File Name: teel reinforced concretetructurea e ment and repair of corro ion .zip
Robert Cook, Esq.
- Potential pitfalls in assessing chloride-induced corrosion of steel in concrete
- The Reinforced Concrete Design Handbook
- Corrosion of steel reinforcement in hot countries, an acute case study
- Corrosion of Steel in Concrete
Furthermore, for those assessingthe condition of structures in the eld, it appears that one mainobjective is to make as many measurements as possible in as short atime as possible, in order to reduce costs. This push for speed is, again,the cause of some of the problems described below.
Potential pitfalls in assessing chloride-induced corrosion of steel in concrete
Broomfield All rights reserved. No part of this book may be reprinted or reproduced or utilised in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any efforts or omissions that may be made.
Reinforcing bars — Corrosion. Steel — Corrosion. Reinforced concrete — Corrosion. B76 The sections on corrosion theory, corrosion monitoring, galvanic cathodic protection and other areas have been introduced or expanded to reflect the changes of the past decade since the first edition. The increasing number of relevant national and international standards is also reflected in the text. The book provides a guide for those responsible for buildings and other reinforced concrete structures as they are engaged to design, construct, maintain and repair them.
It reviews the present state of knowledge of corrosion of steel in concrete from the theory through to site investigations and then remedying the problem. There is also a section on building more corrosion resistant structures.
The aim of the book is to educate and guide engineers, surveyors and owners of structures so that they will have a clear idea of the problem and will know where to go to start finding solutions. There are many experienced engineers and corrosion experts who deal with these problems on a day-to-day basis.
The reader is recommended to seek expert advice when dealing with subjects that are new to him. It is also essential that students of civil engineering, building sciences and architecture understand the problems they will face as they start to practice their skills.
We need more engineers, materials scientists, building surveyors and archi- tects who are trained to look at wider durability issues in these days of sustainable development and conservation of resources. It is impossible in one book to be totally comprehensive. Consequently some subjects such as cement chemistry and concrete admixtures have not been covered in much detail. They are better covered in other specialist texts.
This book concentrates on the corrosion of steel in its cementitious environ- ment and how it is dealt with in methods that are sometimes unique to the corrosion engineering field rather than the civil or building engineering field.
Illustration credits A number of figures are reproduced in this book by kind permission of the copyright holders or authors as appropriate. I started my career after finishing University at the Central Electricity Research Laboratory, working in one of the largest groups of corrosion scientists in the UK and Europe. Sadly that group is dispersed with the privatisation of the Central Electricity Generating Board. I then joined Taywood Engineering and enjoyed carrying out some of the first trials of impressed current cathodic protection on reinforced concrete structures above ground in the UK, Hong Kong and Australia.
I learned enormous amounts about deterioration of reinforced concrete structures, civil engineering and contracting from Roger Browne, Roger Blundell, Roger McAnoy, Phil Bamforth and a powerful team of engineers and scientists who were all at the forefront of concrete technology. I continue to have good relations and helpful exchanges with the Taywood team. I must also thank all my colleagues at SHRP, the researchers who did the real research work and the advisory and expert committee members who gave their time and insights to help create some very valuable manuals and guidance for highway engineers.
The first draft of the first edition of this book was produced three years after returning to the UK as an independent consultant. I had the chance to work with some of the leading experts in the field of corrosion and deterioration of reinforced concrete.
I must specifically acknowledge Andrew Trafford of Aperio who kindly supplied a lot of useful information as well as photographs about radar, radiography, pulse velocity, ultrasonic and impact-echo techniques.
My thanks also go to my publisher, and to Nick Clarke whose helpful suggestions strengthened the first draft of the book considerably. Finally, eternal thanks to my wife, Veronica and my parents, Olive and Philip. Without my parents support I would not have got where I am today.
She has supported my activities while getting on with her own very busy career. My apologies for naming such a small number of the many people who I continue to have the pleasure and privilege of working with.
My thanks to all of them and their willingness to share their knowledge with me and many others. It is better to wear out than to rust out Richard Cumberland, English Divine — Paint, graffiti, and everything else that man can do cannot win against rust.
Rust trumps all. It can be moulded to a variety of shapes and finishes. In most cases it is durable and strong, performing well throughout its service life. However, in some cases it does not perform adequately due to poor design, poor construction, inadequate materials selection, a more severe environment than anticipated or a combination of these factors.
The corrosion of the reinforcing steel in concrete is a major problem facing civil engineers today as they maintain an ageing infrastructure. Potentially it is a very large market for those who develop the expertise to deal with the problem. It is also a major headache for those who are responsible for dealing with structures suffering from it.
Worldwide, more concrete is used than any other man made material with approximately 12 billion tonnes being manufactured annually.
The United Kingdom produces M tonnes equivalent to 2 tonnes of concrete per head per year Frost, According to the US Portland Cement Association, the consumption of cement in North America for is expected to reach more than million metric tonnes, a 3. An average annual increase of 2. Correctly selected intervention that repairs a concrete structure cost effectively helps in conserving resources and reducing pollution. In a more recent cost of corrosion study Koch et al.
The eventual cost may therefore be 10 times the DoT estimate. The statistics for Europe, the Asian Pacific and Australia are similar. In the Middle East the severe conditions of warm marine climate, especially in the more heavily populated areas, with saline ground waters, increases all corrosion problems. This is made worse by the difficulty of curing concrete that has led to very short lifetimes for reinforced concrete structures Rasheeduzzafar et al.
In many countries with rapidly developing infrastructure, economies or poor supervision and quality control procedures in construction have led to poor quality concrete and low concrete cover to the steel leading to carbonation problems. Corrosion became a fact of life as soon as man started digging ores out of the ground, smelting and refining them to produce the metals that we use so widely in the manufacturing and construction industries.
When man has finished refining the steel and other metals that we use, nature sets about reversing the process. The refined metal will react with the non-metallic environment to form oxides, sulphates, sulphides, chlorides and so on, which no longer have the required chemical and physical properties of the consumed metal.
Billions of dollars are spent every year in protecting, repairing and replacing corrosion damage. Occasionally lives are lost when steel pipes, pressure vessels or structural elements on bridges fail.
But corrosion is a slow process and is usually easy to detect before catastrophic failure, and the consequences of corrosion are usually economic rather than death or injury. The corrosion of steel in concrete used to be considered to cause engineering and economic problems. Car park collapses Simon, and other major failures have been recorded in the United States, Canada and the United Kingdom not always directly attributed to reinforcement corrosion.
The economic loss and damage caused by the corrosion of steel in con- crete makes it arguably the largest single infrastructure problem facing industrialized countries. Our bridges, public utilities, chemical plants and buildings are ageing.
Some can be replaced, others would cause great cost and inconvenience if they were taken out of commission. One of the biggest causes of corrosion of steel in concrete is the use of deicing salts on our highways.
In the United States approximately 10 million tonnes of salt are applied per year to highways. In the United Kingdom 1—2 million tonnes per year are applied but to a proportionately far smaller road network. In continental Europe the application rates are comparable, except where it is too cold for salt to be effective, or the population density too low to make salting worthwhile e.
However, research in the United States has shown that the use of deicing salt is still more economic than the alternative, more expensive, less effective deicers Transportation Research Board, In the early years of this century corrosion of steel in concrete was attributed to stray current corrosion from electric powered vehicles. It was only in the s in the United States that it was finally accepted that there were corrosion problems on bridges far from power lines but in areas where sea salt or deicing salts were prevalent.
During the s attempts were made to quantify the problem and in the s the first cathodic protection systems were installed to deal with the problem.
In Europe and the Middle East sea water for mixing concrete and the addition of calcium chloride set accelerators were acceptable until the s and still used until the s in a mistaken belief that most of the chlorides would be bound up in the cement and would not cause corrosion.
This was found to be an expensive error over the next 20 years, particularly in the Middle East, where the low availability of potable water led to the frequent use of sea water for concrete mixing. While corrosion of steel in concrete is a major cause of deterioration it is not the only one.
Out in the real world we must not become blinkered to other problems like alkali-silica reactivity, freeze thaw damage and the structural implications of the damage done and of repairs. In this setting, however, we will concentrate on the corrosion issue although there will be passing references to other problems where relevant.
SHRP was probably the largest single effort to address the problem of corrosion of steel in concrete and provide practical solutions for engineers to use. The text draws on corrosion problems and experience from around the world where possible, attempting to achieve a balanced view of different approaches in different countries, particularly comparing the European and North American approaches which are sometimes quite different.
Chapters 2 and 3 explore the basics of corrosion of steel in concrete. The author has attempted to be thorough but also to start from the position of the generalist, with a minimal memory of chemistry. The first requirement when addressing a deterioration problem is to quan- tify it. Chapter 4 discusses condition evaluation and the testing procedures and techniques we can use to assess the causes and extent of the corrosion damage on a structure.
The Reinforced Concrete Design Handbook
The premature deterioration of concrete structures due to corrosion of the steel reinforcement is a major problem in the field of civil engineering, particularly when aggressive environmental conditions are encountered. This paper presents an acute case of widespread corrosion damage observed on a ground slab of a huge prestigious building complex constructed at the southern part of Iraq in the late eighties. The paper describes the remedial measures necessary for extending the service life of the structure. The test programme comprises detailed visual inspection of the retrieved samples including the condition and the number of protective layers, thickness of cover to reinforcement, description of reinforcement size and distribution, signs and degree of corrotion. The concrete cores were then subjected to different chemical and physical tests.
Parking Structures pp Cite as. Although concrete is a relatively durable construction material, preventive maintenance and necessary corrective actions are required to extend the useful life of parking structures. Parking facilities experience harsh exposure conditions which can contribute to accelerated concrete deterioration and adversely affect the life expectancy of the structure. Quite often, owners and operators have to repair deteriorated structures with only years of service Figure 15—1. Unable to display preview. Download preview PDF. Skip to main content.
PDF | Reinforced concrete (RC) structures in marine environments are susceptible to Chloride-induced corrosion of reinforcing steel is maintenance and possible failure modes of the struc- concrete cover due to corrosion appear before corro- tration of chloride ions into concrete is a complex.
Corrosion of steel reinforcement in hot countries, an acute case study
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Подождите, - сказала Сьюзан, меняя позицию и придвигаясь ближе. - Хорошо, теперь давайте.
Corrosion of Steel in Concrete
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Меган с силой толкнула стенку секции, но та не поддавалась.
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Мы успеем найти его партнера. - Думаю. У нас есть кое-какие данные.