SIST-TS CEN/TS 14038-2:2012
(Main)Electrochemical re-alkalization and chloride extraction treatments for reinforced concrete - Part 2: Chloride extraction
Electrochemical re-alkalization and chloride extraction treatments for reinforced concrete - Part 2: Chloride extraction
This Technical Specification specifies a procedure for carrying out impressed current electrochemical chloride extraction from chloride
bearing concrete in existing structures. It is applicable to atmospherically exposed parts of structures with ordinary reinforcement and/ or post-tensioned tendon ducts embedded in concrete.
This Technical Specification does not apply to pretensioned concrete which may suffer hydrogen embrittlement on the stressing bars during chloride extraction, or to concrete containing epoxy-coated or galvanised reinforcement.
Elektrochemische Realkalisierung und Chloridextraktionsbehandlungen für Stahlbeton - Teil 2: Chloridextraktion
Diese Technische Spezifikation legt ein Verfahren zur elektrochemischen Chloridextraktion aus chloridbelas-teten Stahlbetonbauwerken fest. Sie ist anwendbar an atmosphärisch exponierten Bauteilen dieser Bauwerke, welche normal bewehrt oder als Spannbeton mit nachträglichem Verbund ausgeführt sind. Im letztgenannten Fall ist es erforderlich zu prüfen, dass keine Gefahr von Wasserstoffversprödung besteht; falls notwendig kann dies durch die Durchführung von Probeläufen und die Installation von Monitoren während der Behandlung erreicht werden. Diese Technische Spezifikation ist nicht anwendbar für Spannbetonbauteile mit sofortigem Verbund, bei denen während der elektrochemischen Chloridextraktion wasserstoffinduzierter Sprödbruch auftreten kann, und für Stahlbetonbauteile, deren Bewehrung mit einem Korrosionsschutz auf Epoxydharzbasis oder galva-nisch beschichtet ist.
Traitements électrochimiques de réalcalinisation et d'extraction de chlorures applicables au béton armé - Partie 2: Extraction de chlorures
L’extraction des chlorures vise à réhabiliter un élément de béton armé qui se dégrade par corrosion et à conférer une protection à long terme contre la corrosion des armatures en acier du béton qui ont été altérées par des chlorures ; ce procédé a pour objectif de rétablir la capacité d’auto-protection du béton. La durée approximative du traitement est de plusieurs semaines, voire de plusieurs mois, en fonction de la quantité de chlorures accumulés, de la perméabilité du béton et de la disposition des armatures, entre autres facteurs. Il convient que la décision d'arrêter le traitement soit prise conformément aux exigences spécifiques détaillées dans la présente spécification technique.
Il existe d’autres procédés électrochimiques qui peuvent être utilisés pour assurer une protection contre la corrosion de l’acier présent dans les structures en béton. On peut citer la protection cathodique et la réalcalinisation. Une Norme européenne (EN 12696) traite de la protection cathodique de l’acier dans le béton et une Spécification technique européenne (TS 14038-1) se rapporte à la réalcalinisation du béton carbonaté.
Lors de l’élaboration de la présente Spécification technique, il a été pris pour principe que l'exécution des dispositions qu'elle renferme sera confiée à des personnes compétentes et qualifiées à l’usage desquelles elle est destinée.
Elektrokemična realkalizacija in postopki kloridne ekstrakcije za armirani beton - 2. del: Kloridna ekstrakcija
Ta tehnična specifikacija določa postopek za izvedbo elektrokemične kloridne ekstracije s priključenim tokom iz betona, ki vsebuje klorid, v obstoječih strukturah. Velja za atmosfersko izpostavljene dele struktur z običajnim armiranjem in/ali prednapetimi veznimi vodi, vdelanimi v beton. V zadnjem primeru je treba preveriti, da ni nevarnosti za vodikovo krhkost, po potrebi z izvedbo preskusov in nadzorom med obdelavo.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 14038-2:2012
01-januar-2012
(OHNWURNHPLþQDUHDONDOL]DFLMDLQSRVWRSNLNORULGQHHNVWUDNFLMH]DDUPLUDQLEHWRQ
GHO .ORULGQDHNVWUDNFLMD
Electrochemical re-alkalization and chloride extraction treatments for reinforced concrete
- Part 2: Chloride extraction
Elektrochemische Realkalisierung und Chloridextraktionsbehandlungen für Stahlbeton -
Teil 2: Chloridextraktion
Traitements électrochimiques de réalcalinisation et d'extraction de chlorures applicables
au béton armé - Partie 2: Extraction de chlorures
Ta slovenski standard je istoveten z: CEN/TS 14038-2:2011
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
SIST-TS CEN/TS 14038-2:2012 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TS CEN/TS 14038-2:2012
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SIST-TS CEN/TS 14038-2:2012
TECHNICAL SPECIFICATION
CEN/TS 14038-2
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
February 2011
ICS 91.100.30
English Version
Electrochemical re-alkalization and chloride extraction
treatments for rein-forced concrete - Part 2: Chloride extraction
Traitements électrochimiques de réalcalinisation et Elektrochemische Realkalisierung und
d'extraction de chlorures applicables au béton armé - Partie Chloridextraktionsbehandlungen für Stahlbeton - Teil 2:
2: Extraction de chlorures Chloridextraktion
This Technical Specification (CEN/TS) was approved by CEN on 15 May 2010 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2011 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 14038-2:2011: E
worldwide for CEN national Members.
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SIST-TS CEN/TS 14038-2:2012
CEN/TS 14038-2:2011 (E)
Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Normative references .5
3 Terms and definitions .5
4 Principle .6
5 Assessment and repair of the structure .6
5.1 General .6
5.2 Review of records .6
5.3 Inspection .6
5.4 Determination of chloride content .7
5.5 Carbonation depth measurement .7
5.6 Concrete cover thickness and reinforcement location measurements .7
5.7 Alkali aggregate reaction .7
5.8 Reinforcement continuity and size .7
5.9 Repair .8
5.9.1 General .8
5.9.2 Concrete removal.8
5.9.3 Reinforcement preparation .8
6 Materials and equipment .8
6.1 Calibration of instrumentation .8
6.2 Anode system .8
6.2.1 General .8
6.2.2 Anode .8
6.2.3 Anode zone .8
6.2.4 Alkaline electrolyte solution .9
6.3 Electric cables .9
6.4 Power supply .9
7 Installation procedures .9
7.1 Electrical continuity .9
7.2 Other metallic parts within the treatment area .9
7.3 Performance monitoring . 10
7.4 Installation of anode system . 10
7.5 Protection of electrolyte solution . 10
7.6 Electrical installation . 10
7.7 Preliminary testing and documentation . 10
8 Commissioning, operation and termination of treatment . 11
8.1 Visual inspection . 11
8.2 Safety precautions . 11
8.3 Energising and adjustment of current output . 11
8.4 Routine inspection and maintenance . 11
8.5 Chloride extraction process monitoring . 11
8.6 Termination of treatment . 12
9 Final report . 12
10 Post-treatment coating and monitoring . 13
Bibliography . 14
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SIST-TS CEN/TS 14038-2:2012
CEN/TS 14038-2:2011 (E)
Foreword
This document (CEN/TS 14038-2:2011) has been prepared by Technical Committee CEN/TC 219 “Cathodic
protection”, the secretariat of which is held by BSI.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations 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, Lat-
via, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia,
Spain, Sweden, Switzerland and the United Kingdom.
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SIST-TS CEN/TS 14038-2:2012
CEN/TS 14038-2:2011 (E)
Introduction
The purpose of chloride extraction is to rehabilitate a reinforced concrete part from corrosion activity and to
provide long term corrosion protection of steel reinforcement in concrete which has been affected by chloride
and to re-establish self protection ability. The duration of treatment is from several weeks up to as much as
several months, depending on the amount of accumulated chloride, the permeability of the concrete, the lay-
out of the reinforcement and other factors. The decision to terminate the application should be made accord-
ing to the specific requirements detailed in this technical specification.
There are other electrochemical procedures that can be used to provide corrosion protection of steel in con-
crete structures. These include cathodic protection and re-alkalisation. There is a European standard for ca-
thodic protection of steel in concrete (EN 12696) and a European Technical Specification for the re-
alkalisation of carbonated concrete (TS 14038-1).
It has been assumed in the drafting of this Technical Specification that the execution of its provisions will be
entrusted to appropriately qualified and competent people, for whose use it has been prepared.
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CEN/TS 14038-2:2011 (E)
1 Scope
This Technical Specification specifies a procedure for carrying out impressed current electrochemical chloride
extraction from chloride bearing concrete in existing structures. It is applicable to atmospherically exposed
parts of structures with ordinary reinforcement and/ or post-tensioned tendon ducts embedded in concrete. In
the latter case, it is essential to verify that there is no risk of hydrogen embrittlement, if necessary by conduct-
ing trials and installing monitoring during the treatment.
This Technical Specification does not apply to pretensioned concrete, which may suffer hydrogen embrittle-
ment on the stressing bars during chloride extraction, or to concrete containing epoxy-coated or galvanised
reinforcement.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated refer-
ences, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
EN 1504-2:2004, Products and systems for the protection and repair of concrete structures: Definitions, re-
quirements, quality control and evaluation of conformity - Part 2: Surface protection systems for concrete
EN 1504-9, Products and systems for the protection and repair of concrete structures - Definitions, require-
ments, quality control and evaluation of conformity - Part 9: General principles for the use of products and sys-
tems
EN 12696, Cathodic protection of steel in concrete
EN 14629, Products and systems for the protection and repair of concrete structures - Test methods - Deter-
mination of chloride content in hardened concrete
EN 14630, Products and systems for the protection and repair of concrete structures - Test methods - Deter-
mination of carbonation depth in hardened concrete by the phenolphthalein method
EN ISO 8044:1999, Corrosion of metals and alloys — Basic terms and definitions (ISO 8044:1999)
3 Terms and definitions
For the purposes of this Technical Specification, the terms and definitions given in EN ISO 8044:1999 and
EN 1504-2:2004 and the following apply.
3.1
chloride extraction
electrochemical treatment for providing a low chloride content and developing a high pH value to concrete,
which surrounds reinforcing bars, corresponding to sound, carbonated or non-carbonated concrete.
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SIST-TS CEN/TS 14038-2:2012
CEN/TS 14038-2:2011 (E)
4 Principle
Chloride extraction of reinforced concrete is performed by applying an electric field between the steel rein-
forcement embedded in the concrete and an anode surrounded by an alkaline electrolyte solution containing
hydroxyl ions temporarily placed on the concrete surface. Dissolved, negatively charged ions – such as chlo-
ride - will be moved from the reinforcement to the external electrode. This is mainly a physical process.
Coincidentally, the electrochemical reactions occurring at the steel surface provide the evolution of hydroxyl
ions by the reduction of oxygen and water. This process alkalises the concrete in the vicinity of the rebar as
described in CEN/TS 14038-1.
NOTE 1 The chloride content cannot be reduced to zero; an usual target content is an average profile of 0.4 %, related
to the cement mass. To achieve this, the driving voltage between reinforcement and external anode should be set as high
as possible – usually ranging between 30 V and 40 V.
NOTE 2 The chloride extraction effect is not limited to the zone between concrete surface and next reinforcement
layer, but can be triggered in greater depths of concrete, as long as reinforcement is present and is connected with the
upper reinforcement layer. In such a case a multi-stage treatment is required. Even treatments from the opposite side of a
concrete slab are possible, but require an extended time of application.
NOTE 3 If the reinforcement surface is covered by corrosion products, these oxides have to be reduced prior to the
possible reduction of oxygen and water. During this period, which may consume theoretically up to 700 Ah/m², few if any
hydroxyl ions can be developed. In such a case, hydrogen evolution is likely just as in the later stages of the chloride ex-
traction treatment.
NOTE 4 Details of the principle underlying this process are given in the European Federation of Corrosion report [1].
NOTE 5 Some electrolyte materials may change the surface appearance of the concrete.
5 Assessment and repair of the structure
5.1 General
Prior to undertaking chloride extraction, an assessment of the structure, including its physical condition, its
structural integrity and the nature and extent of any repairs which might be needed, shall be performed in ac-
cordance with EN1504-9.
The investigations specified in 5.2 to 5.8 shall be carried out in order to:
a) determine the suitability of the structure for chloride extraction;
b) provide information for design and time of treatment.
5.2 Review of records
All available drawings, specifications, records and notes shall be reviewed for information on the location,
quantity, nature (e.g. mild or high strength steel, smooth or deformed bar, galvanised, epoxy-coated) and con-
tinuity of the reinforcement, as well as the constituents and quality of the concrete.
NOTE The possible sensitivity to reduction of bond strength should be evaluated in the case of smooth reinforce-
ment.
5.3 Inspection
An inspection shall be carried out to ascertain the type, causes and extent of defects and any features of the
structure or of its surrounding environment, which could influence the application and effectiveness of chloride
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extraction. All areas of the structure which require chl
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