COMMON CEMENT TYPES AND CLASSES (ENV 197-1: 1992)

A T COKISHManager, Product Services and Quality DepartmentBlue Circle Industries plc. UK

Abstract

ENV 197-1:1992 is reviewed and compared with British Cement Standards. Itis shown that British Cement Standards are substantially covered by ENV 197-Iand that the use of the latter need not change current UK practises. It is alsoshown that ENV 197-l introduces additional cement types which are unfamiliarto the UK.

1 Introduction

The preparation of a standard for cement was initiated by the EuropeanEconomic Community (EEC) in 1969 and in 1973 the work was transferred tothe European Committee for Standardization (CEN). Technical Committee TC51 was entrusted by CEN with the task of preparing a cement standard for thecountries of Western Europe, comprising the EEC and EFTA members.

The inquiry initiated by CEN/TC 51 in the mid-seventies identified at thattime nearly 20 different types of cement and a second inquiry in 1990 resultedin some further 50 different types of cement, which had all been standardizedon a national basis and which had proved satisfactory in common or specialfields of application under local conditions.

CEN/TC 51 decided in the early eighties to include in ENV 197 only thosecements which were intended for use in any plain and reinforced concrete andwhich were familiar in most countries in Western Europe because they had beenproduced and used in those countries for many years. This earlier view ofCEN/TC 51 was that the more regional cements should continue to bestandardized at the national level. The 1989 draft of ENV 197 followed thisapproach, but did not achieve the majority necessary for acceptance becausea few countries wanted to incorporate all their nationally standardized cementsand because the EEC Construction Products Directive appeared to require theincorporation of all traditional and well tried cements in order to removetechnical barriers to trade in the construction field.Euro-Centem: Impact of ENV 197 on Concrete Construction. Edited by R.K. Dhir andM.R. Jones. Published in 1994 by E & FN Spon, 2-6 Boundary Row, London SE1 SHN.ISBN: 0 419 19980 2.

1 2 Co&h

In view of the large number of different kinds of cement involved, CEN/TC51 then decided to divide ENV 197 into several parts with the first part, ENV197-1, dealing only with “common cements”. This concept was developed to asuccessful conclusion in ENV 197-1:1992 “Cement-Composition, specificationsand conformity criteria - Part 1:Common Cements”. In accordance with CENrules, the development of the pre Standard ENV 197-1 into a full EuropeanStandard EN 197-1 will be considered in 1995.

2 The structure of ENV 197-1:1992

The pre-Standard is laid out in the following sequence:

1 .Scope2.Normative references3.Cement4.Constituents5.Cement types, composition and standard designationG.Mechanical requirements7.Physical requirements8.Chemical requirementsS.Conformity criteria

The normative references in 2. above all relate to test methods which arebeing dealt with in Paper No.6 in this Seminar and the conformity criteria in9. above will be dealt with in detail in Paper No.1 1. Therefore, neither of theseitems will be dealt with in this Paper.

This Paper will deal with the Standard definitions and requirements of theconstituents in 4. above but some aspects of constituents will be dealt with ingreater depth in Papers No.4 and 5.

3 The scope of ENV 197-131992

This, reproduced in its entirety, is as follows:

“This European Prestandard specifies properties of the constituents ofcommon cements and the proportions in which they are to be combined toproduce a range of types and classes of cement. It then specifies themechanical, physical and chemical requirements for these types and classes ascharacteristic values and states the rules for assessing their conformity tothese requirements.

It is recognized that different cements have different properties andperformance. Where performance tests are available (i.e. setting time,strength and soundness), they have already been taken into account in thisEuropean prestandard. In addition, work is being carried out by CEN/TC 51 toidentify any additional tests which are needed to specify further performanceof cement. In the meantime, and during the life of this prestandard, it is

Cement Types and Classes 13

necessary that the choice of cement, especially the type and/or strength classin relation to the exposure class and type of construction in which it isincorporated, should follow the national standards and other regulations validin the place where the cement is used.

In addition to these requirements, an exchange of additional informationbetween the cement producer and user may be helpful. The procedures for suchan exchange are not within the scope of ENV 197-1 but are to be dealt with inaccordance with national standards or regulations or may be agreed betweenthe parties concerned”.

The development of the further performance tests referred to in the Scopeis under way and good progress has been made in freeze-thaw testing andsomewhat slower progress has been made in carbonation testing. The way inwhich performance requirements which call up these future test methods mightbe incorporated in a future EN 197-l has not yet been worked out.

4 The definition of ‘Cemegt” in ENV 197-l:lb92

A fairly general verbal definition of cement is given in the pre-Standardbecause the wide range of cement types covered prevents a more preciseapproach to definitions. One specific technical requirement is given:Reactive calcium oxide (CaO) + reactive silicon dioxide (SiO$ L 50%Footnotes describe the test methodologies for arriving at the reactive CaO andSiO.2 levels.

5 Permitted constituents

The various constituents of cement are described in Clause 4 of ENV 197-1.In some cases no specific technical requirements are called up and in othercases technical requirements are called up but not all are supported by testmethods. The situation is summarised in Table 1.

Specific points arising from the Table deserve a special mention:The “glassy slag” requirement for granulated blastfurnace slag is not

supported by a specified test method and the wide range of results which canbe obtained from different test methods diminish the value of this specificrequirement.

National pozzolanas(P) have a long history of successful use in cementwithout specific technical requirements but industrial pozzolanas(Q1, especiallynon-ferrous slag containing significant quantities of heavy metals, have a muchshorter history of use and the lack of specific technical requirements isd i s a p p o i n t i n g .

To arrive at the “reactive” CaO and Si02 requirements for siliceous fly ash(V)and calcareous fly ash(W), is necessary to make some adjustments to the CaOand Si02 values produced from conventional analyses but the pre Standarddescribes how to do this.

14 Corish

Table 1. ENV 197-1: Permitted constituents

Constituent Designation Specification requirement

Portland cement Kclinker

gc2s 266.7%

22.0MOO

Granulated sblastfurnace slag

Natural pozzolana P

Industrial pozzolan Q

'Glassy slag* 266.7%c+s*o ~66.7%(C+M90)tS a 1.0

Siliceous fly ash V Loss on ignition 55.0%'Reactive' C ‘ 5%'React,ve' S 225%

Calcarexs fly ash W Loss on ignit3on 55.0% or 55.0%*Reactive' C 25% >15%'Reactive' C r15X'Reactive' S ~25%Expansion <lciml ~1Omll28 days strength - t10N/mn2

Ektrnt shale T 28 days strength ~25.0 N/mn2Expansion

<lDllBll

Limestone L C&O3 275%Clay content (MBA) r1.2g/lOOgOrganic material content (TCC) 50.20%

r0.50X (national option)

Silica fume D Amxptwus s 285%Loss on lgnitron 64%Spenfic surface r15m2/g

Filler F

Calcium sulfate -

Additives

The calcareous fly ash clause effectively covers two different calcareous flyashes with a different set of requirements depending upon the ‘reactive’ CaObeing above or below 15%. In the case of the higher lime material, a strengthrequirement is introduced which recognises the significant hydraulic activityof these materials even in the absence of cement.

Burnt shale(T) also has a strength requirement which recognises an evengreater hydraulic activity than that of high lime calcareous fly ash.

Filler(F) has no specific technical requirements but their status as minoradditional constituents limit their additional levels to 5% on cement. Additivesare normally limited to 1% on cement.

6 Cement types

ENV 197-1 identifies 25 types of cement built around the constituents

Cement Types and Classes 1 5

previously described and the wide range of national practices existing withinEurope. The full list of cements is given in Table 2.

Table 2. ENV 197-1: Cement types

Cement Designation Notation Clinkertype K

I Portland cement I 95-100

Portland slag cement II/A-S 80-94

II/B-S 65-79

I I

Portland silica fumecement

Portland pozzolana cement

Portland fly ash cement

Portland burnt shalecement

11/A-D 90-94

II/A-P 80-94

I I/B-P 65-79

II /A-Q 80-94

II/B-C 65-79

II/A-V m-94

I I/B-V 65-79

I I/A-W 80-94

I I/B-W 65-79

I I/A-T 80-94

II/B-T 65-79

Portland limestone cement II/A-L 80-94

II/B-L 65-79

Portland cmlpos7te cement II/A-M 80-94

II/B-M 65-79

I I I Blastfurnace cement III/A 35-64

III/B 20-34

III/C 5-19

I V Pozzolanlc cement IV/A 65-89

IV/B 45-64

V callps1te cement VIA 40-64

V/B 20-39

In all cases, the non clinker component would consist of one or more of theconstituent materials described in 5. “Permitted constituents”. Also, in allcases the non clinker component might include up to 5% of filler(F).

For cement types II, the main non clinker component would be described bythe final letter of the notations described in 5. “Permitted constituents”. Theexception is the designation M (“mixed”) for Portland composite cementwhich might contain several different constituents.

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The separate classification III for certain slag cements is necessary becauseuniquely low levels of clinker are sometimes possible in these cements.

Pozzolanic cements IV may contain mixtures of silica fume(D), naturalpozzolana(P), industrial pozzolana(Q) and siliceous fly ash(V).

Composite cements V may contain mixtures of granulated blastfurnaceslag(S), natural pozzolana(P), industrial pozzolana(Q) and siliceous fly ash(V).

An example of the actual ingredients in an industrially produced cementmight be:Portland fly ash cement II/B-V

% %used permitted

Clinker(K) 6 8Siliceous fly ash(V) 28Filler(F) 4

65-7921-35)o-5

Calcium sulfateAdd i t i ve

1 0 0

50.1 o-1

105.1

It should be noted that the 100% total is considered as the “cementnucleous” and does not include calcium sulfate or addition. The prestandardplaces no limit on calcium sulfate addition as such but the amount is of coursecontrolled by the cement SO3 limits. The additive might typically be a grindingaid which would normally be used at considerably below the 1% maximumpermitted level.

7 Cement strengths

ENV 197-1 adopts the increasingly accepted convention of both mimimum andmaximum strength requirements at 28 days. The detailed requirements are inTable 3.

Paper No.11 will deal with the detailed statistical background to thesen u m b e r s .

The preStandard permits all cement types to be supplied to all strengthclasses but in practice the most likely types of cements to be supplied to thedifferent strength classes are indicated in Table 4.

This Table is illustrative and not definitive. Also, it should be noted that ifthe R (higher early strength) classification is reached, the lower classificationis not claimed in the Table but a manufacturer might still choose to claim thelower early strength classification. For example, a coarsely ground cementType I with 28 days strength greater than 32.5 N/mm2 and less than52.5 N/mm2 i.e. Class 32.5, is highly likely to substantially exceed the 2 daysstrength requirement of 10 N/mm2 for Class 32.5R. However, the cement

Cement Types and Classes 17

Table 3. ENV 197-1: Cement strength classes

Compressive strength (in N/m*)

Class

32,5

32,s R

42,5

42.5 R

Early strength Standard strength

2 days 7 days 28 days

2 162 32,s J 52,s

L 10

2 10I 42.5 5 62,s

L 20

52.5 2 202 52.5

52.5 R 2 30

Table 4. ENV 197-1: Likely available strength classes

Cement notations

I

Likely strength classes available

32.5 32.5R 42.5 42.5R 52.5 52.5R

/ f f f f

II/A-S f f f f

II/A-D f f f

II/A-P,Q,V.W,T,L,M f f

II/B-S

II/B-P.Q.V.W,T,L.M

III/A. III/B. IV/A

f f f

f f

III/C. IV/B. VA, V,B f

manufacturer may choose to market the cement only claimin5

to meet the lessonerous early strength requirement of Class 32.5 (16 N/mmeasier to reach than 10 N/mm2 at 2 days).

at 7 days is far

8 Cement physical and chemical requirements

The initial setting times of cements to strength classes 32.5 and 42.5 arerequired to be at least 60 minutes but this requirement is relaxed to 45 minutesfor strength class 52.5 in recognition that higher strength cements can havefaster setting times than lower strength cements.

Cements to ENV 197-1 are all required to meet classical soundnessrequirements in terms of expansion. These requirements are not onerous formodern cements.

The chemical requirements of ENV 197-1 are summarised in Table 5.

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Table 5. ENV 197-l: Chemical requirements

Property

Loss onignition

Insolubleresidue

Test Cement Strength Requirements')reference type class

EN 196-2 CEM I a l l I 5.0 xCEM III classes

EN 196-2 CEM I a l l J 5.0 xCEM III ClSSSC+S

32.5 s3.5x32,5 R

EEZ :I 2, 42.5

Sulfate EN 196-2 CEM I V ' 42,5 R

(a* SO3) CEM V 52.552.5R

CEM 1113)s 4.0 x

all

Chloride EN 196-21 all types41 a l l s 0.10 xClSSSeS

Pozzolanicity EN 196-5 CEM IV a l l Satisfies thecla9+GX+ test

1) Requirements are g,ven as percentages by mass.

2) This indication covers cement types CEM II/A and CEM II/B includingPortland composite cements containing only one other main constituent. e.g.II/A-S or II/B-V except type CEM II/B-T.all strength classe.

which may contain up to 4,5X SO3 for

3, Cement type CEM III/C may contain up to 4,5X S03.

4) Cement type CEM III may contain more than 0.10% chloride but in that casethe actual chloride content shall be declared.

The lack of loss on ignition and insoluble residue requirements for CEM II, IVand V follows from the possibility that high loss on ignition materials, e.g.limestone or high insoluble residue materials e.g. fly ashes and pozzolanasmight be in these cements.

The sulfate and chloride limits are similar to those recently agreed forBritish cement Standards. I

The pozzolanicity requirement for CEM IV cement is helpful in ensuring thatgood quality pozzolanas are used, bearing in mind the relatively loosespecifications applying to some pozzolanic constituents which were reviewedin 5. Permitted constituents.

9 ENV 197-1 and British Cement Standards

The main British Cement Standards were revised in 1991 to align as far aspossible with the 1989 version of prENV 197-I which had been approved by theUK. Close correspondence still exists between these British Standards and ENV197-1:1992 and the National Foreword to DD ENV 197-I will describe the exactrelationship.

Cement Types and Classes 19

In terms of cement types, Table 6 shows where ENV 197-1 corresponds toBritish Standards. It can be seen that 8 out of the 25 Types of cement in ENV197-1 are already covered by existing British Standards.

Table 6. Cement types in ENV 197-1 and British cement Standards

Cement Designation Notation Clinker Content of corres-type CEM content other main poding

constituents Britishx x standard

I mrt1and Cement I 95-100 B.s12:1991

Portland slag cement II/B-S m-94 6-20 BS146:1991

II/B-S 65-79 21-35

Portland silica II/A-D 90-94 6-10 Nomfume cement

I I

Portland pozzolanacement

Portland fly ashCBment

Portland burntshale cenent

Portland limestonecement

II/A-P 80-94 6-20Nme

II/B-P 65-79 21-35

II/A-Q 8 0 - 9 4 6-20

II/B-Q 6 5 - 7 9 21-35

II/A-V 80-94 6-20 Bs6588:1991

I I /B -V 6 5 - 7 9 21-35 BS65@8-1991

I I/A-W 8 0 - 9 4 6-20 None

II/B-W 6 5 - 7 9 21-35

II/A-T 80-94 6-20 None

II/B-T 65-79 21-35

II/A-L 80-94 6-20 Bs7583:1992

I I/B-L 65-79 21-35 NOW

Portland canposite I I/A-M 80-94 6-20 Nonecement

I I /B-M 6 5 - 7 9 21-35

I I I Blastfurnace cement III/A 35-64 35-65 BS146:1991*

III/B 20-34 66-80 None*

III/C 5-19 81-95 None*

IV Pozzolanic cment IV/A 65-89 11-35 NOW

IV/B 45-64 36-55 Bs6610:1991

V Cmposite cement '.'/A 40-64 36-60 None

V/B 2 0 - 3 9 61-80* BS 4246:1991 ccavers a blastfurnance slag content of 50-85X

British Standards do not exactly copy all the chemical requirements ofENV 197-1 and an important exception is the requirement for sulfate (as SO31.British Standards do not allow the 4.0% SO3 limit in Table 5 and retain aneffective limit of 3.5% SO3 for all cements.

20 Corish

Whilst the UK takes a more conservative view than ENV 197-1 in terms ofcement Types and sulfate levels, it takes a far more liberal view in terms ofcement strength classes and this is summarised in Table 7. British Standardsgenerally adopt the ENV 197-1 strength classes but add several more. Theseextra strength classes in British Cement Standards will almost certainly lapsewhen ENV 197-1 progresses to a full European Standard. The 62.5 strengthclass in BS 12 is of little practical value. The “L” classes in BS 146 andBS 4246 may well eventually appear in a future European Low heat cementStandard. The future of the special strength classes in BS 6610 and BS 6699 isunclear.

Table 7. Cement strength classes in ENV 197-1 and British cement Standards

Standard Cement Class MinTmum N/mn2 Maximum N/mn2

2d 7d 2ed 2ed

ENV 197-1 32.5 16 32.5 52.5

32.5R 10 32.5 52.5

42.5 10 42.5 62.5

42.5R 20 42.5 62.5

52.5 20 52.5

52.5R 30 52.5

KS12 62.5 20 62.5

BS146 52.5L 1 0 52.5

42.5L 20 42.5 62.5

ES4246 32.5L 12 32.5

BS6610 22.5 12 32.5

BS6699 37.5 1 6 37.5 57.5

47.5L 20 47.5 67.5

10 Conclusions

The 1991 series of British Cement Standards revisions relate closely to therequirements of one third of the cement types listed in ENV 197-1:1992. Theadoption of ENV 197-1:1992 instead of equivalent British Standards should notcreate any technical risks but will introduce an administrative burden in thatdesignations of familiar cements will change and require revisions ofspecification documentation.

The cement Types specified in ENV 197-1:1992 which are not currentlycovered in British Standards are clearly identifiable. This gives the Specifieror User the opportunity to choose whether or not to approve of or use theseunfamiliar cements.

Cement Types and Classes 21

References

ENV 197-I:1992 Cement, composition, specification and conformitycriteria - Part 1: Common cementsE3S12: 1991 Specification for Portland cementsEIS146:1991 Specification for Portland blastfurnace cementsBS4246:1991 Specification for High slag blastfurnace cementELS6588:1991 Specification for Portland pulverized-fuel ash cementsELS6610:1991 Specification for Pozzolanic pulverized-fuel ash cementES7583:1992 Specification for Portland limestone cement