oSIST prEN 196-13:2026

• Abstract:

  This document specifies the apparatus and procedure for determining the effective alkali content of cements and other hydraulic binders. The method determines the effective alkali content after 28 days of hydration by extracting pore water from cement stone and determining the concentration of sodium and potassium (method A) or hydroxyl ions in the solution (method B).

• 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 196-13 - Methods of testing cement - Part 13: Effective alkali content

oSIST prEN 196-13:2026 is the Slovenian version of draft European standard prEN 196-13 from CEN/TC 51. It specifies how to determine the effective alkali content of cements and other hydraulic binders after 28 days of hydration, by extracting pore water from cement stone and measuring sodium and potassium, or hydroxyl ions, in the extract. Laboratories, cement producers, and other users of cement test data use it when they need a comparable alkali result for quality control or technical assessment.

What does oSIST prEN 196-13:2026 specify?

oSIST prEN 196-13:2026 specifies the apparatus and procedure for measuring effective alkali content in cements and other hydraulic binders. The method is based on the surplus water extraction method (SWE) and then follows one of two analytical routes: method A for sodium and potassium, or method B for hydroxyl ions.

The document is organised into:

• Clause 1 - Scope
• Clause 2 - Normative references
• Clause 3 - Terms and definitions
• Clause 4 - Reagents
• Clause 5 - Apparatus
• Clause 6 - Effective alkalis from SWE test
• Bibliography

What are the key requirements of oSIST prEN 196-13:2026?

Sample preparation and SWE procedure

oSIST prEN 196-13:2026 requires a cement paste made with equal masses of water and cement, mixed thoroughly and sealed airtight. The paste is stored upright at controlled temperature for 28 days, then the liquid above the paste is removed and filtered through a 0,45 µm filter.

This matters because the result depends on collecting the pore water from a paste that has had time to hydrate. The procedure also emphasises protection from carbon dioxide, because carbonation can change the hydroxyl-ion result and, in practice, distort the alkali content you report.

Method A - sodium and potassium

oSIST prEN 196-13:2026 allows the concentrations of sodium and potassium to be measured by flame photometric detection based on EN 196-2, or according to EN 14911. It also permits other methods if they give similar results.

The standard gives calibration solutions and a calibration curve approach. In practice, this means the laboratory must prepare known sodium and potassium standards, measure the extract against them, and then calculate the effective alkali content as effective sodium oxide equivalent, Na2Oeq,eff.

Method B - hydroxyl ions

oSIST prEN 196-13:2026 also gives an alternative route based on hydroxyl-ion titration with 0,05 mol/l hydrochloric acid and methyl orange indicator. The acid concentration is checked with sodium carbonate, and the document requires duplicate determinations.

This route is useful when the laboratory prefers titration instead of direct sodium and potassium measurement. The duplicate results must agree within the stated relative limit, otherwise a third determination is needed. The final hydroxyl-ion result is then converted into Na2Oeq,eff.

Reporting and precision

oSIST prEN 196-13:2026 requires the test report to identify the document used, the test dates, the cement name and origin, the method used, the ion concentration result, the effective alkali content, and any deviations from the method.

It also states precision data for the effective alkali content. For the reader, this tells you how much variation to expect between repeated measurements and between different laboratories, which is important when comparing results for acceptance, troubleshooting, or supplier evaluation.

What terms does oSIST prEN 196-13:2026 define?

• SWE - surplus water extraction method, the procedure used to obtain the pore-water extract from the cement paste.
• Na2Oeq,eff - effective sodium oxide equivalent, the way the final alkali content is expressed.
• Method A - the route that determines sodium and potassium concentrations in the extract.
• Method B - the alternative route that determines hydroxyl-ion concentration and converts it to Na2Oeq,eff.
• f-factor - the factor used to standardise the 0,05 mol/l hydrochloric acid solution before titration calculations.
• Repeatability - the spread expected between repeated results under the same conditions.
• Reproducibility - the spread expected between results obtained under different conditions or in different laboratories.

Who uses oSIST prEN 196-13:2026?

This standard is used by cement testing laboratories, quality control laboratories, and technical centres in the cement and construction materials sector. It is relevant to producers of cement and other hydraulic binders, because effective alkali content is a property they may need to measure consistently across batches.

It is also useful for buyers, specifiers, and certification or inspection bodies that rely on test reports when comparing products, checking conformity, or investigating performance issues linked to alkali content.

Which standards are used with oSIST prEN 196-13:2026?

• EN 196-2 - used for chemical analysis of cement and for the calibration approach in method A.
• EN 14911 - provides an alternative ion-chromatography method for determining dissolved ions in water and waste water, which the standard allows for sodium and potassium analysis.
• EN 196-7 - listed in the bibliography for taking and preparing cement samples.

What does the oSIST prEN 196-13:2026 document contain?

Clause 4 lists the reagents, including acids, stock solutions, buffer solution, methyl orange, and sodium carbonate for standardising the titration acid. Clause 5 lists the apparatus, such as the analytical balance, climate chamber, filters, burette, titration device, inert gas supply, and wide-neck bottle.

Clause 6 gives the full test sequence for SWE, then separates the analysis into method A and method B. It includes a calibration solution table, calculation formulas, the HCl standardisation step, the test report content, and precision statements for repeatability and reproducibility.

SLOVENSKI STANDARD
01-oktober-2026
Metode preskušanja cementa - 13. del: Učinkovita vsebnost alkalij
Methods of testing cement - Part 13: Effective alkali content
Prüfverfahren für Zement – Teil 13: Effektiver Alkaligehalt
Méthodes d'essais des ciments - Partie 13 : Teneur en alcalins effectifs
Ta slovenski standard je istoveten z: prEN 196-13
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
Methods of testing cement - Part 13: Effective alkali
content
Méthodes d'essais des ciments - Partie 13 : Teneur en Prüfverfahren für Zement - Teil 13: Effektiver
alcalins effectifs Alkaligehalt
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 196-13:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Reagents . 6
4.1 Distilled water . 6
4.2 Dilute hydrochloric acid (1+9): mix 9 volumes of water with 1 volume of concentrated
hydrochloric acid. . 6
4.3 Hydrochloric acid 0,05 mol/l, p.a . 6
4.4 sodium stock solution 1 000 mg/l: Dissolve (2,542 ± 0,001) g of sodium chloride in water
in a 1000 ml volumetric flask an make up to the mark. Commercially available solution can
also be used. . 6
4.5 potassium stock solution 1 000 mg/l: Dissolve (1,907 ± 0,001) g of potassium chloride in
water in a 1 000 ml volumetric flask an make up to the mark. Commercially available
solution can also be used. . 6
4.6 Buffer solution: Dissolve 50 g of caesium chloride and 250 g of aluminium nitrate
(Al(NO ) .9H O) in water and make up to 100 ml. . 6
3 3 2
4.7 Methyl orange indicator (dimethylaminoazobenzene p-sodium sulfonate): Dissolve
(0,020 ± 0,002) g of methyl orange in water and make up to 1 000 ml. . 6
4.8 Sodium carbonate (Na CO ) dried to constant mass at (250 ± 10) °C . 6
2 3
5 Apparatus . 6
5.1 Balance, analytical balance, capable of weighing to an accuracy of ± 0,01 g. 6
5.2 Climatic cabinet or chamber, capable of maintaining a temperature of (20,0 ± 2,0) °C . 6
5.3 Suction bottle, 250 ml . 6
5.4 Microlitre pipette, 1 ml to 5 ml or syringe with needle . 6
5.5 Filter with a filter pore size of 0,45 µm. Filter made of hydrophile Polytetrafluoroethylene
(PTFE) . 6
5.6 Volumetric pipette, 100 ml . 6
5.7 Volumetric burette, 50 ml . 6
5.8 Titration device (e.g. titrator) . 6
5.9 Argon or N gas . 6
5.10 Wide-neck bottle, made of Polyethylen (PE), Polypropylen (PP), Polyvinylchlorid (PVC) or
equivalent with screw cap (250 ml or 300 ml) . 6
5.11 Glass rod . 6
6 Effective alkalis from SWE test (surplus water extraction method) . 6
6.1 Principle . 6
6.2 Preparation of surplus water by extraction method (SWE) . 7
6.3 Determination of effective alkali content . 7
6.3.1 Method A: Determining the concentration of sodium and potassium . 7
6.3.2 Calculation . 8
6.3.3 Method B: determining the hydroxyl ion concentration (alternative) . 9
6.4 Test report . 10
6.5 Precision . 10
6.5.1 Repeatability . 10
6.5.2 Reproducibility . 10
Bibliography . 11
EN 196-13:2026 (E)
European foreword
This document (prEN 196-13:2026) 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 specifies the apparatus and procedure for determining the effective alkali content of
cements and other hydraulic binders. The method determines the effective alkali content after 28 days of
hydration by extracting pore water from cement stone and determining the concentration of sodium and
potassium (method A) or hydroxyl ions in the solution (method B).
2 Normative references
The following documents are referred to in the text in such a way that some or all 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 196-2, Methods of testing cement — Part 2: Che
...