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.

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.

This manual contains updated information on the current practices in the use, design, and construction of post- tensioning. The 6th Edition has been extensively rewritten and expanded from the 5th Edition. The Manual contains 12 new chapters that give design guidance on modern applications of post-tensioning. All of the original chapters have been totally revised and modified to reflect the current industry practices. New topics include Seismic Design, Post-Tensioned Concrete Floors, Parking Structures, Slab-on-Ground, Bridges, Stay Cables, Storage Structures, Barrier Cables, Dynamic and Fatigue, Durability, Inspection and Maintenance, and Field and Plant Certification. The Manual provides the industry standard for design and construction of post-tensioned structures. This book is an invaluable resource for practicing engineers, architects, students, educators, contractors, inspectors, and building officials. The 6th Edition of the Post-Tensioning Manual provides basic information and the essential principles of post-tensioning.

Essential reading for researchers, practitioners, and engineers, this book covers not only all the important aspects in the field of corrosion of steel reinforced concrete but also discusses new topics and future trends. Theoretical concepts of corrosion of steel in concrete structures, the variety of reinforcing materials and concrete, including stainless steel and galvanized steel, measurements and evaluations, such as electrochemical techniques and acoustic emission, protection and maintenance methods, and modelling, latest developments, and future trends in the field are discussed. - Comprehensive coverage of the corrosion of steel bars in concrete, investigating the range of reinforcing materials, and types of concrete - Introduces the latest measuring methods, data collection, and advanced modeling techniques - Second edition covers a range of new, emerging topics such as the concept of chloride threshold value, concrete permeability and chloride diffusion, the role of steel microstructure, and innovations in corrosion detection devices

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.

This textbook imparts a firm understanding of the behavior of prestressed concrete and how it relates to design based on the 2014 ACI Building Code. It presents the fundamental behavior of prestressed concrete and then adapts this to the design of structures. The book focuses on prestressed concrete members including slabs, beams, and axially loaded members and provides computational examples to support current design practice along with practical information related to details and construction with prestressed concrete. It illustrates concepts and calculations with Mathcad and EXCEL worksheets. Written with both lucid instructional presentation as well as comprehensive, rigorous detail, the book is ideal for both students in graduate-level courses as well as practicing engineers.

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.

Die zweite Auflage dieses Klassikers - jetzt als Paperback - bietet Profis auf diesem Gebiet eine aktuelle und kompetente Präsentation der Technologie der Vorbelastung von Stahlbeton. Grundlegende Techniken, Materialien und Systeme werden behandelt und vielfältige Anwendungen - Gebäude, Brücken, Bohrplattformen, Straßen, Rollbahnen, Rohrleitungen - erläutert.

The purpose of this publication is to show how precast concrete may be mixed in combination with other structural materials to maximise overall building performance. The other materials are: cast insitu concrete, reinforced and post-tensioned, structural steelwork, timber and glue-laminated timber, masonry in brickwork and blockwork, glass and glazing. The aim is to provide a companion volume to composite Floor Structures [FIP, 1998] and to show some of the many other ways that precast concrete can be used to advantage with other materials. The term mixed precast construction is used to describe these other combinations. The intention is not to discuss design calculations - that is for a future 'fib Guide to good practice'. Instead, the bulletin is meant as a 'State-of-art' publication showing photographs, sketches and details of precast concrete with other materials. There are no design equations, although some technical information on how to combine the materials, e.g. bearings, connections, tolerances, thermal and shrinkage effects, etc., is included if appropriate. Thus, the document focuses on the use of mixed construction in multistorey buildings, offices, housing, grandstands, parking garages, and industrial warehouses, etc. i. e. on precast concrete as the main construction material and looks at the manner in which other materials can be integrated. Chapter by chapter the strengths and weakness of each material studied are assessed as part of the total building design. In some cases it is obvious that the load carrying performance of one material outweighs another. In other cases aspects such as thermal, fire, vibration, fatigue, creep, acoustic, seismic and visual characteristics, and the geographical local availability of that material, may be critical. A world-wide survey, presented in Table 1.1, found that precast concrete is a universal building material, but mixed construction is limited mostly to developed countries where structural steelwork and types of timber, such as glue-laminated timber, is readily available. In addition there may be design, detailing, production, transportation, erection and maintenance limitations, which do or do not favour mixed construction.