oSIST prEN 196-17:2026

• Abstract:

  This document describes two equivalent test methods for determining the glass content in Granulated blast furnace Slag (GBS) as constituent for common cement as defined on EN 197-1.; Method A - Method of determining the glass content of GBS by X-ray diffraction.; Method B - Method of determining the glass content of GBS by polarized optical microscopy.; The glass content (or glassy/amorphous phase) in GBS is the fraction of the material that lacks a crystalline structure, having solidified rapidly from the melt in the form of amorphous glass.; It is usually expressed as a percentage (wt%) of the total slag.; In the absence of a product standard or a specification in the product standard, the constituent is tested at the fineness of the intended use.; Furthermore, these test methods are used in manufacturing control of cement constituents for assessing their conformity to the limit indicated in EN 197-1.

• Status: Not Published
• Public Enquiry End Date: 22-Oct-2026
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: CAA - Mineral binders and masonry
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 06-Aug-2026
• Due Date: 24-Dec-2026
• Ref Project: prEN 196-17 - Method of testing cement - Part 17: Determination glass content of granulated blast furnace slag as constituent for common cement

oSIST prEN 196-17:2026 is the Slovenian publication of draft European Standard prEN 196-17 from CEN, prepared by CEN/TC 51. It specifies two equivalent test methods for determining the glass content of granulated blast furnace slag (GBS) used as a constituent for common cement. The document is intended for testing laboratories and for manufacturing control when checking conformity to the limit given in EN 197-1.

What does oSIST prEN 196-17:2026 specify?

oSIST prEN 196-17:2026 covers the determination of glass content in GBS as used in common cement. It gives two equivalent routes - Method A by X-ray diffraction and Method B by polarized optical microscopy - and says the choice depends on the equipment available.

The scope also explains what “glass content” means in practice: the amorphous fraction of the slag, usually reported as a percentage by mass. Where a product standard does not set a different basis, the constituent is tested at the fineness of intended use. That matters because particle size can influence the measured result.

The document is arranged in seven clauses:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 4 General requirements for testing
• Clause 5 Principle of test methods
• Clause 6 Procedures
• Clause 7 Precision

What are the key requirements of oSIST prEN 196-17:2026?

Clause 4 sets the testing and reporting rules. If the analysis is part of a statistically controlled series, a single test is the minimum; otherwise, two tests are required. The document also requires all individual results to be recorded, which helps traceability when results are questioned later.

Clause 4.3 fixes how to express measurements and results. Masses are given to the nearest 0,001 g, single results are reported with the precision stated for the method, and two results are averaged. If two results differ by more than twice the repeatability standard deviation, the test is repeated and the mean of the two closest results is used.

Clause 5 states that Method A and Method B are equivalent. The standard does not prefer one method over the other, so laboratories can choose according to the instruments and skills they have available.

Clause 6.1 gives the sample preparation route for both methods. The laboratory sample is taken according to EN 196-7, reduced to a homogeneous test sample, and dried before testing; coarse material is reduced to powder as needed, with care not to create extra fine grinding that could change the true glass content. In practice, this is important because poor preparation can bias the result.

Clause 6.2 provides a moisture content method for GBS. The sample is dried in an oven at (105 ± 5) °C to constant mass, then reported as moisture content. That step supports the later glass-content determination because the test sample must be dry.

Clause 6.3 defines Method A by X-ray diffraction (XRD). The sample is ground to a fine powder, the diffractogram is processed by Rietveld refinement, and the amorphous fraction is obtained through direct or indirect strategies. The procedure relies on qualified operator interpretation and on suitable instrumental setup.

Clause 6.4 defines Method B by polarized optical microscopy. The sample fraction is prepared for microscopic examination, at least 1000 grains are counted, and grains are grouped by how much glass they contain. The final glass content is then calculated from those counts, which makes the method more manual and classification-based than Method A.

Clause 7 gives the stated precision for both methods: repeatability and reproducibility are expressed by the same coefficients for Method A and Method B.

What terms does oSIST prEN 196-17:2026 define?

• Granulated blast furnace slag (GBS) - the slag material whose glass content is measured as a cement constituent.
• Glass content - the fraction of GBS that is amorphous rather than crystalline, usually reported as a mass percentage.
• Glassy/amorphous phase - the non-crystalline part of the slag, which is what both methods are trying to quantify.
• X-ray diffraction (XRD) - the analytical technique used in Method A to identify and quantify phases from a diffraction pattern.
• Quantitative X-ray diffraction (QXRD) - the data-processing approach used with XRD to quantify crystalline and amorphous phases.
• Repeatability - closeness of results obtained with the same method, same laboratory, same operator and same equipment over a short time.
• Reproducibility - closeness of results obtained with the same method in different laboratories with different operators and equipment.

Who uses oSIST prEN 196-17:2026?

oSIST prEN 196-17:2026 is used by cement laboratories, cement producers, and quality-control teams that need to measure or verify the glass content of GBS. It is also used by operators running XRD or polarized optical microscopy, because the standard sets out the sample preparation, measurement and reporting steps they must follow.

Manufacturing control teams use it to assess whether a cement constituent conforms to the limit referred to in EN 197-1. That makes it relevant wherever GBS is purchased, tested, or released for use in common cement production.

Which standards are used with oSIST prEN 196-17:2026?

Standard	What it contributes
EN 197-1	Defines common cement and the conformity limit referred to for GBS as a constituent.
EN 196-7	Gives the sampling and sample-preparation basis used before testing.

What does the oSIST prEN 196-17:2026 document contain?

The document contains the full testing framework for glass-content determination in GBS, including sample preparation, moisture determination, and two alternative analytical methods. It also includes the XRD principle, apparatus and data-processing routes such as Rietveld refinement, including direct and indirect strategies.

For polarized optical microscopy, it gives the slide preparation, grain-size screening, microscope setup, grain classification and count-based calculation. The document also includes a schematic XRD figure, reporting rules, and precision statements for both methods.

SLOVENSKI STANDARD
01-oktober-2026
Metoda preskušanja cementa - 17. del: Določanje vsebnosti stekla v granulirani
plavžni žlindri kot sestavini za običajni cement
Method of testing cement - Part 17: Determination glass content of granulated blast
furnace slag as constituent for common cement
Prüfverfahren für Zement - Teil 17: Bestimmung des Glasgehalts von Hüttensand als
Bestandteil von Normalzement
Méthode d'essai des ciments - Partie 17: Détermination de la teneur en verre du laitier
granulé de haut-fourneau comme constituant d'un ciment courant
Ta slovenski standard je istoveten z: prEN 196-17
ICS:
91.100.10 Cement. Mavec. Apno. Malta Cement. Gypsum. Lime.
Mortar
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2026
ICS 91.100.10
English Version
Method of testing cement - Part 17: Determination glass
content of granulated blast furnace slag as constituent for
common cement
Prüfverfahren für Zement - Teil 17: Bestimmung des
Glasgehalts von Hüttensand als Bestandteil von
Normalzement
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 51.
If this draft becomes a European Standard, 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.

This draft European Standard was established by CEN 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 CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 196-17:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 General requirements for testing . 4
4.1 Number of tests . 4
4.2 Repeatability and reproducibility . 5
4.2.1 Repeatability . 5
4.2.2 Reproducibility . 5
4.3 Expression of masses, volumes, factors and results . 5
5 Principle of test methods (A and B) . 5
6 Procedures. 5
6.1 Preparation of a GBS sample . 5
6.2 Method of determining the moisture content of GBS . 6
6.2.1 Principle . 6
6.2.2 Apparatus . 6
6.2.3 Procedure. 6
6.2.4 Calculation . 6
6.2.5 Report . 6
6.3 Method A, X-ray diffraction . 6
6.3.1 Principle . 6
6.3.2 Apparatus . 7
6.3.3 Sample preparation . 8
6.3.4 Procedure. 8
6.3.5 Data processing . 9
6.3.6 Report .10
6.4 Method B, Polarized optical microscopy .10
6.4.1 Principle .10
6.4.2 Apparatus and materials .11
6.4.3 Sample preparation .11
6.4.4 Procedure.12
6.4.5 Report .13
7 Precision .13
7.1 Method A, X-ray diffraction .13
7.1.1 Repeatability and reproducibility .13
7.2 Method B, Polarized optical microscopy .13
7.2.1 Repeatability and reproducibility .13
Bibliography .14

European foreword
This document (prEN 196-17:2026) has been prepared by Technical Committee CEN/TC 51 “Cement and
building limes”, the secretariat of which is held by NBN.
This document is currently submitted to the CEN Enquiry.
1 Scope
This document describes two equivalent test methods for determining the glass content in Granulated
blast furnace Slag (GBS) as constituent for common cement as defined on EN 197-1.
Method A – Method of determining the glass content of GBS by X-ray diffraction.
Method B – Method of determining the glass content of GBS by polarized optical microscopy.
The glass content (or glassy/amorphous phase) in GBS is the fraction of the material that lacks a
crystalline structure, having solidified rapidly from the melt in the form of amorphous glass.
It is usually expressed as a percentage (wt%) of the total slag.
In the absence of a product standard or a specification in the product standard, the constituent is tested
at the fineness of the intended use.
Furthermore, these test methods are used in manufacturing control of cement constituents for assessing
their conformity to the limit indicated in EN 197-1.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 197-1, Cement — Part 1: Common cement — Performance assessment and declaration
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 document, the terms and definitions given in EN 197-1 and EN 196-7, and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 General requirements for testing
4.1 Number of tests
For each determination, one or more tests shall be carried out in which the number of measurements to
be taken shall be as specified in the relevant clause of this document (see 6.3 and 6.4).
Where the analysis is one of a series subject to statistical control, the determination of each property by
a single test shall be the minimum required.
Where the analysis is not part of a series subject to statistical control, the number of tests for
determination of each property shall be two.
4.2 Repeatability and reproducibility
4.2.1 Repeatability
Precision under repeatability conditions where independent test results are obtained with the same
method on identical test items (material) in the same laboratory by the same operator using the same
equipment within short intervals of time.
4.2.2 Reproducibility
Precision under reproducibility conditions where test results are obtained with the same method on
identical test items (material) in different laboratories with different operators using different
equipment.
4.3 Expression of masses, volumes, factors and results
Express masses in grams to the nearest 0,001 g.
Express the results, where a single test result has been obtained, to one decimal for method A (6.3) and
for method B (6.4).
Express the results, where two test results have been obtained, as the mean of the results, to one percent.
If the two test results differ by more than twice the standard deviation of repeatability, repeat the test
and take the mean of the two closest test results.
The results of all individual tests shall be recorded.
5 Principle of test methods (A and B)
This document describes two test methods used to the determination of glass content of Granulated
Blast-furnace Slag (GBS).
Method A – Method of determining the glass content of GBS by X-ray diffraction.
Method B – Method of determining the glass content of GBS by polarized optical microscopy.
The results of these test methods can be used to determining the content of glass of GBS.
There is no requirement to preferentially use of Method A and Method B for a given purpose, both
methods are considered equivalent. In many instances the choice is based on the user’s determination of
available equipment.
6 Procedures
6.1 Preparation of a GBS sample
Before the analysis (method A and method B), treat the laboratory sample, taken in accordance with
EN 196-7, as follows to obtain a homogeneous test sample.
If the GBS that has been sampled is a powder, take approximately 100 g of the laboratory sample by
means of a sample divider or by quartering.
If the GBS that has been sampled is not a powder, quartering and size reduction operations are carried
out to obtain representative 100 g in powder with a particle size inferior to 200 µm.
NOTE The size reduction operation can be carried out carefully to avoid any extended fine grinding that can
generate a pollution or a partial amorphisation and then modify the actual glass content.
Before testing the ground GBS, method A (6.3) and method B (6.4), the sample shall be dry at (105 ± 5)
°C for 24 h after the determination of the moisture content of GBS according to 6.2.
Transfer the sample to a clean dry container with an airtight closure and shake vigorously to mix it
thoroughly.
6.2 Method of determining the moisture content of GBS
6.2.1 Principle
The moisture content of the GBS is determined by drying a sample in an oven until constant mass is
achieved.
6.2.2 Apparatus
6.2.2.1 Balance, capable of weighing to an accuracy of ± 0,000 5 g.
6.2.2.2 Shallow glass container, of about 20 g capacity
6.2.2.3 Electric oven, with natural ventilation controlled at (105 ± 5) °C
6.2.2.4 Desiccator, containing a dried desiccant salt like magnesium perchlorate or equivalent
6.2.3 Procedure
Weigh to the nearest 0,001 g, (10 ± 0.050) g of ground GBS into the shallow glass container (6.2.2.2),
which has previously been dried and weighed. Place the container in the electric oven (6.2.2.3) at
(105 ± 5) °C. Heat it for 1 h.
Remove the shallow glass container and allow it to cool in the desiccator (6.2.2.4) to room temperature
and weigh it. Repeat the heating and cooling cycle until constant mass is achieved, i.e. when the difference
between two successive weighings is less than 0,005 g.
6.2.4 Calculation
Calculate the moisture content, C, of the sample as a percentage, to the nearest 0.1 %, from the following
equation:
MM−
( )
C ×100
M
where:
M1 is the mass of initial sample (in g).
M2 is the mass of dried sample (in g).
6.2.5 Report
Report the moisture content as a percentage of the dry mass to the nearest 0,1 %.
6.3 Method A, X-ray diffraction
6.3.1 Principle
X-ray diffraction is a process by which the atoms of a crystalline material interact with radiation in the X-
ray range, generating coherent scattering of the radiation. The diffraction angle depends on the crystal
structure of the material, and the diffraction intensity can be correlated with the amount of material
within the sample.
NOTE Cf. EN 13925-1 and EN 13925-2 for more details.
=
prEN 196-
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