EN 12390-11:2015
(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 European Standard is a method for determining the unidirectional non-steady state chloride diffusion and surface concentration of conditioned specimens of hardened concrete. The test method enables the determination of the chloride penetration at a specified age, e.g. for ranking of concrete quality by comparative testing. Since resistance to chloride penetration depends on the ageing, including the effects of continual hydration, then the ranking may also change with age.
The test procedure does not apply to concrete with surface treatments such as silanes and it may not apply to concrete containing fibres (see E.1).
Prüfung von Festbeton - Teil 11: Bestimmung des Chloridwiderstandes von Beton - Einseitig gerichtete Diffusion
Diese Europäische Norm beschreibt ein Verfahren zur Bestimmung der einseitig gerichteten instationären Diffusion und der Oberflächenkonzentration von Chlorid bei vorkonditionierten Probekörpern aus Festbeton. Dieses Prüfverfahren ermöglicht die Bestimmung des Chlorideindringens bei einer bestimmten Altersstufe, um z. B. die Betongüte durch Vergleichsprüfungen einzustufen. Da der Widerstand gegen Chloridein¬dringen von der Alterung einschließlich der Auswirkungen fortschreitender Hydratation abhängt, kann sich auch die entsprechende Einstufung mit dem Alter ändern.
Dieses Prüfverfahren gilt nicht für Beton mit Oberflächenbehandlungen, z. B. mit Silanen, und ist unter Umständen nicht auf Beton, der Fasern enthält, anwendbar, siehe E.1.
Essais pour béton durci - Partie 11 : Détermination de la résistance du béton à la pénétration des chlorures, diffusion unidirectionnelle
La présente Norme européenne est une méthode de détermination du coefficient de diffusion unidirectionnelle des chlorures en régime non stationnaire et de la concentration de surface d’éprouvettes conditionnées de béton durci. Cette méthode d’essai permet de déterminer la pénétration des chlorures à un âge spécifié, par exemple pour classer la qualité du béton par des essais comparatifs. La résistance à la pénétration des chlorures dépendant du vieillissement, notamment des effets de la poursuite de l’hydratation, le classement des bétons peut également varier avec l’âge.
Le mode opératoire d’essai ne s’applique pas à des bétons ayant subi des traitements de surface, tels que les silanes, et il peut ne pas s’appliquer à un béton contenant des fibres (voir E.1).
Preskušanje strjenega betona - 11. del: Ugotavljanje odpornosti betona proti kloridom, enosmerna difuzija
Ta evropski standard zajema metodo za ugotavljanje enosmerne difuzije in površinske koncentracije kloridov v pogojene preskušance iz strjenega betona v položaju, ki ni mirujoč. Ta preskusna metoda omogoča določanje prodiranja kloridov pri določeni starosti, npr. za razvrščanje kakovosti betona glede na primerjalno preskušanje. Ker je odpornost na prodiranje kloridov odvisna od staranja, vključno z učinki stalne hidracije, se lahko tudi razvrščanje s starostjo spremeni.
Preskusni postopek se ne uporablja za beton s površinsko prevleko, kot je silan, ter se morda ne uporablja za beton, ki vsebuje vlakna, glej E.1.
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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Preskušanje strjenega betona - 11. del: Ugotavljanje odpornosti betona proti kloridom, enosmerna difuzijaPrüfung von Festbeton - Teil 11: Bestimmung des Chloridwiderstandes von Beton - Einseitig gerichtete DiffusionEssais pour béton durci - Partie 11: Détermination de la résistance du béton à la pénétration des chlorures, diffusion unidirectionnelleTesting hardened concrete - Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion91.100.30Beton in betonski izdelkiConcrete and concrete productsICS:Ta slovenski standard je istoveten z:EN 12390-11:2015SIST EN 12390-11:2015en,fr,de01-oktober-2015SIST EN 12390-11:2015SLOVENSKI
STANDARDSIST-TS CEN/TS 12390-11:20101DGRPHãþD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 12390-11
August 2015 ICS 91.100.30 Supersedes CEN/TS 12390-11:2010English Version
Testing hardened concrete - Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion
Essais pour béton durci - Partie 11 : Détermination de la résistance du béton à la pénétration des chlorures, diffusion unidirectionnelle
Prüfung von Festbeton - Teil 11: Bestimmung des Chloridwiderstandes von Beton - Einseitig gerichtete Diffusion This European Standard was approved by CEN on 19 June 2015.
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. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists 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, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, 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:
Avenue Marnix 17,
B-1000 Brussels © 2015 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12390-11:2015 ESIST EN 12390-11:2015
2 Contents Page European foreword .3 Introduction .5 1 Scope .6 2 Normative references .6 3 Term, definitions symbols and abbreviated terms .6 3.1 Terms and definitions .6 3.2 Symbols and abbreviated terms .7 4 Principle .8 5 Reagents and apparatus .8 5.1 Reagents .8 5.2 Apparatus .9 6 Preparation of specimens . 10 6.1 Preparing sub-specimens . 10 6.2 Conditioning and preparation of profile specimen for chloride testing . 11 7 Procedure . 13 7.1 Exposure conditions . 13 7.2 Exposure method. 14 7.3 Exposure period. 14 7.4 Determination of initial chloride content (Ci) . 14 7.5 Profile grinding . 15 7.6 Chloride analysis . 16 8 Regression procedure and expression of results . 16 9 Test report . 19 10 Precision . 19 Annex A (informative)
Diffusion coefficients . 21 Annex B (informative)
Core test specimen . 22 Annex C (informative)
Typical equipment and procedure for vacuum saturation . 23 Annex D (normative)
Immersion method for large specimens. 25 Annex E (informative)
Guidance on the test procedure . 26 Annex F (informative)
Examples for calibration of the calculation procedure
for regression analysis . 28 Bibliography . 33
3 European foreword This document (EN 12390-11:2015) has been prepared by Technical Committee CEN/TC 104 “Concrete and related products”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by February 2016 and conflicting national standards shall be withdrawn at the latest by February 2016. 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. This document supersedes CEN/TS 12390-11:2010. In comparison to CEN/TS 12390-11:2010, the following changes have been made: — In Clause 2, the normative references have been updated; — In Clause 8, a minimum value of the coefficient of determination has been added and further guidance on the calculations has been added; — In Clause 9, a graph and details of points included and excluded plus the coefficient of determination have been added; — In Clause 10, Table 3 has been added; — A new Annex E (informative) "Guidance on test procedure" has been added; — A new Annex F (informative) "Examples for calibration of the calculation procedure for regression analysis" has been added; — The Bibliography has been reviewed; — The standard has been revised editorially. The drafting of this European Standard was delegated to CEN/TC 51(CEN/TC104)/JWG12/TG5. 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 European Standard is based on their recommendations. In addition, this European Standard 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]. The series EN 12390, Testing hardened concrete includes the following parts: — Part 1: Shape, dimensions and other requirements of specimens and moulds — Part 2: Making and curing specimens for strength tests — Part 3: Compressive strength testing of specimens — Part 4: Compressive strength - Specification of testing machines — Part 5: Flexural strength of test specimens SIST EN 12390-11:2015
4 — 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 - Scaling (Technical Specification) — Part 10: Determination of the relative carbonation resistance of concrete (Technical Specification) — Part 11: Determination of the chloride resistance of concrete, unidirectional diffusion — Part 13: Determination of the secant modulus of elasticity in compression According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. SIST EN 12390-11:2015
5 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 working 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 and this European Standard sets out a test method that may be applied to specimens cast or core specimens to assess the potential chloride resistance properties of a concrete mix.
Specifications regarding the test procedure with core specimens are given in Annex B. NOTE This test method takes a minimum of 119 d comprising a minimum age of the specimen prior to testing of 28 d, a minimum of one day to prepare and condition the specimen and then 90 d to expose the specimen to the chloride solution. SIST EN 12390-11:2015
6 1 Scope This European Standard is a method for determining the unidirectional non-steady state chloride diffusion and surface concentration of conditioned specimens of hardened concrete. The test method enables the determination of the chloride penetration at a specified age, e.g. for ranking of concrete quality by comparative testing. Since resistance to chloride penetration depends on the ageing, including the effects of continual hydration, then the ranking may also change with age. The test procedure does not apply to concrete with surface treatments such as silanes and it may 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. 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 European Standard Fick’s Law is adopted. Note 2 to entry: See Annex A. SIST EN 12390-11:2015
7 3.1.6 initial chloride content
Ci 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 non-steady state diffusion coefficient
Dnss diffusion coefficient that takes into account simultaneous chloride binding Note 1 to entry: The steady-state chloride diffusion coefficient is measured on water saturated specimens where chloride diffuses through a thin specimen between two reservoirs of chloride solution, where one reservoir is at a higher concentration than the other. This steady state chloride diffusion is not covered by this test method. The steady-state chloride diffusion coefficient only reflects the ionic transport diffusion through concrete, as the concrete is unable to bind any more chloride ion. Note 2 to entry: See Annex A. 3.1.8 profile grinding dry process grinding a concrete specimen in thin successive layers 3.1.9 vacuum saturated condition specimen that is vacuum saturated with water 3.2 Symbols and abbreviated terms Ci Initial chloride content, % by mass of concrete; Cm,j
Measured chloride content of concrete layer j, % by mass of concrete Cr,j Chloride content of layer j calculated according to Formula (1) using the most suitable combination of Cs and Dnss, % by mass of concrete Cs Calculated chloride content at the exposed surface, % by mass of concrete Cx Chloride content measured at average depth x and exposure time t, % by mass of concrete Dnss Non-steady state chloride diffusion coefficient, m2 s-1; F Sum of squares of the residuals FR Flow rate (flux) in mol m-2·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 R2 Coefficient of determination SIST EN 12390-11:2015
8 sr Repeatability standard deviation sR Reproducibility standard deviation S Sum of squares t Exposure time, seconds. 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 Adimensional parameter with no units xc∂∂/ Gradient of concentration with the concentration expressed in mol/m3 4 Principle A specimen, either a cylinder or cube, shall be cast and cured in accordance with EN 12390-2, with a curing period of not less than 28 d. 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. The specimen is 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, Ci. This initial figure is taken as the chloride level of the cast concrete. The profile specimen is vacuum saturated with distilled or demineralized water, 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 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 D. 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 non-linear regression analysis by least squares curve fitting, the surface chloride content (Cs) and the non-steady state chloride diffusion coefficient (Dnss) are determined. Because of the high coefficient of variation, ~ 15 – 30 % for Dnss for the test, the number of specimens should be increased until the required precision is achieved. The results shall be reported separately and the average value. NOTE 1 The chloride diffusion coefficient varies with the age of the concrete and the period of exposure. NOTE 2 The diffusion test described in this European Standard is only valid for a constant initial chloride content. 5 Reagents and apparatus 5.1 Reagents Reagents of analytical quality shall be used. SIST EN 12390-11:2015
9 NOTE Unless otherwise stated ‘percent’ means percent by mass. 5.1.1 Calcium hydroxide, Ca(OH)2. 5.1.2 Chloride exposure solution. 5.1.2.1 Reference solution Dissolve 30 g of analytical quality NaCl in 970 g of distilled or demineralized water having an electrical conductivity ≤ 0f5 mpm-1 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. 5.1.2.2 Other exposure solutions Where the concentration of the chloride exposure solution is other than that in 5.1.2.1, 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 have been used to reflect the exposure of the construction works. NOTE 2 Higher concentrations of NaCl, such as 16,5 %, and shorter exposure periods (e.g. 35 d) have been used to accelerate the development of a chloride profile. 5.1.3 Chloride ion diffusion proof two-component polyurethane or epoxy-based paint or other equivalent barrier system. 5.1.4 Chemicals for chloride analysis, to EN 14629. 5.1.5 Distilled or demineralized water, having an electrical conductivity ≤ 0f5 mpm-1. 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 cm2 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 will vary 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. SIST EN 12390-11:2015
10 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 cm2 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. 5.2.12 Vacuum container, capable of containing at least three specimens. 5.2.13 Vacuum pump, capable of maintaining an absolute pressure of less than 50 mbar (5kPa) in the container, e.g. a water-jet pump. 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 curing period is not less than 28 d. NOTE 1 The aim of the test will normally be to assess the potential resistance to chloride ingress for a concrete mix. Where the concrete contains secondary cementing materials, such as fly ash or ground granulated blastfurnace slag, then it may be appropriate to increase the minimum age at testing as it is known that chloride resistance may increase significantly at ages greater than 28 d. After at least 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 may 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 will be reported under sub-clause 9 m), as it is a non-standard test condition. SIST EN 12390-11:2015
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 Vacuum saturation of the profile specimens After sawing the specimens, vacuum saturate the profile specimens with water. Annex C shows a typical arrangement for vacuum saturation. Place the profile specimens in the vacuum container and reduce the absolute pressure to a value between 10 mbar to 50 mbar (1 kPa to 5 kPa) within a few minutes of closing the container. Maintain this absolute pressure for 3 h and then with the vacuum pump still running, fill the container with distilled or demineralized water until that all the profile specimens are completely immersed. Maintain the absolute pressure for a further hour before allowing air to re-enter the container. Leave the profile specimens immersed in either this water or normal curing tank water until the process of surface sealing starts, see E.2. 6.2.2 Sealing surfaces other than the surface to be exposed Start the sealing within 24 h of completing the vacuum saturation. All surfaces of the profile specimen except for the sawn face shall be sealed, see Annex D for an exception. After sealing the surfaces, place the specimens in saturated calcium hydroxide solution for 18 h. 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’. SIST EN 12390-11:2015
12 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. 6.2.3 Profile specimen for immersion After storage in saturated calcium hydroxide solution, 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 cm2 of exposed surface 2 seal surfaces 3 exposed surface Figure 2 — Example of an immersed specimen and sealed surfaces 6.2.4 Profile specimen for ponding After storage in saturated calcium hydroxide solution, 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 there will not be unidirectional chloride ingress. SIST EN 12390-11:2015
13 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 6.2.5 Profile specimen for inversion After sealing in accordance with 6.2.2 and storage in the calcium hydroxide solution, 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 cm2 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 5.1.2.1. If the chloride exposure solution is other than the reference solution (see 5.1.2.2), it shall be reported. The chloride exposure solution concentration after use shall be measured, recorded and reported. SIST EN 12390-11:2015
14 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). NOTE 1 During the test period the concentration of the chloride exposure solution will reduce. The volume of chloride exposure solution has been selected so that it 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 2 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
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