BS EN 12350-3-2009 Testing fresh concrete nPart 3 Vebe test《新拌混凝土试验 第3部分 韦伯试验》.pdf

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1、BS EN12350-3:2009ICS 91.100.30,NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDTesting fresh concretePart 3: Vebe testThis British Standardwas published under theauthority of the StandardsPolicy and StrategyCommittee on 31 May 2009 BSI 2009ISBN 978 0 580 58790 0

2、Amendments/corrigenda issued since publicationDate CommentsBS EN 12350-3:2009National forewordThis British Standard is the UK implementation of EN 12350-3:2009. It supersedes BSEN 12350-3:2000 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee B/517/1, Con

3、crete production and testing.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are responsible for its correct application.Compliance with a British Standard c

4、annot confer immunityfrom legal obligations.BS EN 12350-3:2009EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 12350-3March 2009ICS 91.100.30 Supersedes EN 12350-3:1999 English VersionTesting fresh concrete - Part 3: Vebe testEssais pour bton frais - Partie 3: Essai Vb Prfung von Frischbeton - Teil

5、 3: Vebe-PrfungThis European Standard was approved by CEN on 20 January 2009.CEN members 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 biblio

6、graphical references concerning such nationalstandards 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 translationunder the responsibility of a

7、 CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,France, Germany, Greece, Hungary, Iceland, Ireland, I

8、taly, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 B

9、russels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN 12350-3:2009: EBS EN 12350-3:2009EN 12350-3:2009 (E) 2 Contents Page Foreword 31 Scope 52 Normative references 53 Principle 54 Apparatus .55 Sampling .66 Procedure .67 Test

10、 result .78 Test report 79 Precision .8BS EN 12350-3:2009EN 12350-3:2009 (E) 3 Foreword This document (EN 12350-3:2009) 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

11、national standard, either by publication of an identical text or by endorsement, at the latest by September 2009, and conflicting national standards shall be withdrawn at the latest by September 2009. Attention is drawn to the possibility that some of the elements of this document may be the subject

12、 of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 12350-3:1999. This standard is one of a series concerned with testing concrete. This series EN 12350 includes the following parts. Part 1: Sampling; Part 2:

13、Slump-test; Part 3: Vebe test; Part 4: Degree of compactability; Part 5: Flow table test; Part 6: Density; Part 7: Air content - Pressure methods; Part 8: Self-compacting concrete - Slump-flow test (in preparation); Part 9: Self-compacting concrete - V-funnel test (in preparation); Part 10: Self-com

14、pacting concrete - L-box test (in preparation); Part 11: Self-compacting concrete - Sieve segregation test (in preparation); Part 12: Self-compacting concrete - J-ring test (in preparation). CAUTION When cement is mixed with water, alkali is released. Take precautions to avoid dry cement entering th

15、e eyes, mouth and nose whilst mixing concrete. Prevent skin contact with wet cement or concrete by wearing suitable protective clothing. If 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

16、immediately. BS EN 12350-3:2009EN 12350-3:2009 (E) 4 The following amendments have been made to the 1999-10 edition of this standard: editorial revision time allowed for raising the mould changed from between 5 s and 10 s to between 2 s and 5 s. According to the CEN/CENELEC Internal Regulations, the

17、 national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Nor

18、way, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 12350-3:2009EN 12350-3:2009 (E) 5 1 Scope This European Standard specifies a method for determining the consistency of fresh concrete by means of the Vebe time. It is not applicable to concre

19、te of which the maximum size of aggregate exceeds 63 mm. If the Vebe time is less than 5 s or more than 30 s, the concrete has a consistency for which the Vebe test is unsuitable. 2 Normative references The following referenced documents are indispensable for the application of this document. For da

20、ted references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. EN 12350-1 Testing fresh concrete Part 1: Sampling 3 Principle The fresh concrete is compacted into a slump mould. The mould is lifted clear of th

21、e concrete and a transparent disc is swung over the top of the concrete and carefully lowered until it comes in contact with the concrete. The slump of the concrete is recorded. The vibrating table is started and the time taken for the lower surface of the transparent disc to be fully in contact wit

22、h the grout (the Vebe time), is measured. 4 Apparatus 4.1 Vebe meter (Consistometer) 4.1.1 Container, made of metal not readily attacked by cement paste, cylindrical in shape (A), having an internal diameter of (240 5) mm and a height of (200 2) mm. The thickness of the wall shall be approximately 3

23、 mm and that of the base approximately 7,5 mm. The container shall be watertight and of sufficient rigidity to retain its shape under rough usage. It shall be fitted with handles and brackets, the latter enabling it to be securely clamped to the top of the vibrating table (G) (see 4.1.4) by means of

24、 wing nuts (H). 4.1.2 Mould, made of metal not readily attacked by cement paste and not thinner than 1,5 mm. The interior of the mould shall be smooth and free from projections such as protruding rivets and shall be free from dents. The mould shall be in the form of a hollow frustum of a cone having

25、 the following internal dimensions: diameter of base: (200 2) mm; diameter of top: (100 2) mm; height: (300 2) mm. The base and the top of the mould shall be open and parallel to each other and at right angles to the axis. The mould shall be provided, on the upper portion, with two handles at approx

26、imately two-thirds of the height, to facilitate lifting it from the moulded concrete test specimen in a vertical direction, as required by the test. BS EN 12350-3:2009EN 12350-3:2009 (E) 6 4.1.3 Disc, transparent, horizontal (C), attached to a rod (J) which slides vertically through a guide sleeve (

27、E) mounted on a swivel arm (N) and which can be fixed in position by a screw (Q). The swivel arm also supports a funnel (D), the bottom of which coincides with the top of the conical mould when the latter is positioned concentrically in the container. The swivel arm is located by a holder (M) and ca

28、n be fixed in position by a set screw (F). When in the appropriate position, the axes of the rod and of the funnel shall be coincident with the axis of the container. The transparent disc shall be (230 2) mm in diameter and (10 2) mm in thickness. A weight (P) placed directly above the disc shall be

29、 provided such that the moving assembly comprising rod, disc and weight has a mass of (2 750 50) g. The rod shall be provided with a scale at 5 mm intervals to record the slump of the concrete. 4.2 Vibrating table (G), having minimum dimensions of (380 3) mm in length and (260 3) mm in width and sup

30、ported on four rubber shock absorbers on a hollow base (K), which in turn rests on three rubber feet. A vibrator unit (L) is securely fixed to the bottom of the table. The vibrator shall operate at a nominal frequency of 50 Hz to 60 Hz and the vertical amplitude of the table with the empty container

31、 on top of it shall be approximately 0,5 mm. 4.3 Compacting rod, of circular cross-section, straight, made of steel, having a diameter of approximately 16 mm and length approximately 600 mm and with rounded ends. 4.4 Stopwatch or clock, capable of recording time to an accuracy of 0,5 s. 4.5 Remixing

32、 container, flat tray of rigid construction and made from a non-absorbent material not readily attacked by cement paste. It shall be of appropriate dimensions such that the concrete can be thoroughly re-mixed, using the square-mouthed shovel. 4.6 Shovel, with square mouth NOTE The square mouth is re

33、quired to ensure proper mixing of material on the re-mixing tray. 4.7 Moist cloth. 4.8 Scoop, width approximately 100 mm. 5 Sampling The sample shall be obtained in accordance with EN 12350-1. The sample shall be re-mixed using the remixing container and the square mouthed shovel before carrying out

34、 the test. NOTE Alternative sampling procedures may be given in national standards or provisions in the place of use of concrete. 6 Procedure Place the Vebe meter on a rigid horizontal base, ensuring that the container (A) is firmly fixed to the vibrating table (G) by means of the wing nuts (H). Dam

35、pen the mould (B) and place it in the container. Swing the funnel (D) into position over the mould and lower onto the mould. Tighten the screw (F) so that the mould cannot rise from the bottom of the container. From the sample of concrete obtained in accordance with Clause 5, fill the mould in three

36、 layers, each approximately one-third of the height of the mould when compacted. Compact each layer with 25 strokes of the compacting rod, ensuring that the strokes are uniformly distributed over the cross-section of each layer. BS EN 12350-3:2009EN 12350-3:2009 (E) 7 For the bottom layer, this will

37、 necessitate inclining the rod slightly and positioning approximately half the strokes spirally toward the centre. Compact the concrete throughout its whole depth, taking care not to strike the base. Compact the second layer and the top layer throughout its depth, so that the strokes just penetrate

38、into the underlying layer. In filling and tamping the top layer, heap the concrete above the mould before tamping is started. If necessary, add further concrete to maintain an excess above the top of the mould throughout the compacting operation. After the top layer has been tamped, loosen the screw

39、 (F) and raise the funnel (D) and swing it out of the way and tighten the screw (F) in the new position. Ensure that the mould (B) does not rise or move prematurely and concrete is not allowed to fall into the container (A). Strike off the concrete level with the top of the mould with a sawing and r

40、olling motion of the compacting rod. Remove the mould (B) from the concrete by raising it carefully in a vertical direction, using the handles. Perform the operation of raising the mould in 2 s to 5 s by a steady upward lift with no lateral or torsional motion being imparted to the concrete. If the

41、concrete shears, as shown in Figure 2b), collapses, as shown in Figure 2c), or slumps to the extent that it touches the wall of the container (A), record the fact. If the concrete has not slumped into contact with the wall of the container (A), and a slump, as shown in Figure 2a) has been obtained,

42、record the fact. Swing the transparent disc (C) over the top of the concrete, loosen the screw (Q) and lower the disc very carefully until it just comes into contact with the concrete. Provided there has been a true slump, when the disc (C) just touches the highest point of the concrete, tighten the

43、 screw (Q). Read and record the value of the slump from the scale (J). Loosen the screw (Q) to allow the disc (C) to easily slide down into the container to rest fully on the concrete. If there has not been a true slump ensure that screw (Q) is loosened to allow the disc (C) to slide down into the c

44、ontainer to rest on the concrete. Start the vibration of the table and the timer simultaneously. Observe the way the concrete is remoulded through the transparent disc (C). As soon as the lower surface of the disc (C) is fully in contact with the cement grout, stop the timer and switch off the vibra

45、ting table. Record the time taken to the nearest second. Carry out the entire operation, from the start of the filling, without interruption, and complete within 5 minutes. NOTE The consistence of a concrete mix changes with time, due to hydration of the cement and, possibly, loss of moisture. Tests

46、 on different samples should, therefore, be carried out at a constant time interval after mixing, if strictly comparable results are to be obtained. 7 Test result Record the time read from the stopwatch, to the nearest second. This is the Vebe time, expressing the consistency of the mix under test.

47、8 Test report The report shall include: a) identification of the test sample; b) location of performance of test; c) date of test; BS EN 12350-3:2009EN 12350-3:2009 (E) 8 d) type of slump true/collapse/shear; e) measured true slump, to nearest 10 mm (if appropriate); f) Vebe time in s; g) any deviat

48、ion from standard test method; h) declaration by the person technically responsible for the test that it was carried out in accordance with this document, except as noted in item g). The report may include: i) temperature of the concrete sample at time of test; j) time of test. 9 Precision There is

49、currently no precision data for this test. Dimensions in millimetres Key: A Container J Scale B Mould K Hollow base C Transparent disc L Vibrator unit D Funnel M Holder E Guide sleeve N Swivel arm F Screw P Weight G Vibrating table Q Screw H Wing nuts Y-Y Detail X-X Detail Figure 1 Typical Consistometer (Vebe meter) BS EN 12350-3:2009EN 12350-3:2009 (E) 9 a) True slump b) Shear Slump c) Collapse slump Figure 2 Forms of slump BS EN12350-3:2009BSI GroupHeadquarters 38