second generation of the eurocodes addressing … jrc side event to the 4th eu standardisation...

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JRC side event to the 4th EU Standardisation Summit Riga, LV, June 3, 2015

Second generation of the Eurocodes –

addressing new challenges

Michael N. Fardis University of Patras, Greece

Vice-Chairman, CEN/TC250: ”Structural Eurocodes”

EUROCODES

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Role of Technical Standards

in the European Economic Area

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Technical Standards as barriers to international trade

World Trade Organisation (WTO) (ex-GATT):

Agreement on Technical Barriers to Trade

(“The Standards Code”):

• Binds the 161 WTO Members to ensure that technical standards or regulations do not create unnecessary obstacles to trade.

• Has created the basis for International Standards (IS), ensuring their supremacy to national ones.

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WTO Agreement on Technical Barriers to Trade (“Standards Code”)

‒ “Members shall ensure that technical regulations or standards are not

prepared, adopted or applied with a view to or with the effect of creating

unnecessary obstacles to international trade”.

‒ “Where technical regulations or standards are required and relevant

international standards exist or their completion is imminent, Members shall

use them .. as a basis for their technical regulations”.

‒ “A Member preparing, adopting or applying a technical regulation which may

have a significant effect on trade of other Members shall .. explain the

justification for that technical regulation .. ”.

‒ “Members shall play a full part, within the limits of their resources, in the

preparation by appropriate international standardizing bodies of International

Standards for products for which they either have adopted, or expect to

adopt, technical regulations or standards.. ”.

‒ “..unnecessary duplication should be avoided between the work under this

Agreement and that of governments in other technical bodies..”.

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Agreement between ISO and CEN (“Vienna Agreement”)

CEN achieved a derogation from the “Standards Code”:

“Agreement on technical co-operation between ISO

and CEN” (the “Vienna Agreement” 1991)

Freedom to develop European Technical Standards

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The “Vienna Agreement” 1991

• .. recognises the primacy of International Standards.

• .. recognises that particular needs of the Single European Market might require .. standards for which a need has not been recognised at the international level.

• The prioritization of ISO work is such that in some instances CEN needs to undertake work which is urgent in the European context, but less so in the international one.

• ISO recognises and respects that CEN operates within and must respect a political environment set both in the EEA and through a co-operation of the European Standards Organizations;

• ISO and CEN are committed to values such as transparency, openness, coherence, impartiality and relevancy. CEN supports coherence via withdrawal of conflicting national standards upon publication of a European standard;

• Standards development is done in either ISO or CEN, but both bodies ensure that the processes of consensus confirmation and approval are synchronized to achieve the objective of simultaneous publication;

• The transfer of work from CEN to ISO is the preferred route, but is not automatic;

• When expected results are not attained, the party which is not satisfied can decide to proceed separately;

• CEN commits to respond adequately to comments from non-CEN ISO members.

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Structural design standards (CEN): The Eurocodes

Material standards (steel,

concrete, etc) – CEN;

Product standards (e.g.,

structural bearings,

prefabricated structural

members) - CEN

ETAs: European

Technical Approvals

(eg, Fibre-Reinforced

Polymers, prestressing

systems, etc.) - EOTA

Execution standards (construction of concrete,

steel, etc, structures) - CEN

Test standards - CEN

The Eurocodes in the system of European Standards for construction

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The history and the context of the

Eurocodes at a glance

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25/3/1957

Rome

Treaty

10/3/1979

European

Monetary

System

12/7/1986

Unique Act

New

Approach

The Eurocodes in the European Economic Community

Public

Procurement

Directive

71/305/CEE

1989 Construction Products

Directive 89/106/CEE

Essential requirements

1) Mechanical resistance & stability

2) Safety in case of fire

3) Hygiene, health, environment

4) Safety in use

5) Protection against noise

6) Energy economy, heat retention

Interpretative documents 1994

Directive

92/50/CEE

Public

procurement

contracts

Directive

93/37/CEE

Public works

contracts

1976

Steering

Committee of

Eurocodes

1980

First

Eurocodes

(ECs)

1990

Transfer of

ECs to CEN

TC250

1991-96

pre-

Standards

ENVs

1/11/93

EEC

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The Eurocodes in the European Union

1998

«Conversion»

of ENVs to

ENs starts

1997

Directive

97/52/CE

Public

procurement

services

2003 Commission’s

Recommendation to Member

States 03/C4639 /CEE

“Implementation & use of

Eurocodes”

1) Adopt ECs

2) Use ECs in Specs for

public sector & energy, water,

transport, telecom works

3) Member States competent

on safety & economy:

Nationally Determined

Parameters (NDPs)

4) Compare, harmonize NDPs

2011 Construction Products

Regulation 305/2011/EU

Basic requirements

1) Mechanical resistance &

stability

2) Safety in case of fire

3) Hygiene, health,

environment

4) Safety in use

5) Protection against noise

6) Energy economy, heat

retention

7) Sustainable use of

resources

EU

Dec. 2012

Specific Mandate M515

EC invites CEN to

develop work

programme for 2nd

generation of EN-

Eurocodes

2007

All

Eurocodes

published

as ENs

2004

Directive

04/18/CE

Public

procurement

1/11/93

2014

Directive

14/24/EU

Public

procurement

Dec. 2014

Grant Agreement

EC to CEN: Phase

1 of 2nd

generation of EN-

Eurocodes

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Commission Recommendation: Implementation/Use of Eurocodes

European Commission: “Commission Recommendation on the implementation and use of Eurocodes for construction works & structural construction products” Document No. C(2003)4639, Brussels (2003)

• Member States (MSs) should adopt the Eurocodes as a suitable tool for designing construction works, checking the mechanical resistance of components or checking the stability of structures.

• The Eurocodes are to be used by contracting authorities in technical specifications relating to the coordination of procedures for the award of public service contracts ... Technical specifications are to be defined by the contracting authorities by reference to national standards implementing European standards.

• MSs should take all necessary measures to ensure that structural construction products calculated in accordance with the Eurocodes may be used, and should therefore refer to the Eurocodes in their national regulations on design.

• MSs should inform the Commission of all national measures in accordance with the Recommendation.

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Objectives of the Eurocodes

• Means to prove compliance of building and civil engineering works

with the essential requirements of Council Directive 89/106/EEC &

European Regulation 305/2011/EU, particularly with Requirements

N°1 – Mechanical resistance and stability – and N°2 – Safety in case

of fire;

• Basis for specifying contracts for construction works and related

engineering services;

• Framework for drawing up harmonized technical specifications for

construction products (ENs and ETAs)

• Means to improve the functioning of the Single Market for products &

engineering services, by removing obstacles arising from different

nationally codified practices for structural design

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The present

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The first generation of EN-Eurocodes

EN 1990 Eurocode: Basis of structural design

EN 1991 Eurocode 1: Actions on structures

EN 1992 Eurocode 2: Design of concrete structures

EN 1993 Eurocode 3: Design of steel structures

EN 1994 Eurocode 4: Design of composite (steel-concrete)

structures

EN 1995 Eurocode 5: Design of timber structures

EN 1996 Eurocode 6: Design of masonry structures

EN 1997 Eurocode 7: Geotechnical design

EN 1998 Eurocode 8: Design of structures for earthquake

resistance

EN 1999 Eurocode 9: Design of aluminium structures

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EN1990

EN1991

EN1992

concrete

EN1993

steel

EN1994

composite (steel-concrete)

EN1995

timber

EN1996

masonry

EN1999

aluminium

Structural

safety,

serviceability

durability

Actions

on

structures

Material

Eurocodes,

design &

detailing

EN1997

geotechnical

EN1998

seismic

Horizontal

service

Eurocodes

Interrelation and hierarchy of Eurocodes

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Flexibility in the Eurocode system

• Eurocodes do not allow design with rules other than their own.

• National choice may be exercised through the National Annex, only where the

Eurocode itself explicitly allows:

1. Choosing a value for a parameter, for which a symbol or range of values is

given in the Eurocode;

2. Choosing among alternative classes/models fully described in the

Eurocode;

3. Adopting an Informative Annex or referring to an alternative national

document, complementing and not contradicting the Eurocode.

• Items of national choice in 1-2: Nationally Determined Parameters (NDPs)

• National choice through NDPs:

On issues controlling safety, durability & economy (national competence) &

where there are geographic or climatic differences (eg, seismic hazard)

• For cases 1 & 2, the Eurocode itself recommends (in a Note) a choice. The

European Commission urges Member States to adopt the recommended

choice, to minimize diversity within the Single Market.

• If a National Annex does not exercise national choice for a NDP, designer

and/or the owner may choose, depending on the conditions of the project.

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Towards the 2nd Generation of

EN-Eurocodes

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From the 1st to the 2nd generation

2010

National Standards

withdrawn

Programming

Mandate of EC to

CEN for 2nd

generation of ECs

CEN response to Programming

Mandate. Construction

Products Regulation

Maintenance: Corrigenda; Amendments

of EN-Eurocodes, without major changes.

Preparation of evolution of EN-

Eurocodes.

Dec. 2012: Specific Mandate M515 of EC to CEN for 2nd generation;

April 2013: CEN/TC250’s response to Mandate. Dec. 2014: EC/EFTA Contract with CEN, Phase 1

Evolution to the 2nd

generation of

Eurocodes:

New Eurocodes and

revision of 1st generation

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Specific Mandate 515 of EC to CEN

• Scope:

Amend Eurocodes of 1st generation;

Develop new Eurocodes.

• Directions:

Encourage innovation;

Take into account new demands and needs of society;

Harmonise national technical initiatives on new topics

of interest for construction sector;

Improve user-friendliness.

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CEN/TC250’s response to specific Mandate 515

• Finalised: April-May 2013.

• Drawn up by CEN/TC250 Chairman, Steve Denton, with

input/support from CEN/TC250.

• ~140p.-long document, specifying in detail the technical

work programme and its organisation.

• Work to be carried out in four overlapping Phases, each

one to take ~three-and-a-half years and start with ~one-

year time-lag from the previous one.

• Phase 1 is the most important and corresponds to about

one-half of the total effort and cost.

• Target end-date of all four Phases: 2020-21.

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Grant Agreement EC-CEN for Specific Mandate 515

• Funding ≈ €4.3M for Phase 1 out of 4

of the evolution to the 2nd generation;

• Duration of Phase 1: Jan. 1, 2015 to

Oct. June 30, 2018 (42 months);

• Budget-wise, the largest-ever

standardisation agreement; Yet, amount of technical effort which will

be, or has already been invested, directly

or indirectly, in Phase 1: one order of

magnitude more than the EC funding.

• Over 200 experts directly involved: International open call for interest and

tenders and two-tier evaluation by different

panels of select experts;

Direct involvement of those serving CEN/

TC250 from positions of responsibility (see

next slide) and the members of TC250’s

subcommittees.

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Mode of work

• For each Eurocode part, a six-strong “Project Team” (including the

convenor) will be chosen via the two-tier evaluation, to prepare

under contract:

drafts of the new Eurocode,

background documents.

• “Project Teams” will report on a bimonthly basis.

• The competent Subcommittee of CEN/TC250 will monitor and

technically evaluate the drafts to be produced by each “Project

Team” and have them revised to its satisfaction.

• National standards bodies and mirror groups will evaluate the drafts

and comment (indirectly, via the Subcommittee members, or

directly, through a structured review and commenting procedure).

• The final outcome of the joint effort of a “Project Team”, the

competent Subcommittee and the experts working at national level

in mirror groups will be issued first as a Technical Specification:

the basis for Formal Voting by National Standards Bodies as a new EN

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General objectives of the evolution

• Reduce number of Nationally Determined Parameters.

• Enhance “Ease of use” by:

Improving clarity;

Simplifying routes through the Eurocodes;

Limiting, where possible, alternative application rules;

Avoiding/removing rules of little practical use in design;

etc.

• Fill voids in scope.

• Consolidate; produce short, succinct texts.

• Ensure stability for users:

Evolution, not Revolution!

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Principles (listed in order of decreasing importance):

1. Improve clarity/understandability of technical provisions;

2. Improve accessibility to technical rules, ease of navigation between them;

3. Improve consistency within and between Eurocodes;

4. Include State-of-the-Art material based on commonly accepted research

results & validated by practical experience

5. No fundamental changes to design approach in 1st generation EN-

Eurocodes & in document structure;

6. Clear guidance for all common design cases;

7. Limit coverage of special cases, very rarely encountered by designers, to

only general and basic technical provisions;

8. Expert practitioners free to work from first principles & innovate;

9. Limit alternative application rules for the same situation.

10. Simplified methods only if a) of general application and for common

situations, b) technically justified and safe-sided.

11. Improve consistency with standards for products or execution;

12. Avoid rules sensitive to execution tolerances unfeasible in situ.

Overarching idea: Enhance ease-of-Use

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EN1990

EN1991

EN1992

concrete

EN1993

steel

EN1994

composite (steel-concrete)

EN1995

timber

EN1996

masonry

EN1999

aluminium

Structural

safety,

serviceability

durability

Actions

on

structures

Material

Eurocodes,

design &

detailing

EN1997

geotechnical

EN1998

seismic

Horizontal

service

Eurocodes

New elements in the 2nd generation of Eurocodes

ENXXXX

structural glass

As

se

ss

me

nt

& r

etr

ofi

ttin

g o

f e

xis

tin

g s

tru

ctu

res

Ro

bu

stn

es

s o

f s

tru

ctu

res

Fibre-Reinforced

Polymer structures membrane

structures

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Research needs for the 2nd generation of Eurocodes

• Eurocodes should be based on mature, consensus

knowledge, not on recent, untested research outcomes.

• Nevertheless, some limited, co-normative research may be

needed, for the new Eurocode in the 2nd generation:

ENXXXX structural glass

or the new Eurocode parts concerning horizontal issues:

Assessment & retrofitting of existing structures;

Robustness of structures;

Impact of climate change.

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Research needs for Assessment & Retrofitting

Questions: 1. To what extent physical deterioration affects resistance?

2. When do changes in design requirements due to

revision of design codes make assessment necessary?

3. Are the target reliability levels for assessment of existing

structures different from those applying to design of new

structures, taking into account human safety, costs and

consequences of failure?

4. How can we update the values of the partial safety

factors based on knowledge of the structure & its

conditions (the materials, the actions it has been

subjected, its past performance, etc)?

5. How to take into account the remaining life time of the

structure for its design live loads, variable actions etc.

6. How do we account for uncertainties and define the

partial safety factors when we use nonlinear analysis?

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Research needs for Robustness

• Catastrophic failures due to unforeseen reasons more

frequent than what theory predicts for ‘normal’ loads

• Reason: Local failures have disproprtionate effect on

integrity of the whole.

• Holistic approach for hazards beyond ’normal’ design:

• accidental (explosion, impact, etc), quasi-

accidental (fire, earthquake), or human error.

• Design for one hazard should ensure synergies and

avoid antagonising resistance against other hazards.

Oklahoma

City

bombing Roland Point

gas explosion

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Research needs for climate change

• Reconcile energy efficiency with structural integrity and safety.

• Disastreous effects of anti-thermal-bridge measures on building

façades; L’Aquila (IT) earthquake of 2009.

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Research needs for the 3rd generation of Eurocodes

• Design per the current Eurocodes meets “basic requirements” 1 and

2 (“mechanical resistance & stability”, “safety in case of fire”) of

Construction Products Regulation, at near-optimal cost.

• To meet also “basic requirement 7: “Sustainable Use of Resources”:

• Need to develop quantitative criteria and limits for Sustainability, to

be addressed and met in the design of new structures or the

assessment & retrofitting of old ones, e.g.:

Global Warming Potential;

Fossil fuel consumption;

Water consumption;

Ecosystem capacity limits; etc

on a life-cycle basis and at various possible levels:

local;

regional, or

global.

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Basis for sustainability considerations in the Eurocodes:

• CEN Standards (CEN/TC350“Sustainability of construction works”) EN 15643-1:2010 “Sustainability of construction works - Sustainability

assessment of buildings - General framework”.

EN 15643-2:2011 “Sustainability of construction works - Assessment of

buildings - Framework for the assessment of environmental performance”.


buildings - Framework for the assessment of social performance”.


buildings - Framework for the assessment of economic performance”.

EN 15978:2011 “Sustainability of construction works — Assessment of

environmental performance of buildings — Calculation method”

EN 15804:2012 “Sustainability of construction works - Environmental

product declarations - Core rules for the product category of construction

products.”

EN 15942:2011 Sustainability of construction works - Environmental

product declarations - Communication format business-to-business.

EN 16309:2014 “Sustainability of construction works - Assessment of

social performance of buildings - Calculation methodology”.

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Basis for sustainability considerations in the Eurocodes (cont’d)

• ISO Standards:

ISO 14040:2006 “Environmental management – Life-cycle assessment –

Principles and framework”

ISO 15392:2008 “Sustainability in building construction - General

principles”

ISO 21931-1:2010 “Sustainability in building construction - Framework for

methods of assessment of the environmental performance of construction

works - Part 1: Buildings”.

ISO 21929-1:2011 “Sustainability in building construction - Sustainability

indicators - Part 1: Framework for the development of indicators and a

core set of indicators for buildings”.

ISO 13315-1:2012 “Environmental management for concrete and concrete

structures - Part 1: General principles”.

ISO 13315-2:2014 “Environmental management for concrete and concrete

structures - Part 2: System boundary and inventory data”.

ISO/TS 12720:2014 “Sustainability in buildings and civil engineering works

- Guidelines on the application of the general principles in ISO 15392”

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Sustainability: a 3rd generation issue

It is a long way from: the general principles and the background set out in

current standards for Sustainability, to

application rules implementing them in the Eurocodes.

Needed: a change in mentality;

A holistic, life-cycle approach to design.

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Thank you !

EUROCODES

second generation of the eurocodes addressing … jrc side event to the 4th eu standardisation...

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