Download or read book Grouting of Tendons in Prestressed Concrete written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2002-01-01 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Grouting of tendons in prestressed concrete written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1990-01-01 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: This guide deals with the grouting of tendons inside concrete members, using cement grout, and tackles the essential day to day practical matters which produce good grouting. Afer a review of objectives, it looks at ducts, inlets and outlets, grout materials and grout properties, equipment, site preparations, the grouting operation, site control and after-measures.
Download or read book Grouting of Tendons in Prestressed Concrete written by and published by . This book was released on 1990 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deals with the grouting of tendons inside concrete members using cement grout, and tackles the day to day matters, which produce good grouting. After a review of objectives, this guide looks at ducts, inlets and outlets, grout materials and grout properties, equipment, site preparations, the grouting operation, site control, and after-measures.
Download or read book Durability of Post tensioning Tendons written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 279 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Prestressed Concrete written by and published by Thomas Telford. This book was released on 1989 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Post-tensioning and grouting operations can be dangerous if the required care is not taken in planning, in site preparations and in execution. For prestressed concrete a good working environment is also a prerequisite for high quality. Many accidents in this type of work may be attributed to a lack of training, poor supervision, poor planning or over-familiarity with the process. This guide to good practice highlights important safety measures which are particularly applicable to prestressed concrete, dealing with precautions necessary for post-tensioning and grouting operations on site.
Download or read book Durability of Post tensioning Tendons written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2006 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Grout for Prestressing Tendons Grouting Procedures written by British Standards Institute Staff and published by . This book was released on 1912-11-30 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grouting, Construction operations, Tendons, Prestressed concrete, Construction equipment, Construction materials, Temperature, Quality control, Inspection
Download or read book Preparation of specifications for post tensioning work written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1992-10-01 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Grout for Prestressing Tendons Test Methods written by British Standards Institute Staff and published by . This book was released on 1997-11 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grouting, Construction materials, Tendons, Prestressed concrete, Testing conditions, Calibration, Compression testing, Moulding (process), Test specimens, Volume measurement
Download or read book Grout for Prestressing Tendons Basic Requirements written by British Standards Institute Staff and published by . This book was released on 1912-11-30 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Grouting, Prestressed concrete, Tendons, Construction materials, Compressive strength, Volume, Dimensional changes, Viscosity, Mixing, Accuracy, Composition, Conformity
Download or read book Materials and systems for external prestressing written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1996-08-01 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Survey of Durability Performance of Post tensioning Tendons written by Morris Schupack and published by . This book was released on 1978 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Prestressed Concrete Bridges written by Nigel R. Hewson and published by Thomas Telford. This book was released on 2003 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prestressed concrete decks are commonly used for bridges with spans between 25m and 450m and provide economic, durable and aesthetic solutions in most situations where bridges are needed. Concrete remains the most common material for bridge construction around the world, and prestressed concrete is frequently the material of choice. Extensively illustrated throughout, this invaluable book brings together all aspects of designing prestressed concrete bridge decks into one comprehensive volume. The book clearly explains the principles behind both the design and construction of prestressed concrete bridges, illustrating the interaction between the two. It covers all the different types of deck arrangement and the construction techniques used, ranging from in-situ slabs and precast beams; segmental construction and launched bridges; and cable-stayed structures. Included throughout the book are many examples of the different types of prestressed concrete decks used, with the design aspects of each discussed along with the general analysis and design process. Detailed descriptions of the prestressing components and systems used are also included. Prestressed Concrete Bridges is an essential reference book for both the experienced engineer and graduate who want to learn more about the subject.
Download or read book Extending Span Ranges of Precast Prestressed Concrete Girders written by Reid Wilson Castrodale and published by Transportation Research Board. This book was released on 2004 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: At head of title: National Cooperative Highway Research Program.
Download or read book Recommendations for the design of flat slabs in post tension concrete using unbonded and bonded tendons written by FIB – International Federation for Structural Concrete and published by FIB - International Federation for Structural Concrete. This book was released on 1980-05-01 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Admixtures for Concrete Mortar and Grout Admixtures for Grout for Prestressing Tendons Definitions Requirements Conformity Marking and Labelling written by British Standards Institute Staff and published by . This book was released on 2009-06-30 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt: Concrete admixtures, Cement and concrete technology, Concretes, Mortars, Grouting, Prestressed concrete, Tendons, Composition, Quality control, Marking
Download or read book Factory Applied Corrosion Protection of Prestressing Steel written by fib Fédération internationale du béton and published by fib Fédération internationale du béton. This book was released on 2001-01-01 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Without doubt, active corrosion protection of prestressing steels by cement grout can be one of the most economic and durable solutions, if properly executed. Numerous other corrosion protection systems which fulfill requirements such as controllability and exchangeability are available. This state-of-the-art report, prepared by a task group and approved by fib Commission 9 Reinforcing and prestressing materials and systems, concentrates exclusively on factory applied corrosion protection that can be produced in controlled processes which should assure a better quality than corrosion protection applied on site. The report is addressed to designers and installers (executing persons) attempting to inform them about the various possibilities for industrially applied corrosion protection and to provide the necessary knowledge for their application.
