Construction Science and Materials

About the Author SURINDER SINGH VIRDI is a lecturer in construction at South and City College Birmingham and visiting lecturer at City of Wolverhampton College. He worked as a civil and structural engineer for a number of years before starting his career in further and higher education. He has been teaching construction science, environmental science, mathematics, ICT and CAD on BTEC National and Higher National courses for over 25 years.

Preface to the second edition xv

About the companion website xvii

1 Introduction to Physics 1

1.1 Speed and Velocity 1

1.2 Acceleration 1

1.3 Mass 2

1.4 Gravitation 2

1.5 Weight 3

1.6 Volume 4

1.7 Density 4

1.8 Specific Gravity 6

1.9 Newton’s First Law of Motion 6

1.10 Newton’s Second Law of Motion 6

1.11 Newton’s Third Law of Motion 7

1.12 Friction 7

1.13 Work 8

1.14 Energy 9

1.14.1 Potential Energy 9

1.14.2 Kinetic Energy 10

1.15 Power 11

Exercise 1.1 12

Reference/Further reading 12

2 Introduction to chemistry 13

2.1 Introduction 13

2.2 Electrovalency and covalency 15

2.2.1 Covalent Bond 17

2.3 Elements and Compounds 18

2.4 Symbols and Formulae 19

2.5 Acids and bases 20

2.5.1 Acids 20

2.5.2 Bases 21

Exercise 2.1 22

References/Further reading 23

3 Effects of Chemicals and the Atmosphere on Materials 25

3.1 Introduction 25

3.2 Oxidation 25

3.2.1 Experiment: To Show that Oxygen (Or Air) and Water are Necessary for the Rusting of Iron 26

3.3 Electrolysis 27

3.4 Electrolytic Corrosion 28

3.4.1 Examples of Electrolytic Corrosion 30

3.4.2 Protection of Steel from Corrosion 31

3.5 Applications of Electrolysis 32

3.5.1 Electroplating 32

3.5.2 Extraction of Aluminium 32

3.6 Acid rain 33

References/Further Reading 33

4 Electricity 35

4.1 Introduction 35

4.2 Coulomb’s law 35

4.3 Electric current 36

4.4 Potential difference 36

4.5 Electromotive force (e.m.f.) 37

4.6 Ohm’s law 37

4.7 Electrical resistivity and conductivity 39

4.8 Resistors in Series/Parallel 39

4.8.1 Resistors in series 39

4.8.2 Resistors in parallel 40

4.9 Transformers 43

4.10 Power generation 44

4.11 Power distribution 45

4.12 Supply to small buildings 47

Exercise 4.1 48

Reference/Further reading 49

5 Introduction to Construction Technology 51

5.1 Introduction 51

5.2 Substructure and Superstructure 51

5.2.1 Soil investigation 52

5.3 Foundations 53

5.3.1 Settlement 54

5.4 Forms of Construction 55

5.5 The External Envelope 56

5.5.1 Functions of the External Envelope 57

5.5.2 Ground Floors 60

5.5.3 Cavity Walls 61

5.5.4 Suspended Timber Upper Floors 61

5.5.5 Roofs 61

References/Further Reading 61

6 Introduction to Building Services 63

6.1 Introduction 63

6.2 Cold Water Supply 63

6.3 Hot Water Supply 65

6.4 Central Heating Systems 65

6.5 Underfloor Heating Systems 66

6.6 Drainage Systems 67

6.6.1 Below‐ground Drainage System 67

6.6.2 Above‐ground Drainage System 68

6.7 Integration of Services into Building Design 68

References/Further Reading 72

7 Thermal Energy 1 73

7.1 Introduction 73

7.2 Temperature 73

7.2.1 Temperature Scales 74

7.3 Units of Heat 74

7.4 States of Matter 75

7.4.1 Changes in the Physical State 75

7.4.2 Experiment: The Physical States of Water 75

7.5 Expansion and Contraction of Solids 77

7.5.1 Linear Expansion 77

7.5.2 Experiment: Determination of Coefficient of Linear Expansion 78

7.5.3 Practical Examples of Expansion and Contraction 79

7.6 Heat Transfer 81

7.6.1 Conduction 81

7.6.2 Experiment: To Compare the Thermal Conductivity of Metals 84

7.6.3 Convection 84

7.6.4 Radiation 85

Exercise 7.1 86

References/Further Reading 86

8 Thermal Energy 2 (Including Humidity) 87

8.1 Introduction 87

8.2 Thermal Insulation 87

8.2.1 Experiment: To Compare the Thermal Insulation Values of Expanded Polystyrene, Vermiculite, Mineral Wool, Glass Fibre and Cork 88

8.3 Heat Transmission 90

8.3.1 Thermal Conductivity 90

8.3.2 Thermal Resistivity (r) 91

8.3.3 Thermal Resistance (R) 91

8.4 Thermal Transmittance 92

8.5 Heat Loss from Buildings 98

8.6 Temperature Drop Through Materials 102

8.7 Humidity 104

8.7.1 Measurement of Relative Humidity 105

8.8 Condensation 107

8.8.1 The Psychrometric Chart 108

8.8.2 Prevention of Surface Condensation 108

8.8.3 Interstitial Condensation 110

Exercise 8.1 116

References/Further Reading 117

9 Forces and Structures 1 119

9.1 Introduction 119

9.2 Force 119

9.2.1 Internal and External Forces 120

9.3 Bending 120

9.3.1 Deflection 122

9.4 Types of Loading 123

9.4.1 Dead Load 123

9.4.2 Imposed Load 123

9.4.3 Wind Load 123

9.4.4 Loading from other Effects 123

9.4.5 Point Load 123

9.4.6 Uniformly Distributed Load 125

9.4.7 Triangular Load 125

9.5 Stress and Strain 126

9.5.1 Stress 127

9.5.2 Strain 127

9.6 Elasticity 128

9.6.1 Experiment 1: Proof of Hooke’s Law 128

9.6.2 Experiment 2: Proof of Hooke’s Law 129

9.6.3 Factor of Safety 131

Exercise 9.1 132

References/Further Reading 133

10 Forces and structures 2 135

10.1 Moment of a force 135

10.1.1 Sign convention 136

10.2 Laws of equilibrium 139

10.3 Analysis of beams 139

10.3.1 Beam reactions 139

10.3.2 Shear force (S.F.) 144

10.3.3 Bending moment (B.M.) 149

10.4 Triangle of forces 156

10.4.1 Bow’s notation 159

10.4.2 Frames and roof trusses 161

Exercise 10.1 166

References/Further reading 169

11 Forces and structures 3 171

11.1 Introduction 171

11.2 Beams 171

11.2.1 Tension and compression in beams 171

11.2.2 Shear 172

11.2.3 Deflection 173

11.2.4 Lateral buckling 174

11.3 Reinforced concrete (R.C.) beams 175

11.3.1 Shear reinforcement 175

11.4 Steel beams 177

11.4.1 Bending 177

11.4.2 Plastic hinge 178

11.4.3 Shear 178

11.5 Timber joists 179

11.5.1 Failures in Timber Joists 180

11.5.2 Lateral buckling 181

11.6 Slabs 182

11.7 Columns 183

11.7.1 Slenderness ratio 183

11.7.2 Effective height of columns 184

11.7.3 Eccentric loading on columns 186

11.7.4 Steel columns 187

11.7.5 Reinforced Concrete Columns 188

11.8 Foundations 188

11.8.1 Strip foundation 189

11.8.2 Pad foundation 190

11.8.3 Other foundations 191

References/Further reading 192

12 Fluid mechanics 193

12.1 Introduction 193

12.2 Pressure of fluids at rest 193

12.3 Why do Liquids Flow? 196

12.4 Centre of pressure 197

12.5 The flow of a fluid 199

12.5.1 Flow rate 200

12.5.2 Bernoulli’s theorem 201

12.5.3 The venturimeter 204

12.5.4 Flow in pipes: Energy loss 205

12.5.5 Flow in Open Channels 206

Exercise 12.1 208

References/Further reading 210

13 Sound 211

13.1 Introduction 211

13.2 Frequency, wavelength and velocity of sound 212

13.2.1 Frequency (f) 212

13.2.2 Wavelength (λ) 212

13.2.3 Velocity (v) 212

13.3 Measurement of sound 214

13.3.1 Threshold values of sound 215

13.3.2 The Decibel Scale 215

13.4 Addition of Sound Levels 217

13.4.1 Approximate addition of Sound Levels 217

13.5 Transmission of sound in buildings 219

13.5.1 Noise 220

13.5.2 Requirements of Sound Insulation 220

13.5.3 Sound‐Insulation Techniques 221

13.5.4 Noise in a workplace 224

13.5.5 Measurement of Sound Insulation 224

13.6 Sound absorption 225

13.6.1 Reverberation 227

13.6.2 Reverberation time 227

13.6.3 Types of Sound Absorbers 231

13.7 Sound‐level Meter 232

Exercise 13.1 232

References/Further reading 233

14 Light 235

14.1 Introduction 235

14.2 Additive and Subtractive Colours 236

14.3 Measuring light 237

14.3.1 Angular measure 237

14.3.2 Solid angle 237

14.3.3 Luminous intensity (I) 238

14.3.4 Luminous flux (F) 238

14.3.5 Illuminance (E) 239

14.3.6 Luminance 239

14.4 Inverse Square Law of Illuminance 240

14.5 Lambert’s Cosine Law of Illuminance 241

14.6 Lamps and luminaires 243

14.7 Design of Interior Lighting 245

14.7.1 Light Output Ratio 246

14.7.2 Direct ratio 246

14.7.3 Room index 247

14.7.4 Reflection of light 247

14.7.5 Level of illuminance 247

14.7.6 Utilisation factor (UF) 249

14.7.7 Maintenance factor (MF) 249

14.7.8 Lumen Design Method 252

14.7.9 SHR 253

14.8 Light meter 258

14.9 Daylighting 258

14.9.1 Uniform sky 258

14.9.2 CIE Standard Overcast Sky 258

14.9.3 Daylight factor 259

Exercise 14.1 261

References/Further reading 263

15 Human Comfort 265

15.1 Introduction 265

15.2 Temperature 265

15.2.1 Air Temperature 266

15.2.2 Mean Radiant Temperature 267

15.2.3 Environmental Temperature 267

15.2.4 Dry Resultant Temperature 267

15.2.5 Activity 268

15.2.6 Clothing 268

15.3 Air movement 268

15.4 Humidity 269

15.5 Ventilation 269

15.6 Predicted Mean Vote 269

15.7 Noise 270

15.8 Lighting 271

References/Further Reading 272

16 Construction materials 273

16.1 Introduction 273

16.2 Bricks 274

16.2.1 Clay bricks 274

16.2.2 Size 274

16.2.3 Classification 275

16.2.4 Manufacture 275

16.2.5 Properties 275

16.2.6 Deterioration of brickwork 277

16.2.7 Environmental implications 278

16.2.8 COSHH 278

16.3 Aerated Concrete Blocks 279

16.3.1 Manufacture 279

16.3.2 Size 279

16.3.3 Properties 279

16.3.4 Environmental implications 280

16.4 Cement 280

16.4.1 Raw materials 281

16.4.2 Manufacture 281

16.4.3 Setting and hardening of cement 282

16.4.4 Constituents of Portland Cement 282

16.4.5 Types of cement 282

16.4.6 Compressive strength 283

16.4.7 Environmental implications 284

16.4.8 COSHH 284

16.5 Concrete 284

16.5.1 Raw materials 285

16.5.2 Manufacture of concrete 285

16.5.3 Concrete mix 285

16.5.4 Properties of Fresh Concrete 287

16.5.5 Properties of Hardened Concrete 289

16.5.6 Deterioration of concrete 290

16.5.7 Environmental implications 291

16.6 Metals 291

16.6.1 Ferrous metals 291

16.6.2 Non‐Ferrous Metal: Aluminium 295

16.7 Timber 296

16.7.1 Seasoning 297

16.7.2 Properties 298

16.7.3 Deterioration 299

16.7.4 Preservation 300

16.7.5 Environmental implications 300

16.8 Plastics 300

16.8.1 Raw Materials and Manufacture 301

16.8.2 Classification 301

16.8.3 Properties and uses 302

16.9 Glass 303

16.9.1 Properties 303

16.9.2 Types of glass 305

References/Further reading 306

17 Assignments 307

17.1 Assignments for Level 2 courses 307

17.1.1 Assignment No. 1 307

17.1.2 Assignment No. 2 307

17.1.3 Assignment No. 3 307

17.2 Assignments for Level 3/4 courses 308

17.2.1 Assignment No. 1 308

17.2.2 Assignment No. 2 309

17.2.3 Assignment No. 3 310

Appendix 1 Formulae for Example 8.2 313

Appendix 2 Solutions for Example 13.10 315

Appendix 3 Answers to exercises 317

Index 325