fib-news is produced as an integral part of the fib Journal Structural Concrete. Larger quantities of offprints are made available to National Member Groups on request.
fib award for outstanding structures
The fib was established to develop at an international level the study of scientific and practical matters capable of advancing the technical, economic, aesthetic and environmental performance of concrete construction. It clearly belongs to these objectives to encourage the development of structural concrete performing in an outstanding way in one or more of these realisations.
To recognise the many significant contributions to these objectives and to publicise the many excellent examples of concrete structures erected each year, it was decided in 1998 to continue the awards scheme established by the former FIP.
You are invited to enter the competition for the 2002 fib awards for outstanding structures by filling-in the form given below. Note that the signature of your country's Head of Delegation or Secretary of the National Group is needed to make a valid application. The procedures are described in the following:
Procedures
According to the byelaws approved by Council, the fib Award for Outstanding Structures is given every four years at the fib Congresses to improve the international recognition of concrete structures, which demonstrate the versatility of concrete as a structural medium. The award consists of a bronze plaque to be displayed on the structure, and of certificates given to the principal parties responsible for the work. Nominations are made by the fib National Delegations. A jury designated by the Presidium selects the winners.
Applications are invited by the fib secretariat by publishing this text and mailing to each National Member Group entry forms (see also fib‘s website). The deadline for applications has been fixed by the Presidium as 31 December 2001. The National Member Groups are asked to disseminate the information and invite candidates (designers, contractors or owners) to submit their entry.
Entry forms are to be filled in by the candidates. They need to be countersigned by a Head of Delegation or the National Member Group Secretary in order to confirm the authenticity of the indicated authors.
The structures submitted have to be completed during the last four years before the Congress at which the award is to be attributed, not counting the year of the Congress. (For the Osaka Congress in 2002 this means that nominations for awards are now sought covering the period 1998–2001. The jury may accept an older structure, completed one or two years before, provided that it has not been submitted for the previous award attribution (Amsterdam 1998).
In addition to the entry form, candidates have to send to the fib secretariat a CDROM with all necessary information for use by the jury. A summary of about 500 words, should give essential information on the project, for example the
history of the project
description of the structure
particularities of its realisation (difficulties encountered etc.).
These documents have to be made available electronically as pdf-files (on the CD). Moreover, about 3–5 representative photos of the whole structure and/or any important details or plans, should also be submitted on the CD (each photo twice in format jpeg, 72 dpi for computer use (about 768 × 1024 pixels), and 300 dpi for photo sizes up to 18 × 24 cm, for later publication in printed media (for example the journal Structural Concrete, or a separate brochure). By applying for an award, the copyright to publish one or more of these photos, or part thereof, will be granted to fib.
The jury will be set-up by the Presidium. The awards will be attributed in the two categories Civil Engineering Structures (including bridges), and Buildings.
The jury will attribute one or two ‘Awards’ and two or three citations ‘Special Mention’ in each category, but is free to change these numbers according to the entries received. It will take into account criteria such as
design aspects including aesthetics and design detailing
construction practice and quality of work
environmental aspects of the design and its construction
durability and weathering potential
significance of the contribution made by the entry to the development and improvement of concrete construction.
The decisions of the jury are definitive and cannot be challenged. They will be unveiled during a special ceremony at the Congress. There is no entry fee for the competition. However, to promote and document this event by giving it international publicity, fib may, on decision by the jury, publish a booklet compiling all or selected entries, including the ‘Awards’ and ‘Special Mentions’. To balance the publication cost, a financial participation to the edition of this booklet will be required by the fib secretariat from each published entry. The candidates participating will be offered extra copies of this promotional booklet at special discount rates.
New bulletins
The series of fib Bulletins counting for the subscription year 2001 started in January with number 11 Factory applied corrosion protection of prestressing steel, and was continued in the meantime with number 12 Punching of structural concrete slabs and the new Directory 2001, mailed to all corporate and individual subscribing members in July. A brief description is given in the following. Non-members may order Bulletin 12 or former publications from the fib secretariat by simply using the form below or through fib‘s internet website http://fib.epfl.ch.
Punching of structural concrete slabs (fib technical report)
Punching is considered to be one of the most difficult problems in structural concrete design and mechanical models or theoretical analyses were developed rather late in the history of concrete research attempts.
This fib Bulletin reviews the development of design models and theoretical analyses since the CEB Bulletin 168 Punching shear in reinforced concrete—State-of-the-Art report published in 1985. The role of the concrete tensile strength was specially addressed. In this respect the present bulletin is also following-up the CEB Bulletin 237 Concrete tension and size effects—utilisation of concrete tension in structural concrete design and relevance of size effect—contributions from CEB Task Group 2.7 published in 1997.
Apart from new theoretical developments a comprehensive databank for comparisons with experimental evidence is included. About 400 punching tests were critically reviewed and evaluated in a consistent manner. This is thought to be the first step towards a generally agreed selection of reliable tests. The evident value of such a data bank is illustrated by comparisons carried out between the data and some of the analytical proposals as well as empirical code formulas
fib Bulletin 12, Format 204 × 290mm, (approx DIN A4), 314 pages, 141 tables, 205 illustrations
non-member price: 110 CHF, surface mail included,. airmail at extra charge.
Directory 2001
The new directory starts with a review of fib‘s mission and operating structure. It then gives the current composition of Presidium, Steering Committee and Council and lists the members in the different categories indexed by country.
The working programmes and state of progress of all commissions, task groups and special activity groups are presented along with the names of experts participating in the work. The statutes and a brief historical survey follow and a table of all awarded or honoured in CEB, FIP and fib is given. Finally, a complete address list of all members in fib and participants in one of its working bodies, including their phone and fax numbers and e-mail addresses, completes this useful compendium that has been mailed to all members in July
fib Directory 2001, Format 204 × 290 mm, (approx DIN A4), 120 pages.
Bulletins may be ordered via the internet (http://fib.epfl.ch) or by mailing or faxing the Bulletin order form. They are sent regularly to all individual subscribing and corporate members of fib as part of their annual subscription. Ordinary members receive the Journal only. They are entitled, however, to order once a year a Bulletin at a discount rate.
Upcoming symposia
6th International symposium on ‘Utilisation of high strength/high performance concrete’
The 6th International symposium on ‘Utilisation of high strength/high performance concrete’ sponsored by fib, ACI, DAfStb and dbv will be held at the University of Leipzig, Germany from 16–20 June, 2002. Following the success of the previous conferences, this symposium will again bring together researchers, designers, contractors and practicing engineers for exchanging new ideas and knowledge in the field of high-performance and high-strength concrete. The technological state-of-the-art as well as the potentials for further developments will be discussed and colleagues from all over the world can be met.
The symposium will be held in one of Europe's most modern congress centres situated on the grounds of the new Leipzig Trade Fair area. The unique and well-known glass-hall is the centre of the exhibition site.
Papers are invited under the following headings.
New structural concepts
Design—design methods and criteria, recent and current research, codes and specifications
Construction—new techniques, applications and case studies
Materials—HSC, HPC, Ultra HSC, HSLWAC, concrete mix design, mechanical properties, durability
Concrete production, transportation and placing
In-service durability, in-field performance, design life
For further information contact the symposium secretariat Martina Hoepfner (phone: +49-341-9733-800; fax: +49-341-9733-809; e-mail: hoepfner@wifa.uni-leipzig.de) or visit http://www.hpc2002.de.
Reports from fib commissions and task groups
Workshop on fire design of concrete structures
In recent years fire design of concrete structures has been of topical interest. Structural damage due to fire in tunnels and other structures has illustrated the seriousness of the problem. A number of research programmes have been initiated and test programmes have been carried out. Nevertheless there are still a number of black spots in the fire design of concrete structures.
After a long successful history of the former task group on fire design in CEB (see the substantial publications in CEB-Bulletins), the present fib task group 4.3 Fire design of concrete structures was established in 1999 with the scope to concentrate on conceptual design considerations for fire, aiming at a good balance of material response and structural response aspects. Further research and development in this field will be proposed and stimulated, and supporting material for practical structural fire design will be prepared.
The task group organised a workshop on fire design of concrete structures in Malta on 19 March 2001, in connection with the inter-association conference on Safety, risk and reliability—trends in engineering, organised by IABSE on behalf of the Liaison Committee (CIB—ECCS—FIB—IABSE—RILEM).
The purpose of the workshop was to discuss the state-of-the-art and the state-of-practice among experts within the field of fire design of concrete structures. Thirty engineers with particular interest and knowledge within fire design of concrete structures from 12 countries exchanged experiences and points of view in a very interactive workshop atmosphere. At the workshop particularly two topics were discussed: spalling and structural stability.
Spalling is one of the important ‘missing links’ in modelling of fire damage. The discussion took the starting point in result of European research and testing programmes and both design, testing, material science and theoretical modelling was presented and discussed. Also possible measures to prevent the problem were discussed.
Structural application looking at the overall stability of the structure was the second important aspect of fire design of concrete structures. It was discussed how the behaviour of fire and fire damaged structural components interacted with the remaining structure. Also the shear resistance of hollow core slabs was presented and discussed.
The programme of invited presentations comprised the following.
Compressive strength of HPCs at high temperature (M. Cheyrezy).
Utilisation of results of research: modelling, assumptions and tests (U.-M. Jumpannen).
Modelling of structural behaviour of concrete during fire and its application in practice (G. Khoury).
Overall stability of concrete structures exposed to fire (A. van Acker).
Fire resistance of concrete columns (J. C. Dotreppe).
Shear resistance of prestressed hollow core slabs (J. C. Dotreppe).
Fire Test on a slab of prestressed concrete girders (A. Arteaga).
Shear resistance of fire exposed hollow core slabs (J. Fellinger).
Tensile behaviour of thermally damaged HPC (R. Felicetti).
Material ductility and failure modes in thermally damaged RC members (P.Gambarova).
Effect of polypropylene fibres on performance in fire of high grade concrete columns (T. Lennon).
At the task group meeting just after the workshop it was decided to form two working parties within the task group. WP4.3.1 chaired by Gabriel Khoury (UK) will concentrate on spalling and modelling of concrete behaviour under fire, and WP4.3.2, preliminarily chaired by Arnold van Acker (B) will deal with fire design and structural application. The Working Parties will meet during summer and plan to produce a draft technical report until the next meeting of Task Group 4.3, which will take place in Berlin in October 2001, in connection with the fib Symposium Concrete and Environment.
Participants in Malta found the format of a workshop very successful as it allowed an open discussion among experts based on high quality presentations. It is intended to arrange another workshop occasionally, when the tasks of the working parties have been accomplished.
The Joint Committee on Structural Safety
Scope and history
The Joint Committee on Structural Safety (JCSS) is concerned with fundamental and pre-normative research in the field of structural reliability and risk analysis. The basic idea is that reliability and safety principles should be the same for all types of materials and for all types of elements encountered in civil and building engineering structures. Therefore, in 1971, the international professional associations co-operating in the Liaison Committee, created the JCSS to co-ordinate and harmonise the research activities in this field. Today still the JCSS is supported by the associations forming the Liaison Committee
CIB: Conseil International du Batiment
ECCS: European Convention for Constructional Steelwork
Fib: Fédération Internationale de Béton
IABSE: International Association for Bridge and Structural Engineering
RILEM: Réunion Internationale des Laboratoires dˇEssais et de Recherches sur les Matériaux et les Constructions.
The JCSS acted for a long time under the continuous presidency of the late Julio Ferry-Borges. In 1989 he was succeeded by Jörg Schneider and then later by Rüdiger Rackwitz. Last year the author of this note was elected for this task. During its existence the JCSS has had about 50 meetings and has discussed a large number of reliability related documents. As direct output of the JCSS one may refer to a set of documents, the ones published after 1990 can be found in the attached list of publications. The two most recent documents are discussed in more detail below. Indirectly the JCSS has had a large influence on the contents of many reliability related reports by the various associations (e.g. CIB publications by WG18, WG32, WG81, the CEB and ECCS Model Codes, IABSE Structural Engineering Document 5, etc) and on official code type documents like ISO2394 and the Euro-code 1, Part 1, Basis of Design.
The message that has been spread continuously by the JCSS was (and still is) that decisions with respect to structural design and assessment should be based on the theory of probabilistic decision making. It is claimed that such an approach offers the best framework to combine theory, observations, experience and judgement into consistent and rational decisions. The depth of the analysis may of course vary from case to case. In some cases advanced probabilistic analysis is advocated, in other cases it may be sufficient to be aware of some simple principles.
More detailed information on the JCSS can be found in the internet on http://www.jcss.ethz.ch/
Publications since 1990
IABSE-publications, 1989–1990
Proposal for a code for the direct use of reliability methods in structural design.
Estimation of structural properties by testing for use in limit state design.
Design for durability including deterioration and maintenance procedures.
Geometrical variability in structural members and systems.
Structural performance criteria.
Bayesian decision analysis as a tool for structural engineering decisions.
Stochastic modelling of material properties and quality control.
Action scenarios and logic trees.
ECCS Publication 94, March 1996
Background documentation, Eurocode 1, Part 1: Basis of Design.
Structural Safety, vol. 19, no. 3, 1997
The JCSS probabilistic model code.
Structural reliability codes for probabilistic design—a debate paper based on elementary reliability and decision analysis concepts.
Report of the working group on dynamics.
Uncertainties in probabilistic numerical analysis of structures and solids.
Stochastic finite elements.
RILEM publication 2001
Probabilistic Assessment of Existing Structures (ISBN 2–912143–24–1)
Rilem Publishing Sarl, Ens, F-94235
Cachan Cedex France
Press release and order form can be
downloaded from the web
Internet Publication
The JCSS Probabilistic Model Code (http://www.jcss.ethz.ch/)
Short Summary of the two most recent publications
Probabilistic Assessment of Existing Structures (2000)
It is well known, but often forgotten, that the assessment of an existing structure may differ very much from the design of a new one. Existing structures, for instance, have been inspected or can be inspected, reducing the uncertainties sometimes substantially. Another point is that the strengthening of an existing structure may be quite expensive. As a result the safety levels to be maintained and the margins necessary to reach those levels may be completely different for design and assessment.
Having this in mind the JCSS has written a report on the specific procedures and tools that are required in order to judge the safety of existing structures. The following basic goals for this document have been set
to standardise methods and terminology
to be operational for the consulting engineer
to be generally applicable for various materials and various structural types
to be useful as guidelines of pre-codification state i.e. to build the basis of future codes, standards or code type recommendations.
Although the nature of the report is educational, it contains practical and operational recommendations and rules for the assessment of existing structures also illustrated in characteristic examples and real case studies. The document consists out of four parts. Part 1 discusses the general issues and procedures and can easily be read without a mathematical probabilistic background. The Parts 2–4, however, are of a more specialist nature and contain many formulas from probability decision theory.
The JCSS Probabilistic Model Code 2001
The present ISO 2394 document on reliability of structures considers the partial factor method and the full probabilistic methods as equivalent procedures for the verification of structural reliability. In fact, the partial factor method is considered as a simplification of the probabilistic method. Also the Draft version Eurocode EN1990, Basis of Design, now under vote for acceptance, offers for the member states of the European Union the possibility to accept probabilistic methods as an alternative procedure for the verification of structural reliability.
In practice, however, only the partial factor method is directly operational as it is supported by a set of action and material codes that provide adequate information on calculation models, characteristic values, partial factor values, load combinations and so on. At this moment the full probabilistic procedures clearly lacks such a follow up.
Therefore, the JCSS have written a Probabilistic Model Code. The model code exists out of three main parts: a Basis of Design part, an Action part and a Material part. The paper discusses these parts in some detail and gives some examples of the use of the code. It should be noted that the code is not intended as a text book on structural or reliability engineering. The code is written in a condensed way and little or no educational explanations are given.
Of course, this first version may have many shortcomings. Researchers and designers are therefore invited to read and use the document and to make comments so that a better draft can be issued within one or two years. The code also needs extensions, in particular for items like loads and materials not yet covered and models for fatigue and other durability aspects. The JCSS makes a general invitation to bring in documents that can help in this respect.
The task to write a Probabilistic Model Code is quite an ambitious one. We still face a number of unsolved problems and lack of data. On the other hand, it is the JCSS's firm belief that it is worth while to bring together the many research achievements and experiences of the past in a document that standardises models and methods to facilitate the use of probabilistic methods in practice.
