EN 1428:2026
(Main)Bitumens and bituminous binders - Determination of water content in bituminous emulsions - Azeotropic distillation method
- Abstract
This document specifies a method for the determination of the water content in bituminous emulsions by means of azeotropic distillation.
WARNING — The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.
- Status
- Not Published
- Publication Date
- 10-Nov-2026
- Technical Committee
- CEN/TC 336 - Bituminous binders
- Drafting Committee
- CEN/TC 336/WG 2 - Emulsions and fluxed bitumens
- Current Stage
- 6055 - CEN Ratification completed (DOR) - Publishing
- Start Date
- 11-Oct-2026
- Due Date
- 17-May-2027
- Completion Date
- 11-Oct-2026
EN 1428:2026 is a CEN document that specifies an azeotropic distillation method for determining the water content in bituminous emulsions. It is intended for laboratories and other users who need a comparable mass-percentage result for quality control, routine production control, or referee testing. The method uses heated distillation equipment and solvents, so users must apply appropriate safety and regulatory precautions.
What does EN 1428:2026 specify?
EN 1428:2026 specifies one laboratory method for measuring water content in bituminous emulsions by azeotropic distillation. The document is organized into scope, references, terms, principle, reagents, apparatus, sampling, procedure, calculation, expression of results, precision, test report, and a normative annex for apparatus verification.
The method is limited to bituminous emulsions and is written so that the water result is reported as a mass percentage. That matters in practice because the same test can be used for routine plant control and, when needed, for referee work between parties.
What are the key requirements of EN 1428:2026?
Sampling and test portions, Clause 7 - The laboratory sample is taken in accordance with EN 58 and the test sample is prepared in accordance with EN 12594. The test sample is then divided into two test portions, and both are tested for referee purposes. This gives comparable results when a formal comparison is needed.
Apparatus verification, Clause 8.1 and Annex A - New apparatus must be verified before first use, and verification is also required when there are doubts about reliability. Annex A checks the recovery of a known amount of water. In practice, this prevents bad glassware or assembly faults from distorting the water result.
Reagents and carrier liquid, Clause 5 - The method uses a water-immiscible solvent-carrier liquid, with toluene as the reference solvent-carrier liquid and xylene allowed for routine tests. If the solvent water content is not known, it is determined using EN ISO 12937. This matters because moisture in the solvent would bias the result.
Test conditions and assembly, Clause 6 and 8.2 - The distillation assembly uses a 500 ml flask, a 25 ml graduated receiver reading to 0,1 ml, and a water-cooled condenser. The test is run at normal laboratory conditions of (23 ± 5) °C, with a controlled boiling rate. The method therefore depends on stable handling, not on special automated equipment.
Sample size and handling, Clause 8.2.4 and Table 1 - The emulsion mass is chosen so that the distillate gives about 15 ml to 25 ml of water, depending on binder content. The balance reading for the emulsion mass is recorded to the nearest 0,1 g. This ensures the receiver is used in a practical measuring range and the calculation is based on a weighed sample.
Completion of distillation and reading, Clause 8.2.7 to 8.2.9 - Distillation continues until the water volume is constant and no water remains outside the receiver. The water layer is then read to the nearest 0,1 ml and taken as equal in mass in grams. This is the measured value that goes into the calculation.
Calculation, reporting, and precision, Clauses 9 to 11 - Water content is calculated as a mass percentage from the water mass and emulsion mass. Results are reported to the nearest 0,1 %, or as the arithmetic mean of two tests for referee purposes. The document also states repeatability, reproducibility, and a separate reproducibility value for emulsions containing a flux.
What terms does EN 1428:2026 define?
- Water content (W) - The mass percentage of water determined by the method in this document.
- Solvent-carrier liquid - The water-immiscible liquid used to carry the water over by azeotropic distillation.
- Distillation regulator - Material such as anti-bumping granules or glass beads used to control boiling.
- Repeatability, r - The closeness of two results obtained by the same operator, apparatus, and conditions.
- Reproducibility, R - The closeness of two results obtained by different operators in different laboratories.
- Referee purposes - The use of duplicate testing and mean results when a formal, agreed result is needed.
- Test portion - The part of the prepared sample that is weighed and tested in the apparatus.
Who uses EN 1428:2026?
EN 1428:2026 is used by laboratories that test bituminous emulsions, including quality control laboratories, production control teams, and independent test labs. It is also relevant to producers, purchasers, and specifiers who need a common result for acceptance checks or disputes. The method is especially useful where the water content of an emulsion must be measured in the same way from one site to another.
What changed in EN 1428:2026 from the previous edition?
EN 1428:2026 supersedes EN 1428:2012. The foreword states these changes:
- the definition of a suitable solvent-carrier liquid in 5.1 has been reviewed;
- the balance description in 6.3 has been completed;
- apparatus verification in 8.1 is now limited to new apparatus and cases of doubt;
- the precision of emulsion weighing in 8.2.4 has been defined.
Which standards are used with EN 1428:2026?
- EN 58 - Sampling of bituminous binders.
- EN 12594 - Preparation of test samples.
- EN 12597 - Terminology used for bitumens and bituminous binders.
- EN ISO 12937 - Used to determine the water content of the solvent when it is not known.
- EN ISO 3696:1995 - Cited for recommended distilled or deionised water of grade 3.
What does the EN 1428:2026 document contain?
EN 1428:2026 contains the full laboratory procedure for azeotropic distillation, including the principle, required reagents, apparatus, sampling, and step-by-step test method. It also includes a calculation formula, guidance for expressing results, and precision statements for repeatability and reproducibility. Figure 1 shows the typical distillation assembly, and Table 1 guides the test portion size according to binder content.
Annex A gives the normative apparatus-verification procedure, including a water-recovery check for the 25 ml receiver. The test report clause lists the information that should be recorded, which makes the document usable for routine reporting, audit trails, and referee testing.
Relations
- Effective Date
- 13-Dec-2023
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Frequently Asked Questions
EN 1428:2026 is a draft published by the European Committee for Standardization (CEN). Its full title is "Bitumens and bituminous binders - Determination of water content in bituminous emulsions - Azeotropic distillation method". This standard covers: This document specifies a method for the determination of the water content in bituminous emulsions by means of azeotropic distillation. WARNING — The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.
This document specifies a method for the determination of the water content in bituminous emulsions by means of azeotropic distillation. WARNING — The use of this document can involve hazardous materials, operations and equipment. This document does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this document to establish appropriate safety and health practices and to determine the applicability of regulatory limitations prior to use.
EN 1428:2026 is classified under the following ICS (International Classification for Standards) categories: 75.140 - Waxes, bituminous materials and other petroleum products; 91.100.50 - Binders. Sealing materials. The ICS classification helps identify the subject area and facilitates finding related standards.
EN 1428:2026 has the following relationships with other standards: It is inter standard links to EN 1428:2012. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
EN 1428:2026 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
oSIST prEN 1428:2026
01-marec-2026
Bitumen in bitumenska veziva - Določanje vode v bitumenskih emulzijah - Metoda
azeotropske destilacije
Bitumens and bituminous binders - Determination of water content in bituminous
emulsions - Azeotropic distillation method
Bitumen und bitumenhaltige Bindemittel - Bestimmung des Wassergehaltes von
Bitumenemulsionen - Azeotropisches Destillationsverfahren
Bitumes et liants bitumineux - Détermination de la teneur en eau dans les émulsions
bitumineuses - Méthode de distillation azéotropique
Ta slovenski standard je istoveten z: prEN 1428
ICS:
75.140 Voski, bitumni in drugi naftni Waxes, bituminous materials
proizvodi and other petroleum products
91.100.50 Veziva. Tesnilni materiali Binders. Sealing materials
oSIST prEN 1428:2026 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
oSIST prEN 1428:2026
oSIST prEN 1428:2026
DRAFT
EUROPEAN STANDARD
prEN 1428
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2026
ICS 91.100.50 Will supersede EN 1428:2012
English Version
Bitumens and bituminous binders - Determination of
water content in bituminous emulsions - Azeotropic
distillation method
Bitumes et liants bitumineux - Détermination de la Bitumen und bitumenhaltige Bindemittel -
teneur en eau dans les émulsions bitumineuses - Bestimmung des Wassergehaltes von
Méthode de distillation azéotropique Bitumenemulsionen - Azeotropisches
Destillationsverfahren
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 336.
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 1428:2026 E
worldwide for CEN national Members.
oSIST prEN 1428:2026
prEN 1428:2026 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Reagents and materials . 5
6 Apparatus . 5
7 Sampling . 7
8 Procedure. 7
8.1 Verification of apparatus . 7
8.2 Test . 7
9 Calculation . 8
10 Expression of results . 8
11 Precision . 8
11.1 Repeatability, r . 8
11.2 Reproducibility, R . 8
12 Test report . 9
Annex A (normative) Verification of apparatus .10
Bibliography .11
oSIST prEN 1428:2026
prEN 1428:2026 (E)
European foreword
This document (prEN 1428:2026) has been prepared by Technical Committee CEN/TC 336 “Bitumens
and Bituminous binders”, the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 1428:2012.
prEN 1428:2026 includes the following significant changes with respect to EN 1428:2012:
a) in 5.1, the definition of suitable solvent carrier liquid has been reviewed;
b) in 6.3, the description of the balance has been completed;
c) in 8.1, the requirement for the apparatus verification has been limited to any new apparatus and in
case of doubts;
d) in 8.2.4, the precision of the emulsion weighting has been defined.
oSIST prEN 1428:2026
prEN 1428:2026 (E)
1 Scope
This document specifies a method for the determination of the water content in bituminous emulsions
by means of azeotropic distillation.
WARNING — The use of this document can involve hazardous materials, operations and equipment. This
document does not purport to address all of the safety problems associated with its use. It is the
responsibility of the user of this document to establish appropriate safety and health practices and to
determine the applicability of regulatory limitations prior to use.
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 58, Bitumen and bituminous binders — Sampling bituminous binders
EN 12594, Bitumens and bituminous binders — Preparation of test samples
EN 12597, Bitumens and bituminous binders — Terminology
EN ISO 12937, Petroleum products — Determination of water — Coulometric Karl Fischer titration method
(ISO 12937)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 12597 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
3.1
water content
W
mass percentage of water determined
...