Lightweight Sandwich Construction

Sandwich panels are being used increasingly as the cladding of
buildings like factories, warehouses, cold stores and retail sheds.
This is because they are light in weight, thermally efficient,
aesthetically attractive and can be easily handled and erected.
However, to date, an authoritative book on the subject was lacking.
This new reference work aims to fill that gap.

The designer, specifier and manufacturer of sandwich panels all
require a great deal of information on a wide range of subjects.
This book was written by a group of European experts under the
editorship of a UK specialist in lightweight construction. It
provides guidance on:

• materials used in manufacture

• thermal efficiency and air- and water-tightness

• acoustic performance

• performance in fire

• durability

• special problems of sandwich panels in cold stores and chill
  rooms

• architectural and aesthetic considerations

• structural design at the ultimate and serviceability limit
  states

• additional structural considerations including fastenings, the
  effect of openings and the use of sandwich panels as load-bearing
  walls

• test procedures

The book concludes with some numerical design examples and is
highly illustrated throughout.

Autorentext

J.M. Davies DSc, PhD, FREng, FICE, FIStructE is Professor of
Structural Engineering at the University of Manchester.

He has spent a lifetime carrying out research and consultancy
into many aspects of steel construction and has written more than
150 technical papers. In recent years, he has concentrated on
aspects of lightweight construction, including cladding and its
supporting members. Sandwich construction has been an important
part of his work. At the University of Manchester, he has a large
fire engineering laboratory and has developed an increasing
interest in the performance of lightweight construction in
fire.

He is a joint author of Plastic Design to BS 5950,
written for the Steel Construction Institute and published by
Blackwell Science, and also The Manual of Stressed Skin
Diaphragm Design.

Zusammenfassung
Sandwich panels are being used increasingly as the cladding of buildings like factories, warehouses, cold stores and retail sheds. This is because they are light in weight, thermally efficient, aesthetically attractive and can be easily handled and erected. However, to date, an authoritative book on the subject was lacking. This new reference work aims to fill that gap. The designer, specifier and manufacturer of sandwich panels all require a great deal of information on a wide range of subjects. This book was written by a group of European experts under the editorship of a UK specialist in lightweight construction. It provides guidance on:

• materials used in manufacture

• thermal efficiency and air- and water-tightness

• acoustic performance

• performance in fire

• durability

• special problems of sandwich panels in cold stores and chill rooms

• architectural and aesthetic considerations

• structural design at the ultimate and serviceability limit states

• additional structural considerations including fastenings, the effect of openings and the use of sandwich panels as load-bearing walls

• test procedures

The book concludes with some numerical design examples and is highly illustrated throughout.

Inhalt

List of Contributors xii

Preface xiii

1 Introduction 1

1.1 The origins of sandwich technology 1

1.2 Principles of sandwich construction 2

1.3 Requirements for sandwich cladding panels 4

1.4 Wall panels 5

1.5 Panels for cold stores 6

1.6 Roof panels 7

1.7 Methods of manufacture 8

1.7.1 Manufacture of facings 8

1.7.2 Panels with bonded cores 8

1.7.3 Foamed cores 9

1.8 Design requirements for structural sandwich panels 10

1.9 Structural design of sandwich panels 11

1.10 Layout of this book 12

2 Materials 14

2.1 Introduction 14

2.2 Facing materials 14

2.2.1 Steel facings 15

2.2.2 Aluminium sheeting 20

2.2.3 Other metal face materials 22

2.2.4 Other facing materials 24

2.3 Core materials 26

2.3.1 Rigid plastic foam materials 28

2.3.2 Characteristic properties of rigid foams 33

2.3.3 Inorganic core material 36

2.3.4 Characteristic properties of mineral wools 38

2.4 Honeycomb cores 39

2.5 Adhesives and other components 40

2.5.1 Mechanical properties 41

2.6 Fasteners and other components 41

2.7 References 41

3 Thermal Performance and Water-Tightness 43

3.1 Introduction 43

3.2 Insulation theory 43

3.2.1 Factors influencing the thermal conductivity of a material 44

3.3 Thermal resistance 46

3.3.1 Total thermal resistance of a building element 47

3.4 Thermal transmittance coefficient (U-value) 47

3.4.1 Calculation method for profiled panels 48

3.5 Thermal capacity 49

3.6 Thermal bridges 50

3.7 Air-tightness 51

3.7.1 Test methods for air-tightness 53

3.8 Water-tightness 53

3.8.1 Test methods for water-tightness 54

3.9 Moisture 55

3.9.1 Surface condensation 57

3.9.2 Moisture transfer 57

3.10 Thermographic surveys 58

3.11 The advantage of sandwich construction in the context of thermal insulation 59

3.12 Energy saving 59

3.13 Reference 61

4 Acoustics 62

4.1 Introduction 62

4.2 What is sound? 62

4.2.1 Decibel arithmetic 64

4.3 Fundamental acoustic parameters 65

4.4 Sound insulation 66

4.4.1 Example 1 67

4.5 Weighted sound reduction index 67

4.6 Overall sound reduction index 68

4.6.1 Example 2 69

4.7 Flanking transmission 69

4.8 Sound reduction index for holes and slits 70

4.9 Sound reduction index for a sandwich panel 71

4.10 Sound in rooms 73

4.10.1 Sound absorption 73

4.10.2 Sound absorption for sandwich panels 74

4.11 Noise reduction in small industrial premises 75

4.11.1 Example 3 76

4.12 Noise reduction in large industrial premises 76

4.12.1 Reverberation time 76

4.12.2 Room classification 77

4.12.3 Sound propagation 78

4.12.4 General sound level reduction 78

4.12.5 Example 4 79

4.13 References 80

5 Fire 81

5.1 General aspects of fire behaviour 81

5.1.1 Introduction 81

5.1.2 Objectives of fire safety design 82

5.1.3 Phases of a fire 83

5.1.4 Assessment of the threat to life 86

5.1.5 Fire severity 88

5.1.6 Introduction to reaction to fire 92

5.1.7 Introduction to fire resistance 94

5.1.8 Fire safety legislation 97

5.1.9 Large-scale fire tests and experience of actual fires 98

5.2 Fire tests 99

5.2.1 Use of standard fire tests 99

5.2.2 Reaction-to-fire tests 99

5.2.3 Fire resistance tests 102

5.3 Material properties at elevated temperature 103 ...