prEN 12390-11
(Main)Testing hardened concrete - Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion
Testing hardened concrete - Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion
This document describes a method for determining the unidirectional apparent chloride diffusion coefficient and surface concentration of conditioned specimens of hardened concrete. The test method enables the determination of the chloride penetration after a specified length of curing and length of exposure to NaCl solution.
Since resistance to chloride penetration depends on ageing which includes the effects of continual hydration and interactions with the chloride solution, then the apparent diffusion coefficient also changes with age. A procedure to determine this ageing, expressed here by an ageing exponent, is included in this document and described in Annex A.
The test procedure does not apply to concrete with surface treatments such as silanes and it does not apply to concrete containing fibres (see E.1).
Prüfung von Festbeton - Teil 11: Bestimmung des Chloridwiderstandes von Beton – Einseitig gerichtete Diffusion
Dieses Dokument beschreibt ein Verfahren zur Bestimmung des einseitig gerichteten scheinbaren Chloriddiffusionskoeffizienten und der Oberflächen-Chloridkonzentration von konditionierten Probekörpern aus Festbeton. Das Prüfverfahren ermöglicht die Bestimmung der Chlorideindringung nach einer festgelegten Lagerungsdauer und einer festgelegten Dauer der Einwirkung einer NaCl Lösung.
Da der Widerstand gegen Chlorideindringung von der Alterung abhängt, die die Auswirkungen von fortschreitender Hydratation und Wechselwirkungen mit der Chloridlösung umfasst, ändert sich der scheinbare Diffusionskoeffizient ebenfalls mit dem Alter. Ein Verfahren zur Bestimmung dieser Alterung, hier durch einen Alterungsexponenten ausgedrückt, ist in diesem Dokument ebenfalls enthalten und in Anhang A beschrieben.
Das Prüfverfahren gilt nicht für Beton mit Oberflächenbehandlungen, wie z. B. mit Silanen, und es gilt nicht für faserhaltige Betone (siehe E.1).
Essais pour béton durci - Partie 11 : Détermination de la résistance du béton à la pénétration des chlorures, diffusion unidirectionnelle
Le présent document décrit une méthode de détermination du coefficient de diffusion unidirectionnelle apparent des chlorures et de la concentration de surface d’éprouvettes conditionnées de béton durci. Cette méthode d’essai permet de déterminer la pénétration des chlorures après des durées spécifiées de cure et d’exposition à une solution de NaCl.
La résistance à la pénétration des chlorures dépendant du vieillissement, notamment des effets de la poursuite de l’hydratation et des interactions avec la solution de chlorures, le coefficient de diffusion apparent varie également avec l’âge. Un mode opératoire de détermination de ce vieillissement, exprimé ici par un exposant de vieillissement, est inclus dans le présent document et décrit à l’Annexe A.
Le mode opératoire d’essai ne s’applique pas à des bétons ayant subi des traitements de surface, tels que les silanes, et il ne s’applique pas à un béton contenant des fibres (voir E.1).
Preskušanje strjenega betona - 11. del: Določanje odpornosti betona proti kloridom, enosmerna difuzija
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-december-2025
Preskušanje strjenega betona - 11. del: Določanje odpornosti betona proti
kloridom, enosmerna difuzija
Testing hardened concrete - Part 11: Determination of the chloride resistance of
concrete, unidirectional diffusion
Prüfung von Festbeton - Teil 11: Bestimmung des Chloridwiderstandes von Beton –
Einseitig gerichtete Diffusion
Essais pour béton durci - Partie 11 : Détermination de la résistance du béton à la
pénétration des chlorures, diffusion unidirectionnelle
Ta slovenski standard je istoveten z: prEN 12390-11
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2025
ICS 91.100.30 Will supersede EN 12390-11:2015
English Version
Testing hardened concrete - Part 11: Determination of the
chloride resistance of concrete, unidirectional diffusion
Essais pour béton durci - Partie 11 : Détermination de Prüfung von Festbeton - Teil 11: Bestimmung des
la résistance du béton à la pénétration des chlorures, Chloridwiderstandes von Beton - Einseitig gerichtete
diffusion unidirectionnelle Diffusion
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 104.
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
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12390-11:2025 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
Introduction . 5
Annex A (normative) Procedure to determine the ageing exponent . 21
A.1 General . 21
A.2 Procedure to determine the ageing exponent . 22
A.3 Test report . 22
A.4 Illustration of the procedure . 23
Annex B (informative) Core test specimen . 24
Annex C (normative) Immersion method for large specimens . 26
Annex D (informative) Guidance on the test procedure . 27
D.1 Guidance on suitable concretes types . 27
D.2 Guidance on the selection of the exposure solution . 27
D.3 Curve-fitting to the error-function solution to Fick’s 2nd law . 27
Annex E (informative) Examples for calibration of the calculation procedure for regression
analysis . 29
E.1 Introduction . 29
E.2 Chloride profile 1 . 30
E.3 Chloride profile 2 . 31
E.4 Chloride profile 3 . 32
Bibliography . 34
European foreword
This document (prEN 12390-11:2025) has been prepared by Technical Committee CEN/TC 104
“Concrete and related products”, the secretariat of which is held by SN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 12390-11:2015.
EN 12390-11:2015:
— the property non-steady-state diffusion coefficient, D has been replaced by the time dependent
nss
apparent diffusion coefficient, D (t). D in EN 12390-11:2015 equals D (90 d) in this document;
app nss app
— the surface chloride concentration, C is made time dependent C (t). C in EN 12390-11:2015 equals
s s s
C (90 d) in this document;
s
— In Clause 4 the water curing period of 28 days has been the reference curing period;
— In Clause 4 the exposure period of 90 days has been the reference period of exposure;
— In Clause 6 the requirement for vacuum saturation is removed;
— A new Annex A “Procedure to determine the ageing exponent” is introduced;
— EN 12390-11:2015 Annexes A and C are removed.
The EN 12390 series, under the general title Testing hardened concrete, consists of the following parts:
— Part 1: Shape, dimensions and other requirements for specimens and moulds
— Part 2: Making and curing specimens for strength tests
— Part 3: Compressive strength of test specimens
— Part 4: Compressive strength - Specification for testing machines
— Part 5: Flexural strength of test specimens
— Part 6: Tensile splitting strength of test specimens
— Part 7: Density of hardened concrete
— Part 8: Depth of penetration of water under pressure
— Part 9: Freeze–thaw resistance with de-icing salts - Scaling (Technical Specification)
— Part 10: Determination of the carbonation resistance of concrete at atmospheric levels of carbon
dioxide
— Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion
— Pert 12: Determination of the carbonation resistance of concrete – Accelerated carbonation method
— Part 13: Determination of the secant modulus of elasticity in compression
— Part 14: Semi-adiabatic method for the determination of heat released by concrete during its
hardening process
— Part 15: Adiabatic method for the determination of heat released by concrete during its hardening
process
— Part 16: Determination of the shrinkage of concrete
— Part 17: Determination of creep of concrete in compression
— Part 18: Determination of the chloride migration coefficient
— Part 19: Determination of electrical resistivity
Introduction
Steel reinforced concrete structures exposed to the ingress of chloride, either from seawater or other
sources, need to be durable for at least the intended design service life. The possibility of reinforcement
corrosion is significantly increased as the chloride level at the embedded reinforcement increases. For
this reason, the chloride diffusivity or penetrability of the concrete is an important property to measure.
This document sets out a test method, which is applicable to specimens cast or core specimens, to
assess the potential chloride resistance properties of a concrete mix after a given reference period of
exposure to the chloride-rich environment.
A method is also set out in this document, in order to assess how this potential resistance to chlorides
changes with prolonged periods of exposure (determination of the ageing exponent).
Specifications regarding the test procedure to determine the ageing exponent of the concrete is given in
Annex A
Specifications regarding the test procedure with core specimens are given in Annex B.
NOTE This test method takes a minimum of 118 d comprising a minimum age of the specimen prior to testing
of 28 days and then 90 d to expose the specimen to the chloride solution.
This test method is one of a series concerned with testing concrete. At the behest of CEN, RILEM
reviewed chloride testing methods [1] and this document is based on their recommendations. In
addition, this document draws on recommendations from the EU-project “Chlortest” 5th Framework
Programme (GRD1-2002-71808/G6RD-CT-2002-00855) [2] immersion test recommendation as well as
the Nordtest Method NT Build 443 Concrete, hardened: Accelerated Chloride penetration [3].
1 Scope
This document describes a method for determining the unidirectional apparent chloride diffusion
coefficient and surface concentration of conditioned specimens of hardened concrete. The test method
enables the determination of the chloride penetration after a specified length of curing and length of
exposure to NaCl solution.
Since resistance to chloride penetration depends on ageing which includes the effects of continual
hydration and interactions with the chloride solution, then the apparent diffusion coefficient also
changes with age. A procedure to determine this ageing, expressed here by an ageing exponent, is
included in this document and described in Annex A.
The test procedure does not apply to concrete with surface treatments such as silanes and it does not
apply to concrete containing fibres (see E.1).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
EN 12390-2, Testing hardened concrete - Part 2: Making and curing specimens for strength tests
EN 14629, Products and systems for the protection and repair of concrete structures - Test methods -
Determination of chloride content in hardened concrete
3 Term, definitions, symbols and abbreviated terms
For the purposes of this document, the following terms, definitions, symbols and abbreviated terms
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 Terms and definitions
3.1.1
as-cast surface
surface of a concrete element exposed in the construction works to a chloride environment
3.1.2
chloride content
amount of acid-soluble chloride expressed in percent by mass of concrete
3.1.3
chloride penetration
ingress of chlorides into concrete due to exposure to external chloride sources
3.1.4
diffusion
movement of molecules or ions under a concentration gradient, that is movement from a zone of high
concentration to a zone with a lower concentration
3.1.5
diffusion coefficient
proportionality between the molecular flux (e.g. rate of flow of chloride ions) and the concentration
gradient in the diffusion equation
Note 1 to entry: In this document a modified Fick’s Law is adopted.
3.1.6
initial chloride content
C
i
chloride content at a distance sufficiently remote from the exposed surface as to not have been
influenced by penetration of the chloride exposure solution
Note 1 to entry: It reflects the initial chloride content that came from the constituents when the concrete was
mixed.
3.1.7
apparent diffusion coefficient
D (t)
app
constant equivalent diffusion coefficient giving similar chloride profile as the measured one for a
structure exposed to the chloride environment over a period t
[SOURCE: ISO 16204:2012]
3.1.8
profile grinding
dry process grinding a concrete specimen in thin successive layers
3.1.9
ageing exponent
α
parameter indicating the decrease over time of the apparent diffusion coefficient
Note 1 to entry: The ageing exponent is mathematically defined in Formula A.2
3.2 Symbols and abbreviated terms
α Ageing exponent
C Initial chloride content, % by mass of concrete;
i
C Measured chloride content of concrete layer j, % by mass of concrete
m,j
C Chloride content of layer j calculated according to Formula (1) using the most suitable
r,j
combination of C and D (t), % by mass of concrete
s app
C (t) Calculated chloride content at the exposed surface, % by mass of concrete
s
C Chloride content measured at average depth x and exposure time t, % by mass of
x
concrete
D (t) Apparent chloride diffusion coefficient, m /s;
app
F Sum of squares of the residuals
−2
FR Flow rate (flux) in mol m ·s
j1 to jn Ground layer defined in terms of the number of layers from the exposed surface, the
surface layer being j1
R Repeatability
R Reproducibility
R Coefficient of determination
sr Repeatability standard deviation
sR Reproducibility standard deviation
S Sum of squares
t Exposure time
U Variable of the integral with no units
X Depth below the exposed surface to the mid-point of the ground layer j, m;
Z A dimensional parameter with no units
4 Principle
At least two specimens, either a cylinder or cube, shall be cast and cured in accordance with
EN 12390-2, with a curing period of 28 days. Where the curing period is different than 28 days, this
shall be recorded and reported.
Annex A gives guidance on determination of ageing exponent.
Annex B gives guidance on the testing of core specimens, where the core may be sampled from a test
element, a precast concrete element or a structure.
Annex D gives additional guidance on the test procedure.
The specimens are divided into two sub-specimens, a ‘profile specimen’ that is used to determine the
chloride profile after exposure to unidirectional chloride ingress, and an initial chloride sub-specimen
that is used to determine the initial chloride level, C . This initial figure is taken as the chloride level of
i
the cast concrete.
The profile specimens are coated on all sides but one and then the uncoated face is exposed to a
chloride exposure solution. The exposure is achieved by either complete immersion, ponding the
uncoated face or inverting the specimen and having the uncoated face immersed in the chloride
exposure solution. The reference solution is a 3 % by mass sodium chloride (NaCl) solution, for a
reference period of 90 d (other concentrations or solutions, e.g. artificial seawater, are permitted as are
different exposure periods). The use of large fully immersed specimens is described in Annex C.
The preparation of the specimens from end of water curing till the specimen is exposed to the chloride
solution shall be without unnecessary delays.
After 90 d of exposure, at least 8 parallel layers of the chloride exposed surface are ground off the
profile specimen. The acid-soluble chloride content of each layer and the average depth of the layer
from the surface of the concrete exposed to the chloride solution are determined. The initial chloride
content is determined by grinding a sample from the other sub-specimen and the acid-soluble chloride
content determined.
By nonlinear regression analysis by least squares curve fitting, the surface chloride content (C (t)) and
s
the non-steady-state chloride diffusion coefficient (D (t)) are determined.
app
The results shall be reported separately for each specimen and the average value represents the test
result.
Because of the high coefficient of variation, ~ 15 – 30 % for D (t) from the test, the number of
app
specimens should be increased until the required precision is achieved.
NOTE 1 The apparent chloride diffusion coefficient varies with the length of the curing and the length of
exposure to the chloride solution.
NOTE 2 The test described in this document is only valid for a constant initial chloride content.
5 Reagents and apparatus
5.1 Reagents
Reagents of analytical quality shall be used.
NOTE Unless otherwise stated, ‘percent’ means percent by mass.
5.1.1 Chloride exposure solution.
5.1.1.1 Reference solution
Dissolve 30 g of analytical quality NaCl in 970 g of distilled or demineralized water having an electrical
conductivity ≤ 0,5 mS/m at 20 °C to produce a 3 % by mass NaCl solution. Store it in a clean container.
NOTE This NaCl solution has a similar chloride concentration to that of Atlantic seawater.
5.1.1.2 Other exposure solutions
Where the concentration of the chloride exposure solution is other than that in 5.1.1.1, the
concentration shall be recorded and reported. Where a different solution is used the composition of the
solution shall be recorded and reported.
NOTE 1 Natural and artificial seawater are used to reflect the exposure of construction works.
NOTE 2 Higher concentrations of NaCl, such as 16,5 %, and shorter exposure periods (e.g. 35 d) are used to
accelerate the development of a chloride profile.
5.1.2 Chloride ion diffusion proof two-component polyurethane or epoxy-based paint or other
equivalent barrier system.
5.1.3 Chemicals for chloride analysis, according to EN 14629.
5.1.4 Distilled or demineralized water, having an electrical conductivity ≤ 0,5 mS/m.
5.2 Apparatus
5.2.1 Water cooled diamond saw.
5.2.2 Balance for weighing NaCl and water, capable of weighing to an accuracy of ± 0,1 g.
5.2.3 Thermometer, capable of measuring to an accuracy of ± 1 °C.
5.2.4 Temperature controlled chamber, capable of keeping a temperature of 20 °C ± 2 °C.
5.2.5 Where used, a polyethylene container with airtight lid for immersion of the profile
specimen. The volume of the exposure solution shall exceed the volume of the specimen by not less
than 12,5 ml per cm of exposed surface. A container may contain more than one specimen provided at
least the minimum ratio of exposure solution to exposed surface is achieved. The ratio of exposure
solution to exposed surface shall be recorded and reported.
During the test, the chloride concentration of the chloride exposure solution reduces and if the ratio of
the volume of chloride exposure solution to exposure surface varies, the rate of reduction varies with
nominally identical concrete. For this reason, if a direct comparison of results from different specimens
is required, the ratio of the volume of chloride exposure solution to exposed surface should be constant.
5.2.6 Where used, pond to be attached to profile specimen. The ponds shall have a constant
diameter and initial depth not less than 125 mm.
5.2.7 Equipment for grinding off and collecting concrete powder in layers less than 2 mm deep,
capable of grinding a surface area of at least 40 cm and not grinding within 10 mm of the edge of the
test area.
5.2.8 Compressed air or air blower, to clean dust from specimen and equipment between grinding
layers.
5.2.9 Dust collecting bags.
5.2.10 Equipment for chloride content testing, in accordance with EN 14629.
5.2.11 Calliper, measuring to an accuracy of ± 0,1 mm.
6 Preparation of specimens
6.1 Preparing sub-specimens
A specimen size shall be selected such that after cutting, the minimum dimension of the sub-specimens
used to determine a chloride profile are at least three times the nominal maximum aggregate size. At
least two specimens, either 100 mm diameter or more cylinders or 100 mm or more cubes, are cast and
cured in a water filled bath with a temperature of 20 °C ± 2 °C in accordance with EN 12390-2, where
the reference curing period is28 d.
NOTE 1 Where the concrete contains secondary cementing materials, such as fly ash or ground granulated
blastfurnace slag, then it can be appropriate to increase the length of curing before testing as it is known that
chloride resistance can increase significantly with longer wet curing than 28 d.
After 28 d of standard curing, each cylinder, cube or prism is cut into two sub-specimens using the
water cooled diamond saw. Cylindrical specimens are cut in the direction parallel to the flat surface and
cubical specimens are cut in the direction parallel to the top (trowelled) surface as shown in Figure 1.
The tested surface should be free of voids and visible cracks. No dimension of the sub-specimens used
to determine a chloride profile shall be less than three times the nominal maximum aggregate size. One
sub-specimen (called the ‘profile specimen’) is used to determine the chloride profile, and the initial
chloride sub-specimen is used to determine the initial chloride content. This initial chloride content is
taken as being the chloride content of the cast concrete. The adjacent sawn faces are used to determine
these values.
NOTE 2 Where a chloride profile is required that incorporates the effect of a formed surface then a formed
surface from a cube specimen can be specified as the surface for chloride exposure. However, the results from
such a procedure are difficult to interpret due to variations in the concentration of cement paste and chloride at
the formed surface. The use of this approach has to be reported under Clause 9, m) and o), as it is a non-standard
test condition.
Key
1 trowelled surface
2 cut to separate specimens and produce exposure surface
Figure 1 — Specimen preparation
After sawing, the sub-specimen to be used to determine the initial chloride content shall be placed in a
close-fitting sealed plastic bag or tested immediately.
Where needed, the sub-specimens may be sawn to reduce their size to aid handling, but the sub-
specimen for determining the chloride profile shall not have any dimension less than three times the
nominal maximum aggregate size.
6.2 Conditioning and preparation of profile specimen for chloride testing
6.2.1 Sealing surfaces other than the surface to be exposed
All surfaces of the profile specimen except for the sawn face shall be either sealed or in accordance with
the method in Annex C. After sealing the surfaces, immerse the specimens in tap water for 18 h in order
to re-saturate the samples.
NOTE 1 The purpose of sealing the faces other than the face exposed to the chloride solution is to ensure that
the ingress of chloride ions into the concrete is a pure unidirectional diffusion process and not a mixture of
diffusion and other processes, e.g. capillary suction.
The requirement to seal the faces may be achieved in a number of ways. The following techniques have
established suitability.
a) Sealing technique for immersion, ponding or inversion
The profile specimen shall be dried in laboratory air until its surface is ‘white-dry’.
NOTE 2 This usually takes between 2 h to 4 h.
All faces except the face to be exposed to the chloride solution shall be coated with a layer of epoxy or
polyurethane, paraffin wax, or equivalent making sure that the surface to be tested remains free of the
coating material. The coating material shall be applied and cured in accordance with the
recommendations of the manufacturer.
NOTE 3 Not all epoxy resins and polyurethanes are suitable for this application.
b) Alternate sealing technique for ponding
This technique is only applicable to specimens that are to be ponded. Dry the surfaces with a cloth to
remove free water and wrap all faces except the face to be exposed to the chloride solution with
insulating tape ensuring sufficient overlap of joints.
6.2.2 Profile specimen for immersion
The specimen shall be transferred directly to exposure without surface drying. A suitable arrangement
is shown in Figure 2.
Key
1 chloride solution not less than 12,5 ml per cm of exposed surface
2 seal surfaces
3 exposed surface
Figure 2 — Example of an immersed specimen and sealed surfaces
6.2.3 Profile specimen for ponding
After preparation of the specimen, a pond is sealed to the surface of the specimen in a manner that
prevents leakage of the chloride exposure solution. A suitable arrangement is shown in Figure 3, noting
that the volume of the pond is as defined in 5.2.6. The external border between the plastic tube and
specimen is sealed to prevent leakage. The diameter of the tube used to form the pond may be 10 mm to
20 mm less than the diameter of the specimen to allow the formation of a watertight seal.
NOTE At the edge of such specimens chloride ingress is not unidirectional.
An alternative technique is to use a slightly larger tube and a rubber gasket between the tube and the
sealed side of the specimen.
Key
1 pond
2 seal
3 profile specimen
Figure 3 — Example of a profile specimen and pond sealed to surface
6.2.4 Profile specimen for inversion
After sealing in accordance with 6.2.2, the specimen shall be transferred directly to the inversion
exposure apparatus without surface drying. A suitable arrangement is shown in Figure 4. The volume of
the exposure solution shall not be less than 12,5 ml per cm of exposed surface.
Dimensions in millimetres
Key
1 sealant on specimen
2 NaCI solution
Figure 4 — Example of an inversion specimen arrangement
7 Procedure
7.1 Exposure conditions
7.1.1 Chloride exposure solution
Unless specified otherwise, the chloride exposure solution shall be a 3 % NaCl solution in accordance
with 5.1.1.1. If the chloride exposure solution is other than the reference solution (see 5.1.1.2), it shall
be reported. The chloride exposure solution concentration after use shall be measured, recorded and
reported.
Where testing is related to the intended use in a specific exposure condition, the chloride exposure
solution should reflect the anticipated exposure conditions taking into account the expected depletion
of chloride (see E.3).
The concentration of the chloride exposure solution can decrease in the course of time. The volume of
chloride exposure solution has been selected so that the chloride concentration remains constant and
the exposure solution does not have to be replaced during a test lasting 90 d. If a longer test period is
required, it is advised to replace the chloride exposure solution at 91-day intervals.
NOTE Fick’s Law is based on the assumption that the external chloride concentration remains constant
during the duration of the test. In the normal test situation, the error introduced by assuming that the chloride
concentration remains constant at the initial concentration is small.
7.1.2 Exposure temperature
Where used, the temperature of the water bath for the immersion specimen, the temperature of the
chloride exposure solution in the inversion method and the temperature of the chamber used to store
the ponded specimen shall be maintained at 20 °C ± 2 °C and confirmed at least once per day and the
mean and range over the duration of the test reported.
7.2 Exposure method
7.2.1 General
The exposed (sawn) surface of the profile specimens shall be in direct and continuous contact with the
chloride exposure solution either by immersion, ponding or inversion. The age of the specimen when it
is first exposed to the chloride exposure solution shall be recorded and reported.
7.2.2 Immersion
Profile specimens to be immersed shall be placed within the container containing the chloride exposure
solution and the container completely filled with the solution and sealed. This sealed container shall be
placed in the water bath.
7.2.3 Ponding
For ponded specimens, the pond shall be completely filled with chloride exposure solution and then
sealed with a plastic film. The whole assembly is then placed within a closed chamber maintaining a
relative humidity ≥ 95 %. If the high relative humidity is achieved by partial filling of the chamber with
water, the specimens shall be kept in a manner that prevents direct contact with this water.
7.2.4 Inversion
The profile specimen is turned upside down and placed with the exposure surface immersed in the
chloride exposure solution. It shall be fixed in a manner that ensures the whole exposed surface being in
contact, and remaining in contact, with the solution, e.g. supported on an open mesh that is fixed below
the surface of the chloride exposure solution. The specimens shall be placed in the solution in a manner
that minimizes the risk of entrapped air. The chamber shall be sealed to prevent evaporation.
7.3 Exposure period
The reference period of chloride exposure is 90 d.
7.4 Determination of initial chloride content (Ci)
Recover the initial chloride content specimen from the plastic bag. A 1 mm layer shall be ground from
the sawn surface of the initial chloride content specimen and discarded. The same surface is then
ground to obtain a 20 g sample of dust for chloride analysis. The acid-soluble chloride content is
determined in accordance with EN 14629 and expressed as percentage by mass of concrete and it is
designated C .
i
The initial chloride content may be determined from a single specimen per mix. The content obtained
shall be evaluated based on the mix design and the source of the materials.
NOTE It is assumed that the user of the test results is aware of the initial chloride content being
unrealistically high or low.
7.5 Profile grinding
After 90 d and within 2 h of removing the specimen from the exposure solution at least eight parallel
layers of the profile specimen shall be dry ground where each layer gives a sample of not less than 5 g of
dry concrete, and where layer 1 (surface layer) also has a thickness of not less than 1,0 mm. The
thickness of the layers shall be adjusted according to the expected chloride profile so that a minimum of
6 points covers the profile between the exposed surface and a depth where the chloride content is
above the initial chloride content. Table 1 gives recommended depth intervals for CEM I concrete and
Table 2 depth intervals for concretes containing fly ash, ground granulated blastfurnace slag or silica
fume. Both tables are based on specimens that have been exposed for 28 d of standard curing followed
by 90 d exposure to a chloride solution.
NOTE 1 The values in Tables 1 a
...
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