1、BRITISH STANDARD Test methods for verification of corrosion protection of reinforcement in autoclaved aerated concrete and lightweight aggregate concrete with open structure The European Standard EN 9902002 has the status of a British Standard ICs 91.100.30 v BS EN 990:2002 British Standards NO COPY
2、ING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS EN 990:2002 Amd. No. National foreword Date Comments This British Standard is the official English language version of EN 990:ZOOZ. It supersedes BS EN 990: 1996 which is withdrawn. The UK participation in its preparation was entrust
3、ed to Technical Committee B/523, Prefabricated components of reinforced autoclaved aerated concrete and lightweight aggregate concrete with open structure, which has the responsibility to: - - aid enquirers to understand the text; present to the responsible internationallEuropean committee any enqui
4、ries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The Br
5、itish 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 Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards O
6、nline. 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 confer immunity from legal obligations. This British Standard, having been prepared under the direc
7、tion of the Building and Summary of pages This document comprises a fiont cover, an inside Gont cover, the EN title page, Civil Engineering Sedor Policy pages to and a back cover. and Strategy was published under the authority ofthe Standards policy and The BSI copyright date displayed in this docum
8、ent indicates when the document was last issued. Strategy Committee on 16 October 2002 Amendments issued since publication O BSI 16 October 2002 ISBN O 680 40579 6 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 99Q September 2002 ICs 91.100.30 Supersedes EN 9903 995 English version Test method
9、s for verification of corrosion protection of reinforcement in autoclaved aerated concrete and lightweight aggregate concrete with open structure Mthodes dessai pour la vrification de la protection contre la corrosion des armatures dans le beton cellulaire autoclav et le bton de granulats lgers stru
10、cture ouverte Prfverfahren zur berprfung des Korrosionsschutzes der Bewehrung in dampfgehrtetem Porenbeton und in haufwerksporigern Leichtbeton This European Standard was approved by CEN on 21 July 2002. CEN members are bound to comply with the CEWCENELEC Internal Regulations which stipulate the con
11、ditions 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 Management Centre or to any CEN member. This European Standard exists in three
12、official versions (English, French, German). A version in any other language made by translation under the responsibility of a GEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria
13、, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMfITEE FOR STANDARDIZATION EUROPISCHES KOMITEE FUR NORMUNG COMIT EUROPEN DE NORMALISATION Manage
14、ment Centre: rue de Stassari, 36 B-1050 Brussels 02002 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 990:2002 E EN 990:2002 (E) Contents page Foreword 3 1 2 3 4 5 5.1 5.2 6 6.1 6.1.1 6.1.2 6.2 6.2.1 6.2.2 6.3 6.3.1 6.3.2 7 Scope
15、3 Normative references 3 Principle 4 Apparatus . 4 Test specimens 4 General 4 Sealing of the end faces and conditioning of the test specimens 5 Corrosion tests . 5 Short-term test with alternate wetting with sodium chloride solution and drying in air (method Exposure cycles . 5 Examination of steel
16、surface and evaluation of results 6 Short-term test with alternate wetting with water and drying in warm air (method 2) . 6 Exposure cycles . 6 Examination of the steel surface and evaluation of results 6 Short-term test with alternating temperature (method 3) 6 Exposure cycles . 6 Examination of th
17、e steel surface and evaluation of results 6 Test report 7 1) . 5 2 EN 990:2002 (E) Foreword This document (EN 990:2002) has been prepared by Technicai Committee CEN /TC 177 “Prefabricated reinforced components of autoclaved aerated concrete or light-weight aggregate concrete with open structure“, th
18、e 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 March 2003, and conflicting national standards shall be withdrawn at the latest by March 2003. This document
19、supersedes EN 990:1995. In order to meet the performance requirements as laid down in the product standards for prefabricated reinforced components of autoclaved aerated concrete or for prefabricated reinforced components of lightweight aggregate concrete with open structure a number of standardised
20、 test methods are necessary. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembou
21、rg, Malta, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 1 Scope This European Standard specifies the test methods for verification of the effectiveness of the corrosion protection of reinforcing steel embedded in components of autoclaved aerated concrete (MC) acc
22、ording to prEN 12602 or in components of lightweight aggregate concrete with open structure (LAC) according to prEN 1520. Tests according to this European Standard are not required for LAC-components if corrosion protection is achieved by embedding the reinforcing bars completely in a zone of concre
23、te with closed structure according to prEN 1520:2002, 5.8.3.3. Three different methods of short-term tests (methods 1 to 3) are provided. The test methods can be used to examine the fundamental suitability of a corrosion protective system in combination with a defined manufacturing process for the p
24、roduction of reinforced components. They can also be used for current production control. NOTE rather than on technical needs. The specification of three different short-term test methods is based on historical reasons and established procedures 2 Normative references This European Standard incorpor
25、ates 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, subsequent amendments to or revisions of any of these publications apply to this Europe
26、an Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). prEN 1 520:2002, Prefabricated reinforced components of lightweight aggregate concrete with open structure. prEN 7 2602, Prefabr
27、icated reinforced components of autoclaved aerated concrete. 3 EN 990:2002 (E) 3 Principle Test specimens consisting of autoclaved aerated concrete (AAC) or lightweight aggregate concrete with open structure (LAC) with embedded reinforcing bars are cut from prefabricated reinforced components or man
28、ufactured separately. The test specimens are exposed to a defined corrosive environment for a specified series of exposure cycles. Immediately after the end of the corrosive exposure the concrete and the protective coating are removed from the embedded bars. The steel surface is examined visually fo
29、r corrosion and the area of the corroded surface is determined and compared with the limits according to the relevant product standard prEN 1520 or prEN 12602. 4 Apparatus a) Saw A saw for cutting test specimens from reinforced components without excessive heating or vibrations. b) Equipment for sho
30、rt-term test with alternate wetting with sodium chloride solution and drying in air (method 1): 1) a facility for wetting the test specimens for 2 h with sodium chloride solution (concentration 3 % by mass) by immersion in a tank or by continuous spraying; 2) a ventilated room or cabinet for drying
31、the test specimens in air at (15 to 30) OC for 70 h. The relative humidity and the air movement shall be such that the rate of evaporation from a cylindrical beaker of (80 f 5) mm diameter initially filled with water to 20 mm from its top is (50 f 25) ml per 24 h. c) Equipment for short-term test wi
32、th alternate wetting with water and drying in warm air (method 2): 1) a facility for wetting the test specimens with water (water basin or water spray); 2) a ventilated room or cabinet capable of maintaining an air temperature of (40 f 5) OC and with provisions for circulating air into and out of th
33、e room during the drying period in a uniform manner. The relative humidity and the air movement shall be such that the rate of evaporation from a cylindrical beaker of (80 f 5) mm diameter initially filled with water to 20 mm from its top is (200 f 75) ml per 24 h. NOTE equipment according to 1) in
34、the ventilated room or cabinet and to install an automatic temperature control system. Equipment for short-term test with alternating temperature (method 3): To enable automation of the wetting and drying cycles it can be convenient to accommodate the wetting d) a humidity cabinet for the storage of
35、 the test specimens in moisture saturated air (relative humidity I95 %). The air temperature in the cabinet shall alternate every 3 h between (25 f 5) OC and (55 f 5) OC. The indicated temperatures shall be reached within approximately 1 h in each case and then be maintained constant during the rest
36、 of the 3 h period. 5 Test specimens 5.1 General The test specimens shall be 400 mm long prismatic sections either cut from prefabricated reinforced components of current production (normal case) or especially manufactured for this purpose under conditions as close as possible to those of current pr
37、oduction. Each test specimen shall contain at least two reinforcing bars coated with the protective system to be tested. Where the test specimens are especially manufactured, the bars shall be free from corrosion before applying the protective system. The width and the height (thickness) of the test
38、 specimens shall be such that the reinforcing bars are covered on all sides with at least the minimum nominal concrete cover required in the relevant product standard. 4 EN 990:2002 (E) If the test specimens are cut from prefabricated reinforced components, their height shall extend over the full he
39、ight (thickness) of the component. In order to avoid damage due to the cutting operation the test specimens shall be cut from the reinforced components - not less than 2 d after autoclaving in the case of AAC; - not less than 7 d after casting in the case of LAC. When the test specimens are manufact
40、ured separately, the concrete cover at the bottom shall be equal to the minimum value required in the product standards prEN 1520 or prEN 12602, respectively, and the cover at the top shall be at least equal to that value. Test specimens representing multilayer components shall have the same structu
41、re as the corresponding prefabricated components. For each corrosion test at least three test specimens are required. Three additional companion specimens should be provided to enable comparison of the corrosion phenomena of the reinforcement of the exposed test specimens with that of the reinforcem
42、ent of unexposed specimens. This is not necessary if it is certain that the steel surface has been free of any signs of corrosion before the protective system has been applied. The companion specimens shall be stored in a non-corrosive environment (relative humidity of the air I 70 %) until the end
43、of the corrosion tests. NOTE The purpose of the companion specimens is to enable to differentiate between the corrosion phenomena caused by the test conditions and the corrosion which possibly might have been present on the steel surface initially, before the beginning of the test, due to the use of
44、 reinforcement which had been corroded (to the permissible extent) before applying of the corrosion protective system. Only the (additional) amount of corrosion caused by the test conditions is of interest for the evaluation of the suitability of the corrosion protective system. 5.2 Sealing of the e
45、nd faces and conditioning of the test specimens Precautions shall be taken so that corrosion does not enter from the end faces of the test specimens into the interior, e. g. by application of an impermeable layer on the end faces. For tests according to method 3 the test specimens shall be condition
46、ed prior to the test by storing them for 2 h under water (tap water, approximately 20 OC) and subsequently in air at normal room temperature (15 to 30) OC and normal relative humidity (30 to 70) % for a period of 14 d. The corrosion testing shall be started not less than 7 d after autoclaving in the
47、 case of AAC and not less than 28 d after manufacture in the case of LAC. 6 Corrosion tests 6.1 Short-term test with alternate wetting with sodium chloride solution and drying in air (method 1) 6.1.1 Exposure cycles The test specimens shall be exposed to 1 O exposure cycles. Each exposure cycle cons
48、ists of - 2 h wetting with sodium chloride solution with a concentration of 3 % by mass; - 70 h drying in air under conditions indicated in 4.b 2). The drying period may be extended to a total length of 7 d, if required, e. g. at weekends or holidays. Control of humidity and air movement in order to
49、 achieve the prescribed rate of evaporation is only necessary for a period of 70 h. 5 EN 990:2002 (E) 6.1.2 Examination of steel surface and evaluation of results Immediately (not more than 4 d) after the last drying period the concrete and the protective cover are removed from the reinforcing bars, and the steel surface is examined visually from all sides. For each test specimen the corroded area shall be determined by measurement and calculation and expressed as a percentage of the total surface area of the reinforcement calculated from the measured lengths and diameters o
