Цемент кальцієво-алюмінатний. Склад, технічні умови та критерії відповідності / Calcium aluminate cement - Composition, specifications and conformity criteria

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CONTENTS

page 1 2 4 5 5.1 5.2 6 7 7.1 7.2 7.3 8 9 9.1 9.2 Introduction 1
1 Scope 2
2 Normative references 2
3 Terms and definitions 3
4 Calcium aluminate cement (CAC) ... 4
5 Constituents 5
5.1 Calcium aluminate cement clinker 5
5.2 Grinding aids 5
6 Cement type and composition 5
7 Mechanical, physical and chemical
req uirements 5
7.1 Compressive strength 5
7.2 Initial setting time 6
7.3 Chemical requirements 6
8 Standard designation 7
9 Conformity criteria 7
9.1 General requirements 7
9.2 Conformity criteria and evaluation procedure 9
Annex A (informative) Guidance for the use of calcium aluminate cement in concrete and mortar 14
A.1 Introduction 14
A.2 Specific characteristics of calcium aluminate cement 15
A.3 Hydraulic properties 18
A.4 Production of calcium aluminate cement concrete 23
A.5 Admixtures 24
A.6 Use of calcium aluminate cement in particular conditions 25
A.7 Rapid test to estimate the minimum long term strength of calcium aluminate cement concretes 26
A.8 Bibliography 27

ZA.1 ZA.2 ZA. EN 14647:2005, Annex Water-soluble hexavalent chromium 29
Annex ZA (informative)
Clauses of this European Standard addressing the provisions of EU
Construction Products Directive ... 30
ZA.1 Scope and relevant characteristics 30
ZA.2Procedure for the attestation of conformity of products 33
ZA.3 CE marking and labeling .... 36
Bibliography 39

EN 14647:2005 - - - -

CALCIUM ALUMINATE CEMENT -Composition, specifications and conformity criteria INTRODUCTION
Calcium aluminate cement was developed during the latter stages of the nineteenth century as an alternative to calcium silicate cement (Portland cement) to prevent structural elements from serious sulfate attack.
Whilst it is suitable for sulfate resistance it was also found to be exceptionally rapid hardening and resistant to high temperatures. It was this rapid hardening property that led to more general use particularly in precast applications.
The hydration of calcium aluminate cement is substantially different from that of Portland cement in that the calcium aluminate hydrates formed depend upon the temperature at which hydration takes place. At low and normal temperatures (less than 40 Misunderstanding of this conversion process and unsuccessful attempts to maintain the temporary high strength led to failures in several countries during the 1960's and 1970's. In one of the reported failures, the strength of concrete, made with calcium aluminate cement, was reduced even further as are suit of chemical attack. Che- - - - 1 2 EN 197-2:2000 mical resistance is reduced when porosity of concrete is increased by ahigh water/cement ratio and conversion. As a result, calcium aluminate cement has been, and remains, excluded from the list of cements permitted in structural concretes in some countries.
Guidance for the correct use of this cement is given in Annex A. It includes a method which allows the long term strength, i.e. after conversion, to be predicted.
NOTE 1 Calcium aluminate cement can be produced in a blastfurnace, using a process of reductive fusion (a method used in Germany until the 1980's) but the cement will have a high level of sulfides which would exclude it from this European Standard.
NOTE 2 Calcium aluminate cement has previously been known by several alternative names in different countries, e.g.
- high alumina cement;
- aluminous cement;
- high alumina melted cement.

1 SCOPE

This European Standard gives a general definition of calcium aluminate cement and its composition. It includes requirements for the mechanical, physical and chemical properties and also states the conformity criteria and the related rules.
Calcium aluminate cement used as a constituent material of formulated mixes for specific applications (e.g. dry mixes) is outside the scope of this European Standard.
NOTE Guidance for the correct use of calcium aluminate cement in concrete and mortars is given in Annex A.

2 NORMATIVE REFERENCES

The following referenced documents are indispensable for the application of this European Standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 197-2:2000, Cement - Part 2: Conformity evaluation

EN 196-1 EN 196-2 EN 196-3 EN 196-7 З? 3.1 3.2 3.3 3.4 3.5 3.6 EN 196-1, Methods of testing cement - Part 1: Determination of strength
EN 196-2, Methods of testing cement - Part 2: Chemical analysis of cement
EN 196-3, Methods of testing cement - Part 3: Determination of setting time and soundness
EN 196-7, Methods of testing cement -Part 7: Methods of taking and preparing samples of cement

3 TERMS AND DEFINITIONS

For the purposes of this European Standard, the following terms and definitions apply.
3.1 autocontrol testing
continual testing by the manufacturer of cement spot samples taken at the point(s) of release from the factory/depot
3.2 control period
period of production and dispatch identified for the evaluation of the autocontrol test results
3.3 characteristic value
value of a required property outside of which lies a specified percentage, the percentile P^of all the values of the population
3.4 specified characteristic value
characteristic value of a mechanical, physical or chemical property which in the case of an upper limit is not to be exceeded or in the case of a lower limit is, as a minimum, to be reached
3.5 single result limit values
value of a mechanical, physical or chemical property which - for any single test result - in the case of an upper limit is not to be exceeded or in the case of a lower limit is, as a minimum, to be reached
3.6 allowable probability of acceptance CR
fora given sampling plan, the allowed probability of acceptance of cement with a characteristic value outside the specified characteristic value

3.7 3.8 4 ( 3.7 sampling plan
specific plan which states the (statistical) sample size(s) to be used, the percentile P k and the allowable probability of acceptance CR
3.8 spot sample
sample taken at the same time and from one and the same place, relating to the intended tests. It can be obtained by combining one or more immediately consecutive increments (see EN 196-7)

4 CALCIUM ALUMINATE CEMENT (CAC)

Calcium aluminate cement is a hydraulic binder i.e. it is a finely ground inorganic material which, when mixed with water, forms a paste which sets and hardens by means of hydration reactions and processes and which, after the hydration process has produced stable hydrated phases after conversion, retains its strength and stability.
Cement conforming to this European Standard shall, when appropriately batched and mixed with aggregate and water, be capable of producing concrete or mortar which retains its workability for a sufficient time and shall after defined periods attain specified strength levels and also possess long term volume stability.
The main component is monocalcium aluminate (CaOAI 2 O 3 ). Other mineralogical compounds include calcium alumino-ferrites, dicalcium silicate, and calcium silico-aluminate or gehlenite.
Hydraulic hardening of calcium aluminate cement is primarily due to the hydration of monocalcium aluminate, but other chemical compounds may also participate in the hardening process.
Calcium aluminate cement consists of individual small grains of calcium aluminate clinker statistically homogeneous in composition resulting from quality assured production and material handling processes. The link between these production and material handling processes and the conformity of calcium aluminate cement to this European Standard is elaborated in EN 197-2.

5 5.1 5.2 6 7 7.1 - - - - 5 CONSTITUENTS

5.1 Calcium aluminate cement clinker
Calcium aluminate cement clinker is produced by fusing or sintering a precisely specified mixture of a luminous and calcareous material.
5.2 Grinding aids
Grinding aids are chemical substances or proprietary products added to the calcium aluminate cement clinker during the grinding process to enhance the efficiency of the process. The total quantity of grinding aid on a dry basis shall not exceed 0,2 % by mass of the cement. Grinding aids shall not promote corrosion of reinforcement or impair the properties of the cement or of concrete and mortar made with the cement.

6 CEMENT TYPE AND COMPOSITION

Except for grinding aids that may be used in manufacture, as stated in 5.2, calcium aluminate cement shall be composed of only calcium aluminate cement clinker.

7 MECHANICAL, PHYSICAL AND CHEMICAL REQUIREMENTS

7.1 Compressive strength
The compressive strength of calcium aluminate cement shall not be less than 18,0 MPa at 6 h and 40,0 MPa at 24 h, when tested in accordance with EN 196-1 at 6 h and 24 h (see also Table 1) under the following conditions:
- composition of the mortar shall be 1 350 g of
CEN Standard sand, 500 g of calcium aluminate cement, and 200 g of water, i.e. a water/cement ratio of 0,40;
- all specimens shall be demoulded after 6 h - specimens to be tested at 6 h shall be tested immediately after demoulding;
- specimens to be tested at 24 h shall be stored in water after demoulding, and tested at 24 h

7.2 7.2 Initial setting time
The initial setting time, determined in accordance with EN 196-3, shall not be less than 90 min (see also Table 1).
Other methods than EN 196-3 may be used provided that they give results correlated and equivalent to those obtained with EN 196-3. Table 1 - Mechanical and physical requirements given as characteristic values
NOTE 1 Calcium aluminate cements are very rapid hardening so 28 day strengths at 20 NOTE 2 Values obtained from these tests should not be used for design purposes for concrete. An explanation of the strength development of calcium aluminate cement concretes and a method for predicting their minimum long term strength is given in Annex A.

7.3 7.3 Chemical requirements
The properties of calcium alumi