SIST-TS CEN/TS 17481:2020

SLOVENSKI STANDARD
SIST-TS CEN/TS 17481:2020
01-oktober-2020
Bitumen in bitumenska veziva - Ugotavljanje deleža soli v bitumnu - Metoda
električne prevodnosti
Bitumen and bituminous binders - Determination of salt content in bitumen - Electrical
conductivity method
Bitumen und bitumenhaltige Bindemittel - Bestimmung des Salzgehaltes in Bitumen -
Verfahren durch Messung der elektrischen Leitfähigkeit
Bitumes et liants bitumineux - Détermination de la teneur en sel des bitumes - Méthode
par mesure de conductivité
Ta slovenski standard je istoveten z: CEN/TS 17481:2020
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
SIST-TS CEN/TS 17481:2020 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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CEN/TS 17481
TECHNICAL SPECIFICATION

SPÉCIFICATION TECHNIQUE

July 2020
TECHNISCHE SPEZIFIKATION
ICS 75.140; 91.100.50
English Version

Bitumen and bituminous binders - Determination of salt
content in bitumen - Electrical conductivity method
Bitumes et liants bitumineux - Détermination de la Bitumen und bitumenhaltige Bindemittel -
teneur en sel des bitumes - Méthode par mesure de Bestimmung des Salzgehaltes in Bitumen - Verfahren
conductivité durch Messung der elektrischen Leitfähigkeit
This Technical Specification (CEN/TS) was approved by CEN on 1 June 2020 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

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, Turkey and
United Kingdom.





EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 17481:2020 E
worldwide for CEN national Members.

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Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Principle . 6
5 Products and reagents . 7
6 Apparatus . 7
7 Sampling . 8
8 Operating procedure . 8
8.1 General . 8
8.2 Preparation of the hydro-alcoholic mixture . 8
8.3 Calibration of the conductivity meter and “blank” measurement . 8
8.4 Plotting of the calibration curve . 9
8.5 Measurement on the bitumen . 10
9 Expression of results . 11
10 Precision . 11
10.1 General . 11
10.2 Repeatability . 11
10.3 Reproducibility . 12
11 Test report . 12
Bibliography . 13
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European foreword
This document (CEN/TS 17481:2020) has been prepared by Technical Committee CEN/TC 336
“Bituminous binders”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to announce this Technical Specification: 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, Turkey and the United
Kingdom.
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Introduction
The proposed test method is an adaptation to bitumen of the ASTM D3230-13 applicable to crude oil.
In its principle, the method first extracts the salts contained in the bitumen sample by bringing the latter
(previously dissolved in xylene) in contact with a hydro-alcoholic mixture. It is the water contained in
this mixture which will dissolve those salts and give the mixture a certain electrical conductivity. The
measuring of the intensity of the electrical current obtained when applying a given voltage allows then
to derive an “equivalent NaCl content” of the bitumen solution by referring to a calibration curve plotted
using standard solutions of which the NaCl content is known.
A few simplifications have been introduced in comparison to ASTM D3230-13 [1]. Those consist mainly
in the replacement of the methanol of the hydro-alcoholic solution by denatured ethanol (less health
hazardous) and in the replacement of the mixed salts reference solution (mixture of sodium, calcium and
magnesium chlorides representative of sea water) by a single NaCl solution.
The critical points of the method can be listed as follows:
— to avoid the fouling of the electrodes, the amount of bitumen dissolved in the solution on which the
measurement is performed is relatively small (3 g in 100 mL);
— since the amount of salts extracted from the bitumen sample may be quite small, it is important to
limit as much as possible the incidence of the intrinsic conductivity of the water used for their
extraction on the conductivity of the solution. This explains:
— the small quantity of water in the composition of the hydro-alcoholic mixture;
— the requirements relative to the purity of the used water (presence of conductive impurities);
— the need to not keep the hydro-alcoholic mixture for more than one day after its manufacture.
This is due to its hygroscopic nature (all the more so because the methanol prescribed in
ASTM D3230-13 has been replaced by ethanol, which is more hygroscopic);
— the need to systematically make a new « blank » measure each time a new hydro-alcoholic
mixture is made;
— the need to generate and detect low intensity currents under good conditions makes it necessary to
apply a relative high voltage and explains also the geometry which has been retained for the
electrodes (important rectangular surface area and spacing). Measurements performed with
different electrode geometries should therefore not be compared.
The proposed extraction method (which essentially takes over the procedure specified in
ASTM D3230-13) may however be questioned when applied to bitumen.
— Under the retained operating conditions (small amount of water, only shaking the solution for one
minute), the « transfer » to the water in the hydro-alcoholic mixture of the salts present in the
product should be easier in the case of crude oil than for bitumen. It is very likely that only part of
the salt present in the bitumen is transferred to the water and that the importance and the kinetics
of this transfer depend on the nature of the bitumen. The efficiency and the reproducibility of the
method may probably be enhanced through an optimization of the exchange conditions between the
bitumen solution and the hydro-alcoholic phase.
In the frame of the 2nd Round Robin test of CEN/TC 336 on salt content [3], an increased amount of water
in the hydro-alcoholic mixture (10 g instead of 3 g) and an extended contact time between the hydro-
alcoholic mixture and the bitumen solution have been tested. Both lead to increased measured salt
contents in comparison to the procedure described in this document and which had been tested in the
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first Round Robin [2]. Due to the low number of participating laboratories, the impact on repeatability
and reproducibility could however not be established.
— Also the reason for the use of two different alcohols and for their respective proportions is not known
and should be cleared up.
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1 Scope
This document describes a method for determination of the salt content in bitumen, conventionally
expressed in mg of sodium chloride (noted NaCl as from this point of this document) per kg of bitumen.
This method is valid for “equivalent NaCl contents” between 20 mg/kg and 500 mg/kg.
WARNING — The use of this document may 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, Bitumen and bituminous binders — Preparation of test samples
ISO 385, Laboratory glassware — Burettes
ISO 648, Laboratory glassware — Single-volume pipettes
ISO 1042, Laboratory glassware — One-mark volumetric flasks
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 4788, Laboratory glassware — Graduated measuring cylinders
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
salt content in the bitumen
conventionally, sodium chloride, calcium chloride and magnesium chloride present in the bitumen, other
inorganic chlorides may also be present
Note 1 to entry: Other inorganic chlorides may also be present.
4 Principle
This test method consists in measuring the conductivity of a bitumen solution in a mixture of solvents in
which are immersed two parallel stainless-steel plates constituting electr
...