Download or read book 2018 fib Awards for Outstanding Concrete Structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2018-10-08 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fib Awards for Outstanding Concrete Structures are attributed every four years at the fib Congress, with the goal of enhancing the international recognition of concrete structures that demonstrate the versatility of concrete as a structural medium. The award consists of a bronze plaque to be displayed on the structure, and certificates presented to the main parties responsible for the work. Applications are invited by the fib secretariat via the National Member Groups. Information on the competition is also made available on the fib’s website, and in the newsletter fib-news published in Structural Concrete. The submitted structures must have been completed during the four years prior to the year of the Congress at which the awards are attributed. The jury may accept an older structure, completed one or two years before, provided that it was not already submitted for the previous award attribution (Mumbai, 2014). The submitted structures must also have the support of an fib Head of Delegation or National Member Group Secretary in order to confirm the authenticity of the indicated authors. Entries consist of the completed entry form, three to five representative photos of the whole structure and/or any important details or plans, and short summary texts explaining: - the history of the project; - description of the structure; - particularities of its realisation (difficulties encountered, special solutions found, etc.). A jury designated by the Presidium selects the winners. The awards are attributed in two categories, Civil Engineering Structures (including bridges) and Buildings. Two or three ‘Winners’ and two to four ‘Special Mention’ recipients are selected in each category, depending on the number of entries received. The jury takes 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 sustainability aspects; - 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 are unveiled at a special ceremony during the fib Congress in Melbourne.

Download or read book 2022 fib Awards for Outstanding Concrete Structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-06-15 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fib has two major missions now. One is to work toward the publication of the Model Code 2020, and the other is to respond to the global movement toward carbon neutrality. While the former is steadily progressing toward completion, the latter will require significant efforts for generations to come. As we all know, cement, the primary material for concrete, is a sector that accounts for 8.5% of the world’s CO2 emissions. And the structural concrete that fib handles consume 60% of that. In other words, we need to know the reality that our structural concrete is emitting 5% of the world’s CO2. From now on, fib members, suppliers, designers, builders, owner’s engineers, and academic researchers will be asked how to solve this difficult problem. In general, most of the CO2 emissions in the life cycle of structural concrete come from the production stage of materials and the use stage after construction, i.e. A1 to A3 and B1 to B5 processes as defined in EN15978. Cement and steel sectors, which are the main materials for structural concrete, are expected to take various measures to achieve zero carbon in their respective sectors by 2050. Until then, we must deal with the transition with our low carbon technologies. Regarding the production stage, the fib has recently launched TG4.8 “Low carbon concrete”. And the latest low carbon technologies will be discussed there. On the other hand, in the use stage, there is very little data on the relationship between durability and intervention and maintenance so far. The data accumulation here is the work of the fib, a group of various experts on structural concrete. Through-life management using highly durable structures and precise monitoring will enable to realize minimum maintenance in the use stage and to minimize CO2 emissions. Furthermore, it is also possible to contribute to the reduction of CO2 emissions in the further stage after the first cycle by responding to the circular economy, that is, deconstruction (C), reuse, and recycle (D). However, the technology in this field is still in its infancy, and further research and development is expected in the future. As described above, structural concrete can be carbon neutral in all aspects of its conception, and it can make a significant contribution when it is realized. The fib will have to address these issues in the future. Of course, it will not be easy, and it will take time. However, if we do not continue our efforts as the only international academic society on structural concrete in the world to achieve carbon neutrality, the significance of our very existence may be questioned. Long before Portland cement was invented, Roman concrete, made of volcanic ash and other materials, was the ultimate low-carbon material, and is still in use 2’000 years later because of its non-reinforced structure and lack of deterioration factors. Reinforced concrete, which made it possible to apply concrete to structures other than arches and domes, is only 150 years old. Prestressed concrete is even younger, with only 80 years of history. Now that we think about it, we realize that Roman concrete, which is non-reinforced low carbon concrete, is one of the examples of problem solving that we are trying to achieve. We have new materials, such as coated reinforcement, FRP, and fiber reinforced concrete, which can be used in any structural form. To overcome this challenge with all our wisdom would be to live up to the feat the Romans accomplished 2’000 years ago. Realizing highly durable and elegant structures with low-carbon concrete is the key to meet the demands of the world in the future. I hope you will enjoy reading this AOS brochure showing the Outstanding Concrete Structures Awards at the fib 2022 Congress in Oslo. And I also hope you will find some clues for the challenges we are facing.

Download or read book Proceedings of Italian Concrete Days 2016 written by Marco di Prisco and published by Springer. This book was released on 2018-04-16 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gathers the best peer-reviewed papers presented at the Italian Concrete Days national conference, held in Rome, Italy, on October 27-28, 2016. The conference topics encompass the aspects of design, execution, rehabilitation and control of concrete structures, with particular reference to theory and modeling, applications and realizations, materials and investigations, technology and construction techniques. The contributions amply demonstrate that today’s structural concrete applications concern not only new constructions, but more and more rehabilitation, conservation, strengthening and seismic upgrading of existing premises, and that requirements cover new aspects within the frame of sustainability, including environmental friendliness, durability, adaptability and reuse of works and / or materials. As such the book represents an invaluable, up-to-the-minute tool, providing an essential overview of structural concrete, as well as all new materials with cementitious matrices.

Download or read book Safety and performance concept Reliability assessment of concrete structures written by fib Fédération internationale du béton and published by FIB - Féd. Int. du Béton. This book was released on 2018-08-01 with total page 375 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete structures have been built for more than 100 years. At first, reinforced concrete was used for buildings and bridges, even for those with large spans. Lack of methods for structural analysis led to conservative and reliable design. Application of prestressed concrete started in the 40s and strongly developed in the 60s. The spans of bridges and other structures like halls, industrial structures, stands, etc. grew significantly larger. At that time, the knowledge of material behaviour, durability and overall structural performance was substantially less developed than it is today. In many countries statically determined systems with a fragile behavior were designed for cast in situ as well as precast structures. Lack of redundancy resulted in a low level of robustness in structural systems. In addition, the technical level of individual technologies (e.g. grouting of prestressed cables) was lower than it is today. The number of concrete structures, including prestressed ones, is extremely high. Over time and with increased loading, the necessity of maintaining safety and performance parameters is impossible without careful maintenance, smaller interventions, strengthening and even larger reconstructions. Although some claim that unsatisfactory structures should be replaced by new ones, it is often impossible, as authorities, in general, have only limited resources. Most structures have to remain in service, probably even longer than initially expected. In order to keep the existing concrete structures in an acceptable condition, the development of methods for monitoring, inspection and assessment, structural identification, nonlinear analysis, life cycle evaluation and safety and prediction of the future behaviour, etc. is necessary. The scatter of individual input parameters must be considered as a whole. This requires probabilistic approaches to individual partial problems and to the overall analysis. The members of the fib Task Group 2.8 “Safety and performance concepts” wrote, on the basis of the actual knowledge and experience, a comprehensive document that provides crucial knowledge for existing structures, which is also applicable to new structures. This guide to good practice is divided into 10 basic chapters dealing with individual issues that are critical for activities associated with preferably existing concrete structures. Bulletin 86 starts with the specification of the performance-based requirements during the entire lifecycle. The risk issues are described in chapter two. An extensive part is devoted to structural reliability, including practical engineering approaches and reliability assessment of existing structures. Safety concepts for design consider the lifetime of structures and summarise safety formats from simple partial safety factors to develop approaches suitable for application in sophisticated, probabilistic, non-linear analyses. Testing for design and the determination of design values from the tests is an extremely important issue. This is especially true for the evaluation of existing structures. Inspection and monitoring of existing structures are essential for maintenance, for the prediction of remaining service life and for the planning of interventions. Chapter nine presents probabilistically-based models for material degradation processes. Finally, case studies are presented in chapter ten. The results of the concrete structures monitoring as well as their application for assessment and prediction of their future behaviour are shown. The risk analysis of highway bridges was based on extensive monitoring and numerical evaluation programs. Case studies perfectly illustrate the application of the methods presented in the Bulletin. The information provided in this guide is very useful for practitioners and scientists. It provides the reader with general procedures, from the specification of requirements, monitoring, assessment to the prediction of the structures’ lifecycles. However, one must have a sufficiently large amount of experimental and other data (e.g. construction experience) in order to use these methods correctly. This data finally allows for a statistical evaluation. As it is shown in case studies, extensive monitoring programs are necessary. The publication of this guide and other documents developed within the fib will hopefully help convince the authorities responsible for safe and fluent traffic on bridges and other structures that the costs spent in monitoring are first rather small, and second, they will repay in the form of a serious assessment providing necessary information for decision about maintenance and future of important structures.

Download or read book Serviceability Limit State of Concrete Structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2019-09-01 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: Serviceability limit states are essential for appropriate function and durability of concrete structures. The attention is paid especially to the stress limitation, crack width analysis and deflection analysis. The document provides supplementary information to the fib Model Code 2010 (MC2010), where a limited space did not allow for a detailed description of individual procedures. The principles used in MC2010 in chapter 7.6 are explained in detail within this document. The stress analysis is focused on stresses in concrete and steel including the stress redistribution due to the long-term load and cracking of reinforced concrete and prestressed concrete elements. Crack width analysis explains the mechanism of cracking under mechanical loading and due to deformation restraint. Cracks in prestressed concrete elements are also discussed. Deflection analyses with different levels of accuracy are described including the shear effects. Examples illustrate the practical application of rules defined in the MC2010 of individual serviceability limit states. Simplified and more general methods are used. An important part of the bulletin shows the development and extension of the serviceability limit states after publishing of the MC2010 and alternative approaches. Special attention is paid to deflections of prestressed concrete beams, shear effects on deflection, slenderness limits and influence of the concrete cover. The final part deals with an application of numerical simulations.

Download or read book Sustainability of precast structures written by FIB – International Federation for Structural Concrete and published by FIB - Féd. Int. du Béton. This book was released on 2018-12-01 with total page 163 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sustainability is a crucial concept. Sustainability was first introduced in the fib by creating a Special Activity Group under the convenorship of Prof Sakai. This group encouraged and helped all fib commissions to create their own groups dealing with sustainability. The fib Commission 6 “Prefabrication” took up this challenge and created a Task Group called “Sustainability of Structures with Precast Elements” in 2012. The group was created as a joint group with PCI (Precast Concrete Institute of USA), with the then-active fib Commission 3 “Environmental aspects of design and construction”, and the fib’s SAG8 on Sustainability. Therefore, this Bulletin 88 is a joint publication between PCI and fib. The aim of the work was to gather and study the most recent work that has been developed regarding sustainability – and more particularly Life Cycle Assessment - of structures in which precast elements are used. The final aim of the group would be to provide recommendations for the study and assessment of structures built with precast elements. It will cover all aspects of this kind of structure, from planning, design, execution, use, maintenance and remedial activities to deconstruction, reuse, demolition and recycling. The fib holds sustainability as a high priority, which triggered the creation of a new Commission 7 “Sustainability” during the 2015 fib commissions reorganisation. This commission has been chaired since then by Prof Hájek. Sustainability concepts were already introduced in the Model Code 2010 and are a key part in the elaboration of the Model Code 2020. Experts from many parts of the world contributed to this fib Bulletin 88 which gives the document a broad overview of sustainability sensibilities across different continents. Bulletin 88 starts with a description of the importance of environmental concepts and developments in the world today and the reason why sustainability is a crucial concept that will be even more important in the future. The document then focuses on the different advances of standards and regulations that have been developed or are in the process of being implemented. ISO, European regulations, North American regulations, Brazilian implementation in real precast companies and the developments of the fib Model Codes have been considered in this bulletin. After that, the bulletin examines life cycle aspects of precast structures, taking former fib bulletins as a basis. Then, it moves on to an in-depth study of specific sustainability aspects of precast structures. Then, the bulletin deals with the special methodologies and tools that are available around the world to handle sustainability in general and with precast structures in particular. A selection of tools is described in this chapter. The Task Group also developed proposals about how to deal with the sustainability of precast structures. Some of the proposals are described conceptually in the text. The final chapter compiles several case studies or examples of sustainability applications of precast structures. The examples differ and are grouped by category: buildings, infrastructure and special works.v The task group continues to work on developing other documents that will focus on the detailed practical application of some of the sustainability models described in this document.

Download or read book Towards a rational understanding of shear in beams and slabs written by fib Fédération internationale du béton and published by FIB - Féd. Int. du Béton. This book was released on 2018-05-01 with total page 354 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable performance of beams and slabs in shear is essential for the safety and also for the serviceability of reinforced concrete structures. A possible failure in shear is usually a brittle failure, which underlines the importance of the correct specification of the load carrying capacity in shear. The knowledge of performance in shear is steadily developing and it is now obvious that older structures were not always designed in accordance with contemporary requirements. The increasing load – mainly on bridges – requires the assessment of existing structures, often followed by their strengthening. An appropriate understanding of actual performance of concrete structures in shear is therefore of primary interest. The workshop which was held in Zürich in 2016 brought together a significant number of outstanding specialists working in the field of shear design, who had a chance to exchange their opinions and proposals for improving the current knowledge of shear behaviour in beams and slabs. The specialists came from different parts of the world, which made the workshop general and representative. The workshop was organised by fib Working Party 2.2.1 “Shear in Beams” (convened by O. Bayrak), which is a part of fib Commission 2 "Analysis and Design". Individual contributions mainly address shear in beams with low transversal reinforcement. It is crucial because many existing structures lack such reinforcement. Different theories, e.g. Critical Shear Crack Theory (CSCT), Modified Compression Field Theory (MCFT), Multi-Action Shear Model (MASM), etc. were presented and compared with procedures used in selected national codes or in the fib Model Code 2010. The models for shear design were often based to a great extent on empirical experience. The refined presented models tend to take into account the physical mechanisms in structures more effectively. A brittle behaviour in shear requires not only to check the equilibrium and failure load, but also to follow the progress of failure, including the crack development and propagation, stress redistribution, etc. The significance of the size effect – which causes the nominal strength of a large structure to be smaller than that of a small structure – was pointed out. Nowadays, the fibre reinforcement is used more than before since it allows significant labour costs savings in the construction industry. The contribution of fibres is suitable for shear transfer. It is very convenient that not only ordinary fibre reinforced elements were addressed but also the UHPFRC beams. The production of this new material is indeed growing, while the development of design recommendations has not been sufficiently fast. Fatigue resistance of structures with low shear reinforcement is also an important issue, which was also addressed in this bulletin. It cannot be neglected in prestressed bridges, which are exposed to dynamic loads. A comprehensive understanding of the shear behaviour is necessary. Although many laboratory experiments are carried out, they are suitable only to a limited extent. New testing methods are being developed and show promising results, e.g. digital image correlation. An actual structure performance should rather be tested on a large scale, ideally on real structures under realistic loading conditions.ii The papers presented in the bulletin are a basis for the discussion in view of the development of updated design rules for the new fib Model Code (MC2020), which is currently under preparation. fib Bulletins like this one, dealing with shear, help to transfer knowledge from research to design practice. The authors are convinced that it will lead to better new structures design of as well as to savings and to a safety increase in older existing structures, whose future is often decided now.

Download or read book Guide for Strengthening of Concrete Structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-05-01 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of preparing a technical document for the repairs and interventions upon concrete structures goes back to the former fib COM 5: Structural Service Life Aspects, being the goal of the then TG 5.9. After a long period of reduced activity, and taking into account the reorganization of fib commissions that meanwhile took place, on June 2017 a different approach was proposed to push forward the task of TG 8.1 (formerly TG 5.9). The (new) goal of TG 8.1 was to deliver a ‘how-to-do’ guide, gathering together protection, repair, and strengthening techniques for concrete structures. Chapters are intended to provide both guidelines and case-studies, serving as support to the application of fib MC 2020 pre-normative specifications. Each chapter was written by an editorial team comprising desirably at least a researcher, a designer and a contractor. Templates have been prepared in order to harmonize the contents and the presentation of the different methods. Following the writing process, chapters were reviewed by experts and, after amendments by the authors, they underwent a second review process by COM 8 and TG 3.4 members, as well as by different practitioners. For each protection, repair and strengthening method addressed in this guide, readers have a description of when to adopt it, which materials and systems are required, which techniques are available, and what kind of equipment is needed. It then presents a summary of stakeholders’ roles and qualifications, design guidelines referring to most relevant codes and references, the intervention procedure, quality control measures and monitoring and maintenance activities. Due to the extent of the guide, it was decided to publish it as bulletin 102, addressing protection and repair methods, and bulletin 103, addressing strengthening methods. We would like to thank the authors, reviewers and members of COM 8 and TG 3.4 for their work in developing this fib Bulletin, which we hope will be useful for professionals working in the field of existing concrete structures, especially those concerned with life-cycle management and conservation activities. As noted above, this Bulletin is also intended to act as a background and supporting document to the next edition of the fib Model Code for Concrete Structures, which is currently under development under the auspices of TG10.1 with the working title of ‘fib Model Code 2020’.

Download or read book Precast Concrete in Tall Buildings written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2021-12-01 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: There has been continued global growth in tall building construction over recent years. The variation in the use of such buildings is remarkable, from lavish hotels and apartments to socially affordable units. As the world struggles to cope with growing numbers of people, dwindling resources and movements from rural to urban habitats it is unavoidable that population densities will increase, and more efficient use of scarce land will be needed. Taller buildings are the inevitable consequence. Tall buildings can use several different types of material to form their framework and envelope. Those materials are mixed to provide an optimum building solution to suit client requirements such as structure, occupancy, vision, affordability, timing, sustainability and quality. Precast concrete is one of those materials, and has been used from whole frameworks to facades, and elements mixed with structural steelwork and cast in place concrete. This state of the art report shows how precast concrete can be effectively integrated into tall buildings using modern materials and techniques, drawing on the experience and expertise that is currently available in the global precast concrete industry. The report is aimed at not only building professionals and students, but also at contractors, investors, owners, public bodies and any other parties interested in the possibilities for use of precast concrete in tall building construction. Extensive case studies at the end of the Bulletin illustrate the benefits and applications discussed in the earlier chapters.

Download or read book Fibre Reinforced Concrete written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-11-01 with total page 461 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fibre Reinforced Concrete (FRC) is a composite material characterized by an enhanced post-cracking tensile residual strength, due to the capacity of fibres to bridge the crack faces by means of pull-out mechanism. Due to a better knowledge of FRC and the recent developments worldwide of guidelines for structural design, the fib Special Activity Group 5, who prepared the new fib Model Code, decided to introduce some sections on new materials and in particular on FRC structural design. At that time, working Groups TG 8.3 (“Fibre reinforced concrete”) and TG 8.6 (“Ultra high performance fibre reinforced concrete”) of fib prepared these sections of the new fib Model Code concerning FRC design rules for providing a guidance to engineers to properly and safely design FRC structural elements, both at serviceability and at ultimate limit states, based on the state-of-the-art knowledge. This bulletin was written with the aim to share the main framework used by the two groups to introduce these two sections and to describe the many aspects already known, but not yet introduced in the Model Code. Even though the basic principles introduced in the two sections are mainly obtained from research on steel fibre reinforced concrete, the Model Code is open to every type of fibres, following a performance-based design approach. The bulletin represents a wide effort made by the people of the Task Group 4.1 and 4.2 to trace the knowledge on FRC and aims to be helpful for structural designers when using this new material in the practice.

Download or read book 70 Years of China s Bridges written by Zhongfu Xiang and published by Springer Nature. This book was released on 2024-01-24 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book takes time as the axis, selecting 98 bridges (or bridge groups) across the country and 7 representative bridges out of the country, reflecting the steps and development of China's bridge construction in related majors and engineering technicians in colleges and universities. This book aims to let the general public understand the arduous history of China's bridge construction and the rapid development of China's bridge construction without the country's economic development, strength, and hard work of the bridge people. It is also hoped that the public will enjoy the convenience of bridges, highways, railroads, and urban roads and at the same time enhance their awareness of bridge knowledge, knowledge, love, and scientific use of bridges. This book is used by the general public to understand the development of China's bridge construction, but also as a reference book for teachers and students of bridge engineering-related majors and engineering technicians in colleges and universities.

Download or read book Acceptance of cable systems using prestressing steels written by FIB – International Federation for Structural Concrete and published by FIB - Féd. Int. du Béton. This book was released on 2019-03-01 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cable-stayed structures have become increasingly popular over the last 30 years and have been used in all parts of the world. Modern cable-stayed bridges have a history of over 50-years and have been constructed with span lengths ranging from 15 m to over 1000 m. Many long span cable-stayed bridges have been built for railway and highway traffic applications. Stay cables have also been used on pedestrian structures, many of which are architecturally striking and have become landmark structures. There is growing use in building structures, particularly for cable-supported roofs. Most of the cable supported structures have been in the form of cable-stayed bridges; but in recent years, extradosed bridges have seen increased popularity among the designers. Led by the experience in Japan, more than 200 extradosed bridges have been constructed worldwide in the past 15 years. The first edition of these fib recommendations was published as fib Bulletin 30 in 2005 and was the first specification published by fib for stay cable systems. This new bulletin has been updated based on Bulletin 30 with the aim to reflect the current state of the art and encompass the latest knowledge in cable systems. In addition, it has been the aspiration of Commission 5 and Task Group 5.5 to harmonize the guidance in this updated bulletin with other stay cable recommendations from around the world, including those from Europe, Japan and the USA. This new bulletin is intended to supersede and replace fib Bulletin 30. It is recommended that it be used in lieu of fib Bulletin 30 for all future cable supported applications. The updated bulletin introduces several significant enhancements to the specifications: These recommendations are applicable to both stay cable and extradosed cable applications. In the past, there has been some debate over the boundary between cable-stayed and extradosed bridges. This bulletin presents a new continuous approach valid for both. A completely new testing requirement to assess the performance of cable systems under bending fatigue, including both anchorages and saddles, if applicable, has been added. Testing requirements for saddle systems have been reformulated. In addition to the bending fatigue test noted above, new testing procedures for stay cable saddles with isolated tensile elements are introduced. This includes tests for saddle axial fatigue, friction and tensile testing, and determination of the effective saddle friction coefficient. Expanded system qualification, including requirements for both stay cable and extradosed applications. Includes new provisions for MTE qualification and additional load transferring connection devices. Minimum number of tests is specified for each. A new in-situ damping measurement test has been added to verify the actual damping ratio of the damping devices installed. By testing on site, selected cables may be excited to vibrate without and with the damping devices so that the observed v vibration behaviour can be compared to the specified value. Other revisions have been made to reflect the current state of practice: Expanded quality control testing requirements Inclusion of epoxy-coated prestressing steel as a protection layer. Previous recommendations only considered zinc coatings. Specifications for epoxy coating material are given. Requirements for stainless steel components such as pipes, caps and plates Updated guidance for designing lightning protection systems Detailed recommendations for different levels of inspection of cable systems, including: initial, routine, detailed and exceptional inspections An updated list of references, relevant standards, and extended literature

Download or read book Externally applied FRP reinforcement for concrete structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2019-05-01 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: In December 1996, CEB established a Task Group with the main objective to elaborate design guidelines for the use of FRP reinforcement in accordance with the design format of the CEB-FIP Model Code and Eurocode2. With the merger of CEB and FIP into fib in June 1998, this Task Group became fib TG 9.3 FRP Reinforcement for concrete structures in Commission 9 Reinforcing and Prestressing Materials and Systems. Finally, as a result of the restructuring of fib’s Commissions and Task Groups at the end of 2014, the Task Group became fib T5.1 FRP Reinforcement for concrete structures, chaired by Stijn Matthys at Ghent University, in Commission 5 Reinforcements. The work of former TG 9.3 and current T5.1 was performed by two working parties (WP), one of which is “Externally Applied Reinforcement” (EAR), which produced fib bulletin 14 “Externally bonded FRP reinforcement for RC structures” in July 2001. Following a number of years of relatively slow activity, the WP on externally applied reinforcement was reactivated and started working on an update of bulletin 14. The result of this work is summarised in the present technical report, which aims to give design guidelines on the use of externally applied FRP reinforcement (both externally bonded and near-surface mounted) for concrete structures. An attempt has been made to present some of the topics in a Eurocode-compatible format, so that the material covered may form the basis for the introduction of composites in the next version of Eurocode 2 and for the updating of the text on seismic retrofitting with composites in the next version of Eurocode 8. All persons who participated in the preparation of this Bulletin are mentioned in the copyright page. Further acknowledgements are due to Josée Bastien (Canada), Hans Rudolf Ganz (Switzerland) and Luc Taerwe (Belgium) for revision of the document. To all members of the working party on externally applied reinforcement our sincere thanks are expressed for the high quality and extensive work brought in on a voluntary basis.

Download or read book Advances on bond in concrete written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-12-01 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural behavior of reinforced concrete elements strongly depends on the interaction between the reinforcing bars and the surrounding concrete, which is generally referred as “bond in concrete”. In service conditions, the reinforcement-to-concrete bond governs deformability through the tension stiffening of concrete surrounding the bar as well the crack development and crack width. At Ultimate Limit State, bond governs anchorage and lap splices behavior as well as structural ductility. When plain (smooth) bars were used, the steel-to-concrete bond was mainly associated with “chemical adhesion/friction” that is related to the surface roughness of the rebar. As steel strengths increased the need to enhance interaction between steel and the surrounding concrete was recognized, and square twisted rebars, indented rebars or, later on, ribbed rebars came into the market, the latter being the type of deformed bar most commonly adopted since the 1960/70s. When ribbed rebars became widely used, several research studies started worldwide for better understanding the interaction between ribs and the surrounding concrete. Researchers evidenced the development of micro-cracks (due to the wedge action of the ribs) towards the external face of the structural element. If confinement is provided by the concrete cover, by transverse reinforcement or by an external transverse pressure, the full-anchorage capacity is guaranteed and a pull-out failure occurs, with crushing of concrete between the ribs. On the contrary, with lesser confining action, a splitting failure of bond occurs; the latter may provoke a brittle failure of the lap splice or, in some cases, of anchorages. However, after many years of research studies on bond-related topics, there are still several open issues. In fact, new materials entered into the market, as concrete with recycled aggregates or fibre reinforced concrete; the latter, having a kind of distributed reinforcement into the matrix (the fibres), provides a better confinement to the wedge action of the ribs. In addition, concrete and steel strength continuously increased over the years, causing changes in the bond behavior due to differences in mechanical properties of materials but also to the different concrete composition at the interface with the steel rebar causing a different bond behavior. Moreover, the lower water/cement ratio of these high-strength concrete makes the bleeding phenomena less evident, changing the concrete porosity in the upper layers of the structural element and thus making the current casting position parameters no-longer reliable. Finally, concrete with recycled aggregates are becoming more important in a market that is looking forward to a circular economy. As such, all the experimental results and database that allowed the calibration of bond rules now present in building codes for conventional concrete, may be not be representative of these new types of materials nowadays adopted in practice. Furthermore, after more than 50 years of service life, structural elements may not satisfy the current safety requirements for several reasons, including material degradation (with particular reference to steel corrosion) or increased loads, by also considering the seismic actions that were non considered by building codes at the time of the original design. The structural assessment of existing structures requires proper conceptual models and new approaches for evaluating the reliability of existing structures by also considering the remaining expected service life. In addition, specific rules for older materials, as plain smooth bars, should be revised for a better assessment of old structures. Last, but not least, interventions in existing structures may require new technologies now available such as post-installed rebars. While many advances have been achieved, there remain areas where a better understanding of bond and its mechanisms are required, and where further work is required to incorporate this understanding into safe and economic rules to guide construction and maintenance of existing infrastructures. These aspects were widely discussed within the technical community, particularly in the fib Task Group 2.5 and in the ACI 408 Committee dealing with bond and anchorage issues. Furthermore, special opportunities for discussing bond developments were represented by the International Conferences on ‘Bond in Concrete’ held each decade since 1982 as well as by joint workshops organized by fib TG2.5 and ACI 408. Within this technical collaboration, this Bulletin was conceived, and, thus, it collects selected papers presented at the joint fib-ACI Convention Session on Bond in Concrete held in Detroit (USA) in 2017. The bulletin is based on four main Sections concerning: - General aspects of bond - Anchorages and laps of bars and prestressing tendons - Bond under severe conditions - Degradation of bond for corrosion - Bond in new types of concrete The main aim of the Bulletin is to shed some new lights on the advances in understanding and application of bond related issues achieved over the last few years, and identify the challenges and priorities to be addressed in the next years. Another important aspect of the bulletin is to provide practical information from research findings.

Download or read book Guide for Protection and Repair of Concrete Structures written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2022-03-01 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: The idea of preparing a technical document for the repairs and interventions upon concrete structures goes back to the former fib COM5: Structural Service Life Aspects, being the goal of the then TG5.9. After a long period of reduced activity, and taking into account the reorganization of fib commissions that meanwhile took place, on June 2017 a different approach was proposed to push forward the task of TG8.1 (formerly TG5.9). The (new) goal of TG 8.1 was to deliver a ‘how-to-do’ guide, gathering together protection, repair, and strengthening techniques for concrete structures. Chapters are intended to provide both guidelines and case-studies, serving as support to the application of fib MC2020 pre-normative specifications. Each chapter was written by an editorial team comprising desirably at least a researcher, a designer and a contractor. Templates have been prepared in order to harmonize the contents and the presentation of the different methods. Following the writing process, chapters were reviewed by experts and, after amendments by the authors, they underwent a second review process by COM8 and TG3.4 members, as well as by different practitioners. For each protection, repair and strengthening method addressed in this guide, readers have a description of when to adopt it, which materials and systems are required, which techniques are available, and what kind of equipment is needed. It then presents a summary of stakeholders’ roles and qualifications, design guidelines referring to most relevant codes and references, the intervention procedure, quality control measures and monitoring and maintenance activities. Due to the extent of the guide, it was decided to publish it as bulletin 102, addressing protection and repair methods, and bulletin 103, addressing strengthening methods. We would like to thank the authors, reviewers and members of COM8 and TG3.4 for their work in developing this fib Bulletin, which we hope will be useful for professionals working in the field of existing concrete structures, especially those concerned with life-cycle management and conservation activities. As noted above, this Bulletin is also intended to act as a background and supporting document to the next edition of the fib Model Code for Concrete Structures, which is currently under development under the auspices of TG10.1 with the working title of "fib Model Code 2020".

Download or read book Precast concrete bridge continuity over piers written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2020-07-01 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete bridges are an important part of today's road infrastructure. An important part of those concrete bridges is to a large extent prefabricated. Precast concrete enables all the advantages of an industrialized process to be fully utilized. Contemporary concrete mixtures are used to realize high-strength bridge girders and piers that exactly meet the requirements set, both structurally and aesthetically, with a small ecological footprint. Sustainable and durable! On the construction site, there is no need for complex formwork, the execution time is drastically reduced and where road, water and rail traffic on or under the bridge has to be temporarily interrupted, it is only minimally inconvenienced during the execution of the project. There is a wide variety of prefabricated bridges. In 2004, the fib commission on prefabrication already published the Bulletin 29 Precast concrete bridges which, in addition to the history of prefabricated bridges, also gave an overview of the different bridge types and structural systems. This document elaborates on one specific structural system: the continuous bridge. Task Group 6.5 "Precast concrete bridges" discusses in detail how to achieve continuity over the piers with precast elements. This bulletin bundles the experiences of experts in the field of bridge design so that less experienced designers would be able to identify the points of attention and make a correct design. In addition to the theoretical considerations, the principles are tested against three realizations in the USA and Europe. Commission 6 thanks the Co-Conveners Maher Tadros and Hugo Corres and all active members of the Task Group for sharing their knowledge and experience and for the successful realization of this bulletin.

Download or read book Guidelines for Submerged Floating Tube Bridges written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 2020-10-01 with total page 131 pages. Available in PDF, EPUB and Kindle. Book excerpt: This bulletin is a guidelines document for “Submerged Floating Tube Bridges”, that represents an innovation in Marine Concrete Structures. This theme is considered important for Commission 1 since in the future several applications are forecast in marine environments. Submerged Floating Tube Bridges are a solution that can be proposed to solve different problems in passing water constrains as lakes and fiords, reducing the impact and allowing several economic advantages. The guidelines certainly will boost the application of Submerged Floating Tube Bridges since the document is useful not only for designers but also for construction companies, owners and public administrations. As guidelines, the bulletin gives wide information on the design, construction and management of these structures, allowing all the users to be confident in promoting the use of Submerged Floating Tube Bridges.