Durability Of Post Tensioning Tendons

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 84 pages
File Size : 50,7 Mb
Release : 2006
Category : Technology & Engineering
ISBN : 2883940738

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Durability of Post-tensioning Tendons by fib Fédération internationale du béton Pdf

The durability of post-tensioning tendons depends undoubtedly on the durability of the materials used, but there are design concept specifics which are also of major importance: the post-tensioning layout and layers of protection such as concrete cover and selected materials in view of the aggressivity of the environment for instance. It is well known that sustainability principles guide the Engineer from the very beginning, at the project conception, during construction and the service life of a structure. Decisions made during conceptual and design stage have the largest influence on the durability and sustainability of post-tensioning tendons. fibBulletin 33 addresses the specifics for prestressed concrete structures: the durability of post-tensioning tendons. It should be noted that it does not repeat topics that have been addressed in other fib bulletins and which is common for both reinforced concrete and prestressed concrete structures. Pre-tensioning, which is used extensively in the precast industry, is not considered here, although conclusions and recommendations herein may, in many cases, also be applicable. This recommendation was prepared by Working Party 5.4.2, Durability specifics for prestressed concrete structures, in cooperation with fib Commission 9,Reinforcing and prestressing materials and systems. A preliminary version of this recommendation served as the basic document for the second workshop on "Durability of post-tensioning tendons", held on 11-12 October 2004 in Zurich. This workshop was a follow-up to the first workshop held in Ghent in 2001. Bulletin 33 includes revisions corresponding to the agreed results of the Zurich workshop.

Author : Morris Schupack
Publisher : Unknown
Page : 20 pages
File Size : 49,9 Mb
Release : 1978
Category : Tendons (Prestressed concrete)
ISBN : WISC:89034028803

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A Survey of Durability Performance of Post-tensioning Tendons by Morris Schupack Pdf

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 279 pages
File Size : 50,6 Mb
Release : 2001-01-01
Category : Technology & Engineering
ISBN : 9782883940550

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Durability of Post-tensioning Tendons by fib Fédération internationale du béton Pdf

In some countries durability problems with post-tensioning tendons have in the past led to fairly restrictive regulations. Improvements to execution procedures have been developed since, and new or improved prestressing systems have been proposed, too. This development was, of course, subject of discussions in fib Commission 9 Reinforcing and Prestressing Materials and Sytems and in IABSE Working Commission 3 Concrete Structures. It was decided to organise a workshop with the aim to review the different aspects of the problems encountered and to discuss solutions available today. Keynote speakers from various countries were invited to contribute. Their papers are published in this bulletin, grouped together under the following themes: Inventory and condition (6 papers) Investigation and repair (5 papers) Technical progress (4 papers) Strategies for improvement (6 papers) Supported by the international federation for structural concrete fib, and the international association for bridge and structural engineering IABSE, the workshop took place on 15-16 November 2001 at Ghent University, celebrating the 75th anniversary of the Magnel Laboratory for Concrete Research, whose director also chaired the Scientific Committee and edited the bulletin. It needs to be emphasised that in the bulletin invited experts present their individual views. Although not yet discussed in any of the association's working bodies, the highly topical contents of the bulletin is believed to be of general interest to fib's members and to document a starting point for future work in this field. Therefore, the Council of fib agreed to exceptionally publish these papers within fib's series of Bulletins.

Author : Anonim
Publisher : Unknown
Page : 248 pages
File Size : 52,9 Mb
Release : 2001
Category : Electronic
ISBN : OCLC:938948882

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Durability of Post-tensioning Tendons by Anonim Pdf

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 56 pages
File Size : 43,5 Mb
Release : 2002-01-01
Category : Technology & Engineering
ISBN : 2883940606

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Grouting of Tendons in Prestressed Concrete by fib Fédération internationale du béton Pdf

Prestressed Concrete is a very efficient form of construction; it takes advantage of the strength of concrete in compression. Developed mainly over the second part of the 20th century, it has proven to be reliable and durable. However, in the 1990's some cause for concern was discovered, first in the UK and followed by many other countries of the world. It appeared that the grout, an important means of protection of the steel against corrosion for internally ducted tendons, was in some cases inadequate. Major investigations followed including physical intrusive examination of ducts, mainly in bridges, and re-writing of procedures, processes and specifications, and in 1998 FIP launched a Task Group to review their advice note "Guidelines for Grouting" which had first been published in 1990. The merger of FIP and CEB in 1998 brought this under the auspices of fib. Structural deficiencies have only been found in a small number of bridges and in most of these cases the cause is clearly identifiable as either design detailing, workmanship or materials. In the UK, the Concrete Society report TR47 "Durable Post-tensioned Concrete Bridges" had been published in 1996, which was the culmination of four years of investigative research, and contained major new specifications and procedures aimed at improving the quality of grouting. In the USA, the Post Tensioning Institute published in 2001 their guide "Specification for Grouting of Post-Tensioned Structures", which also represented major steps forward in materials and testing requirements. The American Segmental Bridge Institute has set up a Committee to re-examine their guidelines, as have many other National Bodies worldwide. In Europe, France has issued a "Fascicule No. 65A" covering requirements for grouting and there are many developments in hand in other countries. Also in Europe, a European Technical Approval Guideline (ETAG) has been published for approval of post-tensioning systems which covers several aspects of grout and grouting. In November 2001 an international workshop was held in Ghent, Belgium on "Durability of Post-Tensioning Tendons" [see fib Bulletin 15] at which international experience was exchanged. The theme was clearly apparent; those bridge owners that have looked, have found some problems with a few of their post-tensioned bridges. In most cases steps are being taken to repair existing bridges, where considered necessary, and to improve future construction by reviewing national specifications. Emphasis is being put on a multi-layer protection strategy whereby protection against corrosion is provided by waterproofing, dense impermeable concrete, sealed ducts and good quality grout. Design detailing and rain water management are seen as important aspects. It was, therefore, timely for fib to publish state-of-the-art guidelines to assist in developing and improving the quality of a major line of defence against corrosion, the cement grout. This document represents a consensus view of current practitioners of what is a rapidly developing awareness of some of the shortcomings of previous practice and suggests improvements. This document is a major update of the previous FIP Guidelines and may be taken as a future basis for updating EN 445-447. New areas include understanding of the deleterious effects of an unstable grout, bleeding and how to avoid it, the importance of training and proper procedures, mix design and testing/trials and some new test procedures. It is now understood and generally accepted that the properties of common grout made from cement and water can be very variable and sometimes unpredictable and such grout is not recommended.

Author : FIB – International Federation for Structural Concrete
Publisher : FIB - International Federation for Structural Concrete
Page : 116 pages
File Size : 54,9 Mb
Release : 2021-04-01
Category : Technology & Engineering
ISBN : 9782883941472

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Acceptance of post-tensioning systems for cryogenic applications by FIB – International Federation for Structural Concrete Pdf

Since the Second World War the demand of energy has undergone an exponential growth that has led to a sharp annual increase in the use of natural gas in both, cities and thermal power stations. Nowadays, the strategic relevance of natural gas as a main source of energy is evident with a contribution of more than 20% of the total world consumption. This development in increasing demand of natural gas has led for a need of suitable storage and transportation infrastructure. Various gases, especially hydrocarbons, are preferably stored in liquid form for transportation and storage since the phase transformation from gas to liquid comes with a significant reduction of the volume (e.g. up to 600 times). Gases can be liquefied by raising the pressure or by cooling to their boiling point, which for most gases is below 0°C. This is known as cryogenic storage. The term cryogenic is derived from two Greek words, namely kryos meaning icy-cold and genes which can be translated as shape. These fib recommendations are concerned about post-tensioning systems used in cryogenic tanks and have been formulated on the basis of actual available knowledge with the aim to reflect the current state of the art. Consequently, these recommendations have included a classification of the different cryogenic tanks typologies used in the past and nowadays, the associated different tendon types depending on their exposure to low temperature (e.g. never, only accidentally or during normal tank operation) and the testing regime required for acceptance of the materials and the post-tensioning system according to this document. An international working group comprising more than 20 experts from administrative authorities, universities, laboratories, owners, structural designers, suppliers of prestressing steels and post-tensioning systems suppliers have actively contributed in order to develop these recommendations. This text has been written to cover best construction practices around the world, and to provide material specifications which are considered to be the most advanced available at the time of preparing this text. For ease of use (for Owner, Designer and Post-tensioning System Supplier), the content has been arranged systematically according to the system components into chapters focusing on performance characteristics, requirements and acceptance criteria.

Author : Universiteit (Gand)
Publisher : Unknown
Page : 277 pages
File Size : 42,6 Mb
Release : 2001
Category : Electronic
ISBN : 288394055X

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Durability of Post-tensioning Tendons by Universiteit (Gand) Pdf

Author : Michael Grantham,P A Muhammed Basheer,Bryan Magee,Marios Soutsos
Publisher : CRC Press
Page : 834 pages
File Size : 44,6 Mb
Release : 2014-08-18
Category : Technology & Engineering
ISBN : 9781315737317

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Concrete Solutions 2014 by Michael Grantham,P A Muhammed Basheer,Bryan Magee,Marios Soutsos Pdf

The Concrete Solutions series of International Conferences on Concrete Repair began in 2003 with a conference held in St. Malo, France in association with INSA Rennes. Subsequent conferences have seen us partnering with the University of Padua in 2009 and with TU Dresden in 2011. This conference is being held for the first time in the UK, in associ

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 183 pages
File Size : 41,7 Mb
Release : 2014-12-01
Category : Technology & Engineering
ISBN : 9782883941151

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Polymer-duct systems for internal bonded post-tensioning by fib Fédération internationale du béton Pdf

The purpose of this recommendation - fib Bulletin 75: Polymer-duct systems for internal bonded post-tensioning - is to update and amend fib Bulletin 7:Corrugated plastic ducts for internal bonded post-tensioning, a technical report published in 2000. fib Bulletin 75 is meant as a cornerstone for the technical approval of polymer (plastic) ducts for internal bonded post-tensioning and possibly for the test procedures of a future testing standard. The updated bulletin includes new information on the design and detailing of concrete structures containing tendons with polymer ducts. The recommendation provides detailed test specifications for polymer materials, duct components and duct systems. In addition, the report contains recommendations for approval testing and attestations of conformity for polymer-duct systems. Although the new generation of corrugated polymer ducts for bonded post-tensioning have now been around for approximately twenty years, products still differ in material properties, geometrical detail, installation procedures and on-site use. Unlike corrugated steel ducts or smooth polyethylene (PE) pipes, they have not yet become standardized. It is the opinion of fib Task Group 9.16 and Commission 9 that these plastic ducts should, therefore, still be subjected to a systems approval process. This recommendation offers information acquired from twenty years of experience as well as new specifications that will, hopefully, lead to the standardization of polymer-duct systems.

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 482 pages
File Size : 41,6 Mb
Release : 2012-06-01
Category : Technology & Engineering
ISBN : 9782883941021

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Structural Concrete Textbook, Volume 5 by fib Fédération internationale du béton Pdf

The third edition of the Structural Concrete Textbook is an extensive revision that reflects advances in knowledge and technology over the past decade. It was prepared in the intermediate period from the CEP-FIP Model Code 1990 (MC90) tofib Model Code for Concrete Structures 2010 (MC2010), and as such incorporates a significant amount of information that has been already finalized for MC2010, while keeping some material from MC90 that was not yet modified considerably. The objective of the textbook is to give detailed information on a wide range of concrete engineering from selection of appropriate structural system and also materials, through design and execution and finally behaviour in use. The revised fib Structural Concrete Textbook covers the following main topics: phases of design process, conceptual design, short and long term properties of conventional concrete (including creep, shrinkage, fatigue and temperature influences), special types of concretes (such as self compacting concrete, architectural concrete, fibre reinforced concrete, high and ultra high performance concrete), properties of reinforcing and prestressing materials, bond, tension stiffening, moment-curvature, confining effect, dowel action, aggregate interlock; structural analysis (with or without time dependent effects), definition of limit states, control of cracking and deformations, design for moment, shear or torsion, buckling, fatigue, anchorages, splices, detailing; design for durability (including service life design aspects, deterioration mechanisms, modelling of deterioration mechanisms, environmental influences, influences of design and execution on durability); fire design (including changes in material and structural properties, spalling, degree of deterioration), member design (linear members and slabs with reinforcement layout, deep beams); management, assessment, maintenance, repair (including, conservation strategies, risk management, types of interventions) as well as aspects of execution (quality assurance), formwork and curing. The updated textbook provides the basics of material and structural behaviour and the fundamental knowledge needed for the design, assessment or retrofitting of concrete structures. It will be essential reading material for graduate students in the field of structural concrete, and also assist designers and consultants in understanding the background to the rules they apply in their practice. Furthermore, it should prove particularly valuable to users of the new editions of Eurocode 2 for concrete buildings, bridges and container structures, which are based only partly on MC90 and partly on more recent knowledge which was not included in the 1999 edition of the textbook.

Author : fib Fédération internationale du béton
Publisher : fib Fédération internationale du béton
Page : 56 pages
File Size : 51,9 Mb
Release : 2000-01-01
Category : Technology & Engineering
ISBN : 2883940479

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Corrugated Plastic Ducts for Internal Bonded Post-tensioning by fib Fédération internationale du béton Pdf

Optimum corrosion protection of post-tensioning tendons has been a priority since the beginning of this technology. The temporary ban of grouted post-tensioning tendons in the United Kingdom, from 1992-1996, has initiated a review of all aspects related to durability of post-tensioning tendons. One of the UK conclusions of this review was to require encapsulation of the post-tensioning tendons into wear-resistant and leak-tight plastic ducts to serve as an additional corrosion protection barrier. Since that time, other countries have at least partially adopted similar approaches. Designs of these plastic ducts may vary significantly between different suppliers. In addition, experience with these systems is still relatively limited. Hence, these plastic ducts cannot be standardised at this time. Therefore, the former FIP Commission 2, and now fib Commission 9 Reinforcing and Prestressing Materials and Systems, has set-up a task group to prepare a fib report on corrugated plastic ducts for internal, bonded post-tensioning. This report is written as a guide for an approval process for such plastic ducts. It shall serve readers such as authorities, and engineers as a guide on how to set-up a formal state approval process for these ducts, or at least allow them to properly assess systems offered for a specific project.

Author : Joan Ramon Casas,Dan M. Frangopol,Jose Turmo
Publisher : CRC Press
Page : 2646 pages
File Size : 42,9 Mb
Release : 2022-06-27
Category : Technology & Engineering
ISBN : 9781000798739

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Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability by Joan Ramon Casas,Dan M. Frangopol,Jose Turmo Pdf

Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability contains lectures and papers presented at the Eleventh International Conference on Bridge Maintenance, Safety and Management (IABMAS 2022, Barcelona, Spain, 11–15 July, 2022). This e-book contains the full papers of 322 contributions presented at IABMAS 2022, including the T.Y. Lin Lecture, 4 Keynote Lectures, and 317 technical papers from 36 countries all around the world. The contributions deal with the state-of-the-art as well as emerging concepts and innovative applications related to the main aspects of safety, maintenance, management, life-cycle, resilience, sustainability and technological innovations of bridges. Major topics include: advanced bridge design, construction and maintenance approaches, safety, reliability and risk evaluation, life-cycle management, life-cycle, resilience, sustainability, standardization, analytical models, bridge management systems, service life prediction, structural health monitoring, non-destructive testing and field testing, robustness and redundancy, durability enhancement, repair and rehabilitation, fatigue and corrosion, extreme loads, needs of bridge owners, whole life costing and investment for the future, financial planning and application of information and computer technology, big data analysis and artificial intelligence for bridges, among others. This volume provides both an up-to-date overview of the field of bridge engineering and significant contributions to the process of making more rational decisions on bridge safety, maintenance, management, life-cycle, resilience and sustainability of bridges for the purpose of enhancing the welfare of society. The volume serves as a valuable reference to all concerned with and/or involved in bridge structure and infrastructure systems, including students, researchers and practitioners from all areas of bridge engineering.

Author : FIB – International Federation for Structural Concrete
Publisher : FIB - Féd. Int. du Béton
Page : 707 pages
File Size : 53,8 Mb
Release : 2011-06-01
Category : Technology & Engineering
ISBN : 9788087158296

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Proceedings fib Symposium in Prague Czech Republic Vol1 by FIB – International Federation for Structural Concrete Pdf

Author : FIB – International Federation for Structural Concrete
Publisher : FIB - Féd. Int. du Béton
Page : 804 pages
File Size : 40,8 Mb
Release : 2006-06-01
Category : Technology & Engineering
ISBN : 9788889972069

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2nd fib Congress in Naples Italy Vol2 by FIB – International Federation for Structural Concrete Pdf

Author : Luca Bertolini,Bernhard Elsener,Pietro Pedeferri,Elena Redaelli,Rob B. Polder
Publisher : John Wiley & Sons
Page : 389 pages
File Size : 46,8 Mb
Release : 2013-02-26
Category : Technology & Engineering
ISBN : 9783527651719

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Corrosion of Steel in Concrete by Luca Bertolini,Bernhard Elsener,Pietro Pedeferri,Elena Redaelli,Rob B. Polder Pdf

Steel-reinforced concrete is used ubiquitously as a building material due to its unique combination of the high compressive strength of concrete and the high tensile strength of steel. Therefore, reinforced concrete is an ideal composite material that is used for a wide range of applications in structural engineering such as buildings, bridges, tunnels, harbor quays, foundations, tanks and pipes. To ensure durability of these structures, however, measures must be taken to prevent, diagnose and, if necessary, repair damage to the material especially due to corrosion of the steel reinforcement. The book examines the different aspects of corrosion of steel in concrete, starting from basic and essential mechanisms of the phenomenon, moving up to practical consequences for designers, contractors and owners both for new and existing reinforced and prestressed concrete structures. It covers general aspects of corrosion and protection of reinforcement, forms of attack in the presence of carbonation and chlorides, problems of hydrogen embrittlement as well as techniques of diagnosis, monitoring and repair. This second edition updates the contents with recent findings on the different topics considered and bibliographic references, with particular attention to recent European standards. This book is a self-contained treatment for civil and construction engineers, material scientists, advanced students and architects concerned with the design and maintenance of reinforced concrete structures. Readers will benefit from the knowledge, tools, and methods needed to understand corrosion in reinforced concrete and how to prevent it or keep it within acceptable limits.