SIST-TP CEN/TR 17172:2022
(Main)Validation testing program on chloride penetration and carbonation standardized test methods
Validation testing program on chloride penetration and carbonation standardized test methods
The objective of the document consists in testing concrete mixes complying with EN 206 for particular aggressive environments with the test methods being standardized by TC 51/WG 12 on chloride penetration and carbonation in order to verify their robustness and coherence.
Validierungsprogramm für genormte Prüfverfahren zur Bestimmung der Chlorideindringung und der Karbonatisierung
Programme d'essai de validation des méthodes d'essai normalisées relatives à la pénétration des chlorures et à la carbonatation
Program validacije standardizirane preskusne metode za preskušanje penetracije kloridov in karbonatizacije
Predmet tega dokumenta je preskušanje betonskih mešanic, ki ustrezajo standardu EN 206, v posebej agresivnih okoljih s preskusnimi metodami, standardiziranimi v skladu z določili TC 51/WG 12 za penetracijo kloridov in karbonatizacijo, za namene preverjanja njihove trdnosti in skladnosti.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TP CEN/TR 17172:2022
01-september-2022
Program validacije standardizirane preskusne metode za preskušanje penetracije
kloridov in karbonatizacije
Validation testing program on chloride penetration and carbonation standardized test
methods
Validierungsprogramm für genormte Prüfverfahren zur Bestimmung der
Chlorideindringung und der Karbonatisierung
Programme d'essai de validation des méthodes d'essai normalisées relatives à la
pénétration des chlorures et à la carbonatation
Ta slovenski standard je istoveten z: CEN/TR 17172:2022
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
SIST-TP CEN/TR 17172:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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CEN/TR 17172
TECHNICAL REPORT
RAPPORT TECHNIQUE
June 2022
TECHNISCHER BERICHT
ICS 91.100.30 Supersedes CEN/TR 17172:2018
English Version
Validation testing program on chloride penetration and
carbonation standardized test methods
Programme d'essai de validation des méthodes d'essai Validierungsprogramm für genormte Prüfverfahren
normalisées relatives à la pénétration des chlorures et zur Bestimmung der Chlorideindringung und der
à la carbonatation Karbonatisierung
This Technical Report was approved by CEN on 24 May 2022. It has been drawn up by the Technical Committee CEN/TC 104.
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
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17172:2022 E
worldwide for CEN national Members.
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Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative References . 5
3 Terms and Definitions . 5
4 Concretes and specimens . 5
5 Participating laboratories. 6
6 Testing program . 7
7 Statistical analysis . 7
8 Results . 8
8.1 Accelerated carbonation test prEN 12390-12 . 8
8.2 Remarks from laboratories participating to the testing procedure CEN/TS 12390-12
(ACA) . 9
9 Natural carbonation CEN/TS 12390-10 (NCA) . 9
9.1 Natural carbonation . 9
9.2 Penetration depth dk . 9
9.3 Summary of precision parameters of dk (mm) . 14
9.4 Carbonation rate . 15
0.5
9.5 Summary of precision parameters of carbonation rate k (mm/year ) . 19
CO
2
10 Chloride diffusion test EN 12390-11 . 21
10.1 General . 21
10.2 Precision parameters of the surface concentration C . 26
s
2
10.3 Summary of precision data of D (m /s) and C (% by concrete mass) . 28
nss s
11 Regression coefficients of the profile fitting procedure . 29
2
11.1 Regression coefficients R of the fitting of the error function into the chloride
profiles . 29
Annex A (informative) Concretes and specimens prepared . 32
A.1 General . 32
A.2 Labelling and working program . 36
Annex B (informative) Chloride profiles and their diffusion fitting parameters . 38
Annex C (informative) Climates in-or-near the places where natural carbonation was made . 57
2
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European foreword
This document (CEN/TR 17172:2022) has been prepared by Technical Committee CEN/TC 104
“Concrete and related products”, the secretariat of which is held by DIN.
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.
This document reports the data obtained in the Validation Testing Program (VTP) on chloride
penetration and carbonation organized by CEN/TC 51/WG 12 starting from 2009 as from document
CEN/TC 51/WG 12 – Doc. N 229/2009, where the preparation of specimens, the collection of results and
the statistical analysis were performed by the Institute of Construction Sciences “Eduardo Torroja” of the
CSIC of Spain, IETcc–CSIC, under the managing activities of Prof. Carmen Andrade.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
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Introduction
The procedure for the determination of chloride penetration is described in EN 12390-11:2015, “Testing
hardened concrete — Determination of the chloride resistance of concrete — Unidirectional diffusion” and
it has been published by CEN. The method is based on natural diffusion; a concentration profile after
90 days of contact with the chloride solution is used to fit Fick’s law in order to calculate the chloride
surface concentration, C and the non-steady-state chloride diffusion coefficient, D . The method
s nss
specifies three different modes of contact of the salt solution with one face of the specimen, immersion
(DCL1), ponding (DCL2) and inversion (DCL3).
CEN/TC 51/WG 12 has also produced two methods addressed to the determination of the carbonation
resistance of the concrete, the first one refers to natural condition and has been published as
CEN/TS 12390-10, “Testing hardened concrete — Part 10: Determination of the relative carbonation
resistance of the concrete“, the second one, referring to accelerated condition, has been prepared by
1)
CEN/TC 51/WG 12/TG 5, but it has been disapproved by National Members at Formal Vote CEN TCA .
The upgrading to EN standard of the aforesaid documents should require as first step the evaluation of
robustness and precision data.
Having in mind these needs, CEN/TC 51/WG 12 organized a “Validation Testing Program (VTP) on
chloride penetration and carbonation” for the preliminary evaluation of the robustness and the precision
data of the test methods.
For the scope of the present work as robustness is intended the sensitivity of the test method to a
composition change of concrete that are expected to produce an appreciable change in related
performance.
1)
FprCEN/TS 12390-12:2010, Testing hardened concrete — Part 12: Determination of the potential carbonation
resistance of concrete: Accelerated carbonation method.
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1 Scope
The objective of the report consists in testing concrete mixes for particular aggressive environments with
the test methods being standardized by TC51/WG12 on chloride penetration and carbonation in order
to verify their robustness and coherence.
NOTE See EN 206 for additional information.
2 Normative References
There are no normative references in this document.
3 Terms and Definitions
No terms and definitions are listed in this document.
4 Concretes and specimens
For the VTP four concrete mixes were designed considering the limiting values indicated in Table F.1 of
EN 206 and the scope of assessing the robustness of the methods.
Three composition parameters (cement type, w/c ratio and cement content) were suitably chosen.
The following cement type and class were chosen: CEM II/A-LL 42.5 R and CEM II/B-V 32.5 R.
The w/c ratio was intentionally changed to substantially affect the concrete performances.
3 3
Two cement contents were used, the first one (300 kg/m ) for carbonation, the second one (350 kg/m )
for chloride penetration.
Aggregate “round shaped” of siliceous nature and with a maximum diameter of 14 mm was used. In
Table 1 the composition of concrete mixes is shown.
The use of superplasticizer admixture was modulated, where necessary, to obtain a slump class S3
(100 mm – 150 mm). Table 1 gives the nominal proportions of the mixes used.
Table 1 — Proportions and cement types of the mixes prepared
CARBONATION CHLORIDE
MIX 1 MIX 2 MIX 3 MIX 4 MIX 5 MIX 6 MIX 7 MIX 8
Cement type CEM II/A-LL 42.5R CEM II/B-V 32.5R CEM II/A-LL 42.5R CEM II/B-V 32.5R
3
295 296 296 300 345 351 349 357
Cement amount (kg/m )
3
144 173 144 175 137 173 138 176
Water (l/m )
w/c ratio 0,49 0,58 0,49 0,58 0,4 0,49 0,4 0,49
3
1 049 1 011 1 054 1 025 1 005 977 1 019 993
Gravel (kg/m )
3
857 827 861 838 816 793 827 806
Sand (kg/m )
Superplasticizer
0,60 0,20 0,50 0,15 0,79 0,23 0,57 0,10
(% cement weight)
5
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CARBONATION CHLORIDE
MIX 1 MIX 2 MIX 3 MIX 4 MIX 5 MIX 6 MIX 7 MIX 8
Cement type CEM II/A-LL 42.5R CEM II/B-V 32.5R CEM II/A-LL 42.5R CEM II/B-V 32.5R
3
2 260 2 265 2 294 2 285 2 273 2 313 2 330 2 330
Density (kg/dm )
Air content (%) 5,75 4,9 5,15 3,75 5,7 3,8 4,4 2,3
Slump (cm) 11 10 12 10 10 10 13,5 10
For each laboratory and test method 2 cubes (150 mm) were produced.
In Annex A a summary of the experimental details of the preparation of the specimens and their
submission is described. It is worth noting that the specimen preparation was centralized in one
laboratory (IETcc) in order to have a better homogeneity.
5 Participating laboratories
Fourteen laboratories from different European countries participating in the VTP are indicated in Table 2
with the tests methods they performed.
Table 2 — List of laboratories participating in the exercise with the test types they perform
NATURAL ACCELERATED DIFFUSION CHLORIDE
CARBONATION CARBONATION PENETRATION
COUNTRY LABORATORY
NCA1 NCA2 ACA DCL1 DCL2 DCL3
France Lafarge X X
France LRPC X
Spain University of Alicante X X
Spain IETcc X X X X X X
Belgium CRIC X X
The
KEMA X X X
Netherlands
The
TNO X X X
Netherlands
The
SGS INTRON X X X X
Netherlands
United
Dundee University X X X X
Kingdom
Sweden CBI X X
Germany FIZ/VDZ X X X X
Italy Polytechnic Milan X X X X X
Poland ISCMOIB/OMMB X X
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6 Testing program
The tests performed are summarized in Table 3.
Table 3 — Test methods and standards used in the program
Test methods Reference Methodology Label
a
At 4 % of CO
Accelerated carbonation ACA
2
Natural exposure NCA1
b
Natural carbonation CEN/TS 12390-10
c
Climatic chamber NCA2
Immersion DCL1
Chloride diffusion EN 12390-11 Ponding DCL2
Inversion DCL3
a
The draft test method used for this research received a negative vote and the Work Item was withdrawn;
however it was published by BSI as BS 1881-210. A new accelerated test is being prepared for standardization
with the main change being a carbon dioxide concentration of 3 %. The robustness and precision determined
by the research is expected to be the same as for the test method under development.
b
The procedure described in CEN/TS 12390-10:2007 differs from the method followed in the present report.
CEN/TS 12390-10 prescribes that test specimens shall be tested when they have reached the 50 % of the
compressive strength of the reference concrete. In the present report there was no reference concrete as the
purpose was not to determine the relative carbonation but the robustness of the testing procedures.
c
At 350 ppm of carbon dioxide. An EN to replace CEN/TS 12390-10 is under development and the most
significant change is to increase the carbon dioxide concentration in the chamber test to 400 ppm. This change
is unlikely to impact the robustness and precision determined by this research.
7 Statistical analysis
The statistical treatment has been made following ISO 5725-2, “Determination of the accuracy (trueness
and precision) of measurement methods and results — Part 2: Basic method for the determination of
repeatability and reproducibility of a standard measurement method”.
According to this standard, the parameters to be calculated are the mean value (m), the repeatability
standard deviation (s ), the reproducibility standard deviation (s ). In addition, the limiting values of the
r R
repeatability and reproducibility, r and R, have been also calculated.
The basic model is simple of type I applied to a single experiment. It has been applied in three steps:
1) A critical exam of all data in order to identify and to treat any anomalous value or irregularities which
could prevent the correct application of ISO 5725-2.
2) Once the outliers’ results are identified and discarded the repeatability, r and r (%) and
reproducibility, R and R (%) of the remaining results (excluding the outliers) is calculated.
3) Definitive calculation of the mean and precision values, including the relations between the mean
and the precision for each level (ISO 5725-2).
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8 Results
8.1 Accelerated carbonation test prEN 12390-12
The individual results of carbonation depth are presented in Figure 1. The testing procedure ranks
concretes with CEM II/A-LL 42.5 R as more resistant than concrete with CEM II/B-V 32.5 R for the same
w/c ratios.
Also it can be noticed that the method is sensitive to changes in the w/c ratio for the concrete with the
same cement as it was evidenced by an increase of the carbonation depth with the increase of w/c ratio.
It is not possible to draft any conclusion on the effect of cement type because the strength class of cement
is different. Consequently, different cement lead to different concrete strength and porosity and they are
subjected to the exposure with different degree of porosity evolution in concrete.
Lab 9 has been considered outlier because its results were much lower compared to the other
laboratories. It was identified later that its chamber did not control the relative humidity properly and
this parameter was higher than prescribed in the standard. Then the results of the Lab 9 in this test have
not been used in the calculations. Table 4 shows the results of the statistical analysis.
Key
X laboratory number
Y dk average (mm)
Figure 1 — Individual results averaged for each mix of accelerated carbonation depth
Table 4 — Summary of mean values of carbonation depth obtained for ACA method
Accelerated carbonation Mix 1 Mix 2 Mix 3 Mix 4
Average values (mm) 8,38 15,17 16,79 23,85
s (mm)
Repeatability 0,76 0,56 0,60 0,90
r
Standard deviation
s (mm)
Reproducibility 0,86 0,87 1,41 2,30
R
CV (%)
Variation coef. Repeatability 9,12 3,69 3,56 3,76
r
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Accelerated carbonation Mix 1 Mix 2 Mix 3 Mix 4
CV (%)
Reproducibility 10,27 5,75 8,37 9,66
R
Repeatability r (mm) 2,14 1,57 1,67 2,51
Limit values
Reproducibility R (mm) 2,41 2,44 3,93 6,45
Repeatability r (%) 25,53 10,33 9,96 10,53
Limit
values/average
Reproducibility R (%) 28,77 16,10 23,42 27,04
8.2 Remarks from laboratories participating to the testing procedure CEN/TS 12390-12
(ACA)
The main aspect that should be mentioned is that 2 of 8 laboratories did not consider the indication of
protecting 2 parallel faces of specimen (point 6.2) and then it can be recommended that the description
of the testing procedure regarding measurements points and the number of faces should be improved.
9 Natural carbonation CEN/TS 12390-10 (NCA)
9.1 Natural carbonation
The main aim of this test was to check its comparative ability and the robustness of the two alternative
testing procedures. The “normalization” described in the chapter 6 of CEN/TS 12390-10 was not in the
scope of the VTP.
Two results were considered:
— dk (mm) the penetration depth;
0.5
— k (mm/year ) the carbonation rate.
c
9.2 Penetration depth dk
The test was performed by 6 laboratories, although not all performed both tests (in climatic chamber and
outdoors), number of specimens and testing times. The durations on each test taken by each laboratory
were not exactly those of the standard, but the data collected at different ages by each lab (see Table 5
and 6) were close enough to have relevance: all the tests were performed by taking some data before or
at 1 year and other, at around two years. Due to these different testing ages, the direct comparison of the
penetration depths using dk in mm is made with not all laboratories, however all data were used in the
0.5
case of the rate of carbonation in mm/year because each dk was divided by the exact testing period.
For the sake of appraising the environmental conditions, Annex C gives the average temperature and
relative humidity of the atmospheres where the participating laboratories are located. Their relative
differences are presented also in the psychrometric diagram.
Table 5 — Days of exposure by each laboratory in a climatic chamber or outdoor sheltered from
rain
TESTING TIMES
LABORATORIES
(days)
L2 365, 730
L5 375, 801
L7 365
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TESTING TIMES
LABORATORIES
(days)
L9 190, 730
L11 365, 730, 886
L13 365
Table 6 — Number of laboratory results averaged given in Figures 4 and 7
NUMBER OF LABORATORIES FOR EACH AVERAGED VALUE
Natural carbonation
NCA1 NCA2
Year 1 Year 2 Year 1 Year 2
MIX 1 5 4 4 2
MIX 2 5 5 4 3
MIX 3 5 4 4 2
MIX 4 5 5 4 3
For averaging the values, Table 6 shows the number of laboratories per mix considered giving valid
values. Figures 2 and 3 show averaged “valid” results of the penetration depth per mix obtained by each
laboratory.
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a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
x laboratories
y NCA1 dk (mm)
Figure 2 — Individual results of carbonation depth dk for each mix 1 to 4 in the order in natural
exposure (NCA1) at equal or around 1 year (dark grey bar) and 2 years (light grey bar). (LAB 9
did not test at 365 days but at 190 days)
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A) MIX 1 b) MIX 2
C) MIX 3 d) MIX 4
Key
x laboratories
y NCA2 dk (mm)
Figure 3 — Individual results of carbonation depth dk for each mix 1 to 4 in the order in climatic
chamber (NCA2) at equal or around 1 year (dark grey bar) and at 2 years (light grey bar). (LAB 9
did not test at 365 days but at 190 days)
For comparative purposes between NCA1 and NCA 2 test procedures, the differences in the carbonation
depth dk obtained at around 1 year are given in Figure 4. It is remarkable to deduce that, in spite of the
very different climates in the countries of the different laboratories, the dk values in natural outdoors
sheltered from rain exposure are reasonably similar to those values obtained through NCA2 (climatic
chamber).
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Key
y carbonation depth dk (mm) Average
x mix number and test type
Figure 4 — Comparison of carbonation depth of the testing procedures NCA1 (natural outdoors
sheltered from rain) and NCA2 in the climatic chamber (LAB 9 did not test at 365 days but at 190
days). Individual values per mix at equal or around 1 year
The precision data of both test procedures (carbonation depth obtained in climatic chamber and outdoors
sheltered from rain) are given in Table 7 and 8 for the results at 1 year only because it was considered
that the number of laboratories making the tests at around two years was too few to allow the calculation
of precision at that age. Due to the same reason of the limited number of laboratories, the repeatability
was made with all data by variance analysis.
Table 7 — Summary of precision data of carbonation depth obtained for NCA1 method
at one year testing
dk Natural Carbonation NCA1 outdoors Mix1 Mix2 Mix3 Mix4
Average (mm) 1,57 4,04 3,04 5,99
s (mm)
Repeatability 0,34
r
Standard
deviation
s (mm)
Reproducibility 0,86
R
CV (%)
Repeatability 21,8 8,5 11,3 5,7
r
Variation coef.
CV (%)
Reproducibility 61,2 23,7 31,5 16,0
R
r = 2,8 s (mm)
Repeatability 0,96
r
Limit values
R = 2,8 s (mm)
Reproducibility 2,42
R
r = 2,8 CV (%)
Repeatability 55,2 21,4 28,4 14,4
r
Limit values
R = 2,8 CV (%)
Reproducibility 154,5 59,9 79,6 40,4
R
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Table 8 — Summary of mean values of carbonation depth obtained for NCA2 method at one year
testing
dk Natural Carbonation NCA2
Mix1 Mix3
Climatic chamber
Average (mm) 1,85 3,23
s (mm)
Repeatability 0,30
r
Standard deviation
s (mm)
Reproducibility 0,40
R
CV (%)
Repeatability 16,3 9,3
r
Variation coef.
CV (%)
Reproducibility 21,8 12,5
R
r = 2,8 s (mm)
Repeatability 0,85
r
Limit values
R = 2,8 s (mm)
Reproducibility 1,13
R
r = 2,8 CV (%)
Repeatability 45,7 26,2
r
Limit values
R = 2,8 CV (%)
Reproducibility 61,0 34,9
R
9.3 Summary of precision parameters of dk (mm)
Table 9 summarizes the precision data suggested for CEN/TS 12390-10, “Testing hardened concrete —
Part 10: Determination of the relative carbonation resistance of the concrete“ for measurements of both
test procedures (carbonation depth obtained in climatic chamber and outdoors sheltered from rain).
These data are expressed as standard deviation of the mean of two determinations (two cube specimens).
All the tests were performed by taking data at 1 year by 6 laboratories. Not all laboratories performed
both test in all samples.
Table 9 — Precision data of carbonation depth (CEN/TS 12390-10) for one year testing
Repeatability Reproducibility
Parameter Level s r = 2,8 s s R = 2,8 s
r r R R
(mm) (mm) (mm) (mm)
carbonation depth dk outdoors (NCA1) 0.5–7 (mm) 0.34 0.96 0.86 2.42
carbonation depth in climatic chamber
0.5–7 (mm) 0.30 0.85 0.40 1.13
dk chamber (NCA2)
Precision expressed in terms of coefficient of
CV (%) CV (%)
r (%) R (%)
r R
variation
NCA1 dk ± 12 33 30 84
NCA2 dk ± 13 36 17 48
These are based on a precision exercise undertaken in 2014 using concrete samples fulfilling EN 206 limiting
values for concrete composition.
The carbonation depth results are obtained by 5 laboratories for NCA1 and by 4 laboratories for NCA2 using four
concrete samples (two for test).
The values apply to the two test methods (controlled chamber and outdoors) described in this standard for 1 year
testing.
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As the main objective of the exercise is to validate the test method, it can be confirmed that the standard
is clear enough, being however the number of readings per specimen face and the averaging which would
need improved description.
Remarks on robustness of carbonation test methods:
− both tests methods (natural and accelerated) are sensitive, other parameters being constants, to:
• the change of the considered w/c values;
• the change of the considered cement type and classes.
− On the basis of the comparison between the ranking of cement type and class resulting from the two test methods,
seems that the ranking from accelerated method doesn’t reflect exactly the same ranking derived from the natural
method, even if the difference in dk values is very small (compare data for Mix 2 and Mix 4) in Tables 4 and 7.
9.4 Carbonation rate
Figure 5 shows the values of the carbonation rate k per laboratory for NCA1 method. The carbonation
CO
2
rate values were calculated by dividing each penetration depth by the precise duration of the testing
period. Figure 6 shows the same results for NCA2 method.
a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
0.5
Y carbonation rate k mm/year
CO
2
X laboratory number
Figure 5 — Individual results of carbonation rate k for each mix 1 to 4 in the order in natural
CO
2
exposure (NCA1) at 1 (dark grey bar) and 2 years (light grey bar)
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a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
0.5
Y carbonation rate k mm/year
CO
2
X laboratoriy number
Figure 6 — Individual results of carbonation rate k for each mix in the order in natural
CO
2
exposure (NCA2) at 1(dark grey bar) and 2 years (light grey bar)
The statistical calculations of the rate of carbonation k are given in Tables 10 to13.
CO
2
Table 10 — Summary of precision data of k obtained for NCA1 method at about one-year
CO
2
testing
Natural Carbonation NCA1 outdoors k 1 year
Mix1 Mix 2 Mix 3 Mix 4
co
2
0.5
1,57 4,0 3,0 5,9
Average values (mm/year )
0.5
Repeatability s (mm/year ) 0,29
r
Standard deviation
0.5
Reproducibility s (mm/year ) 0,71
R
CV (%)
Repeatability 19,4 7,2 9,8 4,9
r
Variation coef.
CV (%)
Reproducibility 47,7 17,7 24,0 12,0
R
0.5
Repeatability r = 2,8 s (mm/year ) 0,80
r
Limit values
R = 2,8 s
R
Reproducibility 2,00
0.5
(mm/year )
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Natural Carbonation NCA1 outdoors k 1 year
Mix1 Mix 2 Mix 3 Mix 4
co
2
r = 2,8 CV (%)
Repeatability 54,4 20,2 27,4 13,6
r
Limit values
R = 2,8 CV (%)
Reproducibility 133,7 49,6 67,3 33,5
R
Table 11 — Summary of precision data of k obtained for NCA1 method at about two years
CO
2
testing
Natural Carbonation NCA1 outdoors k 2 years
Mix1 Mix2 Mix3 Mix4
co
2
0.5
1,61 4,08 3,13 5,96
Average values (mm/year )
0.5
Repeatability s (mm/year ) 0,37
r
Standard deviation
0.5
Reproducibility s (mm/year ) 0,63
R
CV (%)
Repeatability 22,8 9,0 11,8 6,2
r
Variation coef.
CV (%)
Reproducibility 39,4 15,5 20,3 10,6
R
0.5
Repeatability r = 2,8 s (mm/year ) 1,03
r
Limit values
R = 2,8 s
R
Reproducibility 1,78
0.5
(mm/year )
r = 2,8 CV (%)
Repeatability 63,9 25,2 32,9 17,3
r
Limit values
Reproducibility R = 2,8 CVR (%) 1
...
SLOVENSKI STANDARD
kSIST-TP FprCEN/TR 17172:2022
01-april-2022
Program validacije standardizirane preskusne metode za preskušanje penetracije
kloridov in karbonatizacije
Validation testing program on chloride penetration and carbonation standardized test
methods
Validierungsprogramm für genormte Prüfverfahren zur Bestimmung der
Chlorideindringung und der Karbonatisierung
Programme d'essai de validation des méthodes d'essai normalisées relatives à la
pénétration des chlorures et à la carbonatation
Ta slovenski standard je istoveten z: FprCEN/TR 17172
ICS:
91.100.30 Beton in betonski izdelki Concrete and concrete
products
kSIST-TP FprCEN/TR 17172:2022 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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kSIST-TP FprCEN/TR 17172:2022
FINAL DRAFT
TECHNICAL REPORT
FprCEN/TR 17172
RAPPORT TECHNIQUE
TECHNISCHER BERICHT
January 2022
ICS Will supersede CEN/TR 17172:2018
English Version
Validation testing program on chloride penetration and
carbonation standardized test methods
Programme d'essai de validation des méthodes d'essai Validierungsprogramm für genormte Prüfverfahren
normalisées relatives à la pénétration des chlorures et zur Bestimmung der Chlorideindringung und der
à la carbonatation Karbonatisierung
This draft Technical Report is submitted to CEN members for Vote. It has been drawn up by the Technical Committee CEN/TC
104.
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.
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 Technical Report. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a Technical Report.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. FprCEN/TR 17172:2022 E
worldwide for CEN national Members.
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Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative References . 5
3 Terms and Definitions . 5
4 Concretes and specimens . 5
5 Participating laboratories. 6
6 Testing program . 7
7 Statistical analysis . 7
8 Results . 8
8.1 Accelerated carbonation test prEN 12390-12 . 8
8.2 Remarks from laboratories participating to the testing procedure CEN/TS 12390-12
(ACA) . 9
9 Natural carbonation CEN/TS 12390-10 (NCA) . 9
9.1 Natural carbonation . 9
9.2 Penetration depth dk . 9
9.3 Summary of precision parameters of dk (mm) . 14
9.4 Carbonation rate . 15
0.5
9.5 Summary of precision parameters of carbonation rate k (mm/year ) . 19
CO
2
10 Chloride diffusion test EN 12390-11 . 21
10.1 General . 21
10.2 Precision parameters of the surface concentration C . 26
s
2
10.3 Summary of precision data of D (m /s) and C (% by concrete mass) . 28
nss s
11 Regression coefficients of the profile fitting procedure . 29
2
11.1 Regression coefficients R of the fitting of the error function into the chloride
profiles . 29
Annex A (informative) Concretes and specimens prepared . 32
A.1 General . 32
A.2 Labelling and working program . 36
Annex B (informative) Chloride profiles and their diffusion fitting parameters . 38
Annex C (informative) Climates in-or-near the places where natural carbonation was made . 56
2
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European foreword
This document (FprCEN/TR 17172:2022) has been prepared by Technical Committee CEN/TC 104
“Concrete and related products”, the secretariat of which is held by DIN.
This document is currently submitted to the Vote on TR.
This document reports the data obtained in the Validation Testing Program (VTP) on chloride
penetration and carbonation organized by CEN/TC 51/WG 12 starting from 2009 as from document
CEN/TC 51/WG 12 – Doc. N 229/2009, where the preparation of specimens, the collection of results and
the statistical analysis were performed by the Institute of Construction Sciences “Eduardo Torroja” of the
CSIC of Spain, IETcc–CSIC, under the managing activities of Prof. Carmen Andrade.
3
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Introduction
The procedure for the determination of chloride penetration is described in EN 12390-11:2015, “Testing
hardened concrete — Determination of the chloride resistance of concrete — Unidirectional diffusion” and
it has been published by CEN. The method is based on natural diffusion; a concentration profile after
90 days of contact with the chloride solution is used to fit Fick’s law in order to calculate the chloride
surface concentration, C and the non-steady-state chloride diffusion coefficient, D . The method
s nss
specifies three different modes of contact of the salt solution with one face of the specimen, immersion
(DCL1), ponding (DCL2) and inversion (DCL3).
CEN/TC 51/WG 12 has also produced two methods addressed to the determination of the carbonation
resistance of the concrete, the first one refers to natural condition and has been published as
CEN/TS 12390-10, “Testing hardened concrete — Part 10: Determination of the relative carbonation
resistance of the concrete“, the second one, referring to accelerated condition, has been prepared by
1)
CEN/TC 51/WG 12/TG 5, but it has been disapproved by National Members at Formal Vote CEN TCA .
The upgrading to EN standard of the aforesaid documents should require as first step the evaluation of
robustness and precision data.
Having in mind these needs, CEN/TC 51/WG 12 organized a “Validation Testing Program (VTP) on
chloride penetration and carbonation” for the preliminary evaluation of the robustness and the precision
data of the test methods.
For the scope of the present work as robustness is intended the sensitivity of the test method to a
composition change of concrete that are expected to produce an appreciable change in related
performance.
1)
FprCEN/TS 12390-12:2010, Testing hardened concrete — Part 12: Determination of the potential carbonation
resistance of concrete: Accelerated carbonation method.
4
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1 Scope
The objective of the report consists in testing concrete mixes for particular aggressive environments with
the test methods being standardized by TC51/WG12 on chloride penetration and carbonation in order
to verify their robustness and coherence.
NOTE See EN 206 for additional information.
2 Normative References
There are no normative references in this document.
3 Terms and Definitions
No terms and definitions are listed in this document.
4 Concretes and specimens
For the VTP four concrete mixes were designed considering the limiting values indicated in Table F.1 of
EN 206 and the scope of assessing the robustness of the methods.
Three composition parameters (cement type, w/c ratio and cement content) were suitably chosen.
The following cement type and class were chosen: CEM II/A-LL 42.5 R and CEM II/B-V 32.5 R.
The w/c ratio was intentionally changed to substantially affect the concrete performances.
3 3
Two cement contents were used, the first one (300 kg/m ) for carbonation, the second one (350 kg/m )
for chloride penetration.
Aggregate “round shaped” of siliceous nature and with a maximum diameter of 14 mm was used. In
Table 1 the composition of concrete mixes is shown.
The use of superplasticizer admixture was modulated, where necessary, to obtain a slump class S3
(100 mm – 150 mm). Table 1 gives the nominal proportions of the mixes used.
Table 1 — Proportions and cement types of the mixes prepared
CARBONATION CHLORIDE
MIX 1 MIX 2 MIX 3 MIX 4 MIX 5 MIX 6 MIX 7 MIX 8
Cement type CEM II/A-LL 42.5R CEM II/B-V 32.5R CEM II/A-LL 42.5R CEM II/B-V 32.5R
3
295 296 296 300 345 351 349 357
Cement amount (kg/m )
3
144 173 144 175 137 173 138 176
Water (l/m )
w/c ratio 0,49 0,58 0,49 0,58 0,4 0,49 0,4 0,49
3
1 049 1 011 1 054 1 025 1 005 977 1 019 993
Gravel (kg/m )
3
857 827 861 838 816 793 827 806
Sand (kg/m )
Superplasticizer
0,60 0,20 0,50 0,15 0,79 0,23 0,57 0,10
(% cement weight)
5
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CARBONATION CHLORIDE
MIX 1 MIX 2 MIX 3 MIX 4 MIX 5 MIX 6 MIX 7 MIX 8
Cement type CEM II/A-LL 42.5R CEM II/B-V 32.5R CEM II/A-LL 42.5R CEM II/B-V 32.5R
3
2 260 2 265 2 294 2 285 2 273 2 313 2 330 2 330
Density (kg/dm )
Air content (%) 5,75 4,9 5,15 3,75 5,7 3,8 4,4 2,3
Slump (cm) 11 10 12 10 10 10 13,5 10
For each laboratory and test method 2 cubes (150 mm) were produced.
In Annex A a summary of the experimental details of the preparation of the specimens and their
submission is described. It is worth noting that the specimen preparation was centralized in one
laboratory (IETcc) in order to have a better homogeneity.
5 Participating laboratories
Fourteen laboratories from different European countries participating in the VTP are indicated in Table 2
with the tests methods they performed.
Table 2 — List of laboratories participating in the exercise with the test types they perform
NATURAL ACCELERATED DIFFUSION CHLORIDE
CARBONATION CARBONATION PENETRATION
COUNTRY LABORATORY
NCA1 NCA2 ACA DCL1 DCL2 DCL3
France Lafarge X X
France LRPC X
Spain University of Alicante X X
Spain IETcc X X X X X X
Belgium CRIC X X
The
KEMA X X X
Netherlands
The
TNO X X X
Netherlands
The
SGS INTRON X X X X
Netherlands
United
Dundee University X X X X
Kingdom
Sweden CBI X X
Germany FIZ/VDZ X X X X
Italy Polytechnic Milan X X X X X
Poland ISCMOIB/OMMB X X
6
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6 Testing program
The tests performed are summarized in Table 3.
Table 3 — Test methods and standards used in the program
Test methods Reference Methodology Label
a
At 4 % of CO
Accelerated carbonation ACA
2
Natural exposure NCA1
b
Natural carbonation CEN/TS 12390-10
c
Climatic chamber NCA2
Immersion DCL1
Chloride diffusion EN 12390-11 Ponding DCL2
Inversion DCL3
a
The draft test method used for this research received a negative vote and the Work Item was withdrawn;
however it was published by BSI as BS 1881-210. A new accelerated test is being prepared for standardization
with the main change being a carbon dioxide concentration of 3 %. The robustness and precision determined
by the research is expected to be the same as for the test method under development.
b
The procedure described in CEN/TS 12390-10:2007 differs from the method followed in the present report.
CEN/TS 12390-10 prescribes that test specimens shall be tested when they have reached the 50 % of the
compressive strength of the reference concrete. In the present report there was no reference concrete as the
purpose was not to determine the relative carbonation but the robustness of the testing procedures.
c
At 350 ppm of carbon dioxide. An EN to replace CEN/TS 12390-10 is under development and the most
significant change is to increase the carbon dioxide concentration in the chamber test to 400 ppm. This change
is unlikely to impact the robustness and precision determined by this research.
7 Statistical analysis
The statistical treatment has been made following ISO 5725-2, “Determination of the accuracy (trueness
and precision) of measurement methods and results — Part 2: Basic method for the determination of
repeatability and reproducibility of a standard measurement method”.
According to this standard, the parameters to be calculated are the mean value (m), the repeatability
standard deviation (s ), the reproducibility standard deviation (s ). In addition, the limiting values of the
r R
repeatability and reproducibility, r and R, have been also calculated.
The basic model is simple of type I applied to a single experiment. It has been applied in three steps:
1) A critical exam of all data in order to identify and to treat any anomalous value or irregularities which
could prevent the correct application of ISO 5725-2.
2) Once the outliers’ results are identified and discarded the repeatability, r and r (%) and
reproducibility, R and R (%) of the remaining results (excluding the outliers) is calculated.
3) Definitive calculation of the mean and precision values, including the relations between the mean
and the precision for each level (ISO 5725-2).
7
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8 Results
8.1 Accelerated carbonation test prEN 12390-12
The individual results of carbonation depth are presented in Figure 1. The testing procedure ranks
concretes with CEM II/A-LL 42.5 R as more resistant than concrete with CEM II/B-V 32.5 R for the same
w/c ratios.
Also it can be noticed that the method is sensitive to changes in the w/c ratio for the concrete with the
same cement as it was evidenced by an increase of the carbonation depth with the increase of w/c ratio.
It is not possible to draft any conclusion on the effect of cement type because the strength class of cement
is different. Consequently, different cement lead to different concrete strength and porosity and they are
subjected to the exposure with different degree of porosity evolution in concrete.
Lab 9 has been considered outlier because its results were much lower compared to the other
laboratories. It was identified later that its chamber did not control the relative humidity properly and
this parameter was higher than prescribed in the standard. Then the results of the Lab 9 in this test have
not been used in the calculations. Table 4 shows the results of the statistical analysis.
Key
X laboratory number
Y dk average (mm)
Figure 1 — Individual results averaged for each mix of accelerated carbonation depth
Table 4 — Summary of mean values of carbonation depth obtained for ACA method
Accelerated carbonation Mix 1 Mix 2 Mix 3 Mix 4
Average values (mm) 8,38 15,17 16,79 23,85
s (mm)
Repeatability 0,76 0,56 0,60 0,90
r
Standard deviation
s (mm)
Reproducibility 0,86 0,87 1,41 2,30
R
CV (%)
Variation coef. Repeatability 9,12 3,69 3,56 3,76
r
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Accelerated carbonation Mix 1 Mix 2 Mix 3 Mix 4
CV (%)
Reproducibility 10,27 5,75 8,37 9,66
R
Repeatability r (mm) 2,14 1,57 1,67 2,51
Limit values
Reproducibility R (mm) 2,41 2,44 3,93 6,45
Repeatability r (%) 25,53 10,33 9,96 10,53
Limit
values/average
Reproducibility R (%) 28,77 16,10 23,42 27,04
8.2 Remarks from laboratories participating to the testing procedure CEN/TS 12390-12
(ACA)
The main aspect that should be mentioned is that 2 of 8 laboratories did not consider the indication of
protecting 2 parallel faces of specimen (point 6.2) and then it can be recommended that the description
of the testing procedure regarding measurements points and the number of faces should be improved.
9 Natural carbonation CEN/TS 12390-10 (NCA)
9.1 Natural carbonation
The main aim of this test was to check its comparative ability and the robustness of the two alternative
testing procedures. The “normalization” described in the chapter 6 of CEN/TS 12390-10 was not in the
scope of the VTP.
Two results were considered:
— dk (mm) the penetration depth;
0.5
— k (mm/year ) the carbonation rate.
c
9.2 Penetration depth dk
The test was performed by 6 laboratories, although not all performed both tests (in climatic chamber and
outdoors), number of specimens and testing times. The durations on each test taken by each laboratory
were not exactly those of the standard, but the data collected at different ages by each lab (see Table 5
and 6) were close enough to have relevance: all the tests were performed by taking some data before or
at 1 year and other, at around two years. Due to these different testing ages, the direct comparison of the
penetration depths using dk in mm is made with not all laboratories, however all data were used in the
0.5
case of the rate of carbonation in mm/year because each dk was divided by the exact testing period.
For the sake of appraising the environmental conditions, Annex C gives the average temperature and
relative humidity of the atmospheres where the participating laboratories are located. Their relative
differences are presented also in the psychrometric diagram.
Table 5 — Days of exposure by each laboratory in a climatic chamber or outdoor sheltered from
rain
TESTING TIMES
LABORATORIES
(days)
L2 365, 730
L5 375, 801
L7 365
9
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TESTING TIMES
LABORATORIES
(days)
L9 190, 730
L11 365, 730, 886
L13 365
Table 6 — Number of laboratory results averaged given in Figures 4 and 7
NUMBER OF LABORATORIES FOR EACH AVERAGED VALUE
Natural carbonation
NCA1 NCA2
Year 1 Year 2 Year 1 Year 2
MIX 1 5 4 4 2
MIX 2 5 5 4 3
MIX 3 5 4 4 2
MIX 4 5 5 4 3
For averaging the values, Table 6 shows the number of laboratories per mix considered giving valid
values. Figures 2 and 3 show averaged “valid” results of the penetration depth per mix obtained by each
laboratory.
10
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a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
x laboratories
y NCA1 dk (mm)
Figure 2 — Individual results of carbonation depth dk for each mix 1 to 4 in the order in natural
exposure (NCA1) at equal or around 1 year (dark grey bar) and 2 years (light grey bar). (LAB 9
did not test at 365 days but at 190 days)
11
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A) MIX 1 b) MIX 2
C) MIX 3 d) MIX 4
Key
x laboratories
y NCA2 dk (mm)
Figure 3 — Individual results of carbonation depth dk for each mix 1 to 4 in the order in climatic
chamber (NCA2) at equal or around 1 year (dark grey bar) and at 2 years (light grey bar). (LAB 9
did not test at 365 days but at 190 days)
For comparative purposes between NCA1 and NCA 2 test procedures, the differences in the carbonation
depth dk obtained at around 1 year are given in Figure 4. It is remarkable to deduce that, in spite of the
very different climates in the countries of the different laboratories, the dk values in natural outdoors
sheltered from rain exposure are reasonably similar to those values obtained through NCA2 (climatic
chamber).
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Key
y carbonation depth dk (mm) Average
x mix number and test type
Figure 4 — Comparison of carbonation depth of the testing procedures NCA1 (natural outdoors
sheltered from rain) and NCA2 in the climatic chamber (LAB 9 did not test at 365 days but at 190
days). Individual values per mix at equal or around 1 year
The precision data of both test procedures (carbonation depth obtained in climatic chamber and outdoors
sheltered from rain) are given in Table 7 and 8 for the results at 1 year only because it was considered
that the number of laboratories making the tests at around two years was too few to allow the calculation
of precision at that age. Due to the same reason of the limited number of laboratories, the repeatability
was made with all data by variance analysis.
Table 7 — Summary of precision data of carbonation depth obtained for NCA1 method
at one year testing
dk Natural Carbonation NCA1 outdoors Mix1 Mix2 Mix3 Mix4
Average (mm) 1,57 4,04 3,04 5,99
s (mm)
Repeatability 0,34
r
Standard
deviation
s (mm)
Reproducibility 0,86
R
CV (%)
Repeatability 21,8 8,5 11,3 5,7
r
Variation coef.
CV (%)
Reproducibility 61,2 23,7 31,5 16,0
R
r = 2,8 s (mm)
Repeatability 0,96
r
Limit values
R = 2,8 s (mm)
Reproducibility 2,42
R
r = 2,8 CV (%)
Repeatability 55,2 21,4 28,4 14,4
r
Limit values
R = 2,8 CV (%)
Reproducibility 154,5 59,9 79,6 40,4
R
13
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Table 8 — Summary of mean values of carbonation depth obtained for NCA2 method at one year
testing
dk Natural Carbonation NCA2
Mix1 Mix3
Climatic chamber
Average (mm) 1,85 3,23
s (mm)
Repeatability 0,30
r
Standard deviation
s (mm)
Reproducibility 0,40
R
CV (%)
Repeatability 16,3 9,3
r
Variation coef.
CV (%)
Reproducibility 21,8 12,5
R
r = 2,8 s (mm)
Repeatability 0,85
r
Limit values
R = 2,8 s (mm)
Reproducibility 1,13
R
r = 2,8 CV (%)
Repeatability 45,7 26,2
r
Limit values
R = 2,8 CV (%)
Reproducibility 61,0 34,9
R
9.3 Summary of precision parameters of dk (mm)
Table 9 summarizes the precision data suggested for CEN/TS 12390-10, “Testing hardened concrete —
Part 10: Determination of the relative carbonation resistance of the concrete“ for measurements of both
test procedures (carbonation depth obtained in climatic chamber and outdoors sheltered from rain).
These data are expressed as standard deviation of the mean of two determinations (two cube specimens).
All the tests were performed by taking data at 1 year by 6 laboratories. Not all laboratories performed
both test in all samples.
Table 9 — Precision data of carbonation depth (CEN/TS 12390-10) for one year testing
Repeatability Reproducibility
Parameter Level s r = 2,8 s s R = 2,8 s
r r R R
(mm) (mm) (mm) (mm)
carbonation depth dk outdoors (NCA1) 0.5–7 (mm) 0.34 0.96 0.86 2.42
carbonation depth in climatic chamber
0.5–7 (mm) 0.30 0.85 0.40 1.13
dk chamber (NCA2)
Precision expressed in terms of coefficient of
CV (%) CV (%)
r (%) R (%)
r R
variation
NCA1 dk ± 12 33 30 84
NCA2 dk ± 13 36 17 48
These are based on a precision exercise undertaken in 2014 using concrete samples fulfilling EN 206 limiting
values for concrete composition.
The carbonation depth results are obtained by 5 laboratories for NCA1 and by 4 laboratories for NCA2 using four
concrete samples (two for test).
The values apply to the two test methods (controlled chamber and outdoors) described in this standard for 1 year
testing.
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As the main objective of the exercise is to validate the test method, it can be confirmed that the standard
is clear enough, being however the number of readings per specimen face and the averaging which would
need improved description.
Remarks on robustness of carbonation test methods:
− both tests methods (natural and accelerated) are sensitive, other parameters being constants, to:
• the change of the considered w/c values;
• the change of the considered cement type and classes.
− On the basis of the comparison between the ranking of cement type and class resulting from the two test methods,
seems that the ranking from accelerated method doesn’t reflect exactly the same ranking derived from the natural
method, even if the difference in dk values is very small (compare data for Mix 2 and Mix 4) in Tables 4 and 7.
9.4 Carbonation rate
Figure 5 shows the values of the carbonation rate k per laboratory for NCA1 method. The carbonation
CO
2
rate values were calculated by dividing each penetration depth by the precise duration of the testing
period. Figure 6 shows the same results for NCA2 method.
a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
0.5
Y carbonation rate k mm/year
CO
2
X laboratory number
Figure 5 — Individual results of carbonation rate k for each mix 1 to 4 in the order in natural
CO
2
exposure (NCA1) at 1 (dark grey bar) and 2 years (light grey bar)
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a) MIX 1 b) MIX 2
c) MIX 3 d) MIX 4
Key
0.5
Y carbonation rate k mm/year
CO
2
X laboratoriy number
Figure 6 — Individual results of carbonation rate k for each mix in the order in natural
CO
2
exposure (NCA2) at 1(dark grey bar) and 2 years (light grey bar)
The statistical calculations of the rate of carbonation k are given in Tables 10 to13.
CO
2
Table 10 — Summary of precision data of k obtained for NCA1 method at about one-year
CO
2
testing
Natural Carbonation NCA1 outdoors k 1 year
Mix1 Mix 2 Mix 3 Mix 4
co
2
0.5
1,57 4,0 3,0 5,9
Average values (mm/year )
0.5
Repeatability s (mm/year ) 0,29
r
Standard deviation
0.5
Reproducibility s (mm/year ) 0,71
R
CV (%)
Repeatability 19,4 7,2 9,8 4,9
r
Variation coef.
CV (%)
Reproducibility 47,7 17,7 24,0 12,0
R
0.5
Repeatability r = 2,8 s (mm/year ) 0,80
r
Limit values
R = 2,8 s
R
Reproducibility 2,00
0.5
(mm/year )
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Natural Carbonation NCA1 outdoors k 1 year
Mix1 Mix 2 Mix 3 Mix 4
co
2
r = 2,8 CV (%)
Repeatability 54,4 20,2 27,4 13,6
r
Limit values
R = 2,8 CV (%)
Reproducibility 133,7 49,6 67,3 33,5
R
Table 11 — Summary of precision data of k obtained for NCA1 method at about two years
CO
2
testing
Natural Carbonation NCA1 outdoors k 2 years
Mix1 Mix2 Mix3 Mix4
co
2
0.5
1,61 4,08 3,13 5,96
Average values (mm/year )
0.5
Repeatability s (mm/year ) 0,37
r
Standard deviation
0.5
Reproducibility s (mm/year ) 0,63
R
CV (%)
Repeatability 22,8 9,0 11,8 6,2
r
Variation coef.
CV (%)
Reproducibility 39,4 15,5 20,3 10,6
R
0.5
Repeatabi
...
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