504). This series EN 12350 includes the following parts where the brackets give the numbers under which particular test methods were published for CEN enquiry: EN 12350 Testing fresh concrete Part 1: Sampling (former prEN 12378:1996); Part 2: Slump test (former prEN 12382:1996); Part
11、 3: Vebe test (former prEN 12350:1996); Part 4: Degree of compactability (former prEN 12357:1996); Part 5: Flow table test (former prEN 12358:1996); Part 6: Density (former prEN 12383:1996); Part 7: Air content ? Pressure methods (former prEN 12395:1996). The standard is based on the draft Internati
12、onal Standard ISO 4848, Concrete Determination of air content of freshly mixed concrete Pressure method: First edition 1980-03-15. Like the ISO standard it specifies two types of meters for carrying out the test, the water column meter and the pressure gauge meter. The results of a recent laboratory
13、 inter-comparison, in part funded by the EC under Measurement and Testing Programme, Contract MAT1-CT-94-0043 which investigated these two methods of measuring air content, did not find significant difference between them. However, it was found in this programme that the use of an internal vibrator
14、to compact specimens of air entrained fresh concrete should only be done with caution, if loss of entrained air is to be avoided. The determination of the aggregate correction value for the two methods has been included in normative annexes A and B. The method of calibrating the two types of apparat
15、us has been included in normative annexes C and D. Caution When cement is mixed with water, alkali is released. Take precautions to avoid dry cement entering the eyes, mouth and nose whilst mixing concrete. Prevent skin contact with wet cement or concrete by wearing suitable protective clothing. If
16、cement or concrete enters the eye, immediately wash it out thoroughly with clean water and seek medical treatment without delay. Wash wet concrete off the skin immediately. ?6FRSH This standard describes two methods for determination of air content of compacted fresh concrete, made with normal weigh
17、t or relatively dense aggregate of maximum size 63 mm. 3DJH? (1? ?%6,? NOTE: Neither method is applicable to concretes made with lightweight aggregates, air cooled blast-furnace slag, or aggregates with high porosity, because of the magnitude of the aggregate correction factor, compared with the ent
18、rained air content of the concrete. ?1RUPDWLYH?UHIHUHQFHV This European Standard incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references,
19、 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 latest edition of the publication referred to applies. EN 12350-1:1999 Testing fresh concrete Part 1: Sampling. EN 123
20、50-6:1999 Testing fresh concrete Part 6: Density. ?3ULQFLSOHV ?*HQHUDO There are two test methods, both of which use apparatus which employ the principle of Boyle-Mariottes law. For the purpose of reference, the two methods are referred to as the water column method and the pressure gauge method and
21、 the apparatus as a water column meter and a pressure gauge meter. ?:DWHU?FROXPQ?PHWKRG Water is introduced to a predetermined height above a sample of compacted concrete of known volume in a sealed container and a predetermined air pressure is applied over the water. The reduction in volume of the
22、air in the concrete sample is measured by observing the amount by which the water level is lowered, the water column being calibrated in terms of percentage of air in the concrete sample. ?3UHVVXUH?JDXJH?PHWKRG A known volume of air at a known pressure is merged in a sealed container with the unknow
23、n volume of air in the concrete sample. The dial on the pressure gauge is calibrated in terms of percentage of air for the resulting pressure. ?:DWHU?FROXPQ?PHWKRG ?$SSDUDWXV ?:DWHU?FROXPQ?PHWHU? an example of which is shown in Figure 1, consisting of: a) b)? 3DJH? (1? ?%6,? c) 6WDQGSLSH, consisting
24、 of a graduated glass tube of uniform bore, or a metal tube of uniform bore with a glass gauge attached. The graduated scale shall indicate air content of 0 % to at least 8 % and preferably 10 %. The scale shall be graduated with divisions every 0,1 %, the divisions being not less than 2 mm apart. A
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