Prefabrication - The International Federation for Structural Concrete

Commission 6
Prefabrication
Chair: Menegotto (Sapienza, University of Rome, Italy)
Deputy-Chair: Fernández Ordoñez (Prefabricados Castelo S.A., Spain)
Secretary: Ronchetti (ASSOBETON, Italy)
Members: Albert (Hochschule Bochum, Germany), Beluzsár (Pfleiderer Labatlani Vasbetonipari Rt.,
Hungary), Calavera (INTEMAC, Spain), Chastre Rodrigues (Univ. Nova de Lisboa, Portugal),
Cholewicki (Building Research Institute (ITB), Poland), Crisp (Crisp Consultants Pty. Ltd.,
Australia), Da Guia Lúcio (Univ. Nova de Lisboa, Portugal), de Chefdebien (LB7, France),
Della Bella (Grupo Centro Nord SpA, Italy), Derkowski (Cracow Technical Univ., Poland),
Doniak (ABCIC, Brazil), Elliott (Consulting Engineer, United Kingdom), Engström
(Chalmers Univ. of Technology, Sweden), Fernández Gómez (Laboratorio Central INTEMAC,
Spain), Ferrari (Consulting Eng., Italy), Falger (BAM Advies & Engineering The Netherlands),
Ferreira (Federal Univ. Sao Carlos, Brazil), Gasperi (Consulting Eng., Italy), Hughes (Hollow
Core Concrete Pty. Ltd., Australia), Jones (CDC Ltd., UK), Kanappan (Larsen & Toubro Ltd.,
India), Karutz (CPI, Germany), Korander (Consolis Technology Oy Ab, Finland), Laliberté
(BPDL Precast Concrete International, Canada), Lindström (Strängbetong, Sweden), Maas
(Echo, Belgium), Mary (Rector Lesage, France), Murayama (Spancrete Corporation, Japan),
Newby (Holmes Consulting Group, New Zealand), Saha (L&T, ECC Division, India), Sasek
(Mott MacDonald Praha, Czech Republic), Scalliet (CERIB, France), Sennour (Consulting
Engineers Group, USA), Seshappa (Composite Technologies Corp., USA), Skjelle (Construction
Products Association, Norway), Suikka (Confed. of Finnish Construction Industries RT, Finland),
Tillmann (FDB, Germany), Tillmann (FDB, Germany), Tsoukantas (National Techn. Univ.
of Athens, Greece), Vambersky (Corsmit Consulting Engineers, The Netherlands), van Acker
(Belgium), van Paassen (VBI Ontwikkeling BV, The Netherlands)
Corr. Members: d’Arcy (The Consulting Engineers Group, Texas, USA), El Debs (Univ. de Sao Paulo, Brazil),
Krohn (PCI, USA)
Recent Meetings: Cavtat (May 07), Cracow (Oct. 07), Amsterdam (May 08), Orlando (Oct. 08), Nottingham
(May 09), Paris (Oct. 09), Washington (May 10), Lisbon (Oct. 10), Helsinki (May 11),
Athens (Sept. 11)
Recent Bulletins: fib Bulletin 41: Treatment of imperfections in precast structural elements
(State-of-art report prepared by former TG 6.8, published 2007)
Names of fib members are given in bold
Scope
fib Bulletin 43: Structural connections for precast concrete buildings
(Guide to good practice prepared by TG 6.2, published 2008)
fib Bulletin 60: Prefabrication for affordable housing
(State-of-art report prepared by former TG 6.7, published 2011)
fib Bulletin 63: Design of precast concrete structures against accidental actions
(Guide to good practice prepared by TG 6.9, published 2012)
Terms of reference
Precast concrete construction is evolving continuously to keep pace with current society’s habits and
needs. The Commission wants to enhance its progress by stimulating, guiding and coordinating
research and development on precast concrete and by disseminating the knowledge. Cooperation with
other international institutes is of great interest to this end.
The scope of the work covers not only issues directly related to precast concrete – i.e. elements,
connections, systems, production, handling and assemblage – but also indirectly related matters such
as materials, structural analysis, building physics, equipment, etc.
The work in the Commission is linked to the state of art within the profession, which in its turn is
based on the current marked demands.
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Areas of interest
Structural efficiency
Structures that occupy less volume inside the building and that can easily accommodate equipment are
increasingly requested. Structural efficiency helps also to save weight, which results in subsequent
savings in the foundations, and, particularly for seismic constructions, also in the whole resisting
system. This applies also to structures other than buildings, e.g. standard bridges, flyovers, etc.
Flexibility in use
Buildings are frequently required to adapt to variable needs of users, achieved by creating large free
internal spaces, without restrictions by possible subdivisions. Also, the typology of the elements must
be open to variations.
Adaptability
Less demolition of entire buildings and more adaptation of older buildings to new requirements will be
required. The design concept should facilitate such renovations and modifications, e.g. changing
façades without demolition of the rest of the structure.
Best use of materials
Each construction material possesses specific properties and optimal applications. The trend is to use a
combination of different materials suited for the particular function among the structural and the
architectural components.
Speed of construction
Construction sites disturb the surrounding area by creating noise and dust and disturbing traffic,
therefore their duration must be as short as possible. The economic advantage of reduced construction
time is obvious.
Quality consciousness
The structural robustness and the quality of materials and execution and also user-friendliness,
comfort, aesthetics, duration are considered, as well as the quality within production, starting from the
work conditions, continuing with the working effectiveness, and up to the output results.
Sustainability
Preserving the environment is of paramount importance on global scale. In addition to encouraging the
reuse of structures for adaptability, further issues include recycling elements and/or materials,
reduction of materials emissions, use of raw materials, waste dumping, noise and dust, etc.
Working programme
Basic research
• performance of precast elements, connections, assemblies, by means of experimental testing and
analytical modeling;
• overall structural behaviour, durability, robustness;
• resistance to fire, fatigue and accidental actions, repair and retrofit;
• innovative materials.
Application of new materials (in co-operation with Commissions 8 and 9)
• high-performance concrete;
• high-strength lightweight concrete;
• self-compacting concrete;
• fiber-reinforced concrete;
• non-metallic reinforcements.
Production technologies and products
• production technologies and optimization of processes;
• hollow-core floors;
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• bridge components;
• railway track systems;
• affordable cost construction;
• cladding panels.
Normative and pre-normative work
• pre- and post-normative studies aimed at supporting the development of codes and standards;
• interaction with fib commissions and participation in the elaboration of the 2010 Model Code;
• elaboration of recommendations and guides to good practice on production, handling, erection and
maintenance of precast elements and structures.
Dissemination of knowledge
• publication of technical reports, state-of-art reports, recommendations, handbooks, etc.;
• interaction with other scientific and technical organizations;
• organization of short courses;
• seminars and workshops for professionals;
• dedicated sessions in congresses and symposia.
Task Group
TG 6.1 Prestressed hollow-core floors
Convener: Maas (Echo, Belgium)
Members: Cholewicki (Building Research Institute (ITB), Poland), Crisp (Crisp Consultants Pty. Ltd.,
Australia Della Bella (Gruppo Centro Nord SpA, Italy), Derkowski (Cracow Technical Univ.,
Poland), Elliott (Consulting Engineer, United Kingdom), Ferreira (Federal Univ. Sao Carlos,
Brazil), Korander (Consolis Technology Oy Ab, Finland), Lindström (Strängbetong,
Sweden), Mary (Rector Lesage, France), Scalliet (CERIB, France), Suikka (Confed. of
Finnish Construction Industries RT, Finland), Tsoukantas (National Techn. Univ. of Athens,
Greece), van Acker (Belgium), van Paassen (VBI Ontwikkeling BV, The Netherlands)
Recent Meetings: as Commission
Names of fib members are given in bold
Terms of reference
In 1988 the FIP Commission on Prefabrication published design recommendations for 'Precast
prestressed hollow core floors', in which the following items were treated: transfer of stresses at the
support zone, shear capacity, transverse load distribution, diaphragm action, fire safety and
connections. In the meantime the Task Group has finalised complementary guidelines for the design
which were published in 1998 as FIP/fib guide to good practice Composite floor structures and in
2000 as fib Bulletin 6 (guide to good practice) Special design considerations for precast prestressed
hollow core floors. The document gives the latest state of knowledge concerning transfer of
prestressing, restrained composite supports, non-rigid supports, floor diaphragm action and floors
under seismic action.
Revision of the FIP design recommendations on precast pre-stressed hollow core floors
Since the first publication of the FIP Recommendations in 1988, the knowledge on the performances
of pre-stressed hollow core floors in various applications has progressed much and a number of new
topics have already been dealt with in two complementary reports. The main goal for the next two
years is to make a complete revision of Design recommendations for precast pre-stressed hollow core
floors.
The content of the chapters will be revised according to today’s state of the art. Supplementary new
subjects will be added to the Recommendations, based on several projects in which members of the
Task Group were involved.
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Task Group
TG 6.2 Structural connections for precast concrete
Convener: Engström (Chalmers Univ. of Technology, Sweden)
Members: Cholewicki (Building Research Institute (ITB), Poland), De Chefdebien (LB7, France), Della
Bella (Grupo Centro Nord SpA, Italy), Elliott (Univ. of Nottingham, United Kingdom),
Fernández Ordoñez (Prefabricados Castelo S.A., Spain), Menegotto (Sapienza Univ. of
Rome, Italy), Newby (Holmes Consulting Group, New Zealand), Skjelle (Construction Products
Association, Norway), Tillmann (FDB, Germany), Tsoukantas (National Techn. Univ. of
Athens, Greece), Vambersky (Corsmit Consulting Engineers, The Netherlands), van Acker
(Belgium), Vinje (Spenncon AS Trondelag, Norway)
Recent Meetings: within PCI/fib joint activity
Recent Bulletins: fib Bulletin 43: Structural connections for precast concrete buildings
(Guide to good practice prepared by TG 6.2, published 2008)
Names of fib members are given in bold
Terms of reference
The proper design of structural connections is one of the keys to successful prefabrication. Existing
studies and literature on the subject deal with classical solutions, known to everybody, but a general
design philosophy is missing. The engineer, confronted with particular problems in his daily practice,
has no theoretical basis to solve the problems. The group's study deals with basic principles for the
transfer of forces through connections and has elaborated guidelines for their design and calculation
treating the following topics:
• precast structural systems and structural interaction;
• flow of forces;
• transfer of compressive, tensile and shear forces;
• transfer of bending and torsion moments;
• unintended restraint, need for movement;
• other design aspects such as excessive loading, seismic loading, fire;
• design examples.
Task Group
TG 6.9 Design of precast concrete structures for accidental
loading
Convener: van Acker (Belgium)
Members: Chastre Rodrigues (Univ. Nova de Lisboa, Portugal), Cholewicki (Building Research Institute
(ITB), Poland), Crisp (Crisp Consultants Pty. Ltd., Australia), Da Guia Lúcio (Univ. Nova de
Lisboa, Portugal), Elliott (Univ. of Nottingham, United Kingdom), Engström (Chalmers Univ.
of Technology, Sweden), Falger (BAM Advies & Engineering, The Netherlands), Suikka
(Confed. of Finnish Construction Industries RT, Finland), Vambersky (Corsmit Consulting
Engineers, The Netherlands)
Corr. Members: Vantomme (Royal Military Academy, Belgium)
Recent meetings: as Commission
Recent Bulletins: fib Bulletin 63: Design of precast concrete structures against accidental actions
(Guide to good practice prepared by TG 6.9, published 2012)
Names of fib members are given in bold
Terms of reference
Precast structures are more sensitive than cast in-situ structures to progressive collapse after explosions or
other accidental action. A structure is normally designed to support loads caused by normal function, but
there should be a reasonable probability that it will not collapse catastrophically under the effects of a
moderate degree of misuse or an accident. No structure can be expected to be resistant to the excessive
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loads or forces that could arise from an extreme cause, but it should not be damaged to an extent that is
disproportionate to the original cause.
The normal design procedure to cope with accidental loads consists of allowing the collapse of a limited
local area of the framework, while ensuring that the adjacent areas of the structure surrounding the
damage provide for an alternative load path, possibly in a distorted condition but without leading to
collapse of the whole structure.
A large amount of literature is available from the period immediately after the Ronan Point incident
(1968). At present, only a few code prescriptions exist and their requirements are sometimes very
different. The subject has become again important since the attack of 11 September 2001 in New York.
Studies are now being carried out, for example at TU Delft, The Military Academy in Belgium, and other
institutes. The objective of the Task Group is to assess the available material and to publish a Guide to
Good Practice for the design of precast concrete skeleton and wall frame structures, designed to avoid the
phenomenon of progressive collapse.
Task Group
TG 6.10 Precast concrete buildings in seismic areas –
practical aspects
Convener: Tsoukantas (National Techn. Univ. of Athens, Greece)
Members: Chastre Rodrigues (Univ. Nova de Lisboa, Portugal), Da Guia Lúcio (Univ. Nova de Lisboa,
Portugal), De Chefdebien (CERIB, France), Dritsos (Univ. of Patras, Greece), Fernández
Ordoñez (Prefabricados Castelo S.A., Spain), Juraszek (CERIB, France), Kremmyda
(Greece), Marreiros (Univ. Nova de Lisboa, Portugal), Pampanin (Univ. of Canterbury, New
Zealand), Psycharis (National Techn. Univ. of Athens, Greece), Saha (L&T, ECC Division,
India), Sener (Yapi Merkezi, Turkey), Tillmann (FDB, Germany), Toniolo (Politecnico di
Milano, Italy), Topintzis (Consulting Engineer, Greece)
Corr. Members: Coelho (Laboratorio Nacional De Engenharia Civil, Portugal), D’Arcy (Consulting Eng. Group
INC, USA), El Debs (University of Sao Paulo, Engineer School of Sao Carlos, Brasil), Ferreira
(Federal University of Sao Carlos, Brasil), Ghosh (S.K.Ghosh Associates Inc., U.S.A.), Hughes
(Hollow Core Concrete PTY LTD, Australia), Menegotto (Sapienza Univ. of Rome, Italy),
Monino (Prefabricados Castelo S.A., Spain), Pinto (Prefabricados Castelo S.A., Spain), Proenca
(Instituto Superior Tecnico, Lisbon, Portugal), Sennour (Consulting Eng. Group INC, USA)
Recent Meetings: Athens (July 07), Lisbon (Nov. 07), Madrid (April 08), Florence (Dec. 08), Athens (Nov.
09), Madrid (Apr. 10), Istanbul (Sept. 10), Lisbon (Oct. 10), Athens (Oct. 11)
Names of fib members are given in bold
Terms of reference
The goal of the Task Group is to prepare a technical report describing steps, procedures, rules and
construction details for precast structures built in seismic areas to comply with the fundamental
requirements of no-collapse and damage limitation, focused mainly on mid-rise buildings.
The main purpose is to assist designers with selecting alternative seismic resisting systems/connections
and drafting proper construction details when designing precast structures under seismic actions to
comply with the above-mentioned fundamental requirements, outlining among other aspects the
following key features:
• particularities of the seismic design of precast structures;
• basic principles of conceptual design and performance criteria applied to precast systems;
• the role of connections on the seismic behaviour of the precast structural system and construction
details;
• the role of diaphragm action of floors on the structural behaviour and construction details;
• detailing of precast elements and structures.
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In two Annexes, reference is also made regarding: 1) ductility requirements and related behaviour
factors of precast systems; and 2) basic considerations on force-based design vs. displacement-based
design for precast concrete structures.
TG 6.11 Precast concrete sandwich panels
Convener: Hughes (Hollow Core Concrete PTY LTD, Australia)
Members: Chastre Rodrigues (Univ. Nova de Lisboa, Portugal), Gasperi (Consulting Eng., Italy), Jones
(CDC Ltd., UK), Karutz (CPI, Germany), Krohn (PCI, USA), Laliberté (BPDL Precast
Concrete International, Canada), Lindström (Strängbetong, Sweden), Saha (L&T, ECC Division,
India), Sennour (Consulting Engineers Group, USA), Seshappa (Composite Technologies Corp.,
USA), Suikka (Confed. of Finnish Construction Industries RT, Finland), Tillmann (FDB,
Germany)
Corr. Members: Tsoukantas (National Techn. Univ. of Athens, Greece), van Acker (Belgium)
Recent meetings: Washington DC (May 10), Lisbon (Oct. 10)
Names of fib members are given in bold
Terms of reference
Precast concrete sandwich panels consist of two layers or ‘Wythes’ of concrete separated by a
continuous internal insulating material. The two layers are held together by connectors. The panels can
be either structural or non-structural façade elements and typically, but not limited to, applications in
apartments, hotels, schools, prisons, cold stores, industrial, commercial and residential projects.
While precast concrete sandwich panels are commonly used worldwide, much of the understanding is
confined to individual manufacturers and/or engineers. This, along with the growing need to build
energy efficient structures, has highlighted a need to produce a document that is able to draw together
and consolidate the knowledge held within the precast industry along with the benefits that can be
achieved with proper consideration of this system. The areas to be covered include:
• different sandwich panel types, surface finishes, aesthetics;
• energy efficiency, thermal and acoustic performance;
• thermal bridging and dew point considerations (humidity);
• loadbearing and flexural design, shear wall considerations;
• panel connectors, connections;
• fire resistance and behaviour under fire;
• durability;
• manufacture of sandwich panels, methods of casting;
• bowing considerations / deformations / shrinkage;
• installation, panel erection and assembly;
• inspection, tolerances, damage and repairs.
TG 6.12: Planning and design handbook on precast building
structures
Convener: Van Acker, Belgium
Members: Crisp (Crisp Consultants Pty. Ltd., Australia), Chastre Rodrigues (Univ. Nova de Lisboa,
Portugal), Da Guia Lúcio (Univ. Nova de Lisboa, Portugal), Elliott (Consulting Engineer,
United Kingdom), Falger (BAM Advies & Engineering The Netherlands), Fernández
Ordoñez (Prefabricados Castelo S.A., Spain), Jones (CDC Ltd., UK), Karutz (CPI, Germany),
Menegotto (Sapienza, University of Rome, Italy), Tsoukantas (National Techn. Univ. of
Athens, Greece)
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Terms of reference
Prefabrication of concrete structures is often considered by uninitiated designers to be a variant
execution technique of cast in-situ construction. In this approach, prefabrication means only that parts
of the construction are precast in specialised plants, to be then assembled on site in such a way that the
initial concept of cast in-situ structures is obtained as closely as possible. This viewpoint is
inappropriate. Every construction system has its own characteristics which to a greater or lesser extent
influence lay-out, storey height, stability, statical system etc. For the best results a design should
respect the specific and particular demands of the intended structure.
To get optimum benefits, it is very important that the design for a precast concrete structure be
conceived according to specific rules from the very outset. The problem is that there is a wealth of
general and detailed information on design guides for the calculation and execution of projects, but
surprisingly little to help engineers and architects to achieve a full understanding of the specific design
philosophy of precast concrete building structures to start a project.
The handbook envisaged fallows and updates the old one edited by the Commission under FIP in
1994. Like that publication, it is intended to fill the above gap, by providing a detailed review of the
subject and thereby promoting a greater awareness and understanding of precast concrete buildings. In
the same time, it will give a synthesis of the work done by fib Commission 6 over the past twenty
years in the domain of precast concrete. The handbook is addressed particularly to people less familiar
with this form of construction, but it will also be of interest to all engineers, architects and others
concerned with the design and erection of buildings, not forgetting the valuable information it can
provide to the education of students in Technical Universities and High Schools.
TG 6.13: Quality control for precast concrete
Convener: Fernández-Gómez (Laboratorio Central INTEMAC, Spain)
Members: Doniak (ABCIC, Brazil), Fernández Ordoñez (Prefabricados Castelo S.A., Spain), Frank
(PCI, USA), Karutz (CPI, Germany), Korander (Finland), Krohn (PCI), López-Agüi
(IECA, Spain), López-Vidal (Andece, Spain), Maas (ECHO, Belgium), Ronchetti (Assobeton,
Italy), Suikka (Confed. of Finnish Construction Industries RT, Finland)
Terms of reference
The goal of the Task Group is to prepare a Technical Report describing the steps, procedures and rules
for the quality control of precast concrete, with respect to both production and product quality, to
improve the quality of prefabricated construction.
The Report will be intended to serve as a basic specification guide for plants and produced precast
concrete elements, defining a program of quality control to monitor the production by measurement or
by comparison to acceptable standards.
The following topics will be included:
− Plant quality assurance program
− Materials and accessories
− Production
− Transport and erection
− Equipment
− Quality control operations
− Maintenance
− Statistical data analysis
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TG 6.14: Precast concrete towers for wind power generators
Convener: Da Guia Lúcio (Univ. Nova de Lisboa, Portugal)
Members: Batista (RES Group Engineering, United Kingdom), Becker (PCI, USA), Brughuis (MECAL
BV, Netherlands), Chastre Rodrigues (Univ. Nova de Lisboa, Portugal), Jones (CDC Ltd.,
Ireland), Tricklebank (United Kingdom), van Keulen (Ingenieursstudio DCK, Netherlands)
Terms of reference
Wind energy production is a growing industry; the energy produced is renewable and environmentally
cleaner than most production means. Supports of wind energy generators may be built with precast
concrete elements, and these solutions can be competitive, compared to other structural systems.
The evolution of technology for wind energy production shows a clear need for larger wind turbines
and, consequently, taller towers. Experience also shows that precast solutions are more competitive
with increasing tower height.
Offshore wind farms have some advantages vs. onshore ones, which explains recent investments in
this area. In this case, the durability of concrete in marine environment, compared with steel’s, gives
greater advantages to precast concrete solutions.
The Task Group will produce a state-of-art report, analyzing and discussing the main issues related to
conception, design, detailing, construction and environmental aspects of precast structural solutions.
Issues to be dealt with:
− Types of concrete towers for wind energy
− Equipment
− Safety
− Actions
− Analysis
− Connections and detailing
− Construction
− Environmental aspects
− Recent developments
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