ISO 16311-2:2024
(Main)Maintenance and repair of concrete structures — Part 2: Assessment of existing concrete structures
Maintenance and repair of concrete structures — Part 2: Assessment of existing concrete structures
This document describes general requirements and procedures for the assessment of concrete structures. The assessment can be initiated under the following circumstances, but not limited to: a) an anticipated change in use or extension of design service life; b) structural deterioration due to time-dependent actions such as corrosion of reinforcement, fatigue, etc.; c) safety and/or serviceability check (e.g. for earthquake and increased traffic actions) as required by authorities, insurance companies, owners, etc.; d) structural damage by accidental actions (see ISO 2394). This document does not cover — qualification of personnel; — contractual matters; — health and safety requirements for the protection of workers during the investigation and testing.
Entretien et réparation des structures en béton — Partie 2: Évaluation des structures en béton existantes
General Information
Relations
Standards Content (Sample)
International
Standard
ISO 16311-2
Second edition
Maintenance and repair of concrete
2024-03
structures —
Part 2:
Assessment of existing concrete
structures
Entretien et réparation des structures en béton —
Partie 2: Évaluation des structures en béton existantes
Reference number
© ISO 2024
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Framework of assessment . 3
4.1 General .3
4.2 Personnel .3
4.3 Objectives of assessment .4
4.4 Scenarios .5
4.5 Preliminary and detailed assessment .5
4.5.1 Levels of assessment .5
4.5.2 Preliminary assessment .6
4.5.3 Detailed assessment .7
4.6 Reporting results of assessment .8
4.7 Judgement and decision .8
4.8 Intervention .9
5 Site and laboratory investigation and data collection. 9
5.1 General .9
5.2 Planning and execution of inspection and data collection .9
5.3 Registration of condition .10
5.3.1 General .10
5.3.2 Registration and documentation of condition .10
5.3.3 Selection of inspection items.10
6 Evaluation and verification .11
6.1 Evaluation of action.11
6.1.1 Principle .11
6.1.2 Evaluation based on documents .11
6.1.3 Evaluation based on investigation . 12
6.2 Evaluation of materials and structural details. 12
6.2.1 General . 12
6.2.2 Average value and variability . 12
6.2.3 Concrete . 12
6.2.4 Reinforcement . 13
6.2.5 Structural details . 13
6.3 Verification of structural performance . 13
6.3.1 General . 13
6.3.2 Basis of verification . 13
6.4 Judgment .14
7 Prediction . 14
8 Recommendation. 14
9 Report . 14
Annex A (informative) Assessment levels, investigative tests and examples of assessments.16
Annex B (informative) Condition and consequence levels.32
Annex C (informative) Evaluation and verification .35
Annex D (informative) Recommendations .38
Annex E (informative) Content of the final report .40
Bibliography .42
iii
Foreword
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This document was prepared by Technical Committee ISO/TC 71, Concrete, reinforced concrete and pre-
stressed concrete, Subcommittee SC 7, Maintenance and repair of concrete structures.
This second edition cancels and replaces the first edition (ISO 16311-2:2014) which has been technically
revised.
The main changes are as follows:
— prediction has been added as Clause 7;
— some terms and definitions have been revised;
— some figures have been revised.
A list of all parts in the ISO 16311 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
Introduction
Assessment of an existing concrete structure identifies and defines areas of distress, and verifies structural
performance based on the evaluated condition of the structure. It includes the whole process from defining
the work through the investigation, evaluation, verification, prediction, and registration to the final report.
This is necessary as a basis for the design of the repair and the preparation of procedures to preserve or
extend its remaining service life.
The report, concluding the assessment, includes a description of the structure, the investigation, the results
of condition assessment, the verified structural performance, the expected future development and a short
presentation of possible repair principles and methods, including appropriate cost calculations. A detailed
planning and design of the repair work (repair or rehabilitation project specification) is not part of the
assessment, see ISO 16311-3.
This document gives the requirements for assessment of concrete structures, including a framework for
the assessment, a format for documentation of the condition assessment with assessed condition level and
consequence level, and a format for documentation of the performance assessment with verified specific
structural performance.
This document is primarily based on the principles given in ISO 13822. ISO 13822:2010, Annex B has a
detailed flowchart, included as Figure 1 in this document.
v
International Standard ISO 16311-2:2024(en)
Maintenance and repair of concrete structures —
Part 2:
Assessment of existing concrete structures
1 Scope
This document describes general requirements and procedures for the assessment of concrete structures.
The assessment can be initiated under the following circumstances, but not limited to:
a) an anticipated change in use or extension of design service life;
b) structural deterioration due to time-dependent actions such as corrosion of reinforcement, fatigue, etc.;
c) safety and/or serviceability check (e.g. for earthquake and increased traffic actions) as required by
authorities, insurance companies, owners, etc.;
d) structural damage by accidental actions (see ISO 2394).
This document does not cover
— qualification of personnel;
— contractual matters;
— health and safety requirements for the protection of workers during the investigation and testing.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements 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 13822:2010, Bases for design of structures — Assessment of existing structures
ISO 16311-1, Maintenance and repair of concrete structures — Part 1: General principles
ISO 16311-3, Maintenance and repair of concrete structures — Part 3: Design of repairs
ISO 16311-4, Maintenance and repair of concrete structures — Part 4: Execution of repairs
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13822, ISO 16311-1 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
accidental action
action that is unlikely to occur with a significant value on a given structure over a given reference period
Note 1 to entry: Accidental actions are in most cases of short duration.
3.2
condition
status of a structure or a structural member at a given time
3.3
condition level
expression of the condition of a structure or a structural member, compared to a reference level
3.4
condition registration
survey and collection of information to define the condition of a structure or structural member
3.5
consequence level
expression of seriousness of consequences related to a defined reference level
3.6
damage
unfavourable change in the condition of a structure that can affect structural performance
3.7
defect
fault or deviation from the intended level of performance of a structure or its parts
3.8
deterioration
process that adversely affects the structural performance, including reliability over time due to
— naturally occurring chemical, physical or biological actions,
— repeated actions such as those causing fatigue,
— normal or severe environmental influences,
— wear due to use, or
— improper operation and maintenance of the structure
3.9
environmental action
assembly of physical, chemical, or biological influence which can cause restraint effects or deterioration to
the materials making up the structure, which in turn can adversely affect its serviceability, restorability,
and safety
3.10
inspection
conformity evaluation by observation and judgement accompanied as appropriate by measurement, testing
or gauging
Note 1 to entry: For structures, this evaluation consists of actions collecting information on the current state of a
structure through observation and simplified non-destructive or destructive testing supplemented with materials
and structural testing, as required.
3.11
risk
combination of the probability or frequency of occurrence of an event and the magnitude of its consequences
3.12
symptom
indicator for the condition of a structure or structural member, based on one or more characteristics
3.13
visual inspection
inspection of a structure by visual observation in the preliminary investigation for its assessment
4 Framework of assessment
4.1 General
The overall assessment procedure shall comply with ISO 13822 and include the following main parts
according to Figure 1, which is a general flowchart copied from ISO 13822:
— objectives of assessment;
— scenarios;
— preliminary assessment;
— detailed assessment;
— reporting results of assessment;
— judgement and decision;
— intervention.
A site visit is recommended prior to initiating the assessment.
4.2 Personnel
An assessment shall be performed by qualified personnel.
NOTE National requirements on qualification for personnel can apply.
Figure 1 — General flowchart for assessment of existing structures
(adapted from ISO 13822:2010, Annex B)
4.3 Objectives of assessment
The objectives of the assessment of an existing concrete structure, in terms of its operable condition and its
future structural performance, shall be specified in consultation with the client (the owner, the authority,
insurance companies, etc.) based on the following performance levels:
a) safety performance level;
b) continued function performance level;
c) special performance requirements of the client.
NOTE Reference is made to ISO 13822:2010, 4.1.
The objectives of the assessment shall be determined or confirmed before starting the assessment activities.
Within the determined objectives of assessment, the assessment shall be carried out with the procedure
given in Figure 1.
The objectives of an assessment, the extent and the application of methods and resources shall be defined in
a project specification.
The extent of an assessment depends on the nature of the structure, if a rough cost estimate of recommended
actions shall be included, etc.
The content of an assessment shall be re-evaluated continuously based on the observations.
NOTE Clause A.1 gives more detailed description of the purpose and scope of a condition assessment.
4.4 Scenarios
One or some scenarios to represent a possible change in structural performance shall be specified prior to
the preparation of assessment to identify possible critical situations for the structure. These scenarios shall
be developed with an understanding of the type of construction, the timeframe of construction, and the
environment to which the structure or structural member were exposed. These scenarios include, but are
not limited to (see also ISO 16311-3):
— chloride exposure, and damage related to chloride-induced corrosion,
— carbonation-induced corrosion damage,
— mechanical damage due to (impact, overload, settlement, vibration, seismic, abrasion, fatigue, explosion, etc),
— chemical damage due to (alkali-aggregate reactions, aggressive agents, biological actions, etc),
— physical damage due to (fire, frost, thermal effects, shrinkage, erosion, wear, etc).
Possible scenarios shall be reviewed thoroughly before carrying out the assessment activities. Scenarios
shall be continuously checked during the assessment to identify possible
— critical situations for the structure, related to structural safety and serviceability,
— amendments of the layout of the assessment.
4.5 Preliminary and detailed assessment
4.5.1 Levels of assessment
The purpose and scope of the assessment is decisive for the level of assessment and the content of each
level. The assessment shall not be taken any further than what is necessary to reach a firm decision on
intervention to be taken.
Normally, the assessment is classified into two levels as follows.
a) Preliminary assessment (see 4.5.2): the aim is to provide information of the condition of the structure,
clarify causes for and seriousness of the deterioration, giving basis for indicating an overall condition
level, and a consequence level of the structure, including future safety and serviceability of the structure.
Possible immediate actions shall be decided. If necessary, a detailed assessment shall be proposed.
b) Detailed assessment (see 4.5.3): the aim is in principle the same as for preliminary assessment, but a
more detailed study of previous documents, a more detailed inspection and material testing, as well
as structural analysis and verification, shall be carried out in order to make the correct judgement and
decisions.
NOTE 1 Clause A.1 provides additional information regarding levels of assessment.
NOTE 2 Clause A.2 provides details on condition registration, including current information from construction and
operation, observation on site, possible tests on site and in laboratory as well as a listing of symptoms and possible
causes for defects.
4.5.2 Preliminary assessment
4.5.2.1 Study of documents and other data
Design and inspection documents, such as original design, drawings, project specification, structural
calculations, as built documentation, previous assessments, and intervention, etc. provide important
information. For many existing structures, it can be difficult to find such information and to be sure that
the information is correct. Both structural requirements (e.g. service load, dead load, overload, wind, snow,
etc.), and environmental conditions (e.g. chlorides, gasses, temperature, etc.) shall be documented, and if
any changes have occurred. The use and possible misuse of the structure, compared to the original design
assumptions, shall be documented, if possible.
4.5.2.2 Preliminary inspection
The preliminary inspection is primarily a visual observation, in some cases supported with simple types of
testing at the structure. This inspection shall give information on the structural system and if any surface
characteristics are visible (e.g. reinforcement corrosion, cracks, spalling, deformation etc.).
4.5.2.3 Preliminary checks
Based on the study of documents and other evidence, and the results of the preliminary inspection,
preliminary checks shall be performed. This is to identify the critical deficiencies related to the future safety
and serviceability of the structure or structural members. Such checks can be based on general knowledge
and experience, or by simple calculations.
The results of the preliminary inspection and checks shall be described by condition levels and
consequence levels.
The choice of an appropriate condition level shall be based on judgement of the observed symptoms and the
preliminary checks and related to a reference level for the structure or a structural member. Normally five
condition levels are defined from “Good” to “Unsafe”.
NOTE 1 Annex B gives a more detailed description of the condition levels.
NOTE 2 Reference levels for different cause(s) for deterioration can be provided with a picture catalogue based on
symptoms.
The consequences of the observed condition and the preliminary checks for a structure or a structural
member, if nothing is done within a certain time, shall be described by consequence levels. The consequence
levels refer to the consequence for the structure itself and are independent of the reliability class of
the structure, which shall also be recorded. Normally, five consequence levels are defined from “No
consequences” to “Potentially hazardous or (structurally) unsafe consequences”.
NOTE 3 Annex B gives more detailed description of consequence levels.
4.5.2.4 Decisions on immediate actions
When the results of the preliminary inspection and/or the checks shows that the structure is in a dangerous
condition, it shall be reported to the client that immediate interventions shall be taken in order to reduce
the dangerous situation with respect to safety of the general public, workers or occupants, and adjacent
structures. If the safety of a structure or structural member is not clearly understood after the preliminary
assessment, a detailed assessment shall be performed immediately to assess the critical deficiencies, and if
necessary, recommendations made to the client for intervention.
4.5.2.5 Recommendation for detailed assessment
When the preliminary inspection and checks clearly show that the consequences of any deficiencies are very
low and that the structure or structural members are reliable for its intended use over the remaining design
service life, a detailed assessment is not required.
In the case where a structure or structural members are reliable for a defined period of time, a plan for
future assessment shall be described.
When the preliminary inspection and checks are not able to give answer to the question of reliability and
serviceability of a structure or a structural member, or the information is insufficient for planning necessary
intervention, a detailed assessment shall be recommended.
4.5.3 Detailed assessment
4.5.3.1 Detailed documentary search and review
The detailed assessment shall be done based on values of basic variables corresponding to the actual
situation. For that purpose, investigation shall be intended to update the knowledge about the present state
of the structure.
This includes a more comprehensive search and review of documents than described in 4.5.2.1 and is based
on the preliminary assessment. Especially documents covering the following, if available, shall be reviewed:
a) drawings, specifications, structural calculations, construction records, inspection and maintenance
records, details of modifications;
b) regulations, by-laws, codes and standards which were originally used for design, calculations and
execution of the structure;
c) topography, subsoil and environmental conditions, groundwater level at the site.
4.5.3.2 Detailed inspection and material testing
The aim of the detailed inspection and material testing is to determine the cause(s) for the deterioration
and the extent, as well as providing necessary information on dimensions of components and properties
of materials assumed for structural analysis and necessary for planning possible interventions. Detailed
inspection and material testing shall be carried out to collect more specific and useful data for evaluating
the detailed information. Some necessary non-destructive and/or minor-destructive test methods shall be
applied.
Detailed inspection and material testing shall result in supplementary information to the information found
in the detailed documentary search and review.
4.5.3.3 Determination of actions
All kind of actions, both mechanical and environmental actions on the structure or structural members, shall
be determined by analysis in accordance with ISO 2394, and evaluated on the basis of the current design
codes, and taking into account provisions laid down in the safety and utilization plan. Changes of actions
caused by the change in use or modification of the structure, shall be taken into consideration per 6.3.2.
4.5.3.4 Determination of properties of the structures
In some situations, the response of the structure or a structural member from action(s) shall be tested in
order to predict the load-bearing capacity. This can be both static and dynamic testing. Load testing of a
structure or structural member is very costly and time-consuming. However, this type of testing is normally
not necessary, and used only when other approaches, such as detailed structural analysis or inspection alone
do not provide clear indication or have failed to demonstrate adequate structural reliability. When this type
of testing has to be performed, reference is made to ISO 13822:2010, Annex D.
4.5.3.5 Structural analysis
Based on detailed documentary review, inspection and material testing, a structural analysis shall be carried
out to determine the effects of the actions on the structure or structural members. When deterioration
of an existing structure is observed, which is the normal situation for existing structures, the reliability
assessment of the structure becomes a time-dependent deterioration challenge and this time-dependent
development shall be taken into account.
A structural analysis can be based on the principles given in ISO 2394. However, the limit state method
developed in ISO 2394, has been adopted and used for preparing and harmonizing national and regional
standards for structural design around the world, and in most situations, national codes and standards for
safety philosophy and structural calculations, shall be employed.
When time-dependent structural analysis has to be performed, some examples of appropriate analysis
methods are found in ISO 13822:2010, Annex E. However, in most situations, national codes, standards, and
guidelines for safety philosophy and time-dependent models, can be employed.
NOTE 1 For time-dependent deterioration, it is often more practical to use limit states like time to initiation of
corrosion for reinforcement corrosion, based on data from the structure.
NOTE 2 ISO 16204 gives methods for evaluating time-dependent deterioration.
4.5.3.6 Verification
Based on the results from the evaluation and from the detailed assessment, the structural performance
shall be verified with reference to defined requirements, i.e. requirements from government (e.g. standards,
codes), owner, designer, user, etc. If necessary, structural analysis can be carried out to investigate structural
behaviours with the consideration of the investigated properties. The results from the assessment shall be
documented to clearly indicate and explain the investigated results.
Current codes and standards shall be used in the verification. Former codes and standards that were valid
at the time of construction of an existing structure shall be used as informative documents. Alternatively,
verification can be based on satisfactory past performance, taking into account time-dependant development
of deterioration processes. If this approach is to be employed, reference is made to ISO 13822:2010, Clause 8.
A more detailed presentation of evaluation and analysis of results of assessment for existing concrete
structures are given in Clause 6.
4.6 Reporting results of assessment
As the final step, all the investigated and assessed results shall be documented in a report as presented in
Clause 9.
4.7 Judgement and decision
Based on all information available from documentary review, inspection, and material testing, judgement
and decisions shall be made.
The condition of a structure is classified in a condition level and a consequence level (see Annex B).
The probability that a given consequence can occur for a structure, or a structural member, at the present
time or in the future, shall be evaluated. The conclusions drawn from this evaluation will provide an estimate
of the risk represented by the defect.
The risk shall be evaluated and reported and be the basis for recommending whether any immediate
action(s) are necessary or not. The consequence(s) leading to the risk shall be reported.
NOTE Annex C gives more detailed description of evaluation and verification.
If necessary, this shall end up with a project specification for maintenance and repair of a structure or a
structural member. Reference shall be made to ISO 16311-3, which gives information on planning and design
of maintenance, repair and prevention.
4.8 Intervention
When intervention of any kind is necessary, this is described in the project specification. Reference shall be
made to ISO 16311-4, which gives information on the execution of maintenance, repair and prevention.
5 Site and laboratory investigation and data collection
5.1 General
The work on site and in the laboratory is a costly part of the assessment. It shall be planned carefully to
perform the work in an effective way and on schedule.
To perform an assessment, the scope, the object to be assessed, the parties involved and their responsibilities
shall be clearly defined by a qualified person. This shall be given in a project specification including at least
— a description of the work to be carried out, methods and the resources to be used,
— safety instructions and care to the surroundings,
— what the report shall include,
— estimated cost and time schedule.
NOTE A project specification can, in some situations, be split into different documents. One part can be a definition
and a description of the work as a basis for tender. One part can cover the planning of the work. One part can cover the
survey and inspection itself. When a project specification is split into several parts, the subsequent parts depend on
the results of the previous parts.
5.2 Planning and execution of inspection and data collection
The procedures and items of inspection shall be properly planned to achieve the aims of the assessment.
Required detailed information for verification shall be obtained from the assessment. The engineer in
charge shall clearly understand any primary concerns on structural performance and durability, and the
importance of inspection items shall be considered before the inspection work starts.
The planning includes all preparatory work to be done by the inspector in order to carry out the assessment
according to the purpose and scope of the assessment.
Conditions where the structure is located, that can be important for the execution of the work on site, shall
be listed. It shall be decided if a visit to the structure is necessary before finalizing the planning.
Original information of the structure like drawings, calculations, and as built information shall be evaluated,
if possible. Pre-stressed concrete structures require specialized expertise to complete their assessment.
Information from the service life of the structure, e.g. loads, environmental exposure, earlier condition
assessments, and possible repair work, shall be evaluated, including strengthening by, e.g. composites.
A system for registration shall be worked out so that all observations and measurements are unambiguously
located on the structure.
A detailed plan for what to do where on the structure, based on the purpose and aim of the inspection, shall
be worked out.
A list of equipment shall be worked out, necessary for carrying out the planned work during the inspection
on site.
Time and cost for the planned work, both on site, in laboratory as well as evaluating the registrations and
the test results, and preparing the report, shall be a part of the planning.
The inspection and data collection shall be executed to obtain required data for verification of structural
performance, durability, and remaining service life, based on the planning of the assessment.
NOTE Clause A.1 gives more detailed description of the planning of an assessment.
5.3 Registration of condition
5.3.1 General
Registration of condition is a systematic collection of observations and test results on site and in laboratory.
The extent of the registration shall be evaluated during the inspection to find out if the purpose and aim of
the work will be achieved.
NOTE Clause A.2 gives more detailed description of registration of condition, including properties that can be
tested on site and in laboratory with current test methods indicated.
5.3.2 Registration and documentation of condition
The condition of a structure, or a structural member, shall be assigned by a condition level (see 4.5.2.3 and
Annex B), based on one or more individual symptoms, or on a combination of more symptoms, or on test
results. The condition level shall be defined based on a reference system given in the project specification
for the assessment.
NOTE The reference for evaluating the condition level is normally the original state of the structure or the
structural member.
The condition shall be documented by description of visual inspection, sketches, drawings, photos, test
results and measurements.
If a defect is registered, with or without symptoms, it shall be given together with the reference system for
evaluation of defects. Defects shall be documented by description of visual inspection, sketches, drawings,
and photos.
5.3.3 Selection of inspection items
The detailed inspection shall include tests and measurements for concrete core strength, cover thickness,
carbonation depth, chloride ion profile, and further document review and visual inspection, if necessary
(see Annex A). The details and extent of data shall meet the requirements so that the engineer can verify
structural performance, durability, and remaining service life.
5.3.3.1 Visual inspection
Visual inspection is the most important part of a preliminary assessment.
NOTE A listing of important defects/symptoms to look for in a visual inspection is given in Table A.1.
When the information from the visual inspection performed in the preliminary assessment is not enough
for fulfilling the goal of the assessment, a further visual inspection shall be done to obtain additional data
required. All possible resources related to deterioration, deformation, and any cause of problems to the
structures, shall be examined in addition to the items of visual inspection in the preliminary assessment.
NOTE Examples of which are presented in Clause A.3.
5.3.3.2 Tests and measurements
The basic tests and measurements during the detailed assessment may include items listed in Annex A.
Annex A has a listing of current properties and test methods to be used on site and in laboratory. The
location and number of data collecting points shall be determined in accordance with the relevant national
codes, considering types of structure and homogeneity of materials. The equipment used for the test and
measurements, shall be checked in terms of accuracy necessary for evaluation and verification.
When samples of concrete and reinforcement are required for estimation of their properties, they also shall be
taken from the locations where the removal or cutting does not diminish the structural integrity and safety.
Actions on the structure shall be appropriately considered during the assessment. The information on
the actions can be obtained from design documents when there is no doubt in their accuracy. However,
the detailed evaluation of actions can be required when they are considered to be more severe than those
specified in design documents or national codes.
5.3.3.3 Documentation of results after inspection
The results of test and measurements, as well as document review and visual inspection in the detailed
inspection, shall be documented so that proper and efficient verification can be performed. The document
shall include at least the following information:
a) list of reviewed documents;
b) necessary part of the documents;
c) summary of document review;
d) method of visual inspection;
e) data of visual inspection including photos and figures;
f) summary of visual inspection;
g) items and methods of tests and measurements;
h) data of tests and measurements;
i) summary of tests and measurements;
j) locations of test specimens in the structure.
NOTE Refer to Clause 8 for additional information.
6 Evaluation and verification
6.1 Evaluation of action
6.1.1 Principle
Actions used for the assessment shall be evaluated on the basis of the current design codes. Changes of
actions caused by the change in use or modification of the structure shall be taken into consideration.
6.1.2 Evaluation based on documents
If deemed appropriate, actions may be determined from construction documents and the current design
codes. For informative purposes, actions for which the structure was originally designed may be determined
from drawings and design codes valid in the period when the original structure was designed.
6.1.3 Evaluation based on investigation
In cases when any uncertainty exists in actions, they shall be determined by investigation. Determination of
long term and extreme actions can require statistical or probabilistic analysis.
NOTE It can be advantageous to consider the specific characteristics of the structure including its surrounding
when determining actions.
6.2 Evaluation of materials and structural details
6.2.1 General
Collection of information from condition registration, including current information from construction and
operation, observa
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