【BS英国标准】BS EN 450-1995 Fly ash for concrete-Definitions, requirements and quality control.doc

国内外标准大全豆丁网国内外标准下载地址 /kmust1licensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsilicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsibritish standard bs en450:1995fly ash for concrete definitions, requirements and quality controlthe european standard en 450:1994 has the status of abritish standardudc 666.971.98:693.5:666.952.2:001.4:658.562bs en 450:1995committees responsible for thisbritish standardthe preparation of this british standard was entrusted by technical committee b/516, cement and lime, to subcommittee b/516/101, pozzolanas, upon which the following bodies were represented:british aggregate construction materials industriesbritish cement associationbritish precast concrete federation british ready mixed concrete association cementitious slag makers associationdepartment of the environment (building research establishment) department of transportelectricity associationfederation of civil engineering contractorsquality ash associationlicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsithis british standard, having been prepared under the direction of the sector board for building and civil engineering, was published under the authority of the standards board and comes into effect on15 december 1995 bsi 07-1999the following bsi references relate to the work on this standard:committee reference b/516/101draft for comment 91/11362 dcisbn 0 580 24612 4amd. no.datecommentsamendments issued since publicationlicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsicontentspage committees responsibleinside front cover national forewordii foreword 2text of en 4503national annex na (informative) comparison betweenbs 3892-1 and bs en 4508national annex nb (normative) requirements permittedto be specified on a national basis9list of referencesinside back coverlicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsinational forewordthis british standard is the english language version of en 450:1994 fly ash for concrete definitions, requirements and quality control prepared under the authority of the european committee for standardization (cen). this standard has been prepared as part of a package of standards harmonized within the member countries of cen to support the essential requirements of the construction products directive.the term “fly ash” used in this standard covers pulverized-fuel ash (pfa) which is the more precise term for fly ashes produced from electricity generating power stations burning pulverized hard coals and which has been in common use in the uk for many years.bs en 450 does not supersede bs 3892-1 which remains in force and covers a processed material, as explained in the introduction of this standard.bs 3892-2:1984 is under revision.this standard was drafted with the cooperation of the uk which proposed a requirement for different classes of ash each with specific applications in order to maintain the successful system of classification and use established underbs 3892 since 1965. this was not required or accepted by the majority of cenmember countries. however, the introduction to en 450 acknowledges that theuk and ireland require that ash, for use as a cementitious component in concrete,be processed in order to restrict variations in quality and to enhance performance in concrete. it further recognizes that the specific requirements for controlled properties which allow such processed ash to be used as a special component of cementitious systems in concrete are not included in en 450. pfa conforming to bs 3892-1 is subject to such processing. bs 5328-1 and bs 8110-1 refer to the useof other fly ashes that do not conform to bs 3892-1 provided that satisfactory dataon their use are available.requirements in both bs en 450 and bs 3892-1 are specified as characteristic values and conformity is assessed by means of a statistical procedure for continuous inspection operated by the ash producer (autocontrol). this includes the concept of “major defects” which are likely to reduce materially the usability of the ash for its intended purpose. in this respect both bs en 450 andbs 3892-1 are based upon the text on conformity criteria given in the european prestandard for cement, env 197-1:1992. subsequent draft revisions of this text have removed reference to major defects, referring instead to “limit values” (upper and lower). the sum of the specified characteristic value and the corresponding major defect is the limit value for the particular property. the latter term is used throughout national annex na in which the main differences between bs en 450 and bs 3892-1 are summarized.bs en 450 makes reference in 3.2, 3.3 and 4.2.2 to certain items which are permitted to be fixed on a national basis. normative national annex nb indicates how these clauses are to be interpreted for the uk.most ash produced in the uk would conform to bs en 450 without further processing. rules to allow ash conforming to bs en 450 to be used in concrete produced in accordance with en 206 are, however, still under development. until such rules have been developed and agreed, users of ash conforming to bs en 450 are advised that, for the specific use as part of the cement content in concrete, pfa is required by bs 5328 and bs 8110 to conform to bs 3892-1. in particular,bs 5328 requires that, when pfa is combined with a portland cement in the concrete mixer to give a combination equivalent to a cement conforming to bs 6588 or bs 6610, the pfa conforms to bs 3892-1. bsi 07-1999iilicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsicross-referencespublications referred to corresponding british standarden 196-1:1994bs en 196-1:1995 methods of testing cementpart 1: determination of strengthen 196-2:1994bs en 196-2:1995 methods of testing cementpart 2: chemical analysis of cementen 196-3:1994bs en 196-3:1995 methods of testing cementpart 3: determination of setting time and soundnessen 196-6:1989bs en 196-6:1992 methods of testing cementpart 6: determination of finenessen 196-7:1989bs en 196-7:1992 methods of testing cementpart 7: methods of taking and preparing samples ofcementen 196-21:1989bs en 196-21:1990 methods of testing cementpart 21: determination of chloride, carbon dioxide andalkali content of cementenv 197-1:1993dd env 197-1:1995 cement composition, specifications and conformity criteriapart 1: common cementsenv 206:1990dd env 206:1992 concrete performance, production, placing and compliance criteriaen 451-1:1994bs en 451-1:1995 method of testing fly ashpart 1: determination of free calcium oxide contenten 451-2:1994bs en 451-2:1995 method of testing fly ashpart 2: determination of fineness by wet sieving.a british standard does not purport to include all the necessary provisions of a contract. users of british standards are responsible for their correct application.compliance with a british standard does not of itself confer immunity from legal obligations.summary of pagesthis document comprises a front cover, an inside front cover, pages i to iv, the en title page, pages 2 to 10, an inside back cover and a back cover.this standard has been updated (see copyright date) and may have had amendments incorporated. this will be indicated in the amendment table on the inside front cover.blankivlicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsieuropean standard norme europenneeuropische normen 450september 1994udc666.971.98:693.5:666.952.2:001.4:658.562descriptors: concrete, fly ash, definitions, specifications, chemical properties, physical properties, quality control, certificationenglish versionfly ash for concrete definitions, requirements and quality controlcendres volantes pour bton dfinitions, exigences et contrle de qualitflugasche fr beton definitionen, anforderungen und gtaberwachungthis european standard was approved by cen on 1994-09-09. cen members are bound to comply with the cen/cenelec internal regulations 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 european 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 national standards bodies of austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland and united kingdom.ceneuropean committee for standardization comit europen de normalisation europisches komitee fr normungcentral secretariat: rue de stassart 36, b-1050 brusselslicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsi 1994 copyright reserved to cen membersref. no. en 450:1994 een 450:19949 bsi 07-1999licensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsiforewordthis european standard was drawn up by the technical committee cen/tc 104, concrete, the secretariat of which is held by din.the preparatory work was carried out by wg 4 of cen/tc 104 since june 1988 in which the following countries participated: austria, belgium, denmark, france, germany, ireland, italy, netherlands, norway, portugal, sweden and united kingdom.this european standard has been prepared under a mandate given to cen by the european commission and the european free trade association, and supports essential requirements of ec directive(s).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 1995, and conflicting national standards shall be withdrawn at the latest by march 1995.it is supported by standards of the series en 451 for test methods for determination of free calcium oxide content and of the fineness by sieve residue. no existing european standard is superseded.according to the cen/cenelec internal regulations, the following countries are bound to implement this european standard: austria, belgium, denmark, finland, france, germany, greece, iceland, ireland, italy, luxembourg, netherlands, norway, portugal, spain, sweden, switzerland, united kingdom.contentspage1scope32normative references33definitions33.1type ii addition33.2fly ash33.3reference cement43.4particle density43.5activity index43.6autocontrol44requirements44.1general44.2chemical requirements44.2.1general44.2.2loss on ignition44.2.3chloride44.2.4sulfuric anhydride44.2.5free calcium oxide44.3physical requirements44.3.1fineness44.3.2activity index54.3.3soundness54.3.4particle density55packaging and marking56quality control56.1conformity criteria56.2autocontrol56.2.1general56.2.2sampling56.2.3frequency of sampling and testing6annexa (informative) sampling plans7a.0introduction7a.1inspection of variables7a.2inspection by attributes7table 1 major defects6table 2 sampling and testing frequency6table 3 acceptability constantka (pa = 10 %)7table 4 acceptable number of defects ca70introduction3licensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsi0 introductionthe use of coal for electricity production results in the generation of large quantities of fly ash. different types of coal and the type of boiler used in this process produce different qualities of fly ash and some, especially those having pozzolanic properties, are used in concrete production. this european standard gives requirements for the chemical and physical properties as well as quality control procedures for fly ashes which may be safely used as a pozzolanic addition for the production of cast-in-situ or prefabricated structural concrete. however, it is beyond the scope of this standard to specify provisions for the use of fly ash in concrete, for which reference should be made to env 206.fly ash may before its use be subject to processing by classification or selection to increase its fineness and to improve other properties. such is the case for example in the uk and ireland which, in order to limit variations in properties and to reduce water demand, have developed a low sieve residue fly ash for use as a special component of cementitious systems. the fineness of this ash is strictly controlled in order to maximize chemical activity and minimize the variability in properties, not only within one source but also between different sources.although such processed fly ash may conform to this standard, the additional requirements for fineness and reduction of water demand which allow this processed fly ash to be used specifically as a special component of cementitious systems in concrete are not included in this standard.when using fly ashes complying with this standard, it should be noted that, apart from pozzolanic properties, other properties of fresh and hardened concrete, in particular the water requirement (lower or higher), the setting time (normally increased) and the early age strength (relative reduction), may be affected. when relevant, such effects have to be considered in concrete mix design (see env 206).1 scopethis european standard specifies requirements for the properties of fly ash for use as a type ii addition in cast-in-situ or prefabricated structural concrete conforming to env 206.fly ash for use in the manufacture of cements according to env 197-1 is outside the scope of this standard.provisions governing the practical application of fly ash in the production of concrete, i.e. requirements concerning composition, mixing, placing, curing etc. of concrete containing fly ash are not part of this standard. as regards such provisions, reference should be made to env 206 or national standards for concrete.2 normative referencesthis 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, 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 196-1:1994, methods of testing cement determination of strength.en 196-2:1994, methods of testing cement chemical analysis of cement.en 196-3:1994, methods of testing cement determination of setting time and soundness.en 196-6:1989, methods of testing cement determination of fineness.en 196-7:1989, methods of testing cement methods of taking and preparing samples of cement.en 196-21:1989, methods of testing cement determination of chloride, carbon dioxide and alkali content of cement.env 197-1:1992, cement composition, specifications and conformity criteria part 1: common cements.env 206:1989, concrete performance, production, placing and compliance criteria.en 451-1:1994, methods of testing fly ash part 1: determination of free calcium oxide content.en 451-2:1994, methods of testing fly ash part 2: determination of fineness by wet sieving.3 definitionsfor the purposes of this standard the following definitions apply. the values appearing in the definitions below shall not form part of the criteria for assessing conformity.3.1type ii additionfinely divided inorganic, pozzolanic or latent hydraulic material that may be added to concrete in order to improve certain properties or to achieve special properties (see env 206)3.2fly ashfine powder of mainly spherical, glassy particles, derived from burning of pulverized coal, which has pozzolanic properties and consists essentially of sio2 and al2o3, the content of reactive sio2, defined and determined as described in env 197-1,being at least 25 % by masslicensed copy: tsinghua user ., tsinghua university library, 18 february 2005, uncontrolled copy, (c) bsifly ash is obtained by electrostatic or mechanical precipitation of dust-like particles from the flue gases or furnaces fired with pulverized anthracite or bituminous coalnote fly ash obtained from firing with sub-bituminous coals may be accepted on a national basis provided that its total content of cao is less than 10 % by mass and that it complies with all other r