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Demolition of special structures
Book r e v i e w s
to various intrinsic material properties such as absorption, porosity, penetration, flow and diffusion characteristics. A very valuable section of this Draft Report is the test data from sites, and several case histories are described. This is very useful information which engineers can utilise in writing compliance requirements. The draft report has an extensive bibliography, which again should form a firm basis for further understanding of the complex property of permeability. There will hardly be any dissent to the fact that durability of concrete very much depends on the permeability of the material to gases, liquids and ions. Nevertheless, there is no data to establish clear relationships between mix design, workability etc. on permeability or between curing and permeability. But this is more a result of lack of coherent and systematic data than any lack of importance of permeability.
Concrete Bridges - Investigation, Maintenance and Repair Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1985. ISBN 0 946691 09 6, Price £25.00; Members £10.00, 98pp. Bridges are designed to provide satisfactory service over a long period of time. In many countries, however, there is strong evidence that extensive deterioration has occurred in many bridge and bridge components. In the United States, for example, the major cause of bridge deck deterioration has been identified as corrosion of the reinforcing steel due to increased use of deicing salts. The problem has assumed significant proportions that have led to traffic restrictions, reduced factors of safety, and increased costs of rehabilitation to avoid costly replacements. This book and the papers included in it are therefore very timely to take a detailed look at the whole process of design, construction and maintenance of bridges. This book represents the proceedings of the one-day Symposium organised by the Concrete Society and held in London on 23 September 1985. There are eight papers presented at the Symposium and included in the book. The problem of identification, investigation and interpretation of the extent of deterioration is discussed in the first paper. Testing and sampling techniques are described, and comments are made on sample representability and costs. Joints on bridges are often a major source of failure, and these are discussed in another paper with an emphasis for more information on actual bridge movements. Three papers are devoted to r e p a i r of concrete viaducts and post-tensioned structures, and the need for quality control and supervision of the repairing process itself. Developments in research to meet these problems are reported in another paper. The nature of the problem is international, and this is well illustrated by two good papers describing German and North American experience in concrete bridge deterioration and maintenance. All the papers point to the need to develop realistic prediction methods for the
residual life of affected bridge structures. This is, unfortunately, a long way away yet but perhaps the more important lessons to be learned relate to quality control, a clear understanding of concrete technology and the adoption of proper construction techniques. This book should prove a ~?ery useful document for everyone involved in bridges.
Developments in Testing Concrete for Durability Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1984. ISBN 0 946691 10 X, Price £25.00, Members £10.00, 90pp. The problem of concrete durability has assumed great importance in recent years, not because of its inherent lack of long term stability, but because of the lack of care and misuse of this amazingly versatile and tolerant material. Several cases of durability problems experienced all over the world have focused attention on some of the basic properties of concrete related to its durability. The papers in this book are devoted to these aspects of concrete properties and were presented at a one-day Symposium held by the Concrete Society in London on 26 September 1984. There are eight papers included in this publication. The first paper sets the background for the symposium and describes the needs for these tests and the wide range of ad-hoc, performance and accelerated tests used for materials and the fresh and hardened concrete. Two papers are devoted to curing - - a much neglected but much required process to ensure proper functioning of concrete. The recent publication of BSI DO 92 on temperature-matched curing of concrete to simulate the conditions existing within a structure should give a new impetus to this important practice. Other test methods dealt with in this Symposium relate to non-destructive testing, chemical analysis of hardened concrete, in situ permeability tests, tests for abrasion resistance and air entrainment. The book also contains discussion of the papers presented. There is valuable information in this book on testing and durability of concrete, the two basic requirements needed if we are to achieve the full portential of this material.
Demolition of Special Structures Published by The Concrete Society, Devon House, 1 2 - ! 5 Dartmouth Street, London SW1H 9BL, England, 1984. ISBN 0 946691 11 8, Price £25.00, Members £10.00, 96pp. Demolition of concrete structures is a specialist task, but when it comes to demoliton of specialist structures, it needs not only specialist knowledge and equipment, but very careful planning involving a wide range of disciplines. This publication presents a comprehensive review of our current state of knowledge in this area The
263
Book r e w e w s
book contains nine papers, and the ensuing discussion on these papers, presented at a one-day Conference organised by The Concrete Society and held in London on 20 September 1984. The papers cover a wide range of specialist structures - - abandonment of offshore structures, demolition of prestressed concrete, and particularly, post-tensioned structures, and the decommissioning of nuclear facilities, and cryogenic storage units. Many of these operations require unusual breadth and depth of expertise, and often specialist groups need to be formed to ensure successful operation. There are some 6000 short-life special structures that would need removal, and these would demand special considerations, well-planned and well-prepared approaches if the operations are not to end in disaster. In other words, demolition has to be designed for. The health and safety aspects of demolition are equally important. Supervision is essential, and specialist structures may require special relationships - - i n terms of contractual relationships - - between the client, the contractor, the engineer and the researcher. The guidance notes prepared by the Health and Safety Executive provide comprehensive advice on preparation, planning, legislation, demolition techniques and health hazards. If all these guidance notes are carefully and strictly adhered to, there is unlikely to be any structure, special or otherwise, that cannot be safely demolished.
Concrete Storage Structures Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1984. ISBN 0 946691 03 7, Price £45.00, Members £18.00, 242pp. This volume contains the papers presented at the two-day symposium organised by the Concrete Society and held at Newcastle-upon-Tyne on 3 and 4 December 1984. Liquid storage tanks have traditionally been fabricated in steel with bolted steel panels or welded plates or in concrete, reinforced or prestressed. Concrete storage structures have latterly become very competitive to steel in terms of performance, maintenance, and therefore, overall total cost. This symposium volume is devoted entirely to the use of concrete in storage structures, and highlights the current knowledge and developments in research, design and construction of such structures. There are t 9 papers included in this volume, divided into four themes of materials and design, structures other than silos, flow of contained materials and silos. Eight papers in section I discuss materials and d e s i g n - these include material properties such as cracking, properties of concrete at cryogenic temperatures and effect of hot crude oil on concrete. The papers on design deal with the advantages of partial prestressing, the development of sprayed concrete silos, and design problems associated with the wall-to-base connection in cylindrical concrete tanks. Two papers discuss structures other than silos. Service reservoirs are traditionally built in concrete and
264
the structural design and construction of these are described in detail in one paper. The second paper reports the fascinating use of reinforced earth with precast concrete facing panels for building large storage structures for coal, minerals, and other bulk solids. These structures are capable of storing over 100000 tonnes, and enable producers, processors and users to take economic advantage of the scale and operational benefits of maintaining materials in a live state. Storage facilities in concrete are invariably large installations, handling and storing a wide range of bulk solids. This requires, on the one hand, mechanical handling plant that has to convey over long distances, at high flow rate, and often operate over a long time span. On the other hand, storage of cohesive solids can create flow problems, and if flow systems are not correctly designed, this can lead to disrupted flow, segregation, ratholing and arching. There are several types of flow and discharge aid d e v i c e s - such as air c a n n o n s - - and low friction lining materials also alleviate flow problems. These matters are discussed in the four papers included in Section 3. Both British and American experience are described to show how performance of these storage structures can be vastly improved by careful design. The last five papers in Section IV are devoted to current practice and developments in the design of concrete silos. The importance of silo design cannot be exaggerated when it is reported that the probability of failure in silo structures is 100 to 1000 times higher than that for most other building structures. A successful design requires a full understanding of the materials to be stored, the main characteristics of mass flow and funnel or core flow, and above all, a realistic determim ation of pressures especially for discharging. These and other design considerations are ably dealt with in the five papers of this section. This is undoubtedly a very valuable conference proceedings which all engineers and constructors of concrete storage facilities will need to possess.
Concrete in the Ground Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London SW1H 9BL, England, 1985. ISBN 0 946691 08 8, Price £45.00, Members £18.00, 249pp. Construction of concrete underground is often much more difficult than placing it above ground not merely because the ground is not always simple ground but also because concrete buried in the ground is soon forgotten. In addition to material and design problems, concrete placed below ground is subject to difficult construction and unclear environmental conditions, such as contaminated soil. A conference to pool together current knowledge and expertise is therefore very appropriate. This book contains the fourteen papers presented at a two-day conference organised by the Concrete Society and held in London on 21-22 May 1984 The papers included in th~s volume are divided tn[o
to various intrinsic material properties such as absorption, porosity, penetration, flow and diffusion characteristics. A very valuable section of this Draft Report is the test data from sites, and several case histories are described. This is very useful information which engineers can utilise in writing compliance requirements. The draft report has an extensive bibliography, which again should form a firm basis for further understanding of the complex property of permeability. There will hardly be any dissent to the fact that durability of concrete very much depends on the permeability of the material to gases, liquids and ions. Nevertheless, there is no data to establish clear relationships between mix design, workability etc. on permeability or between curing and permeability. But this is more a result of lack of coherent and systematic data than any lack of importance of permeability.
Concrete Bridges - Investigation, Maintenance and Repair Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1985. ISBN 0 946691 09 6, Price £25.00; Members £10.00, 98pp. Bridges are designed to provide satisfactory service over a long period of time. In many countries, however, there is strong evidence that extensive deterioration has occurred in many bridge and bridge components. In the United States, for example, the major cause of bridge deck deterioration has been identified as corrosion of the reinforcing steel due to increased use of deicing salts. The problem has assumed significant proportions that have led to traffic restrictions, reduced factors of safety, and increased costs of rehabilitation to avoid costly replacements. This book and the papers included in it are therefore very timely to take a detailed look at the whole process of design, construction and maintenance of bridges. This book represents the proceedings of the one-day Symposium organised by the Concrete Society and held in London on 23 September 1985. There are eight papers presented at the Symposium and included in the book. The problem of identification, investigation and interpretation of the extent of deterioration is discussed in the first paper. Testing and sampling techniques are described, and comments are made on sample representability and costs. Joints on bridges are often a major source of failure, and these are discussed in another paper with an emphasis for more information on actual bridge movements. Three papers are devoted to r e p a i r of concrete viaducts and post-tensioned structures, and the need for quality control and supervision of the repairing process itself. Developments in research to meet these problems are reported in another paper. The nature of the problem is international, and this is well illustrated by two good papers describing German and North American experience in concrete bridge deterioration and maintenance. All the papers point to the need to develop realistic prediction methods for the
residual life of affected bridge structures. This is, unfortunately, a long way away yet but perhaps the more important lessons to be learned relate to quality control, a clear understanding of concrete technology and the adoption of proper construction techniques. This book should prove a ~?ery useful document for everyone involved in bridges.
Developments in Testing Concrete for Durability Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1984. ISBN 0 946691 10 X, Price £25.00, Members £10.00, 90pp. The problem of concrete durability has assumed great importance in recent years, not because of its inherent lack of long term stability, but because of the lack of care and misuse of this amazingly versatile and tolerant material. Several cases of durability problems experienced all over the world have focused attention on some of the basic properties of concrete related to its durability. The papers in this book are devoted to these aspects of concrete properties and were presented at a one-day Symposium held by the Concrete Society in London on 26 September 1984. There are eight papers included in this publication. The first paper sets the background for the symposium and describes the needs for these tests and the wide range of ad-hoc, performance and accelerated tests used for materials and the fresh and hardened concrete. Two papers are devoted to curing - - a much neglected but much required process to ensure proper functioning of concrete. The recent publication of BSI DO 92 on temperature-matched curing of concrete to simulate the conditions existing within a structure should give a new impetus to this important practice. Other test methods dealt with in this Symposium relate to non-destructive testing, chemical analysis of hardened concrete, in situ permeability tests, tests for abrasion resistance and air entrainment. The book also contains discussion of the papers presented. There is valuable information in this book on testing and durability of concrete, the two basic requirements needed if we are to achieve the full portential of this material.
Demolition of Special Structures Published by The Concrete Society, Devon House, 1 2 - ! 5 Dartmouth Street, London SW1H 9BL, England, 1984. ISBN 0 946691 11 8, Price £25.00, Members £10.00, 96pp. Demolition of concrete structures is a specialist task, but when it comes to demoliton of specialist structures, it needs not only specialist knowledge and equipment, but very careful planning involving a wide range of disciplines. This publication presents a comprehensive review of our current state of knowledge in this area The
263
Book r e w e w s
book contains nine papers, and the ensuing discussion on these papers, presented at a one-day Conference organised by The Concrete Society and held in London on 20 September 1984. The papers cover a wide range of specialist structures - - abandonment of offshore structures, demolition of prestressed concrete, and particularly, post-tensioned structures, and the decommissioning of nuclear facilities, and cryogenic storage units. Many of these operations require unusual breadth and depth of expertise, and often specialist groups need to be formed to ensure successful operation. There are some 6000 short-life special structures that would need removal, and these would demand special considerations, well-planned and well-prepared approaches if the operations are not to end in disaster. In other words, demolition has to be designed for. The health and safety aspects of demolition are equally important. Supervision is essential, and specialist structures may require special relationships - - i n terms of contractual relationships - - between the client, the contractor, the engineer and the researcher. The guidance notes prepared by the Health and Safety Executive provide comprehensive advice on preparation, planning, legislation, demolition techniques and health hazards. If all these guidance notes are carefully and strictly adhered to, there is unlikely to be any structure, special or otherwise, that cannot be safely demolished.
Concrete Storage Structures Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London S W l H 9BL, England, 1984. ISBN 0 946691 03 7, Price £45.00, Members £18.00, 242pp. This volume contains the papers presented at the two-day symposium organised by the Concrete Society and held at Newcastle-upon-Tyne on 3 and 4 December 1984. Liquid storage tanks have traditionally been fabricated in steel with bolted steel panels or welded plates or in concrete, reinforced or prestressed. Concrete storage structures have latterly become very competitive to steel in terms of performance, maintenance, and therefore, overall total cost. This symposium volume is devoted entirely to the use of concrete in storage structures, and highlights the current knowledge and developments in research, design and construction of such structures. There are t 9 papers included in this volume, divided into four themes of materials and design, structures other than silos, flow of contained materials and silos. Eight papers in section I discuss materials and d e s i g n - these include material properties such as cracking, properties of concrete at cryogenic temperatures and effect of hot crude oil on concrete. The papers on design deal with the advantages of partial prestressing, the development of sprayed concrete silos, and design problems associated with the wall-to-base connection in cylindrical concrete tanks. Two papers discuss structures other than silos. Service reservoirs are traditionally built in concrete and
264
the structural design and construction of these are described in detail in one paper. The second paper reports the fascinating use of reinforced earth with precast concrete facing panels for building large storage structures for coal, minerals, and other bulk solids. These structures are capable of storing over 100000 tonnes, and enable producers, processors and users to take economic advantage of the scale and operational benefits of maintaining materials in a live state. Storage facilities in concrete are invariably large installations, handling and storing a wide range of bulk solids. This requires, on the one hand, mechanical handling plant that has to convey over long distances, at high flow rate, and often operate over a long time span. On the other hand, storage of cohesive solids can create flow problems, and if flow systems are not correctly designed, this can lead to disrupted flow, segregation, ratholing and arching. There are several types of flow and discharge aid d e v i c e s - such as air c a n n o n s - - and low friction lining materials also alleviate flow problems. These matters are discussed in the four papers included in Section 3. Both British and American experience are described to show how performance of these storage structures can be vastly improved by careful design. The last five papers in Section IV are devoted to current practice and developments in the design of concrete silos. The importance of silo design cannot be exaggerated when it is reported that the probability of failure in silo structures is 100 to 1000 times higher than that for most other building structures. A successful design requires a full understanding of the materials to be stored, the main characteristics of mass flow and funnel or core flow, and above all, a realistic determim ation of pressures especially for discharging. These and other design considerations are ably dealt with in the five papers of this section. This is undoubtedly a very valuable conference proceedings which all engineers and constructors of concrete storage facilities will need to possess.
Concrete in the Ground Published by The Concrete Society, Devon House, 12-15 Dartmouth Street, London SW1H 9BL, England, 1985. ISBN 0 946691 08 8, Price £45.00, Members £18.00, 249pp. Construction of concrete underground is often much more difficult than placing it above ground not merely because the ground is not always simple ground but also because concrete buried in the ground is soon forgotten. In addition to material and design problems, concrete placed below ground is subject to difficult construction and unclear environmental conditions, such as contaminated soil. A conference to pool together current knowledge and expertise is therefore very appropriate. This book contains the fourteen papers presented at a two-day conference organised by the Concrete Society and held in London on 21-22 May 1984 The papers included in th~s volume are divided tn[o