prEN 196-15
(Main)Methods of testing cement - Part 15 - Sulfate resistance - Flat prism method
- Abstract
This document describes test methods (reference and alternative) applicable to cast test specimens for evaluating the Sulftate Resistance (SR characteristic) of cements. Sulfate resistance means that these binders can be used in concrete bodies submitted to sulfate attacks.
In these methods, the test is carried out under controlled exposure conditions using an increased concentration of sulfate solution. These test conditions are intended to accelerate external sulfate attack.
The reference test method is adapted from the modified SVA test method (German Institute for Building Technology (DIBt), Expert Committee (SVA)): “Testing the Sulfate Resistance of Cements with pozzolanic main constituents”. The modified SVA test method is listed in European Assessment Document – EAD 150007-01-0301, Annex C. This test method is appropriate for various binders, in particular those with pozzolanic main constituents.
The alternative test method is listed in European Assessment Document – EAD 150009-01-0301, Annex A. This test method is appropriate for CEM III/A cements.
- Status
- Not Published
- Publication Date
- 24-May-2028
- Technical Committee
- CEN/TC 51 - Cement and building limes
- Drafting Committee
- CEN/TC 51/WG 12 - Special performance criteria
- Current Stage
- 4020 - Submission to enquiry - Enquiry
- Start Date
- 06-Aug-2026
- Due Date
- 11-Feb-2027
- Completion Date
- 06-Aug-2026
prEN 196-15 is a draft European Standard from CEN for testing the sulfate resistance of cement with the flat prism method. It specifies a reference method and an alternative method for cast mortar specimens, so laboratories can assess how cements behave under accelerated external sulfate attack.
What does prEN 196-15 specify?
prEN 196-15 specifies how to prepare, store, measure, calculate and report flat-prism tests used to evaluate the sulfate resistance (SR characteristic) of cements. The methods use sulfate solution exposure and a calcium hydroxide reference storage to compare length change, mass change and dynamic modulus of elasticity over time.
The document is organized into clauses 1 to 11:
| Clause | Content |
|---|---|
| 1 | Scope |
| 2 | Normative references |
| 3 | Terms and definitions |
| 4 | General description of the reference and alternative test methods |
| 5 | Cements |
| 6 | Preparation of test specimens |
| 7 | Storage of test specimens |
| 8 | Initial measurement procedure |
| 9 | Further measurement procedure |
| 10 | Analysis |
| 11 | Test Report |
What are the key requirements of prEN 196-15?
Test principle and duration
prEN 196-15 compares mortar prisms stored in Na2SO4 solution with prisms stored in saturated Ca(OH)2 solution at two temperatures, 5 °C and 20 °C. The reference method runs up to 104 weeks, while the alternative method runs up to 182 days.
In practice, this means the test is designed to show whether a cement develops harmful expansion under sulfate exposure, while the CH storage gives the paired reference behaviour needed for comparison.
Specimen preparation
prEN 196-15 requires mortar made according to EN 196-1 from the cement under test and two reference cements from EN 197-1, with a water/cement ratio of 0.50. From each mortar, 24 flat prisms are prepared, 12 with measuring pins and 12 without, with dimensions 10 mm x 40 mm x 160 mm.
This matters because the method depends on making comparable prisms and separating length measurements from dynamic modulus measurements.
Storage conditions
prEN 196-15 requires 48 ± 2 h in the mould under protected curing, then pre-storage in saturated Ca(OH)2 solution at 20 ± 2 °C until 28 days for the reference method or 14 days for the alternative method. After that, specimens are stored in Na2SO4 solution and CH solution at 5 ± 2 °C and 20 ± 2 °C, with tight, light-proof containers and controlled solution-to-solid ratio.
In practice, the exposure conditions are part of the result, so the laboratory has to control temperature, solution strength, spacing between specimens and solution replacement.
Measurements
prEN 196-15 requires initial and repeated measurements of mass, length and longitudinal resonance frequency. The initial measurements are taken immediately after removing the prisms from pre-storage, and further measurements are made at fixed intervals: every 13 weeks in the reference method, and at 14, 28, 56, 91 and 182 days in the alternative method.
This means the test does not rely on one final reading. It tracks change over time, which is important for identifying ongoing expansion.
Analysis and output
prEN 196-15 calculates length change from the measured prism length after pre-storage and expresses the result in mm/m. It then determines expansion as the difference between sulfate storage and reference storage, and presents the results in a diagram showing relative length change per temperature.
For the reader, this is the core decision point: the test result is a comparative expansion curve, not just a single pass/fail number.
Test report
prEN 196-15 requires the report to identify the cement, specimen type and size, casting and curing details, test start date, exposure periods, gauge length, length changes, mass changes, resonance frequency values, the method used, deviations and the signature/date.
That gives traceability, so the result can be checked, compared or used in conformity assessment.
What terms does prEN 196-15 define?
- Sulfate Resistance (SR) - The ability of a cement binder to be used in concrete bodies exposed to sulfate attack.
- Flat prism method (SFPMm) - The test approach in which mortar is formed into flat prisms and monitored for change during exposure.
- Na2SO4 solution (NS) - The sulfate exposure solution used to accelerate attack on the prisms.
- Saturated Ca(OH)2 solution (CH) - The reference storage solution used for comparison against sulfate exposure.
- Longitudinal resonance frequency - The vibration frequency measured on the prism to determine dynamic modulus of elasticity.
- Dynamic modulus of elasticity - A stiffness-related value calculated from resonance measurements on the specimen.
- Relative humidity (RH) - The moisture condition used during controlled curing and drying steps.
- CEM III/A - The cement type identified in the document as suitable for the alternative method.
Who uses prEN 196-15?
prEN 196-15 is used by cement laboratories, cement manufacturers, and testing organizations that need to assess sulfate resistance of cements and related binders. It is relevant to quality control, product characterization and evaluation of cements intended for concrete exposed to sulfate attack.
Which standards are used with prEN 196-15?
- EN 196-1 - Provides the mortar preparation and specimen-making basis used for the prisms.
- EN 197-1 - Identifies the common cements, including the two reference cements used in the test.
- EN 14146 - Gives the resonance-frequency method used to determine dynamic modulus of elasticity.
- EAD 150007-01-0301 - Contains the modified SVA method on which the reference test is based.
- EAD 150009-01-0301 - Contains the alternative method listed for CEM III/A cements.
What does the prEN 196-15 document contain?
prEN 196-15 contains the full test sequence from specimen preparation through to reporting. It covers mortar casting, curing, pre-storage, sulfate and reference storage, repeated mass and length measurements, resonance-frequency measurements, and the calculation of length change and expansion.
The document also specifies practical test setup details such as container arrangement, solution replacement, specimen spacing, drying before measurement and photo documentation of cracking or spalling. It then requires the final report to include the test conditions, individual and mean results, and any deviations from the procedure.
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Frequently Asked Questions
prEN 196-15 is a draft published by the European Committee for Standardization (CEN). Its full title is "Methods of testing cement - Part 15 - Sulfate resistance - Flat prism method". This standard covers: This document describes test methods (reference and alternative) applicable to cast test specimens for evaluating the Sulftate Resistance (SR characteristic) of cements. Sulfate resistance means that these binders can be used in concrete bodies submitted to sulfate attacks. In these methods, the test is carried out under controlled exposure conditions using an increased concentration of sulfate solution. These test conditions are intended to accelerate external sulfate attack. The reference test method is adapted from the modified SVA test method (German Institute for Building Technology (DIBt), Expert Committee (SVA)): “Testing the Sulfate Resistance of Cements with pozzolanic main constituents”. The modified SVA test method is listed in European Assessment Document – EAD 150007-01-0301, Annex C. This test method is appropriate for various binders, in particular those with pozzolanic main constituents. The alternative test method is listed in European Assessment Document – EAD 150009-01-0301, Annex A. This test method is appropriate for CEM III/A cements.
This document describes test methods (reference and alternative) applicable to cast test specimens for evaluating the Sulftate Resistance (SR characteristic) of cements. Sulfate resistance means that these binders can be used in concrete bodies submitted to sulfate attacks. In these methods, the test is carried out under controlled exposure conditions using an increased concentration of sulfate solution. These test conditions are intended to accelerate external sulfate attack. The reference test method is adapted from the modified SVA test method (German Institute for Building Technology (DIBt), Expert Committee (SVA)): “Testing the Sulfate Resistance of Cements with pozzolanic main constituents”. The modified SVA test method is listed in European Assessment Document – EAD 150007-01-0301, Annex C. This test method is appropriate for various binders, in particular those with pozzolanic main constituents. The alternative test method is listed in European Assessment Document – EAD 150009-01-0301, Annex A. This test method is appropriate for CEM III/A cements.
prEN 196-15 is classified under the following ICS (International Classification for Standards) categories: 91.100.10 - Cement. Gypsum. Lime. Mortar. The ICS classification helps identify the subject area and facilitates finding related standards.
prEN 196-15 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2026
Metode preskušanja cementa - 15. del - Odpornost na sulfate - Metoda ploščatih
prizem
Methods of testing cement - Part 15 - Sulfate resistance - Flat prism method
Prüfverfahren für Zement - Teil15: Sulfatbeständigkeit - Flachprismenmethode
Méthodes d'essais des ciments - Partie 15 : Résistance aux sulfates - Méthode du
prisme plat
Ta slovenski standard je istoveten z: prEN 196-15
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 15 - Sulfate resistance -
Flat prism method
Méthodes d'essais des ciments - Partie 15 : Résistance Prüfverfahren für Zement - Teil15: Sulfatbeständigkeit
aux sulfates - Méthode du prisme plat - Flachprismenmethode
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 196-15:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 General description of the (reference and alternative) test methods . 5
5 Cements . 6
6 Preparation of test specimens . 6
7 Storage of test specimens . 6
8 Initial measurement procedure . 7
9 Further measurement procedure . 7
10 Analysis . 8
11 Test Report . 9
Bibliography . 10
European foreword
This document (prEN 196-15: 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.
Introduction
This document describes test methods (reference and alternative) applicable to cast test specimens for
evaluating the sulftate resistance (SR characteristic) of cements. Sulfate resistance means that these
binders can be used in concrete bodies submitted to sulfate attacks.
They are established within the framework of EN 197-1.
Precision data, coming from broad round robin tests and valid for a European standard, are not yet
available.
1 Scope
This document describes test methods (reference and alternative) applicable to cast test specimens for
evaluating the Sulftate Resistance (SR characteristic) of cements. Sulfate resistance means that these
binders can be used in concrete bodies submitted to sulfate attacks.
In these methods, the test is carried out under controlled exposure conditions using an increased
concentration of sulfate solution. These test conditions are intended to accelerate external sulfate
attack.
The reference test method is adapted from the modified SVA test method (German Institute for Building
Technology (DIBt), Expert Committee (SVA)): “Testing the Sulfate Resistance of Cements with
pozzolanic main constituents”. The modified SVA test method is listed in European Assessment
Document – EAD 150007-01-0301, Annex C. This test method is appropriate for various binders, in
particular those with pozzolanic main constituents.
The alternative test method is listed in European Assessment Document – EAD 150009-01-0301,
Annex A. This test method is appropriate for CEM III/A cements.
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 amendment) applies.
EN 196-1, Methods of testing cement - Part 1: Determination of strength
EN 197-1, Cement – Part 1: Composition, specifications and conformity criteria for common cements
EN 14146, Natural stone test methods - determination of the dynamic modulus of elasticity (by measuring
the fundamental resonance frequency)
3 Terms and definitions
No terms and definitions are listed in this document.
4 General description of the (reference and alternative) test methods
The sulfate resistance shall be determined by the flat prism method (SFPMm) on mortar specimens
aged up to minimum of 728 days (104 weeks) (reference method) or 182 days (alternative method) in a
Na SO -solution (NS), and in a saturated calcium hydroxide (Ca(OH) )-solution (CH) at a storage
2 4 2
temperature (T) of (5 ± 2) °C (T ) and (20 ± 2) °C (T ).
5 20
The length and the mass as well as the longitudinal resonance frequency for the determination of the
dynamic modulus of elasticity of the specimens are determined at the beginning of the storage of the
specimens in the test solutions and every 13 weeks thereafter in the reference method. In the
alternative method, these values are determined at the beginning of the storage and after 14, 28, 56, 90
and 180 days.
With the measured length of the specimens after a storage time t, the length difference of the flat
i
prisms for each storage solution (NS and CH) and storage temperature (T and T ) shall be calculated
5 20
as mean value from 3 specimens (Δl (t ,T) and Δl (t ,T)).
NS i CH i
The difference in elongation between the sulfate storage (Δl (t,T)) and the reference storage
NS i
(Δl (t ,T)) for a storage time (t ) and a storage temperature (T and T ) is given as expansion of the
CH i i 5 20
length (Δl(ti,T)).
In addition, the mass of the specimens (w (t ,T) and w (t ,T)) and the dynamic modulus of elasticity
NS i CH i
(E (t ,T) and E (t ,T)) shall be determined at a storage time t for each storage solution (NS and CH)
NS i CH i i
and storage temperature (T and T ).
5 20
5 Cements
The sulfate resistance shall be tested on specimens made of mortar according to EN 196-1.
6 Preparation of test specimens
Mortar shall be made from each cement (tested cement and the two reference cements according to
EN 197-1) in accordance with EN 196-1, with a water/cement-r
...