DIN CEN TR 16349-2012 Framework for a specification on the avoidance of a damaging Alcali-Silica Reaction (ASR) in concrete English version CEN TR 16349 2012《混凝土中避免破坏硅碱反应(ASR)的规范框架.pdf

1、November 2012 Normenausschuss Bauwesen (NABau) im DINPreisgruppe 8DIN Deutsches Institut fr Normung e. V. Jede Art der Vervielfltigung, auch auszugsweise, nur mit Genehmigung des DIN Deutsches Institut fr Normung e. V., Berlin, gestattet.ICS 91.100.30Zur Erstellung einer DIN SPEC knnen verschiedene

2、Verfahrensweisen herangezogen werden: Das vorliegende Dokument wurde nach den Verfahrensregeln eines Fachberichts erstellt.!$y*“1918607www.din.deDDIN CEN/TR 16349Grundstze fr eine Spezifikation zur Vermeidung einer schdigendenAlkali-Kieselsure-Reaktion (AKR) in Beton;Englische Fassung CEN/TR 16349:2

3、012Framework for a specification on the avoidance of a damaging Alcali-Silica Reaction(ASR) in concrete;English version CEN/TR 16349:2012Cadre dune spcification destine prvenir les dgradations causes au bton parlalcali-raction;Version anglaise CEN/TR 16349:2012Alleinverkauf der Spezifikationen durch

4、 Beuth Verlag GmbH, 10772 Berlin www.beuth.deGesamtumfang 11 SeitenDIN SPEC 18047DIN CEN/TR 16349 (DIN SPEC 18047):2012-11 2 Nationales Vorwort Dieses Dokument (CEN/TR 16349:2012) wurde vom Technischen Komitee CEN/TC 104 Beton und zuge-hrige Produkte“ erarbeitet, dessen Sekretariat vom DIN (Deutschl

5、and) gehalten wird. Der fr die deutsche Mitarbeit zustndige Arbeitsausschuss im DIN ist der als Spiegelausschuss eingesetzte Arbeitsausschuss NA 005-07-02 AA Betontechnik“ des Normenausschusses Bauwesen (NABau) im DIN. Dieses Dokument enthlt unter Bercksichtigung des DIN-Prsidialbeschlusses 1/2004 u

6、nd der Entscheidung der zustndigen Gremien im Normenausschuss Bauwesen (NABau) die englische Fassung des Fachbericht CEN/TR 16349:2012. Es wird auf die Mglichkeit hingewiesen, dass einige Texte dieses Dokuments Patentrechte berhren knnen. Das DIN und/oder die DKE sind nicht dafr verantwortlich, eini

7、ge oder alle diesbezglichen Patentrechte zu identifizieren. Eine DIN SPEC nach dem Verfahren eines Fachberichtes ist das Ergebnis einer Normungsarbeit, das wegen bestimmter Vorbehalte zum Inhalt oder wegen des gegenber einer Norm abweichenden Aufstellungsver-fahrens vom DIN noch nicht als Norm herau

8、sgegeben wird. Zur vorliegenden DIN SPEC (Fachbericht) wurde kein Entwurf verffentlicht. Erfahrungen mit dieser DIN SPEC sind erbeten vorzugsweise als Datei per E-Mail an nabaudin.de in Form einer Tabelle. Die Vorlage dieser Tabelle kann im Internet unter http:/www.din.de/stellungnahme abgerufen wer

9、den; oder in Papierform an den Normenausschusses Bauwesen (NABau) im DIN Deutsches Institut fr Normung e.V., 10772 Berlin (Hausanschrift: Am DIN-Platz, Burggrafenstrae 6, 10787 Berlin). TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16349 April 2012 ICS 91.100.30 English Version Frame

10、work for a specification on the avoidance of a damaging Alkali-Silica Reaction (ASR) in concrete Cadre dune spcification destine prvenir les dgradations causes au bton par lalcali-raction Grundstze fr eine Spezifikation zur Vermeidung einer schdigenden Alkali-Kieselsure-Reaktion (AKR) in Beton This

11、Technical Report was approved by CEN on 14 February 2012. It has been drawn up by the Technical Committee CEN/TC 104. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ir

12、eland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CEN All rights of exploitation in any form and by any means reserve

13、d worldwide for CEN national Members. Ref. No. CEN/TR 16349:2012: E EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN/TR 16349:2012 (E) 2 Contents Page Foreword 3Introduction .41 Scope 52 Alkali-Silica Reaction (ASR) .53 Elements of specificatio

14、ns .54 Characterisation of environment .55 Precautionary measures appropriate to concrete 65.1 General remarks.65.2 Use of cement with a low effective alkali content 75.3 Use of slag, fly ash, silica fume or other pozzolana (in cement or as an addition) 75.4 Limiting the effective alkali content of

15、the concrete 75.5 Verification of the suitability of a concrete mix in a performance test 85.6 Use of a non-reactive aggregate combination 86 Summary .8Bibliography 9DIN CEN/TR 16349 (DIN SPEC 18047):2012-11 CEN/TR 16349:2012 (E) 3 Foreword This document (CEN/TR 16349:2012) has been prepared by Tech

16、nical Committee CEN/TC 104 “Concrete and related products”, the secretariat of which is held by DIN. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such

17、patent rights. This Technical Report is partly based on the recommendation of RILEM TC ACS (Part 1 of AAR-7) 6. DIN CEN/TR 16349 (DIN SPEC 18047):2012-11 CEN/TR 16349:2012 (E) 4 Introduction This Technical Report has been prepared by the Joint Working Group (JWG) on Alkali-Silica Reaction (ASR) that

18、 was set up by the chairmen of CEN/TC 51, CEN/TC 104 and CEN/TC 154 and composed of representatives from CEN/TC 51, CEN/TC 104, CEN/TC 154 and RILEM TC ACS. The following is a list of the members of the JWG on ASR: Name Represents Michel Delort CEN/TC 51 Christer Ljungkrantz CEN/TC 51 Tom Harrison C

19、EN/TC 104 Christoph Mller CEN/TC 104 Philip Nixon (until 2009) CEN/TC 154 Robert Gossling (from 2010) CEN/TC 154 Jean-Marc Vanbelle CEN/TC 154 Terje F. Ronning RILEM Ingmar Borchers (VDZ) Guest In CEN member countries, ASR has been recognised as a problem in concrete structures since the 1970s.Conse

20、quently, a number of countries have established provisions to avoid a damaging ASR. These provisions are currently set out in national guidance documents and specifications. Provisions vary in the different CEN member countries and depend on local experiences; some member countries have not yet foun

21、d the need to set up specifications. The JWG was established to review the situation and to see whether it is possible to go further in providing pragmatic and unified economic European specifications for the avoidance of a damaging ASR in concrete. The JWG concluded that, unless there is any sound

22、scientific explanation of a damaging ASR which can be used uniformly all over Europe, it is premature to have harmonised classes for alkali-reactivity of aggregates and provisions for avoiding a damaging ASR on a European level. Additionally, safety margins are determined at national level and are r

23、elated to the reliability at which a damaging ASR will not occur. Nevertheless, a framework for the specification of the avoidance of a damaging ASR in concrete can be given. DIN CEN/TR 16349 (DIN SPEC 18047):2012-11 CEN/TR 16349:2012 (E) 5 1 Scope This Technical Report gives guidance for avoiding a

24、 damaging Alkali-Silica Reaction (ASR) in concrete. 2 Alkali-Silica Reaction (ASR) Alkali-Silica Reactions in concrete are a result of reaction between the alkaline pore solution in concrete and reactive mineral species (as reactive silica and silicates) in the aggregate. The reaction leads to the f

25、ormation of a gel that can absorb water and exert an expansive force on the concrete. In certain conditions, these reactions can lead to damaging expansions and cracking in the concrete. For such damaging expansion to occur, all of the following conditions must be present simultaneously: a critical

26、amount of reactive mineral species; a sufficiently high alkali hydroxide concentration in the pore solution; a sufficient supply of water. Effective specifications to avoid damage from the reaction are based on ensuring that at least one of these conditions is absent. NOTE Another type of reaction b

27、etween reactive mineral species in the aggregates and the alkaline pore solution, which has been reported (e.g. from Canada and China), is the alkali-carbonate reaction. As alkali-carbonate reaction has not been recognised as a significant problem in Europe, it is not covered by this Technical Repor

28、t. 3 Elements of specifications In order to promote the sustainable use of locally available materials, it is important to tailor the precautions to the environment that the structure is exposed to as well as to local experience in building practice. Based on these principles, specifications for avo

29、iding a damaging ASR in concrete are given within the following structure: a) characterisation of the environment (environmental category): 1) degree of saturation of the concrete with water; 2) alkali supply; 3) further aggravating factors. b) undertaking recommendations for precautionary measures

30、appropriate to concrete, depending on the environmental category. 4 Characterisation of environment When all the necessary compositional factors are present, the likelihood and extent of damaging alkali-silica reaction is dependent on the environment. Three levels of categorisation of environment ar

31、e therefore appropriate: E1: the concrete is essentially protected from extraneous moisture; E2: the concrete is exposed to extraneous moisture; E3: the concrete is exposed to extraneous moisture and additionally to aggravating factors, such as de-icing agents, freezing and thawing (or wetting and d

32、rying in a marine environment) or fluctuating loads. DIN CEN/TR 16349 (DIN SPEC 18047):2012-11 CEN/TR 16349:2012 (E) 6 More details on the factors affecting the environmental categorisation are given in Table 1. Table 1 Environmental categories Environmental categories Description Exposure of the co

33、ncrete a,b,cE1 Dry environment protected from extraneous moisture - Internal concrete within buildings in dry aservice conditions E2 Exposed to extraneous moisture b- Internal concrete in buildings where humidity is high; e.g. laundries, tanks, swimming pools - Concrete exposed to moisture from the

34、external atmosphere, to non-aggressive ground or immersed in plain water or permanently immersed in seawater c. E3 Exposed to extraneous moisture plus aggravating factors - Concrete exposed to de-icing salts - Concrete exposed to wetting and drying by seawater cor to salt spray - Concrete exposed to

35、 freezing and thawing whilst wet - Concrete subjected to prolonged elevated temperatures whilst wet - Concrete roads subject to fluctuating loads aA dry environment corresponds to an ambient average relative humidity condition lower than 75 % (normally only found inside buildings) and no exposure to

36、 external moisture sources. bA risk of a damaging ASR may exist for concrete that is unlikely to dry significantly during its serviceable life, even in a dry environment. Corresponding concrete structural elements should be included in category E2 and their dimensions may be defined in national spec

37、ifications. cConcrete constantly immersed in seawater does not suffer a higher risk of ASR than a similar element exposed to humid air, buried in the ground, or immersed in plain water, because the alkali concentration of sea water is lower than the alkali concentration of the pore solution of most

38、concretes. 5 Precautionary measures appropriate to concrete 5.1 General remarks Depending on the environmental category, precautionary measures have to be applied. The type of measure, as well as the limits and levels in a measure itself, shall be defined on a national level because they depend on t

39、he national safety margin, the experiences of building practices, and the geology and climate. Precautionary measures include: a) no measures necessary; b) use of a non-reactive aggregate combination; c) limiting the alkalinity of the pore solution by: 1) the use of cement with a low effective alkal

40、i content; 2) the use of an adequate proportion of slag, fly ash, silica fume or other pozzolana (in cement or as an addition); 3) conforming to a numerical limit on the effective alkali content of the concrete; 4) verification of the suitability of a concrete mix in a performance test. DIN CEN/TR 1

41、6349 (DIN SPEC 18047):2012-11 CEN/TR 16349:2012 (E) 7 NOTE The appropriate precautionary measures for different environmental categories are found in the provisions valid in the place of use. Examples are the proportion of the fly ash/ground granulated blastfurnace slag (ggbs) that is necessary to a

42、void a damaging ASR, or the limit on the effective alkali content of the concrete. Such examples differ between CEN member countries and depend on both the reactivity of the aggregate combination and the national determined safety margin. 5.2 Use of cement with a low effective alkali content In the

43、case of low-alkali Portland cements (CEM I), an upper limit of 0,60 mass % Na2O-equivalent is generally applied. The use of such low-alkali cements has been found to be effective in some regions in preventing ASR damage. This measure may not be effective in the case of concretes with unusually high

44、cement contents, concretes with significant alkalis from constituents other than the cement, if there are significant sources of extraneous alkali (e.g. concrete roads), or if the passage of moisture concentrates the alkalis in certain parts of the structure. Other cement types with low effective al

45、kali content can be manufactured (for example cement types containing slag, fly ash or natural pozzolanas as a main constituent). The allowable alkali content depends on the percentage of slag, fly ash or natural pozzolanas, although there is no agreed value at European level. 5.3 Use of slag, fly a

46、sh, silica fume or other pozzolana (in cement or as an addition) The use of slag, fly ash, silica fume or other pozzolana (in cement or as an addition) can be very effective in preventing ASR damage. Fly ashes conforming to EN 450-1, ground granulated blastfurnace slag (ggbs) conforming to EN 15167-

47、1 and silica fume conforming to EN 13263-1 have been well-established as effective concrete additions. The effectiveness of cement types containing siliceous fly ash, natural pozzolanas or granulated blastfurnace slag conforming to EN 197-1 is also well-established. Both provide effective protection

48、 against ASR damage, provided a sufficient proportion (as a proportion of the total cementitious material) is used. The proportion necessary depends on the reactivity of the aggregate combination and the properties of the granulated blastfurnace slag/fly ash/silica fume/natural pozzolana. The requir

49、ements naturally differ between CEN member countries. 5.4 Limiting the effective alkali content of the concrete The alkalinity of the pore solution is primarily dependent on the alkali content of the concrete mix. The effective application of limiting the effective alkali content of the concrete requires either the classification of all constituents used for a specific concrete mix with respect to their effective alkali content, or the quality assured declaration of the a