Construction Materials Reference Book

David Doran, Bob Cather, David Doran, Bob Cather

• Publisher: Routledge
• Year: 2013
• ISBN:
  9781135139209
• Edition: 2
• Topic: Tecnologia e ingegneria
• Subtopic: Ingegneria edile

This book is the definitive reference source for professionals involved in the conception, design and specification stages of a construction project. The theory and practical aspects of each material is covered, with an emphasis being placed on properties and appropriate use, enabling broader, deeper understanding of each material leading to greater confidence in their application.
Containing fifty chapters written by subject specialists, Construction Materials Reference Book covers the wide range of materials that are encountered in the construction process, from traditional materials such as stone through masonry and steel to advanced plastics and composites.
With increased significance being placed on broader environmental issues, issues of whole life cost and sustainability are covered, along with health and safety aspects of both use and installation.

1	Introduction

David Doran FCGI BSc(Eng) DIC CEng FICE FIStructE
Consultant, formerly Chief Engineer with Wimpey plc

Bob Cather BSc CEng FIMMM
Consultant, formerly Director of Arup Materials Consulting

 

Choices in materials

To design and construct successfully with materials, it is important to develop an understanding of their inherent properties, their method of manufacture and the constraints and local conditions imposed on them by incorporation into a particular construction. This philosophy is central to the successful adoption of and design with materials in the real world.

For some, adoption of a particular material may be a means to an end to create a final product. For others, there may be more interest in understanding the inner nature of materials and how this understanding might help to create better or more interesting design and construction solutions. Different solutions, new and established, may not all require the same level of materials knowledge, but there will be few that would not benefit from some enhancement of understanding.

The range of properties of interest for a material to be used can be wide, and there is a strong impulse to increase this range.

In mechanical properties, strength and stiffness are frequent requirements. Strength considerations may extend to strength in compression, tension and bending. Strain behaviour under imposed loadings, static or dynamic, for short-term or sustained periods in cracked or uncracked elements begins to demonstrate the complexity of understanding that might be required. Other facets of behaviour that might be important to understand include thermal properties (thermal conductivity, thermal expansion and specific heat capacity), acoustic behaviour, optical characteristics (reflection and transmission), and electrical and magnetic responses.

Increasingly over recent decades a fuller understanding of materials and products under fire conditions has become essential. The importance of this understanding has been driven by people-safety and by commercial-loss considerations. Fire behaviour has wider parameters than some simple concept of ‘burnability’ or ‘nflammability’, requiring understanding of ignition characteristics, flame spread, heat release, strength loss, smoke and potential toxic fume emission. These issues, although based in materials and product contexts, will frequently be assessed in relation to whole-building and building occupant behaviour.

Another aspect of the performance of materials that has achieved higher profile relates to the retention of properties with time – the ‘durability’. It is reasonably straightforward to determine the mechanical, physical or other properties at the beginning of utilisation, but how much of the properties will be lost and at what rate upon exposure to agencies such as rot, corrosion, UV radiation, freezing and thawing, insect attack or biological growths? In many situations it is the retained properties at the end of life that may be of greater importance. Of course, the material alone does not determine the lifetime performance; there is likely to be substantial influence from the mode and method of construction.

The desire to use materials better may derive from a desire to avoid known and recurring ‘problems’. It may be driven by desires to do something differently – to build higher, to span further, to achieve longer life, perhaps with reduced aftercare or maybe just to use a smaller quantity of materials.

Using less material might be seen as one of the key routes to address the widespread concerns on the environmental impact of civilisations and industries. These concerns may be directed at ‘global warming’, carbon dioxide emissions, resource depletion, toxic wastes and emissions and numerous other targets. There appear to be many different routes to considering these issues and, at present, no universal description of need and solution. The extent to which changes to materials alone can provide adequate solutions, and to which change to living needs to be adopted, cannot at present be simply resolved.

It is clear that the proper understanding of material composition, properties and behaviour can form an essential role in reducing the impact on the environment of the use of construction materials. Much is already in place – the use of industrial wastes from iron making and power generation as a component of cement and concrete, the recycling of metallic components, use of alternative fuel sources to heat material production kilns, and the development of higher efficiency insulants are some prominent examples.

The ‘natural world’ offers many opportunities to develop construction materials solutions that not only reduce direct impacts of use but ought to be long-term options with more renewable supplies of materials. Such options may take us beyond wider and beneficial use of timber, straw, cork and sheep's wool to sources for resins, fibres, adhesives, rubbers, polymers, etc. for wide application. Beyond this we can look to the natural world for inspiration on a completely different range of practical solutions – the science of biomimetics.

Over the history of the utilisation of materials, the selection process and detail of use has been by a process that somewhat parallels ‘natural selection’ (also perhaps known as ‘trial and error’). We use things, and those that work we use again; those that don't work we discard. Increasingly technology developments have given us the capabilities – should we choose – to understand the chemistry and microstructure of material, generally headed ‘materials science’. Thus we now have greater ability to understand how existing materials work and perhaps, where beneficial, to design specific new materials for specific applications.

In parallel to the developments in the technology of materials there are considerable changes in the technologies of knowledge acquisition, dissemination and uptake. Together these knowledge technologies form an important basis for enabling the proper selection and utilisation of materials in construction applications. This Construction Materials Reference Book is one substantial component of the knowledge resource in materials.

There are many potential sources and kinds of information built up for materials in construction. This information and experience can be delivered by different mechanisms: word of mouth, research dissemination, dedicated and general electronic systems and printed word. The publication of this second edition of the Construction Materials Reference Book recognises the continuing value of a printed-word compilation of an up-to-date, authoritative and expert record of the best knowledge on materials and their application to construction.

This reference book is the sequel to the successful first edition published in 1992. It has been thoroughly updated and refreshed by the use of a mixture of new authors and some who contributed to the first edition. There is much new content in this edition.

It was neither desirable nor practical to supply authors with a straitjacket of guidelines from which to develop their themes and content. The editors wanted to achieve a record of maximum materials expertise and knowledge but in a format that carried across the whole book. The following list was made available to each contributor to use, as appropriate, as a broad framework for each chapter.

• Introduction & general description
• Sources
• Manufacturing process
• Chemical composition
• Physical properties
• Dimensional stability
• Durability
• Use and abuse
• Proprietary brands
• Hazards in use
• Coatings (paints and anti-corrosion)
• Performance in fire
• Sustainability and recycling
• References and bibliography

The perceived readership for this book is twofold:

(a) professionals (architects, engineers, surveyors, builders and materials specialists), particularly those who are contemplating using a material for the first time

(b) students or laypersons seeking an introduction to construction materials.

Such a book could not have been produced without support and encouragement. The editors would like to thank Alex Hollingsworth (who originally commissioned the book), Brian Guerin, Mike Cash, Mike Travers, Lan Te, Jodi Cusack, Liz Burton and, of course, the authors for bringing this project to a successful conclusion.

2

Aluminium

John Bull Eur Ing BSc PhD DSc CEng FICE FIStructE FIHT FIWSc
Head of Civil Engineering, Brunel University

Contents

2.1 Introduction

2.2 A description of aluminium's properties

2.3 Sources of aluminium

2.4 Manufacturing aluminium

2.4.1 The Bayer process

2.4.2 The Hall-Héroult process

2.4.3 The recycling of aluminium and its alloys

2.4.4 Product form

2.4.5 The fabrication process

2.5 The use of aluminium and aluminium alloys

2.5.1 Aluminium and aluminium alloys in the building, construction and offshore industries

2.5.2 Rolled aluminium and aluminium alloys

2.6 Types of aluminium and aluminium alloys

2.6.1 Classification of aluminium and aluminium alloys

2.6.2 Temper designations

2.7 Chemical compositions and mechanical properties

2.7.1 The master alloys

2.7.2 Chemical composition

2.7.3 Mechanical properties

2.8 Physical properties

2.8.1 Material constants for normal temperature design

2.8.2 Material constants for elevated temperatures

2.9 Special properties

2.9.1 Creep

2.9.2 Fatigue strength

2.9.3 Fire

2.9.4 Thermite sparking

2.9.5 Corrosion of aluminium

2.10 Durability and protection

2.10.1 General

2.10.2 Alloy durability

2.10.3 Protection

2.11 Materials selection

2.11.1 General

2.11.2 Heat-treatable wrought alloys

2.11.3 Non-heat-treatable wrought alloys

2.11.4 Cast products

2.12 Fabrication and construction

2.12.1 Cutting

2.12.2 Drilling and punching

2.12.3 Bending and forming

2.12.4 Machining

2.12.5 Bolting and screwing

2.12.6 Welding

2.12.7 Adhesive bonding

2.12.8 Finishes

2.12.9 Handling and storage of aluminium and its alloys

2.13 Standards

2.14 Acknowledgements

2.15 References

2.15.1 Standards

2.15.2 Structural design standards

2.15.3 Chemical composition, form and temper definition of wrought products standards

2.15.4 Technical delivery conditions standards

2.15.5 Dimensions and mechanical properties standards

2.15.6 Welding standards

2.15.7 Adhesive standards

2.16 Bibliography

2.1 Introduction

Aluminium is the second most used metal throughout the world. Small quantities of al...