SIST ISO 16204:2012

INTERNATIONAL ISO
STANDARD 16204
First edition
2012-09-01
Durability — Service life design of
concrete structures
Durabilité — Conception de la durée de vie des structures en béton
Reference number
ISO 16204:2012(E)
©
ISO 2012

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ISO 16204:2012(E)
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ii © ISO 2012 – All rights reserved

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ISO 16204:2012(E)
Contents Page
Foreword .iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 5
4.1 Abbreviated terms . 5
4.2 Main letters . 5
4.3 Subscripts . 6
5 Basis of design . 6
5.1 Requirements . 6
5.2 Principles of limit state design . 7
5.3 Basic variables . 8
5.4 Verification . 8
6 Verification of service life design .10
6.1 Carbonation-induced corrosion - uncracked concrete .10
6.2 Chloride-induced corrosion - uncracked concrete .13
6.3 Influence of cracks upon reinforcement corrosion .14
6.4 Risk of depassivation with respect to pre-stressed steel .15
6.5 Freeze/thaw attack .15
6.6 Chemical attack .17
6.7 Alkali-aggregate reactions .18
7 Execution .19
7.1 General .19
7.2 Execution specification .19
7.3 Formwork .19
7.4 Materials .19
7.5 Inspection .20
7.6 Action in the event of non-conformity .20
8 Maintenance and condition assessment .20
8.1 General .20
8.2 Maintenance .20
8.3 Condition assessment .21
9 Action in the event of non-conformity .21
Annex A (informative) Basis of design .22
Annex B (informative) Verification of service life design .24
Annex C (informative) Execution .28
Annex D (informative) Maintenance and condition assessment .29
Annex E (informative) Guidance on a national annex .30
Bibliography .31
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ISO 16204:2012(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International
Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 16204 was prepared by Technical Committee ISO/TC 71, Concrete, reinforced concrete and pre-stressed
concrete, Subcommittee SC 3, Concrete production and execution of concrete structures.
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ISO 16204:2012(E)
Introduction
This International Standard is based on the principles given in ISO 2394, General principles on reliability for
1)
structures, ISO 13823, General principles on the design of structures for durability, and fib “Model Code
[1] [2]
for Service Life Design” (MC SLD, today implemented in fib Model Code 2010 ). The two International
Standards were prepared by ISO/TC 98, Bases for design of structures.
The limit-states method, as developed in ISO 2394, has been adopted and used for preparing and harmonizing
national and regional standards for structural design around the world. The objective of ISO 13823 is to provide
a framework for the development of standards to predict the service life of components of a structure and
to ensure that these principles are incorporated in the material-specific standards developed by other ISO
Technical Committees.
The objective of fib MC SLD is to implement the principles of ISO 2394 in service life design of concrete structures.
This International Standard treats design for environmental actions leading to deterioration of concrete and
embedded steel.
The flowchart in Figure 1 illustrates the flow of decisions and the design activities needed in a rational service
life design process with a chosen level of reliability. Two strategies have been adopted; in the first, three levels
of sophistication are distinguished. In total, four options are available.
Strategy 1: Design to resist deterioration
Level 1 Full probabilistic method (option 1)
Level 2 Partial factor method (option 2)
Level 3 Deemed-to-satisfy method (option 3)
Strategy 2: Avoidance-of-deterioration method, (option 4)
Establishing the serviceability criteria
Establishing the general layout, the dimensions and selection of materials
Verification by the Verification by the Verification by the Verification by the
“Full probabilistic” method “Partial factor” method. “Deemed-to- “Avoidance of
Involving: Involving: satisfy” method. deterioration”
* Probabilistic models * Design values Involving: method.
  - resistance  - characteristic values Exposure classes, Involving:
  - loads/exposure   - partial factors  limit states and Exposure classes, limit
  - geometry * Design equations other design states and other design
* Limit states * Limit states provisions provisions
Execution specification
Maintenance plan
Condition assessment plan
Execution of the structure
Inspection of execution
Maintenance Condition assessments during operational service life
Figure 1 — Flowchart for service life design
1) The International Federation for Structural Concrete.
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In the case of non-conformity to the performance criteria,
the structure becomes obsolete or subject to full or partial redesign

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ISO 16204:2012(E)
Within Clause 6 the following deterioration mechanisms are addressed:
— carbonation-induced corrosion;
— chloride-induced corrosion;
— freeze/thaw attack without de-icing agents or sea-water;
— freeze/thaw attack with de-icing agents or sea-water.
For these mechanisms widely accepted mathematical models exist.
The other deterioration mechanisms:
— chemical attack, and
— alkali-aggregate reactions,
are not treated in detail primarily because widely accepted mathematical models do not exist at present.
To make this International Standard complete, the missing models have to be developed and comply with the
general principles of Clause 5.
This International Standard includes four informative annexes giving background information for the application
in service life design and one informative annex giving guidance for the preparation of a possible national annex.
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INTERNATIONAL STANDARD ISO 16204:2012(E)
Durability — Service life design of concrete structures
1 Scope
This International Standard specifies principles and recommends procedures for the verification of the durability
of concrete structures subject to:
— known or foreseeable environmental actions causing material deterioration ultimately leading to failure
of performance;
— material deterioration without aggressiveness from the external environment of the structure, termed self-
ageing.
NOTE The inclusion of, for example, chlorides in the concrete mix might cause deterioration over time without the
ingress of additional chlorides from the environment.
This International Standard is intended for use by national standardization bodies when establishing or
validating their requirements for durability of concrete structures. It may also be applied:
— for the assessment of remaining service life of existing structures; and
— for the design of service life of new structures provided quantified parameters on levels of reliability and
design parameters are given in a national annex to this International Standard.
Fatigue failure due to cyclic stress is not within the scope of this International Standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced document
(including any amendments) applies.
ISO 2394, General principles on reliability for structures
ISO 13823, General principles on the design of structures for durability
ISO 22965-1, Concrete — Part 1: Methods of specifying and guidance for the specifier
ISO 22965-2, Concrete — Part 2: Specification of constituent materials, production of concrete and
compliance of concrete
ISO 22966, Execution of concrete structures
ISO 6935 (all parts), Steel for the reinforcement of concrete
2)
ISO 16311 (all parts), Maintenance and repair of concrete structures
2) To be published. ISO 16311-1, -2, -3 and -4 are under preparation.
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ISO 16204:2012(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
basic variable
part of a specified set of variables representing physical quantities, which characterize actions and environmental
influences, material properties including soil properties, and geometrical quantities
[ISO 2394:1998, 2.2.18]
3.2
characteristic value
X or R
k k
value of a material or product property having a prescribed probability of not being attained in a hypothetical
unlimited test series
NOTE 1 This value generally corresponds to a specified fractile of the assumed statistical distribution of the particular
property of the material or product.
NOTE 2 A nominal value is used as the characteristic value in some circumstances.
3.3
characteristic value of a geometrical property
a
k
value usually corresponding to the dimensions specified in the design
NOTE Where relevant, values of geometrical quantities may correspond to some prescribed fractiles of the statistical
distribution.
3.4
characteristic value of an action
F
k
principal representative value
NOTE It is chosen:
— on a statistical basis, so that it can be considered to have a specified probability for not being exceeded towards
unfavourable values during a reference period;
— on acquired experience; or
— on physical restraints.
[ISO 2394:1998, 2.3.12]
3.5
design criteria
quantitative formulations that describe for each limit state the conditions to be fulfilled
3.6
design service life
assumed period for which a structure or a part of it is to be used for its intended purpose with anticipated
maintenance, but without major repair being necessary
3.7
design situation
set of physical conditions representing a certain time interval for which the design demonstrates that the
relevant limit states are not exceeded
[ISO 2394:1998, 2.2.1]
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ISO 16204:2012(E)
3.8
design value of a geometrical property
a
d
generally a nominal value
NOTE 1 Where relevant, values of geometrical quantities may correspond to some prescribed fractile of the statistical
distribution.
NOTE 2 The design value of a geometrical property is generally equal to the characteristic value. However, it may
be treated differently in cases where the limit state under consideration is very sensitive to the value of the geometrical
property. Alternatively, it can be established from a statistical basis, with a value corresponding to a more appropriate
fractile (e.g. rarer value) than applies to the characteristic value.
3.9
design value of an action
F
d
value obtained by multiplying the representative value by the partial factor γ or γ .
f F
[Modified from ISO 2394:1998, 2.3.16]
3.10
design value of material or product property
X or R
d d
value obtained by dividing the characteristic value by a partial factor γ or γ , or, in special circumstances, by
m M
direct determination
NOTE See 5.4.2 (3).
[Modified from ISO 2394:1998, 2.4.3]
3.11
execution specification
documents covering all drawings, technical data and requirements necessary for the execution of a particular project
NOTE The execution specification is not one single document but signifies the total sum of documents required for
the execution of the work as provided by the designer to the constructor and includes the project specification prepared
to supplement and qualify the requirements of this International Standard, as well as referring to the national provisions
relevant in the place of use.
[ISO 22966:2009, 3.8]
3.12
inspection
conformity evaluation by observation and judgement accompanied as appropriate by measurement,
testing or gauging
[ISO 9000:2005, 3.8.2]
3.13
limit state
state beyond which the structure no longer satisfies the relevant design criteria
NOTE Limit states separate desired states (no failure) from undesired states (failure).
[Modified from ISO 2394:1998, 2.2.9]
3.14
maintenance
set of activities that are planned to take place during the service life of a structure in order to fulfil the requirements
for reliability
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ISO 16204:2012(E)
3.15
project specification
project-specific document describing the requirements applicable for the particular project
[ISO 22966:2009, 3.15]
3.16
reference period
chosen period of time which is used as a basis for assessing values of variable actions, time-dependent
material properties, etc.
[ISO 2394:1998, 2.2.8]
3.17
reliability
ability of a structure or a structural member to fulfil the specified requirements, including the design service life,
for which it has been designed
NOTE 1 Reliability is usually expressed in probabilistic terms.
NOTE 2 Reliability covers safety, serviceability and durability of a structure.
[Modified from ISO 2394:1998, 2.2.7]
3.18
reliability differentiation
measures intended for socio-economic optimization of the resources to be used to build construction works,
taking into account all expected consequences of failures and the cost of the construction works
3.19
repair
activities performed to preserve or to restore the function of a structure that fall outside the definition of maintenance
3.20
representative value of an action
F
rep
value used for the verification of a limit state
NOTE Representative values consist of characteristic values, combination values, frequent values and quasi-
permanent values, but may also consist of other values.
[ISO 2394:1998, 2.3.11]
3.21
resistance
capacity of a member or component, or a cross-section of a member or component of a structure, to withstand
actions that lead to deterioration
3.22
serviceability limit state
state that corresponds to conditions beyond which specified service requirements for a structure or structural
element are no longer met
[ISO 2394:1998, 2.2.11]
3.23
serviceability criterion
design criterion for a serviceability limit state
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ISO 16204:2012(E)
3.24
ultimate limit state
state associated with collapse or with other similar forms of structural failure
NOTE They generally correspond to the maximum load-carrying resistance of a structure or structural element, but
in some cases to the maximum applicable strain or deformation.
[ISO 2394:1998, 2.2.10]
4 Symbols and abbreviated terms
4.1 Abbreviated terms
SLD service life design
SLS serviceability limit state
ULS ultimate limit state
4.2 Main letters
F action in general
R resistance
S action effect
T temperature
X basic variable
a geometric quantity
p probability
t
time
x
distance
α
ageing factor
Δ
margin
γ
partial factor
γ partial factor for concrete
c
γ partial factor for actions without taking account of model uncertainties
f
γ partial factor for actions, also accounting for model uncertainties and dimensional variations
F
γ partial factors for a material property, taking account only of uncertainties in the material
m
property
γ partial factors for a material property, taking account of uncertainties in the material
M
property itself and in the design model used
γ partial factor associated with the uncertainty of the resistance model, plus geometric
Rd
deviations if these are not modelled explicitly
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ISO 16204:2012(E)
4.3 Subscripts
app apparent
crit critical
d design value
dep depassivation
ini initiation
k characteristic value
prop propagation
nom nominal value
rep representative value
SL service life
5 Basis of design
5.1 Requirements
5.1.1 Basic requirements
The service life design (SLD) of concrete structures shall be in accordance with the general principles given in
ISO 2394 and ISO 13823.
The supplementary provisions for concrete structures given in this International Standard shall also be applied.
The service life design shall either:
— follow the general principles for probabilistic service life design of concrete structures outlined in ISO 2394
(the full probabilistic method);
— use the partial factor method given in this International Standard;
— use the deemed-to-satisfy method given in this International Standard;
— be based on the avoidance-of-deterioration method given in this International Standard.
The serviceability criteria related to durability shall be specified for each project and agreed with the client.
NOTE Guidance for the choice of serviceability criteria combined with appropriate target values of reliability are
[3] [1] [6]
given in Annex E of ISO 2394:1998 , Annex A of fib MC SLD and in JCSS Probabilistic Model Code .
5.1.2 Reliability management
Reliability management shall be in accordance with the general principles given in ISO 2394.
[3]
NOTE In ISO 2394:1998 , these provisions are given in Clause 4.
As guidance to reliability differentiation, this International Standard refers to the following general classifications:
— consequence classes CC1, CC2 and CC3;
— reliability classes RC1, RC2 and RC3.
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ISO 16204:2012(E)
The three consequence classes relate to minor, moderate and large consequences of failure or inadequate
serviceability of the structure.
The three reliability classes may be associated with the three consequence classes.
[3]
NOTE 1 The three-level differentiation corresponds to that in ISO 2394:1998 , 4.2
[7]
NOTE 2 ISO 13823:2008 , 8.5 and 8.6 apply a four-level differentiation for consequences of failure.
The required level of reliability may be achieved by measures related to, for example, the robustness
of the design and to measures related to quality assurance adopted in the design, execution as well as
inspection/maintenance during a structure’s service life.
NOTE ISO 22966 defines three execution classes, EXC1, EXC2 and EXC3, for the quality management regime, for
which the required strictness increases from class 1 to class 3.
In addition, for service life design, Annex D classifies four levels of condition assessment during the service life:
CAL0, CAL1, CAL2 and CAL3
5.1.3 Design service life, durability and quality management
The design of service life, durability and quality management shall be in accordance with the general principles
given in ISO 2394.
[3]
NOTE In ISO 2394:1998 these provisions are given in Clause 4.
,
The design service life is the assumed period for which a structure or part of it is to be used for its intended
purpose with anticipated maintenance, but without major repair being necessary.
The design service life is defined by
— a definition of the relevant limit states,
— a number of years, and
— a level of reliability for not passing each relevant limit state during this period.
Durability of a structure exposed to its environment shall be such that it remains fit for use during its design
service life. This requirement may be satisfied in one, or a combination, of the following ways:
— by designing protective and mitigating systems;
— by using materials that, if well maintained, will not degenerate during the design service life;
— by providing such dimensions that deterioration during the design service life is compensated for;
— by choosing a shorter lifetime for structural elements that when necessary are replaced one or more times
during the design life;
— in combination with appropriate inspection at fixed or condition-dependent intervals and appropriate
maintenance activities.
In all cases, the reliability requirements for long- and short-term periods should be met.
5.2 Principles of limit state design
The limit state design shall be in accordance with the general principles given in ISO 2394.
[3]
NOTE In ISO 2394:1998 , these provisions are given in Clause 5.
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ISO 16204:2012(E)
5.3 Basic variables
5.3.1 Actions and environmental influences
Characteristic values of actions for use in SLD shall be
— based on data derived for the particular project, or
— from general field-experience, or
— from relevant literature.
Other actions, when relevant, shall be defined in the design specification for the particular project.
Actions specific to SLD may be given in a national annex to this International Standard.
5.3.2 Material and product properties
The material and product properties shall be identified in accordance with the general principles given in ISO 2394.
[3]
NOTE In ISO 2394:1998 , these provisions are given in Clause 6.
Characteristic values of materials and product properties for use in SLD shall be
— based on data derived for the particular project, or
— from general field-experience, or
— from relevant literature.
Materials and product properties to be determined will depend on the deterioration model used. If different
models with different basic assumptions are applied for mapping the material properties and in the SLD, a
checking process shall be established to ensure that the selected model and applied data are compatible.
Material property values shall be determined from test procedures performed under specified conditions. A
conversion factor shall be applied, when necessary, to convert the test results of laboratory cast and tested
specimens into values that are assumed to represent the behaviour of the material or product in the structure.
5.3.3 Geometric data
Design values of geometrical data for SLD shall be in accordance with ISO 2394 or based on measurements
on the completed structure or element.
[3]
NOTE In ISO 2394:1998 , these provisions are given in Clause 6.
ISO 22966 specifies permitted geometrical deviations. If the design assumes stricter tolerances, the design
assumptions shall be verified by measurements on the completed structure or element.
5.4 Verification
5.4.1 Verification by the full probabilistic method
The general principles for probabilistic service life design of concrete structures outlined in the ISO 2394
shall be followed.
In particular the following three principles shall be applied:
— probabilistic models shall be applied that are sufficiently validated to give realistic and representative results;
— the parameters of the models applied and their associated uncertainty shall be quantifiable by means of
tests, observations and/or experience;
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ISO 16204:2012(E)
— reproducible and relevant test methods shall be available to assess the action- and material-parameters.
Uncertainties associated with models and test methods shall be taken into account.
5.4.2 Verification by the
...