tc250 newsletter

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December 2011, Issue 6

Editorial.....................................................................1

Two outstanding engineers: Marcel Tschumi and JolKruppa ...................................................................... 3

Life is So Concrete 20th BIBM InternationalCongress and exhibition...........................................4

In Memoriam Andrew Beeby................................. 5

Eurocodes workshop in Georgia .............................. 6News from JRC ........................................................7

Moscow State University of Civil Engineering honoursEurocode authors .....................................................8

From construction products to building works: theEuropean input .........................................................9

CEOS.fr - Behaviour and assessment of specialconstruction works: concrete cracking & shrinkage13

Second International Workshop Design of concretestructures and bridges using Eurocodes............... 16

Editorial

The last TC250 Newsletter was published in May2011 and many events have taken place since then.One of the major events was the finalization of theresponse to the Programming Mandate M/466concerning the future work for the Eurocodes.

The mandate M/466 in the field of StructuralEurocodes was formally sent to CEN on the 25th ofMay 2010. After long discussions within CEN/TC250(21st ENC Group meeting in Brussels on the 13th ofApril 2011, 39th meeting of CEN/TC250 in Ispra on the26th and 27th of May 2011), CEN replied to themandate with proposals, work plans and a timestrategy on the 30th of June 2011.

On the 25th of October 2011, a meeting was organizedby the Commission (Manfred Fuchs) with theparticipation of Barry Haseltine and Jean-ArmandCalgaro.

A report of this meeting is given hereafter.

1. The meeting was held to discuss thepreliminary views of the Commission on thereply of CEN to the mandate M466, document

TC/250 N914. The reply has been placed onCIRCA for information, but not (yet) forcomment.

2. Manfred Fuchs explained that he was able tospend one third of his time on Eurocodes. Hewas grateful for the reply and had read it allthrough; he was concerned by the extent of theprogramme and doubted the Commissionsability to fund it all, and also CEN/TC250sability to manage such a large programme. Heconfirmed that he had decided not to involvethe ENC group in the simplification process,so there would not be an ENC ad hoc groupfor that purpose.

The JRC shall provide a platform for allactivities in this field to allow CEN and all otherstakeholders to get an overview and learn formexamples.

3. Jean-Armand Calgaro tabled a plan showingthe possibilities for new and old groups to worktogether on new versions of Eurocodes. Heforesaw a programme of several years (as withthe conversion of ENVs to ENs), with

necessary prioritisation of work items intothose years.

4. Manfred Fuchs foresaw a maximum of threepackages to cover all of the work. Noindication of the funding will emerge until thedetailed work programmes are developed andhave been submitted through CEN to theCommission. The only indication that he couldgive was that the total budget forstandardisation work across all fields is about4.000.000 per year. Management of anyprogramme is a prime user of funding (in theconversion programme, about 50% of the

money went to NSBs for management).Funding for a programme spread out over anumber of years would depend on the otherdemands being made at the relevant times.

5. A specific work item is needed for all parts,either revisions of existing or new parts. Thelevel of detail in the reply is inadequate forfuture use, and a new schedule must be

The newsletter of CEN/TC250 is available athttp://eurocodes.jrc.ec.europa.eu

EditorsJean-Armand Calgaro, Chairman of CEN/TC250

Georgios Tsionis, University of Patras


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prepared. A spreadsheet has been prepared byinitiated by Barry Haseltine, which will need to becompleted by the chairmen of subcommittees andworking groups.

6. Manfred Fuchs will send the reply to members ofthe ENC group for comments, giving perhaps fourweeks to do so. At the same time, he will produce

a draft specific mandate for discussion. Afterreceipt of replies, a meeting of the ENC group willprobably be called, possibly in April.

7. Jean-Armand Calgaro explained how absence ofa direct interest from industry can make financialsupport for drafting imperative. For example, thereare no specific industries behind EN 1990 and EN1991, the concrete industry for EN 1992.

8. After some discussion, it was thought thatpackage 1 could consist of EN 1990, EN 1991,EN 1997, EN 1998, the head parts of WorkingGroup 2 (assessment of existing structures) and

Working Group 6 (robustness) and any necessaryinvolvement of the Horizontal Group Bridges andHorizontal Group Fire.

It does not follow that all of the individual itemslisted in the reply will be treated, but this willdepend on detailed discussions on the work itemsafter they will have been prepared.

Package 2 could consist of the items that lead toimprovements in existing codes and their use,including material-dependent additions related torobustness (Working Group 6) and structuralglass (Working Group 3).

Package 3, if it is required that there be threepackages, might cover fibre-reinforced polymers(FRP - Working Group 4), membrane structures(Working Group 5), and the material-dependentaspects of Working Group 2.

Manfred Fuchs was concerned that FRP andmembrane structures were more niche topics,with not enough empirical research and groundwork in the field of harmonisation, which wouldhardly justify funding by the Commission at thatstage. This does not exclude financing fromindustry, though.

If it turns out that only two packages are required,then the work listed in package three will need tobe re-allocated.

9. Manfred Fuchs plans to attend the CEN/TC250Coordination Group meeting in London to getcomments on the draft specific mandate. The draftmandate will then be completed by the end ofMarch, in time for an ENC meeting in April.CEN/TC250 should see the draft specific mandateand the ENC comments in May. The mandate hasto be sent to the 98/34 committee, whosetimetable is difficult to estimate.

Detailed planning of work items would have to bedone with CEN and could start in May. Funding

would be dealt with as a parallel exercise to thepreparation of work items. The Commission wouldbe involved in the development of financialaspects, so that availability of funds could be fedinto the detailed programming. This would likelymean that further prioritisation would have to beassessed if there were not to be sufficient fundsfor all desired work items. Manfred Fuchs together

with two other members of the Commission staffwill be involved.

Final work items should be ready for theCEN/TC250 meeting in November 2012, so thatthe bureaucracy could be completed for approvalin early 2013 and the work can start in mid-2013,hopefully.

10. How coordination is handled is not clear andshould be discussed with CEN. This affectschairmen of subcommittees, working groups andhorizontal groups.

11. Manfred Fuchs was disappointed to hear thatimprovements in user-friendliness (simplification)could not be expected as a separate exercisefrom the work foreseen in the work items that areproposed in the reply. He requested thatCEN/TC250 should try to prepare documents(could be published as Technical Reports) thatwould assist users with the existing parts, possiblyusing road maps or other ways, such as theDanish partial publications. Manfred Fuchs wouldprefer such help to be given through CEN/TC250rather than to appear piecemeal from countries.He was also concerned that after criticism about

the complexity of the Eurocodes, not providingany guidance to simplify the work of end-usersbefore about 2018 might seriously harm theacceptance of Eurocodes and the standardisationwork in CEN/TC250.This subject needs to bediscussed in Prague.

As a conclusion, 2012 should be a positive year to find asupport from the Commission.

Visit of ELSA Laboratory in May 2011

The CEN/TC250 Meeting in Ispra has been very positive

to formulate the response to the Mandate M466.Jean-Armand CalgaroChairman of CEN/TC250


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Life is So Concrete 20th BIBM International Congress and exhibition

The 20th BIBM international congress and exhibition washeld in Cannes (France) on 16-17 June 2011. For twodays the town of Cannes was the European capital of theprecast concrete industry as all those involved in theEuropean concrete industry gathered for the BIBMCongress under the banner Life is so concrete.

Manufacturers, suppliers, specifiers, buyers, users andall interested parties flocked to the prestigious CarltonHotel on June 16 and 17, 2011. More than 400participants not just from every corner of Europe butalso from Brazil, South Korea and Saudi Arabia tookpart in debates and round tables.

The conference room at the Carlton Hotel

This three-yearly congress run by BIBM since the 1950stakes place in a different European country every time:the 2011 congress was organized in France by theFdration de lIndustrie du Bton (FIB), with the

scientific support of the Study and Research Centre forthe French Precast Concrete Industry (Centre dtudeset de Recherches de lIndustrie du Bton CERIB).

As Pierre Brousse stressed in his opening address,BIBM, the European federation for the precast concreteindustry, fosters the international dimension of its nationalmembers and represents the industrys ambition tocooperate and to speak as one voice in todaysglobalized world.

Bearing this in mind, the event hinged upon meetingsand debates aimed at presenting the latest developmentsand the future prospects of an industry that is firmly in

step with society, offering precast concrete products thatare part of everyday life. The challenges facingtomorrows world such as achieving an environmentalbalance and the social issues involved were the focalpoint of discussions led by prominent European figures.

Around thirty specialist speakers architects, townplanners, sociologists, scientists, academics, engineers,heads of European companies presented theirviewpoints and shared their experience.

Under the heading Life is so concrete, the precastconcrete industry addressed at its 20th internationalcongress several topics of the upcoming policies and

legislation at the European level, as well as markettrends. The congress was organized with round tables

and workshops:o Round Table 1: Sustainable construction of new

towns

o Round Table 2: Society is evolving, concreteindustry and civil engineering companies are

evolvingo Round Table 3: Construction systems and seismic

risk

o Round Table 4: Concrete - it's hard to build better

o Workshop 1: Concrete solutions for architects andtown planning specialists

o Workshop 2: Risks due to fire in buildingso Workshop 3: Energy performance of concrete

buildings

o Workshop 4: Innovation in concrete productionindustry

The major topics developed during the congress weremainly devoted to the sustainable construction, thesustainable development of future cities, the evolution ofconcrete industry and building companies to better takeinto account the new societal needs, the answers ofconcrete industry for the construction of buildings inseismic zones and the contribution of concrete industry tothe improvement of the environment of citizens.

The topic of the opening round table was Building thesustainable cities of tomorrow. Speakers insisted on theneed to clearly position Man and Nature at the core ofurban projects by integrating the benefits of newtechnologies to offer residents a better livingenvironment.

The second round table addressed the changes societyhas undergone and their effects on construction anddevelopment requirements. In a situation where todayseconomic model is evolving towards an as-yet indistinctlydemarcated economic-environmental paradigm, theprecast concrete sector and the companies working in itenjoy advantages that combine the reducedenvironmental impacts of their solutions with theirorganizations ability to adapt.

In parallel with economic evolution, sociological andsocietal phenomena (population growth and ageing,mobility, etc.) are accentuating requirements, particularlyin terms of housing. The precast concrete industry canmeet these challenges with innovative, high-performance,customized solutions.

The third round table presented construction systems andseismic risk. Events in Aquila, Fukushima and Murciahave reminded us that it is vital to take seismic risk intoaccount in the design of construction systems. Eurocode8 includes calculation methods for designing buildings inearthquake-prone regions. The participants to this thirdround table were Prof. J.-A. Calgaro (CEN/TC250Chairman), Prof. M. Menegotto (Chairman of the fib

prefabrication commission), Prof. G. Toniolo (Chairmanof SAFECAST project, which focuses on improving


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The panel for the third round table : Prof. Toniolo, Prof.Calgaro, Mr. Grafeille, Prof. Menegotto, Mr. Juraszek

concrete construction systems to cater for seismicrisks), Eng. N. Juraszek (CERIB) and Captain D.Graffeille of the Brignolles civil defence unit. In hispresentation, Captain Graffeille, who had just returnedfrom Japan, stressed how well structures built inaccordance with seismic-design codes have stood upto earthquakes, and he asked for greater co-operationbetween manufacturers and urban-rescue specialists

to contribute to a better robustness of buildings inseismic zones. One important issue of the discussionwas the possibility to inform safety teams on thepossibility to get into a damaged construction to givefirst aid to people injured during an earthquake.

The last round table discussed the precast concreteindustrys very real contribution to the improvement ofliving conditions, giving users of its solutions anopportunity to speak. Whether in the fields ofarchitecture and aesthetics or in its environmental andsocietal commitments, experience proves that theprecast concrete industry has its finger on the pulse oflife.

The various workshops gave an overview of theperformance of precast concrete products throughoutEurope.

The first workshop presented concrete solutions forarchitects and urban planners. Complementaritybetween the expertise of architects and that ofmanufacturers is essential for the development ofconstruction solutions perfectly adapted to theexpectations of builders, including in respect ofinnovative applications such as self-cleaning materialsand elimination of pollution. Cement and admixturemanufacturers contribute to the success of projects byoptimizing the solutions proposed and by improvingthe conditions of their implementation.

The second workshop dealt with the prevention of firerisks. The most eminent European specialists andacademics have redefined the key role of fire safetyengineering (FSE), particularly with respect to theundertakings of rival techniques. They have exposedthe main avenues on which to engage work to definea FSE strategy for the European precast concreteindustry.

The third workshop surveyed the main Europeanenergy-efficiency benchmarks for buildings(PassivHouse, Btiment Basse Consommation) andhighlighted the solutions already provided by theindustry.

The last workshop examined the innovationsintroduced into concrete manufacturing processesthrough the new technologies developed in Europe byadmixture producers and precast concretemanufacturers in order to improve the industrialquality and performance of concrete products.

Marc LebrunChairman of CEN/TC229, Chief Executive Officer of

CERIB

In Memoriam Andrew Beeby

It can be stated without exaggeration that AndrewBeeby has had a significant influence in the wayreinforced concrete design is carried out in the UKand to an extent in Europe and other countries.This stems from his original research leading topractical application, his influential publications(over 120) and his active participation in codedrafting in the UK and Europe.

After graduating in 1960 from NorthamptonEngineering College (then a college of LondonUniversity now City University), Andrew WalterBeeby joined John Laing & Sons and worked onsite and in the design office for four years onmotorways and multi-storey structures.

In 1964 he took up a position as ResearchEngineer with the Cement and ConcreteAssociation (C&CA). His tasks included anextensive research programme on the predictionand control of cracking in reinforced and pre-stressed concrete, monitoring of structures in

service and development of design aids. He wasalso concerned with the drafting of the first BritishCode of Practice (CP 110) using limit stateprinciples. In 1971, Andrew was awarded a PhD byLondon University for his thesis The prediction ofcracking in reinforced concrete members.

Between 1978 and 1988 he took up differentpositions within C&CA culminating in hisappointment as the Director of Design andConstruction. In this period his research covered awide range of topics, such as impact resistance ofconcrete beams, cracking and corrosion, alkali-

silica reaction, shear and bond.In 1991, Andrew Beeby took up the position ofProfessor of Structural Design at the University ofLeeds. Alongside his teaching, he continued hisresearch and code drafting activities. The researchincluded the influence of ductility on the performanceof reinforced concrete members, behaviour of slabsystems during construction using the full scaleexperimental structure at Cardington, the long terminter action of steel and concrete in tension (tensionstiffening), membrane effects in frames and safety ofstructures.

Andrew Beeby was involved with CEB and fibsincethe early 1970s, when he participated in the work ofCEB commissions on cracking, calculation and


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limitation of deflections, and bending andcompression. He participated actively in all of thesecommissions, leading up to the publication of the 1978Model Code. He later became a member ofCommission 5: Serviceability, and of General TaskGroup 20: Durability and Service Life of ConcreteStructures, contributed to the CEB Design Guide onDurable Concrete Structures, and was chairman ofCEB Commission 2: Material and BehaviourModelling. He was a member of the CEB AdvisoryCommittee and later the fibSteering Committee, headof the British national group in CEB for many years,and was the first Editor-in-Chief of the StructuralConcrete Journal, a position he held until 2001.

He was an active member of fibSpecial Activity Group2, Dissemination of knowledge, contributing to boththe first and second editions of the fibStructuralConcrete textbook (Bulletin 2 in 1999 and Bulletin 52in 2010). In 2004 he was awarded Honorary LifeMembership in fib, in recognition of his manyachievements and contributions.

Andrews technical contribution to code committeeshas been prodigious. Some areas of both BritishStandards and Eurocodes derive directly from hisresearch in the area of serviceability. His work oncracking in the 1960s has stood the test of time andremains the basis for the design of crack control inconcrete structures. His studies in the 70s oncorrosion and cracking still form the basis of views onthe subject more or less world-wide.

Andrew commanded wide respect throughout theindustry. His standing and reputation are indeed highthroughout the world. He was awarded the Fellowship

of the American Concrete Institute in 1991, and in2000 the Institution of Structural Engineers honoredhim with their prestigious Lewis Kent Award. He waselected a Fellow of the Royal Academy of Engineeringin 2003. This recognition particularly pleased him. Inhis own words he was thoroughly chuffed!

He was handicapped by an illness soon after hisretirement from the University in 2004. This was acruel blow, but for which he would have contributedeven more in his field.

Andrew was a mild mannered and courteous, privateman. For all his achievements, he was very modest.

He is survived by his wife Greta, two sons and adaughter.

Concerning the Eurocodes, Andrew Beeby carried outmuch of the work on the ENV Eurocode 2 drafted bythe BCA in the UK. He chaired the working group thatproduced EN1992-3 and contributed significantly tothe development of the cracking rules in EN1991-1-1,an area where there was much debate.

Tony JonesAssociate Director, Advanced technology + Research,ARUP

Eurocodes workshop in Georgia

Following a request from the Ministry of Economyand Sustainable Development of Georgia, aworkshop on Implementation of Eurocodes inGeorgia was organized by TAIEX with thetechnical support of the JRC and CEN/TC250. Theworkshop was held in Tbilisi, Georgia on 26-27

September 2011 with the aim of providingassistance for a successful implementation of theEurocodes in Georgia.

Eurocodes workshop in Tbilisi, Georgia

The workshop was very well attended withapproximately 140 invited participants,representing Georgian national authorities, buildingand construction associations, constructionindustry associations, professionals andpractitioners, and academics. It was the first eventorganized in Georgia presenting the Eurocodesand the participants showed keen interest duringthe event to learn more about the Eurocodes.

The experts presented information that gave asolid global understanding on the scope, structureand general concepts of the Eurocodes.

The experts underlined the benefits from using theEurocodes for the construction sector, the industryand practitioners.

The experts gave advice on the development ofthe National Annexes and setting the NationalDetermined Parameters.

Many structures and bridges designed accordingto the Eurocodes were presented as successful

examples.The support provided by the Commission in theImplementation of the Eurocodes in the MemberStates was presented the participants were veryinterested in the training workshops organised bythe JRC in collaboration with CEN/TC250.

The experts noted that follow-up events arenecessary so as not to lose the momentum fromthis first event, for example: i) a training workshopwith technical content, targeted to professionalsand academics, (ii) experts visit to assist Georgianauthorities in implementation/adaption ofEurocodes.

A. AthanasopoulouJoint Research Centre, European Commission


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News from JRC

The European Commissions Joint Research Centre(JRC) continues to provide support to theimplementation, harmonisation and further developmentof the Eurocodes by developing informatics tools thatfacilitate the practical implementation of Eurocodes,fostering training and promotion of the Eurocodes withinand outside Europe, producing policy support documentsand technical reports and facilitating furtherharmonisation works.

Informatics tools

The European Commission website on Eurocodes(http://eurocodes.jrc.ec.europa.eu) is continuously beingupdated with training and awareness events, publicationsand other material on the Eurocodes. Furthermore, JRCis collecting guidance material (books, manuals,informative leaflets, etc.) on the Eurocodes and alsoinformation about state-of-the-art structures designedfollowing the Eurocodes for publication in the website.Thus, the contribution of information on events andpublications related to the Eurocodes as well asexamples of structures is highly encouraged andappreciated.

The Centralised Eurocodes Helpdesk, an IT platformdeveloped by JRC in order to assist the communicationbetween the National Standardization Bodies (NSBs) andCEN/TC250, is currently being tested by CEN/TC250members and will soon be in operation. The Helpdeskwill provide the informatics infrastructure by which theNSBs will submit/direct questions received fromEurocodes users on national level to CEN/TC250.

Nationally Determined Parameters (NDPs) Database

JRC is continuously monitoring the status of uploading ofthe Nationally Determined Parameters (NDPs) to thedatabase aiming to carry out analysis for furtherharmonisation and evolution of the Eurocodes. Withrecent contributions of Spain and Germany within thesecond semester of 2011, 25 EU member states, twoEFTA countries and one EU candidate country areregistered to the database, while 22 countries arecurrently uploading their NDPs to the database.

Approximately 26% of the total expected NDPs havebeen uploaded and some countries have alreadycompleted or almost completed their uploading (i.e.Czech Republic - 100%, Slovenia - 86%, Norway - 86%,Romania - 75%).

At this stage, the data available cannot be treated yet asa representative sample of all the expected data and thusonly preliminary conclusions can be derived regardingfurther harmonisation works for the Eurocodes. Apreliminary analysis of the available data shows that themean percentage of acceptance of the NDPsrecommended value is 75%.The highest percentages ofacceptance of the recommended values are for EN 1992(~80%), EN 1993 (~87%) and EN 1994 (~89%). Within

0%

5%

10%

15%

20%

25%

30%

35%

EN1990

EN1991

EN1992

EN1993

EN1994

EN1995

EN1996

EN1997

EN1998

EN1999

PercentageofuploadedNDPs

Nov-08Nov-10

May-11

Jul-11

Sep-11

Oct-11

Percentage of uploaded NDPs for each Eurocode in theperiod November 2008 to October 2011

the second semester of 2011, not only the number ofuploaded NDPs with recommended values increased, butalso the percentages of acceptance have ascended. Therate of high acceptance may be interpreted as anindication of the unification of European construction

practices, especially for reinforced concrete, steel andcomposite structures.

As a special case study, JRC performed a statisticalanalysis for a selected set of countries and a group ofNDPs for EN 1992. The results of the case study werepresented in the International Conference Design ofconcrete structures and bridges using Eurocodes held inBratislava on 12-13 September 2011 (A. V. Pinto, A.Athanasopoulou, M. Poljansek and B. Acun,Implementation, Harmonization and Further Developmentof the Eurocodes A case study on Eurocode 2).

Training and promotion of the Eurocodes

In order to facilitate the implementation and use of theEurocodes, JRC is preparing technical reports containingthe practical examples presented in past Eurocodesworkshops with worked examples. These workshopshave been organized by the JRC in collaboration withCEN/TC250 sub-committees, DG ENTR and nationalauthorities/contact points. Two reports are currentlyedited by JRC and will soon be published and availableto download from the Eurocodes website, namely:

o Bridge Design to Eurocodes Workedexamples (Y. Bouassida, E. Bouchon, P. Crespo,P. Croce, L. Davaine, S. Denton, M. Feldmann, R.

Frank, G. Hanswille, W. Hensen,B. Kolias, N.Malakatas, G. Mancini, M. Ortega, G. Sedlacek,G. Tsionis)

o Eurocode 8: Seismic Design of Buildings Worked examples (P. Bisch, E. Carvalho, H.Degee, P. Fajfar, M. Fardis, P. Franchin, M.Kreslin, A. Pecker, P. Pinto, A. Plumier, H. Somja)

Further, the series of training and dissemination eventsorganized by JRC continued with a workshop dedicatedto the design of concrete buildings following Eurocode 2.The workshop Eurocode 2: Design of ConcreteBuildings was held in Brussels (20-21 October 2011).

The workshop, targeted to trainers at national level,designers and Eurocode users had emphasis on worked


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120 participants from Europe and abroad attended the JRCworkshop on the design of buildings with Eurocode 2

examples. The step-by-step design of a reinforcedconcrete cast on site building following Eurocode 2was presented with each session focusing on adifferent part in the design process, namely:

conceptual design, structural analysis, limit statesdesign and verification, detailing of reinforcement andmembers, foundation and fire design. All thepresentations from the workshop are published in theEurocodes website.

Approximately 120 national delegates were registeredto the Eurocode 2 workshop and 85 delegatesattended the lectures each day of the workshop. Theparticipants were delegates from the EU memberstates, EU candidate countries and EFTA memberstates. Participants also came from countries outsideEurope (e.g. Israel, Malaysia, Morocco) showing keeninterest in the European standards for construction.The participants had the opportunity to contactcolleagues from other countries and exchange viewsand experiences on the implementation of Eurocodes(and in particular Eurocode 2) for the design ofconcrete buildings in their countries.The majority ofthe participants considered that the workshop wasuseful for subsequent training and promotion atnational level and gave a very positive evaluation ofthe organization, the technical aspects and the overallimpact of the workshop.

Mr. Tapani Mikkeli, Deputy Head of Unit from DGENTR (Construction, pressure equipment and

metrology Unit) gave a welcome speech andaddressed the importance of Eurocodes and trainingworkshops for the construction industry and policymaking. In particular, Mr. Mikkeli referred to theimportance of the JRC activities in support to theimplementation, promotion and further development ofthe Eurocodes, underlying DG ENTR plans tocontinue the collaboration with JRC-ELSA Unit.

Evolution of Eurocodes to additional fields ofdesign

JRC is promoting activities aiming to expand theconcept of Eurocodes to additional fields of designand to incorporate aspects related to sustainability,energy efficiency and other emerging issues in the

design standards for construction. These activities arein close collaboration with CEN/TC250, CEN BT/WG206 and other CEN technical committees with relevantscope of activities.

In this line, JRC participated and made a presentationat the CEN Construction Sector ConferenceInteroperability and sustainability for constructionheld in Brussels on 9-10 June 2011. The presentation

focused on the objective to achieve a full set ofcompatible and interoperable standards for the designand assessment of buildings and other civilengineering works addressing all Basic WorkRequirements (BWR) of the Construction ProductsRegulation (CPR). It was proposed that a Head-Standard (like EN 1990 Basis of Design) should bedeveloped for each BWR stating general principles inaccordance with the CPR, leading to an integratedperformance quantification and allowing also to setminimum performance requirements.

For further information visit the JRC website on

Eurocodes http://eurocodes.jrc.ec.europa.eu

orcontact us at [email protected].

A. Pinto, M. Poljansek, A. Athanasopoulou, B. AcunJoint Research Centre, European Commission

Moscow State University of CivilEngineering honours Eurocodeauthors

On the evening of Monday, November 14 aceremony was organised in Prague by adelegation coming from the Moscow StateUniversity of Civil Engineering (MGSU). Thedelegation was composed of M. Leybman, vice-rector, Prof. O. Egorychev, first vice-chancellor,Prof. I. Kirillov and Dr. O. Igorevna. During theceremony, Prof. H. Gulvanessian, Prof. M.Holicky and Prof. J.-A. Calgaro received the titleDoctor Honoris Causa of the University, thehighest award of MGSU, for their multiple scientificservices in the field of civil and structuralengineering, particularly their work on development

of the Eurocodes.

Prof. M. Holicky, Prof. J.-A. Calgaro and Prof. H.Gulvanessian during the award ceremony


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From construction products to building works: the European input

Introduction

The European Union is born from a step-by-step processdesigned by Jean Monnet and initiated by the famousdeclaration of Robert Schuman speaking on behalf of theFrench Government on 9 May 1950: Europe will not be

made all at once, or according to a single plan. It will bebuilt through concrete achievements which first create ade facto solidarity. [] The pooling of coal and steelproduction should immediately provide for the setting upof common foundations for economic development as afirst step in the federation of Europe, and will change thedestinies of those regions which have long been devotedto the manufacture of munitions of war, of which theyhave been the most constant victims.

France and Germany, together with Italy, Belgium, theNetherlands and Luxembourg, started in 1951 bycreating the European Coal and Steel Community, andlater on the European Economic Community which is, byfar, the most important achievement. Its purpose, definedby the Treaty of Rome of 1957, was to establish acustoms union, based on four freedoms: freedom ofmovement of goods, services, capital and people.

The economic growth over the years resulting from itsimplementation became so attractive that the EuropeanCommunities enlarged progressively to many newMember States. But the opening of national borders wasnot enough to get a common market of free trade. Onthe contrary, a proliferation of national technicalstandards increased the partitioning of markets, so that,in 1986, the 12 Member States signed the Single Act in

order to adopt the measures needed to eliminate allbarriers to trade and to create effectively a single unifiedmarket.

A New Approach to technical harmonization andstandards was adopted in 1989, providing a framework toharmonize national regulations for industrial products,and to develop flexible and technology-neutral legislation,by moving from detailed descriptive specifications forindividual products, to defining the performance-basedessential requirements for types of products, thuspromoting innovation and competitiveness. This NewApproach has been implemented for the construction

sector in 1989 by the European Directive 89/106/EEC,called the Construction Products Directive (CPD).

Actually, the European legislation includes:

o European regulations, which are entirely bindingand directly applicable;

o European directives, which are binding onMember States as to the result to be achieved,but leave to the respective national authorities todecide how the objectives set out in the directiveare to be incorporated into their domestic legalsystem before a certain date, and

o European decisions applying the Europeanlegislation, which are binding only on those towhom they are addressed.

It is to be noted that a new Construction ProductsRegulation (CPR) has been voted by the EU Parliament

in 2011, in order to revise and replace the CPD, and toupgrade its legal force.

Construction Products

For the purpose of the CPD, construction product meansany product which is produced for incorporation in apermanent manner in construction works, including bothbuildings and civil engineering works. Shortly, it is whatenters into the work site.

The basic principle of the CPD was established in 1979by a judgment of the European Court of Justice (the so-

called Cassis de Dijon judgment): a product soldlawfully in one Member State may not be prohibited inanother Member State.

This principle of mutual recognition effectively reversesthe burden of proof, by requiring a Member State, whichdoes not want to accept such a product on its market, todemonstrate why compliance with the requirements ofanother Member State would not adequately protect itscitizens.

Furthermore, the Court ruled that if there were Europeanregulations, directives or decisions prescribing technicalrequirements for certain products, these exceed the

national rules, and because the national rules give rise totrade restrictions, they would no longer be lawful whenEuropean technical requirements exist.

The CPD was drafted to prescribe such technicalrequirements for construction products, so that a productresponding to its prescriptions cannot anymore berefused:

o Mandatory essential requirements are defined toensure a high level of protection regarding healthand safety. They must be worded in terms thatcan be uniformly enforced by Member States, andthey must enable conformity assessment bodies

to evaluate conformity of products andstandardization bodies to develop standards toensure, partly or completely, the fulfilment ofthose essential requirements.

o Manufacturers are free to choose any appropriatetechnical solution that meets the essentialrequirements.

o Products that comply with harmonizedstandards, references to which have beenpublished in the Official Journal of the EuropeanUnion, are presumed to meet the correspondingessential requirements.

Shortened version of a contribution given to the International Conference Sustainable construction, dedicated to the 90th anniversary of theFaculty of Industrial and Civil Engineering of the Moscow State University, 19-21 April 2011


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o Appropriate conformity assessment proceduresare defined, taking into account, among otherthings, the type of risk related to the products.Where appropriate, these procedures require theintervention of third party conformity assessmentbodies, known as notified bodies.

o For any product that is not covered or not fullycovered by a harmonized standard, the

manufacturer may request alternatively for aEuropean Technical Assessment, and aEuropean Assessment Document shall be drawnup and adopted by the organization of TechnicalAssessment Bodies.

o The CE Marking symbolizes the fact that themanufacturer has verified that the productconforms to all the harmonization provisions thatapply to it and that the product has been thesubject of the applicable conformity assessmentprocedures. In a declaration of conformity, themanufacturer presents the required information on

the product and its characteristics, in the languageof the Member State in which the product is to beused. Note that this declaration of conformity,required from the manufacturer by the CPD, willbe replaced according to the new CPR by adeclaration of performance of the essentialcharacteristics of the construction product.

o Member States shall take all appropriateenforcement measures, including marketsurveillance, to ensure that non-conformingproducts are withdrawn from the market.

Performance of construction works and products

When we speak of performance, we mean the propertiesof a construction work that have to do with the behaviourdemanded of it during use so that it correctly fulfils itsfunctions. These properties are determined using unifiedsets of scientific methods (testing, measurement,calculation and observation) regardless of the materials

and processes used.

When specifying the performances of a building, ratherthan describing construction materials and processes inthe specifications, we replace an obligation of means byan obligation of results. Various constructive solutionsmay thus be compared on an equal footing, whilefreedom as large as possible is left to the designer inorder to encourage innovation.

A major step in the implementation of the performanceconcept in buildings has been accomplished at the jointRILEM-ASTM-CIB Symposium organized in 1972 by theUS National Bureau of Standards, where manypioneering researchers and developers such as G.Atkinson (UK), O. Birkeland (Norway), G. Blachre(France), J. Eberhard (USA) and I. Karlen (Sweden)gathered and shared their experiences.

Short afterwards, the author began his engineers careerwithin SECO on an ambitious Belgian inter-industrial/construction research program in this field,partly financed by the Belgian State. Under R. dHav,

former Director of SECO, he drafted the PerformanceGuide for Buildings (R. dHav & P. Spehl, Guide desPerformances du Btiment, Syndicat dEtudes IC-IB,Brussels, 1980, 9 volumes), which presents theperformance specifications, testing and calculationmethods already available or developed at the time, andthe international standard ISO 6241 Performancestandards in building Principles for their preparationand factors to be considered, in 1982, as technicalsecretary of a working group within the ISO/TC59Building construction chaired by G. Blachre.

Both documents did inspire R. Mourareau of the

European Commission, who drafted the CPD whichstates that the harmonized standards should be"expressed as far as possible in terms of productperformance", and which has been since 1989 the basisof the whole European Commission policy to unify themarket in the construction sector.

Annex I of the CPD defines the six essentialrequirements regarding health and safety, which are

ISO 6241 : 1984

Table 1: User requirements CPD : 1989Annex I: Essential requirementsCPR : 2011

Annex I: Basic requirements forconstruction works

1. Stability requirements

2. Fire safety requirements

3. Safety in use requirements

4. Tightness requirements

5. Hygrothermal requirements

6. Air purity requirements

7. Acoustical requirements

8. Visual requirements

9. Tactile requirements

10. Dynamic requirements

11. Hygiene requirements

12. Requirements for the suitability

of spaces for specific uses

13. Durability requirements

14. Economic requirements

1. Mechanical resistance andstability

2. Safety in case of fire

3. Hygiene, health and theenvironment

4. Safety in use

5. Protection against noise

6. Energy economy and heatretention

1. Mechanical resistance andstability

2. Safety in case of fire

3. Hygiene, health and theenvironment

4. Safety and accessibility in use

5. Protection against noise

6. Energy economy and heatretention

7. Sustainable use of naturalresources

The essential requirements inISO 6241 (1984), theConstruction ProductsDirective (1989) and theConstruction ProductsRegulation (2011)


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applicable to construction works in order to be fit for theirintended use. This list may be compared to the standardlist of user requirements from ISO 6241, where otheraspects than health and safety are covered, and toAnnex I of the new CPR, where a seventh requirementSustainable use of natural resources has been added.

In addition to the CPD, for each essential requirement, an

interpretative document defines qualitativelytheperformance characteristics to be required from theconstruction products in order that the construction worksmade of them will respond to the essential requirementconcerned. These performance characteristics which areneeded for the end use of products are then definedquantitativelyin harmonized product standards referringto performance testing standards, calculation standardsand classification standards.

It is to be noted that the jurisdiction of the EuropeanUnion covers construction products, according to theCPD, but not construction works which remain in thejurisdiction of the Member States and their regulatoryauthorities.

National and European jurisdictions according to the CPD

CEN Standards

The European Committee for Standardization (CEN)gathers the national standardization organizations fromthe 27 EU Member States, one candidate to EU (Croatia)and the 3 members of the European Free TradeAssociation: Iceland, Norway and Switzerland. Thestandardization organizations of 20 other States areaffiliated or partners and may take part to the CENtechnical committee meetings, but without voting.

Although a weighted vote is used to approve standards,the aim of the works within working groups and projectteams preparing them is to reach a consensus, which isdefined by ISO as a general agreement, characterizedby the absence of sustained opposition to substantialissues by any important part of the concerned interestsand by a process that involves seeking to take intoaccount the views of all parties concerned and toreconcile any conflicting arguments (note: consensusdoes not necessarily imply unanimity). The good practiceof this principle proves to be the best way to obtainstandards widely accepted.

CEN has been mandated under the CPD by theEuropean Commission to draft about 600 harmonizedproduct standards (hEN) and about 1500 standards on

performance test methods. This vast standardizationprogram of more than 20 years has been realizedthrough 55 standardization mandates from the EuropeanCommission, which have involved more than 80 CENtechnical committees. This makes the constructionsector, by far, the largest sector in CEN.

CEN standards for the construction sector (2010)

In addition to the product standards, CEN has receivedstandardization mandates from the EuropeanCommission regarding construction works and generalaspects of safety:

o Sustainability: Development of horizontalstandardized methods for the assessment of theintegrated environmental performance ofbuildings (EC mandate 350).

o Energy performance: Elaboration and adoption ofstandards for a methodology calculating theintegrated energy performance of buildings inaccordance with the EPBD (Energy Performanceof Buildings Directive) (EC mandate 343).

o Dangerous substances: Emission to indoor airand release to soil, surface water and groundwater (EC mandate 366). It is to be noted that, inthe new CPR, the declaration of performancerequired for every construction product will haveto include the hazardous substance informationrequired by the REACH regulation.

o Fire safety: Evaluation of construction products inrespect of their reaction to fire (EU mandate 88),

Evaluation of construction products and elementsin respect of their resistance to fire (EU mandate117) and Fire alarm/detection, fixed fire fighting,fire and smoke control and explosion suppressionproducts (mandate 109).

o Eurocodes: Agreement between the EC andCEN concerning the work on Eurocodes for thedesign of building and civil engineering works(BC/CEN/03/89).

Eurocodes

In this last case, the European Commission tookalready the initiative in 1975 to establish a set ofharmonized technical rules with the aim to eliminate


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technical obstacles to trade, which led to the firstgeneration of European codes in the 1980s. This workwas transferred in 1989 to CEN/TC250 StructuralEurocodes in order to provide them with a futurestatus of European Standard (EN).

The second generation of Eurocodes were publishedin 1999 as 62 pre-standards (ENVs) and after a period

of experimental use in the Member States, on thebasis of the comments received, they have beenconverted into 58 European Standards (ENs)published in 2010. There are still NationallyDetermined Parameters for which the ENs are givingrecommendations, but it is left to the NationalStandardization Bodies to publish National Annexes(NA) with national choices for each of them which maydiffer from the EN recommendations. It is to be notedthat, even if individual Eurocodes are devoted tospecific structural materials (concrete, steel, timber,masonry, etc.), these have been drafted in order tocorrespond to the same safety level, and they may

therefore be considered as a whole set ofperformance-based calculation methods.

A third generation will be prepared in 2011-2015 (ECmandate 466), extending to other structural materials,such as glass, fibre-reinforced polymers or tensilemembranes, and with the aim, strongly supported bythe European Commisison, to remove all thedifferences between the NAs, except those which maybe justified by natural causes (climate, seismology,etc.) or those which express overall performances ofconstruction works, such as partial safety factors,which remain within the jurisdiction of the MemberStates.

Regulations

The first construction regulation in history was theHammurabi code dating from 1760 BC: it coverssafety of persons as well as safety of goods, and fixesalready performance-based requirements, togetherwith (rather extreme!) penalties in case of failure.

Since 1804, article 1792 of the Civil Code establishedby Napoleon, which is still the basis of the legalsystems of several European countries, fixes the

performance requirement as a 10-years liability ofarchitects and contractors, but leaves to the Courts ofJustice, not only the fixing of the penalties, but, beforethat, the evaluation of the responsibilities on basis ofthe good practice at the time of construction.

Among the rules of good practice referred to in theJurisprudence of the Courts, the Eurocodes willbecome, from now on, the dominating reference (butnot the only one possible) for the stability andmechanical resistance of structures.

In Belgium for example, besides specific regulationson fire safety, dangerous goods and electrical

installations, article 1792, as it is, is still the onlygeneral construction regulation, and this leaves an

Applicability of standards (calculation methods e.g. Eurocodes)

optimal freedom and a full responsibility to designers.

Other European countries have established moredetailed Building Regulations by law, and these willhave to be adapted in order to comply with theEurocodes, which will then become compulsory inthese countries.

The universal nature of the Eurocodes means thatthey can be completed with national regulations andlocal customs. Regulations exist because there are

those who will do any odd thing and against whomsociety believes should take precautions in the form ofsafeguards. Regulations are the expression of aculture at a given moment, and should represent theminimum consensus in the public interest. Standardsare clearly very useful as a common reference tool forall interested parties. They must exist, but they shouldnot in the least diminish the responsibility of theperson who applies them, and it can be verydangerous to transform them into regulations, so thatthought is dispensed with, and an attitude of if it's incompliance, it's okay!prevails.

Conclusion

It is to be emphasized that the standardization workon European level is bringing much more than theaddition of national contributions: by gatheringtogether the best expertise available throughoutEurope on each specialized domain, newdevelopments are possible which cant happen whenthese experts work separately in their country.

When starting a new project team of the EuropeanCoal and Steel Community, J. Monnet used to say atthe first meeting: There are two categories of human

beings: those who want to be someone, and thosewho want to do something. And he added: If you arefrom the first category, there is no room here for you!This principle speaks obviously to the mind of anyengineer. And in his Memoirs, J. Monnet further wrote:Beyond the defence of national positions, somethingnew and strong comes into living within the team: itsthe European spirit which is the fruit of the worktogether and, above all, of the need to come to acommon conclusion after the discussion.

Pierre Spehlsenior civil engineer of SECO, Brussels; honorary

Professor of Universit Libre de Bruxelles and EcoleNationale des Ponts et Chausses, Paris


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CEOS.fr - Behaviour and assessment of special construction works: concretecracking & shrinkage

Background

CEOS.fr, coming from a French initiative, is a researchproject on the behaviour and assessment of specialconstruction works (in particular structures with thick

walls or girders) as regards cracking and shrinkage ofconcrete. The kick-off meeting was held in Paris on the11th of April 2008.

The purpose of the research is to establish refinedmodels concerning the development and the evolution ofcracks in special concrete members with the objective topropose to the technical community a betterunderstanding of phenomena and to bring a scientificcontribution to the evolution of design codes, in particulardesign standards like Eurocode 2.

The organisation of the project, based on the activeparticipation of several partners, is composed of asteering committee, including P. Labb (Chairman), J.Mazars (scientific director), P. Bisch (technical director),D. Chauvel (management officer), C. La Borderie(modelling programme), J. Cortade (engineeringprogramme) and L. Demilecamps (experimentalprogramme). It is also composed of a scientific andtechnical committee and an international expert panel incharge of the periodic evaluation of the research. Themembers of the international expert panel are Prof. J.-A.Calgaro (France), Prof. M. Fardis (University of Patras,Greece), Prof. G. Mancini (Chairman of CEN/TC250/SC2 Eurocode 2, Politecnico di Torino, Italy) and Dr. A.Pinto (Joint Research Centre, Ispra, Italy). The workshoporganizing committee includes J. Mazars (Grenoble-INP,chairman), C. Rospars (IFSSTAR) and C. Bernardini(IREX).

In the context of the CEOS.fr research programme,special structures are those which are not covered bythe current engineering practice, either because theirdimensions are unusual (in particular very massivestructures) or because of unusual serviceabilityrequirements (life duration, leak tightness, etc.), orbecause of special requirements relating to the protectionagainst external threats or hazards, or for any similarreason. In most encountered cases, addressing the

design of such structures does not imply only discussingtheir strengthening capacity, but also describing expectedcrack patterns.

Crack formation is a complex mechanical phenomenon,very difficult to model. In the current engineering practice(such as for instance codified in the Eurocode 2), crackwidth and crack spacing are estimated through formulaethat give very rough results and which are notsatisfactory for thick walls. Moreover, using design codesfor thermo-hydro-mechanical loads is difficult becausedescription of data and/or methodologies are not easy tounderstand. Thus there is a necessity for improving crack

modelling techniques for practical engineering purposes.In this context, the general objective of CEOS.fr is to

improve significantly engineering practices for assessingcrack patterns of concrete structures and predicting theexpected pattern under anticipated conditions. Thisgeneral objective is detailed in three areas,

corresponding to three different types of physicalphenomena to be considered and modelled.

o Cracking under monotonic loading: the purpose isto calibrate appropriate methods and to definetheir field of applicability. It is anticipated that newmethods and formulae will be proposed,calibrated for special structures.

o Thermo-hydro-mechanical behaviour: under thistitle different phenomena generating strains will beconsidered and studied, in particular: early agebehaviour, different types of shrinkage,consequences of long-term drying, boundary

conditions, etc.o Seismic and cyclic loads: this area is connected to

containment reliability and to other safetyconsiderations (such as anchoring of equipment),either during the seismic transient or after theevent. The cumulative damaging effect of loadcycles will be considered.

Expected progress should provide engineeringcompanies with more efficient, accurate and reliableengineering tools for the description of crack patterns.It is anticipated that these tools will consist of bothpost-processors of finite element computer codes and

appropriate formula to be included in design codes,and more specifically in Eurocode 2.

The first evaluation workshop

The research programme includes several steps. A firstevaluation workshop took place in Paris on 28-29 May2009. Several presentations showed that:

o the research is of major interest for the design ofconcrete structures;

o the research teams are undoubtedly motivated;

o the work which has been carried out up to now isof high quality;

o there is a real will to contribute to theevolution/improvement of design codes in thisalways controversial topic.

The research, managed at present by the Frenchorganisation IREX (Institut pour la recherche applique etlexprimentation en genie civil Institute for appliedresearch and testing in civil engineering), will acquire aninternational dimension via a participation to the fib(Fdration internationale du bton-Internationalfederation for structural concrete) activity andsubsequently the establishment of proposals in theframework of further evolution of the Eurocodes, and


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more specifically Eurocode 2.

From a scientific point of view, the expert panelrecommended to go into depth in some importantaspects like durability, combined effects of concretecreep and shrinkage, effects of cyclic loading, etc.Sustainable construction will be of major importance inthe future, and the present research is fully in line with

the objectives defined by the European Commission.Moreover, in order to open up new relations with theinternational community it was suggested to organizenew workshops at European level so as to exchangeideas and results with the major teams on the subject.

The second workshop ConCrack1, 2009

The workshop Control of Cracking in ConcreteStructures (ConCrack1), was organized in Paris on the10th and 11th of December 2009. The workshop wasattended by 66 participants from 14 countries. 21

contributions by international experts were presented,covering the fields of engineering, experimental andnumerical approaches of concrete cracking. Participantsexpressed their interest in the matter discussed duringthe workshop and their wish that a framework isestablished to pursue exchange of views on the subjectof concrete cracking.

The workshop was an occasion to present newexperimental data (relating for instance to early agebehaviour, restrained shrinkage, effect of stirrups andstatistical analysis) and to exchange ideas on them.Participants expressed the wish that experimentaloutputs be collected in a comprehensive data base andsupplemented at different scales for complex mechanicalloading cases and in the field of thermo-hydro-mechanics.

New developments in modelling techniques were alsopresented relating to:

o micromechanical models (homogenisationapproach, multi-phase models, meso-models,rough crack contacts, etc);

o continuous models (multi-physics coupling,continuous vs. discrete models, etc);

o

numerical techniques (discrete elements, X-FEM,special elements with embedded discontinuities,solver event by event, etc);

o reinforced concrete modelling (bound models,homogenisation approach, etc).

A common view of the participants was that modellingtechniques should be developed at different scales, thatthey should be improved so as to be more robust andsimple and that their sensitivity to input data, includingstatistical variability, should be established.

Members of the CEOS.fr International Expert Committeewere invited to participate in a panel discussion to drawconclusions from the workshop. It was first stated that theinternational community shares the views that current

engineering practices for assessing crack patterns ofconcrete structures are poor and that there is a necessityto improve them significantly. The French initiativeCEOS.fr is a first step in this direction, which should bedeveloped at an international scale.

The workshop can be regarded as the starting point of aninternational network of scientists and engineers

interested in such developments. The initiative of aninternational benchmark based on CEOS.fr experimentswas highly appreciated by the participants and regardedas an opportunity to strengthen this network.

Sustainability of the CEOS.fr network could beestablished at a European scale by different means to beconsidered in the range of possible frameworks proposedby the European Community: European ConstructionTechnology Platform, Marie Curie networks, InitialTraining Networks, Industry and Academia PartnershipPathway.

It was acknowledged that works carried out in France

under CEOS.fr are of utmost interest for the internationalcommunity. Consequently, it was decided, based on theexperience driven from CEOS.fr, to organize aninternational benchmark dealing with the modelling of thebehaviour of the mock-ups tested (monotonic and cyclicloading on shear walls and large beams with preventedor free shrinkage).

French experts were invited to consider an extended andmore active participation in the fibactivities relating to thedevelopment of future building codes, so that thecommunity takes benefit of ideas and results currentlydeveloped and obtained in France.

The third workshop ConCrack 2, 2011

Between the second and the third workshop, manyexperiments were organised to provide basic data to becompared to results of calculations with several models.Based on these experiments, the internationalbenchmark ConCrack deals with the modelling of thebehaviour of the tested mock-ups.

Shear wall specimens

The aim of this sub-program was to get data on crackingmechanism and pattern when a wall is subject to

monotonic or alternate loading applied within itssymmetry plane. The overall dimensions for the testingspeciments were 4.201.500.15 m (length height thickness) and the scaling was 1/3.

Two load cases were selected for the purpose of thisbenchmark (same geometry and reinforcement scheme):

1. specimen under monotonic shear loading (test 1)

2. specimen under cyclic shear loading (test 2)

Large beam specimens

Large-scale specimens (L=6.10 m, l=1.60 m, h=0.80 m)have been designed to check the influence of different


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Testing bench (top) and dimensions (bottom) of theshear wall specimens

"second order" parameters. Once cast, twoprocedures were used:

o Free-shrinkage beams were allowed to set free,slightly protected against the major climaticconditions, for about four weeks. Then they wereplaced on a bending bench, tightened to it byprestressed bars and brought to the bending limitstate by two rows of four 100 t jacks.

o I-shaped beams experience restrained shrinkagedue to struts and, as for free shrinkage beams,they were tested at the bending bench after 4weeks.

The following teams participated to the benchmark:

o G. Liliu, C. Frissen, C. Damoni, B. Belletti; TNODiana BV (NL), University of Parma (IT)

o G. Meschke; Rhur-University Bochum (DE)

o V. Cervenka, D. Pryl; Cervenka Consulting (CZ)

o F. Vecchio, S.-C. Lee; University of Toronto (CA)

o M. Pimentel, R. Faria, M. Azenha; University ofPorto, University of Minho (PT)

o W. Arnold, T. Jones; ARUP (UK)o M. Jirasek, P. Havlasek; Czech Technical

University in Prague (CZ)

o E. Schlangen, B. Savija; Delft University (NL)

o M. Aschaber, G. Hofstetter; University ofInnsbruck (AT)

o D. Linero, A. Huespe, X. Oliver; University ofColombia, University of Santa F (AR),Polytechnic University of Catalonia (ES)

o P. Mark; Rhur-University Bochum (DE)o B. Schrefler, G. Scium; Padova University (IT)

o D. Kuchma; University of Illinois (USA)

o S. Billington & Y. Dang; Stanford University (USA)

o C. Burns; ETH Zurich (CH)

o T. Jefferson, P. Lyons; University of Cardiff &LUSAS (UK)

o A. Mar, J. Bairn; Universitat Politcnica deCatalunya Barcelona (ES)

o H. Nakamura, Y.Yamamoto; Nagoya University,National Defence Academy (JP)

The benchmark was organized in a blind way(experimental results were not given). Starting June 2010,eight months were given at the participants to do thework. Afterwards it was possible for them to considerexperimental results in order to prepare their workshoppresentations.

A 120-pages synthesis report has being drafted, basedon the experimental and the numerical results. It allowspointing out the capability of models to forecast crackingphenomena both for mechanical load and for THM loads

at early age.However, the purpose of this benchmark was not toachieve a ranking of the work of the different teams, butrather to highlight the ability of particular types ofmodelling strategy. In modelling there are various optionslinked to the model and to the orientation of thecalculation (type of discretisation, boundary conditions,etc). It is the whole which leads to the relevance or not ofthe results.

As a general conclusion on the results for shear wallsand beams, it is very encouraging to see the quality ofthe simulations. They appear to be operational to

model complex coupled problems. A problem thatdoes not appear totally solved is that of goodestimating indicators for cracking, especially in terms

Scheme of the test on large beams Geometry and reinforcement scheme forthe free-shrinkage specimens

I-shaped geometry for the restrained-shrinkage specimens and restrain system


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of opening. However advanced research on thissubject is in progress.

Key findings from the round table at the end ofworkshop

It is recommended to:

o Strengthen the involvement of Frenchscientists and engineers in the sub-groups offib, for example in the TG4.1, in order to form asub-group of actors including French expertsand some benchmark participants to percolatethe CEOS.fr results in the work of fib.

o Work further towards the approximation of thetools from the academic world and those of theengineering world. Relevant and simplifiedsimulation tools need to be developed.

o Take advantage of the synergy created byCEOS.fr to prepare the future research

programs. Themes such as the variability ofparameters, treatment of uncertainties and theintroduction of probabilities in the analysis ofthermo-hydro-mechanical behaviour ofconcrete structures appear appropriate.

Decisions from the meeting of the CEOS.frInternational Committee

Following the benchmark, the web site concrack.orgbecomes a platform for exchange of informationbetween participants and members of the nationalproject CEOS.fr.

The synthesis of the benchmark and the presentationsof participants in the ConCrack2 workshop areavailable online.

In addition, all results (benchmark and postbenchmark, including those from CEOS.fr members)will be published in a special issue of the EuropeanJournal of Environmental and Civil Engineering at thebeginning of 2013.

A proposal is made to participants who wish tocontinue the calculations to other tests performed inthe context of CEOS.fr.

Finally, it was decided to support the organization of anew workshop, ConCrack3 (15-16 March 2012). Theobjective is the presentation and the analysis of theguide on the "control of cracking at young age of massconcrete structures" realized in Japan as part of aJapan Concrete Institute (JCI) working group chairedby Professor Sato (Hiroshima University).

Jacky MazarsGrenoble Polytechnic Institute

Jean-Armand Calgaro

Chairman of CEN/TC250

More information at: ceosfr.org

Second International WorkshopDesign of concrete structures andbridges using Eurocodes

12 - 13 September 2011, Bratislava, Slovakia

The workshop was organised by the SlovakUniversity of Technology in Bratislava, Faculty of

Civil Engineering, in cooperation with the CzechTechnical University in Prague, and the TechnicalUniversity in Vienna.

Modern bridge in Slovakia

The workshop focused on the application of EN1991-2, EN 1992-1-1 and EN 1992-2, since thesestandards have been introduced and accepted asnational standards in many European countriesand there is already some practical experience

with their use.The workshop comprised a series of keynotelectures:

o Background to EN 1991-2 Traffic loads onroad and railway bridges, Jean-ArmandCalgaro

o Improvements of the strut-and-tie method inEN 1992-1-1, Tony E. Jones

o EN 1992-2: give because a why, GabrieleBertagnoli & Giuseppe Mancini

o Design of structures and the contribution of

codes, Konrad Zilcho Development of design of concrete

construction Eurocode 2, JaroslavProchzka

The remaining of the workshop was organised insessions dedicated to specific topics:

o Background, future and proposal of majorchanges;

o Eurocodes vs. national standards and NationalAnnexes;

o Design according to EC2;

o Experience with bridges design.

More information at: http://enconcrete.sk

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