《BS-EN-480-14-2006.pdf》由会员分享，可在线阅读，更多相关《BS-EN-480-14-2006.pdf（14页珍藏版）》请在三一文库上搜索。
1、BRITISH STANDARD BS EN 480-14:2006 Admixtures for concrete, mortar and grout Test methods Part 14: Determination of the effect on corrosion susceptibility of reinforcing steel by potentiostatic electro-chemical test The European Standard EN 480-14:2006 has the status of a British Standard ICS 91.100
2、.30 ? Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 480-14:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 30 November 2006 BSI 2006 ISBN 0 580 49498 5 National foreword
3、This British Standard was published by BSI. It is the UK implementation of EN 480-14:2006. The UK participation in its preparation was entrusted by Technical Committee B/517, Concrete, to Subcommittee B/517/3, Admixtures. A list of organizations represented on B/517/3 can be obtained on request to i
4、ts secretary. 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 cannot confer immunity from legal obligations. Amendments issued since publication Amd. No. DateComments Licens
5、ed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 480-14 October 2006 ICS 91.100.30 English Version Admixtures for concrete, mortar and grout - Test methods - Part 14: Determination of the effect
6、on corrosion susceptibility of reinforcing steel by potentiostatic electro-chemical test Adjuvants pour bton, mortier et coulis - Mthodes dessai - Partie 14 : Dtermination de leffet sur la tendance la corrosion de lacier pour armature au moyen dun essai lectrochimique potentiostatique Zusatzmittel f
7、r Beton, Mrtel und Einpressmrtel - Prfverfahren - Teil 14: Bestimmung des Korrosionsverhaltens von Stahl in Beton - Elektrochemische Prfung bei gleich bleibendem Potential This European Standard was approved by CEN on 19 August 2006. CEN members are bound to comply with the CEN/CENELEC Internal Regu
8、lations 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 Central Secretariat or to any CEN member. This E
9、uropean 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 Central Secretariat has the same status as the official versions. CEN members are the n
10、ational 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, Slovenia, Spain, Sweden, Switzerland and United
11、Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2006 CENAll rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 480-14:2006: E
12、 Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 480-14:2006 (E) 2 Contents Page Foreword3 1 Scope 4 2 Normative references4 3 Test principle4 4 Equipment, materials and test specimens5 4.1 Equipment and materials5 4.1.1 Electrodes.5 4.1.
13、2 Reference mortar.5 4.1.3 Moulds 5 4.1.4 Test cell solution5 4.1.5 Polarisation circuit.5 4.2 Preparation of test specimens .6 4.2.1 General6 4.2.2 Preparation of the working electrode6 4.2.3 Preparation of the mortar specimens6 5 Testing6 5.1 Preparation for testing 6 5.2 Test procedure.7 5.3 Test
14、 result.7 6 Test report7 Bibliography10 Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 480-14:2006 (E) 3 Foreword This document (EN 480-14:2006) has been prepared by Technical Committee CEN/TC 104 “Concrete and related products”, the sec
15、retariat 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 April 2007, and conflicting national standards shall be withdrawn at the latest by April 2007. This document has b
16、een prepared by Subcommittee 3 (SC 3) of TC 104 “Admixtures of concrete.” This document is part of the series EN 480 “Admixtures for concrete, mortar and grout - Test methods“ which include the following: Part 1: Reference concrete and reference mortar for testing Part 2: Determination of setting ti
17、me Part 4: Determination of bleeding of concrete Part 5: Determination of capillary absorption Part 6: Infrared analysis Part 8: Determination of the conventional dry material content Part 10: Determination of water soluble chloride content Part 11: Determination of air void characteristics in harde
18、ned concrete Part 12: Determination of the alkali content of admixtures Part 13: Reference masonry mortar for testing mortar admixtures Part 14: Determination of the effect on corrosion susceptibility of reinforcing steel by potentiostatic electro- chemical test This document is applicable together
19、with the standards of the series EN 934 “Admixtures for concrete, mortar and grout. 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, Est
20、onia, 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. Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00
21、 2006, Uncontrolled Copy, (c) BSI EN 480-14:2006 (E) 4 1 Scope This European Standard defines: A test method for determining the influence of an admixture on the corrosion of a steel bar embedded in a mortar sample held at an increased potential in an electrochemical cell. The method can be used to
22、determine the harmlessness of admixtures with regard to corrosion of reinforcing but not stressed steel. It applies to all admixtures for concrete, mortar and grout in contact with reinforcing steel. NOTE 1 This test method does not apply to assessing corrosion behaviour of admixtures when used with
23、 high tensile steel. NOTE 2 This test method does not assess the efficacy of admixtures defined as corrosion inhibitors. NOTE 3 The quantity of chloride ion present in admixtures is covered by a separate requirement in the relevant parts of the EN 934 series. 2 Normative references The following ref
24、erenced 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 196-1, Methods of testing cement Part 1: Determination of stren
25、gth EN 197-1, Cement Part 1: Composition, specifications and conformity criteria for common cements 3 Test principle During the test, a steel bar, embedded in a cement mortar containing the admixture, is maintained at a constant potential relative to a reference electrode. The potential chosen is cl
26、ose to the higher level of the passive state for steel in plain concrete. Any detrimental effect from the addition of the admixture will be immediately obvious as the passive state will change, leading to increased anodic dissolution rates and corrosion currents above those of the control. The test
27、specimen containing the admixture, is compared with a control specimen without admixture, to assess the effect that the admixture has on the corrosion process. Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 480-14:2006 (E) 5 4 Equipment,
28、 materials and test specimens 4.1 Equipment and materials 4.1.1 Electrodes 4.1.1.1 Working electrode: comprising a smooth bar, without visible scratches or corrosion, of low carbon mild steel (carbon less than 0,4 %, steel tensile strength 300 MPa), e.g. S235JRG1 to EN 10025-1 and 10025-2. The worki
29、ng electrode is cylindrical, (7 + 1) mm in diameter and the length in contact with mortar is 65 mm (see Figure 1). 4.1.1.2 Reference electrode: saturated calomel electrode, silver/silver chloride electrode or mercury/mercuric oxide electrode. 4.1.1.3 Counter electrode: platinum electrode or a thin s
30、heet of stainless steel (e.g. EN 10088-1 type X2CrNi19-11) with a submerged length equal to the length of the working electrode in contact with the mortar. 4.1.2 Reference mortar The composition of the reference mortar shall conform to EN 196-1. The cement shall be a CEM I in accordance with EN 197-
31、1 and C3A content 3,0 %; water shall be de-ionized and the water/cement ratio shall be 0,50. Preparation of the mortar shall be in accordance with EN 196-1. For each test, two mixes are prepared: a reference control mortar, without admixture, and a reference test mortar which contains the admixture
32、or admixture constituent being tested at the maximum recommended dose. All mortar is made using materials from the same delivery. If a liquid admixture is being tested, it is added to the mixing water of the test mortar and the amount of mixing water is decreased by the water content of the admixtur
33、e. If a powder/granulated admixture is being tested it is added to the sand for the test mortar. NOTE In some cases it may be difficult to obtain a dense, uniform and fully compacted mortar specimen when using the admixture at its maximum recommended dose under the specified test conditions. Segrega
34、tion, excessive retardation, air entrainment or poor compaction due to early stiffening all have to be avoided as they may affect the test result. In such cases, modifications to the mixing and test procedures such as test and/or curing temperature or time/method of filling the mould should be agree
35、d with the manufacturer and recorded in the test report. In exceptional cases, when testing retarding admixtures it may be necessary to increase the mix and curing temperature. When testing set accelerating admixtures for sprayed concrete use a w/c = 0,55, cool the constituents to (5 1) C and add th
36、e admixture 15 s before the end of mixing. 4.1.3 Moulds Moulds used in the preparation of a particular set of specimens (control and test) shall be made from cardboard, plastic or steel and essentially identical in internal dimensions. A suitable arrangement, including the dimensional requirement, i
37、s shown in Figure 1. 4.1.4 Test cell solution The electrolyte of the cell shall be a saturated calcium hydroxide solution at a temperature of (20 + 2) C. The electrolyte shall be made from analytical grade calcium hydroxide in de-ionised water. 4.1.5 Polarisation circuit The polarisation circuit inc
38、ludes: potentiostat to apply a potential between the working electrode and the reference electrode, maintained at (+ 500 5) mVNHE. The potentiostat provides a constant voltage between the working electrode and the Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncont
39、rolled Copy, (c) BSI EN 480-14:2006 (E) 6 counter electrode relative to the reference electrode. The potentiostat should have a minimum impedance of 100 M. ammeter, with an accuracy 0,1 A, to measure changes in the current between the working electrode and the counter electrode. The range of the amm
40、eter should be between 0 A and x A where x = 100 times exposed surface of the working electrode in cm. 4.2 Preparation of test specimens 4.2.1 General Condition all the materials at (20 + 2) C before preparing the specimens. NOTE Following the note in 4.1.2 a different conditioning temperature may b
41、e necessary when some admixtures are tested at their maximum recommended dose. 4.2.2 Preparation of the working electrode All steel bar working electrodes used in a particular set of tests shall be from the same heat. Before making the reinforced mortar specimen, clean the working electrode using me
42、tallographic emery paper, grade 400 and then degrease with acetone or other suitable solvent. Handle the bars (working electrodes) with gloved hands only from this point in the procedure. Immediately after cleaning, coat each working electrode with an appropriate epoxy resin for a length of approxim
43、ately 40 mm centred about the point where it emerges from the mortar (see Figure 1). Measure the length and diameter of the uncoated part of the electrode to be encased in mortar to the nearest 1,0 mm and 0,1 mm respectively. NOTE 1 If the working electrode is not incorporated in mortar immediately
44、after cleaning and coating, store it in a desiccator at a relative humidity 30 %. If the surface has become tarnished it should be cleaned again before use. NOTE 2 Other coatings can be used in place of epoxy resin if they can be shown to give equivalent results. 4.2.3 Preparation of the mortar spec
45、imens Prepare three similar specimens from each mortar mix. Place the working electrode centrally in the mould so that the mortar cover to the embedded part without coating is (20 5) mm and secure it to prevent movement during filling, compaction and whilst the mortar remains in the plastic state. F
46、ill the moulds and compact to ensure complete compaction without segregation. If the mortar is not fully compacted or is subject to segregation, this can induce corrosion and invalidate the test. In such cases the test shall be repeated, if necessary with a change to the test conditions as suggested
47、 in the note in 4.1.2. NOTE The working electrode may be placed in the mould after filling, provided it can be centrally located and full contact between the mortar and the bar achieved. After preparation store the specimens at (20 2) C and 95 % RH for 24 h prior to demoulding. If the specimens do n
48、ot harden in 24 h, demould after hardening and record the age for inclusion in the test report. 5 Testing 5.1 Preparation for testing After demoulding place the specimen vertically into a test cell, fill with the test cell solution (clause 4.1.4), to within 10 mm of the top of the mortar cylinder, a
49、nd leave for 24 h at (20 2) C. Do not allow water or the test cell solution to come into contact with the top surface of the specimen at any time as moisture around the embedded bar may lead to errors in the test. Licensed Copy: sheffieldun sheffieldun, na, Sat Dec 02 14:39:17 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 480-14:2006 (E) 7 5.2 Test procedure After the 24 h equilibration period, thoroughly clean the exposed end of the working electr