1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationPD CEN/TR 16443:2013Backgrounds to the revision ofEN 450-1:2005+A1:2007 Flyash for concretePD CEN/TR 16443:2013 PUBLISHED DOCUMENTNational forewordThis Published Document is the
2、UK implementation of CEN/TR 16443:2013.The UK participation in its preparation was entrusted to Technical Committee B/517/4, Additions for concrete.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the n
3、ecessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2013. Published by BSI Standards Limited 2013ISBN 978 0 580 78799 7 ICS 91.100.30 Compliance with a British Standard cannot confer immunity from legal obligations.This Published Do
4、cument was published under the authority of theStandards Policy and Strategy Committee on 30 April 2013. Amendments issued since publicationDate Text affectedPD CEN/TR 16443:2013TECHNICAL REPORT RAPPORT TECHNIQUE TECHNISCHER BERICHT CEN/TR 16443 March 2013 ICS 91.100.30 English Version Backgrounds t
5、o the revision of EN 450-1:2005+A1:2007 - Fly ash for concrete Contexte de la rvision de lEN 450-1:2005+A1:2007 - Cendres volantes pour bton Hintergrnde zur berarbeitung der EN 450-1:2005+A1:2007 - Flugasche fr Beton This Technical Report was approved by CEN on 29 October 2012. It has been drawn up
6、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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembo
7、urg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2013 CEN Al
8、l rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. CEN/TR 16443:2013: EPD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 2 Contents Page Foreword 3 Introduction .4 1 Scope 5 2 List of relevant references 5 3 General 5 3.1 General and objective .5 3.2
9、Structure of the report .6 4 Overview of requirements in EN 450-1:2005+A1:2007 and EN 450-1:2012 6 5 Background for modification of the requirements in EN 450-1 7 5.1 Definition of fly ash7 5.2 Co-combustion materials 8 5.3 Loss on ignition 11 5.4 Free calcium oxide 13 5.5 Reactive silicon dioxide .
10、 14 5.6 Phosphate 15 6 Background for the statistical evaluation for assessment procedure by variables 16 7 Background for modification of test methods in EN 450-1 18 7.1 Chemical composition . 18 7.2 Fineness wet/dry . 18 8 Measures within EN 450-1 to assure fly ash quality . 20 8.1 Production proc
11、ess 20 8.2 Quality control and conformity evaluation technical properties . 21 8.3 Conformity evaluation toxicological and environmental aspects . 21 9 Impact of co-combustion on the release of regulated dangerous substances . 22 9.1 General . 22 9.2 Overruling regulation regarding toxicological and
12、 environmental aspects . 22 9.3 Environmental regulations (Leaching) . 23 Annex A (informative) List of abbreviations 25 Annex B (informative) Generation of fly ash . 26 B.1 The chain from fuel to fly ash, ready for use in concrete . 26 B.2 Ash formation during combustion 27 Annex C (informative) Ov
13、erview of tested fly ashes obtained from co-combustion 31 Annex D (informative) Calculated maximum co-combustion amounts 33 D.1 Objective 33 D.2 Method . 33 D.3 Data 33 D.4 Results . 33 Bibliography . 36 PD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 3 Foreword This document (CEN/TR 16443:2013) has been
14、prepared by Technical 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
15、any or all such patent rights. PD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 4 Introduction Following five years of experience using EN 450-1, it was clear that some clauses need improvement within the standards. In the existing standards the maximum amount of fly ash from co-combustion was limited to c
16、ertain proportions. Experience gained with fly ashes conforming to a European Technical Approval (ETA), where higher co-combustion amounts were permitted, showed that the requirements in the corresponding Common Understanding of Assessment Procedure (CUAP) were sufficient guarantee for fly ashes to
17、produce excellent performance in concretes, mortars, grouts and cements. As agreed in CEN/TC 104, the experience gained with ETA fly ashes should be incorporated in the revision of EN 450-1. In this background report it is proved that wider ranging limits and types of co-combustion materials can be
18、safely applied in the revised EN 450-1. It is also shown that in practice some requirements in EN 450-1 have been proven to be unrealistic. Improvements have been proposed for the definition of fly ash, the loss on ignition, free calcium oxide, reactive silicon dioxide and the limits for phosphate.
19、The conformity procedures have also been evaluated, especially the assessment procedure for inspection by variables. Based on this evaluation work, modifications are needed for the LOI1)classes B and C. The revised version of the standard incorporates the European Technical Approvals (ETA) and EU me
20、mbers experience gained with fly ash in concrete. The requirements of the revised standard will result in fly ashes which will perform similarly to those conforming to EN 450-1:2005. 1) LOI Loss on ignition. PD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 5 1 Scope This Technical Report describes the back
21、grounds to the revision on EN 450-1:2005+A1:2007, Fly ash for concrete Part 1: Definition, specifications and conformity criteria. 2 List of relevant references The following references are covered by the present document: EN 450-1:2005+A1:2007, Fly ash for concrete Part 1: Definition, specification
22、s and conformity criteria; EN 450-1:2012 (revised EN 450-1 2), Fly ash for concrete Part 1: Definition, specifications and conformity criteria; EN 450-2:2005, Fly ash for concrete Part 2: Conformity evaluation; EN 196-2, Methods of testing cement Part 2: Chemical analysis of cement; EN 197-1:2000, C
23、ement Part 1: Composition, specifications and conformity criteria for common cements; EN 14588:2010, Solid biofuels Terminology, definitions and descriptions. 3 General 3.1 General and objective Fly ash has been used for many decades in concrete as an addition for its positive influence on workabili
24、ty, heat of hydration, strength development and durability. After the encouraging pilot projects some decades ago with positive results, licenses for regular use and later on technical approvals were granted by the national building authorities, certificates and standards. Today, regulations and sta
25、ndards exist for the use of fly ash in mortar and concrete. In 1995, the first EU standard was published, namely EN 450, Fly ash for concrete Definitions, requirements and quality control. This edition was followed up by a harmonised standard based on Mandate M 128 in 2005 (EN 450-1:2005), together
26、with a second standard (EN 450-2:2005), specific for conformity evaluation. The scope of EN 450-1:2005 states that fly ashes with percentages of co-combustion material higher than those covered in EN 450-1:2005, Clause 4 or with other types of co-combustion material are outside the scope of EN 450-1
27、:2005. In some countries, the use of fly ash with a higher percentage of co-combustion material was already common practice and it was not accepted by these countries that these fly ashes, containing higher amounts of co-combustion and other co-combustion materials, were excluded from CE marking. It
28、 was agreed that European Technical Approvals (ETAs) could be granted for this product according to Article 8.2 of the Construction Products Directive. The mandate M 128 was updated with the clarification that fly ash produced with other types than those covered by EN 450-1 and fly ash produced with
29、 a percentage of co-combustion material outside the limits defined in EN 450 (all parts), can be subject to ETAs, in order to allow these products to be CE marked. The experience gained with the fly ashes conforming to these ETAs has been used for the next revision of EN 450-1. Due to the regular fi
30、ve-year revision, WG 4 of CEN TC 104 incorporated the knowledge gained with the fly ashes conforming to these ETAs with EN 450-1. Other issues for the revision were identified as a lack of clarity regarding the conformity evaluation and some of the other requirements. 2) In this present Technical Re
31、port a reference to the revised EN 450-1 always refers to EN 450-1:2012. PD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 6 The objective of this report is to provide insight into the background to the modifications that have been taken up in EN 450-1:2012 (revised EN 450-1) and of those requirements that
32、have been deleted from EN 450-1:2005+A1:2007 3.2 Structure of the report Clause 4 provides an overview of the requirements of EN 450-1:2005+A1:2007 and EN 450-1:2012. In Clause 5 the background for the modifications of the requirements within EN 450-1 is described. Clause 6 gives the background for
33、the statistical evaluation for assessment procedure by variables, Clause 7, the background for the required test methods, regarding chemical composition and the determination of fineness. In Clause 8, an overview how fly ash quality is assured within the production process itself, the quality contro
34、l system and the conformity evaluation of toxicological and environmental aspects is given. Clause 9 deals with the impact of co-combustion on the release of regulated dangerous substances. More background information about the generation of fly ash can be found in Annex B. 4 Overview of requirement
35、s in EN 450-1:2005+A1:2007 and EN 450-1:2012 An overview of the requirements in the revised EN 450-1 is presented in Table 1. The requirements are related to fresh and hardened concrete. The chemical requirements concern Loss On Ignition (LOI), chloride (Cl), reactive and free Calcium Oxide or lime
36、(CaO), reactive Silicon Dioxide (SiO2), the sum of SiO2+ Al2O3+ Fe2O3, Magnesium Oxide (MgO) and soluble Phosphorus Pentoxide (P2O5). The physical requirements concern (or: are related to) fineness and the maximum deviation of particle density. The performance based requirements are water requiremen
37、t, initial setting, activity index and soundness. In relation to the previous standard, the following changes have been adapted: The definition of fly ash has been modified (EN 450-1:2012, 3.2). The permitted amount and type of co-combustion materials have been changed (EN 450-1:2012, 4.1). The requ
38、irement for the lower limit of LOI for category B and C fly ash has been deleted (EN 450-1:2012, 5.2.2). The requirement for free lime (CaO) has been changed (EN 450-1:2012, 5.2.5). The amount of total phosphate has been limited by a new requirement (EN 450-1:2012, 5.2.11). PD CEN/TR 16443:2013CEN/T
39、R 16443:2013 (E) 7 Table 1 Properties and requirements of fresh and hardened mortar and concrete Phase Property Unit EN 450-1:2005+A1:2007 EN 450-1:2012 workability loss on ignition (LOI) class A class B class C % by mass 5,0 2,0 7,0 4,0 9,0 5,0 7,0 9,0 water requirementa% 95 n.m.efineness fraction
40、45 m % by mass 40 (cat. N)d 12 (cat. S) n.m.einitial strength development soluble phosphate (P2O5) mg/kg 100 n.m.etotal phosphate (P2O5) % by mass 5,0 initial setting min. 2Cbn.m.estrength development sum SiO2+ Al2O3+ Fe2O3% by mass 70 n.m.ereactive SiO2% by mass 25 n.m.eactivity index 28 days 91 da
41、ys % 75 85 n.m.en.m.ealkali silica reaction (ASR) total content of alkalis (Na2O equivalent) % by mass 5,0 n.m.ereactive calcium oxide (CaO) % by mass 10,0 n.m.esoundness/ durability sulphuric anhydride (SO3) % by mass 3,0 n.m.efree calcium oxide (CaO) % by mass 2,5 cfsoundness mm 10 n.m.emagnesium
42、oxide (MgO) % by mass 4,0 n.m.echloride (Cl-) % by mass 0,10 n.m.eaOnly applicable for category S fly ash. bInitial setting of fly ash cement paste shall not be more than twice as long as the initial setting time of the test cement alone. c If the content of free lime is greater than 1,0 % by mass,
43、the fly ash shall be tested for conformity to the requirement for soundness. d The fineness shall not vary by more than 10 % from the declared value. e n.m. = not modified. f If the content of free lime is greater than 1,5 % by mass, the fly ash shall be tested for conformity to the requirement for
44、soundness. 5 Background for modification of the requirements in EN 450-1 5.1 Definition of fly ash 5.1.1 Text of EN 450-1:2005+A1:2007 Fine powder of mainly spherical, glassy particles, derived from the burning of pulverised coal, with or without co-combustion materials, which has pozzolanic propert
45、ies and consists essentially of SiO2and Al2O3. The content of reactive SiO2, as defined and described in EN 197-1 being at least 25% by mass. 5.1.2 Text of EN 450-1:2012 (revised EN 450-1) Fine powder of mainly spherical, glassy particles, derived from the burning of pulverised coal, with or without
46、 co-combustion materials, which has pozzolanic properties and consists essentially of SiO2and Al2O3. PD CEN/TR 16443:2013CEN/TR 16443:2013 (E) 8 5.1.3 Background The requirement of reactive SiO2has been deleted in the definition of the revised EN 450-1, but still exists as requirement for initial ty
47、pe testing (EN 450-1:2012, 5.2.7). By definition fly ash has to be derived from the burning of pulverised coal and co-combustion materials. This is only possible in dedicated boilers where combustion of finely ground fuel takes place in a cloud, with combustion temperatures of 1 300 1 500 C. This me
48、ans that ashes from other boilers like grate-fired and fluidised bed combustion boilers do not meet this definition. In other words, the definition guarantees that combustion takes place at high temperature, which is high enough to facilitate glass formation in the fly ash. The definition includes c
49、o-combustion, but, in EN 450-1:2012, 4.1, the amount and type of combustion material are further restricted. Also, as noted in EN 450-1, municipal and industrial waste incineration ashes do not conform to the definition of this clause. This implies that the fuel always contains coal. Coal contains mineral matter that will form the glass phase during combustion. Also part of the secondary fuel also contains mineral matter that contributes to glass formation. On a performance level, the
