Construction Science and Materials

Surinder Virdi is a lecturer in construction at South Birmingham 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 xiii Acknowledgements xv List of units, prefixes and symbols xvii 1 Using a scientific calculator 1 1.1 Introduction 1 1.2 Keys of a scientific calculator 1 References/Further reading 8 2 Units and their conversion 9 2.1 Introduction 9 2.2 Length 10 2.3 Mass 11 2.4 Area, volume and capacity 12 2.5 Temperature 14 References/Further reading 15 3 Introduction to physics 17 3.1 Speed and velocity 17 3.2 Acceleration 18 3.3 Mass 18 3.4 Gravitation 18 3.5 Weight 20 3.6 Volume 20 3.7 Density 20 3.8 Specific gravity 22 3.9 Newton s first law of motion 23 3.10 Newton s second law of motion 23 3.11 Newton s third law of motion 24 3.12 Friction 24 3.13 Work 26 3.14 Energy 26 3.14.1 Potential energy 27 3.14.2 Kinetic energy 27 3.15 Power 29 References/Further reading 31 4 Introduction to chemistry 33 4.1 Introduction 33 4.2 Electrovalency and covalency 36 4.2.1 Covalent bond 36 4.3 Elements and compounds 38 4.4 Symbols and formulae 40 4.5 Acids and bases 40 4.5.1 Acids 41 4.5.2 Bases 42 References/Further reading 43 5 Effects of chemicals and atmosphere on materials 45 5.1 Introduction 45 5.2 Oxidation 45 5.2.1 Experiment: To show that oxygen (or air) and water are necessary for the rusting of iron 46 5.3 Electrolysis 47 5.4 Electrolytic corrosion 49 5.4.1 Examples of electrolytic corrosion 50 5.4.2 Protection of steel from corrosion 51 5.5 Applications of electrolysis 52 5.5.1 Electroplating 52 5.5.2 Extraction of aluminium 53 5.6 Acid rain 53 References/Further reading 54 6 Electricity 55 6.1 Introduction 55 6.2 Coulomb s law 55 6.3 Electric current 56 6.4 Potential difference 57 6.5 Electromotive force (e.m.f.) 57 6.6 Ohm s law 57 6.7 Electrical resistivity and conductivity 59 6.8 Resistors in series/parallel 60 6.8.1 Resistors in series 60 6.8.2 Resistors in parallel 61 6.9 Transformers 64 6.10 Power generation 66 6.11 Power distribution 67 6.12 Supply to small buildings 68 References/Further reading 70 7 Introduction to construction technology 71 7.1 Introduction 71 7.2 Substructure and superstructure 71 7.2.1 Soil investigation 72 7.3 Foundations 73 7.3.1 Settlement 73 7.4 Forms of construction 75 7.5 The external envelope 77 7.5.1 Ground fl oors 78 7.5.2 Cavity walls 78 7.5.3 Suspended timber upper floors 79 7.5.4 Roofs 80 References/Further reading 82 8 Thermal energy 1 83 8.1 Introduction 83 8.2 Temperature 83 8.2.1 Temperature scales 84 8.3 Units of heat 85 8.4 States of matter 85 8.4.1 Changes in the physical state 85 8.4.2 Experiment: The physical states of water 86 8.5 Expansion and contraction of solids 87 8.5.1 Linear expansion 88 8.5.2 Experiment: Determination of coefficient of linear expansion 89 8.5.3 Practical examples of expansion and contraction 90 8.6 Heat transfer 93 8.6.1 Conduction 93 8.6.2 Experiment: To compare the thermal conductivity of metals 95 8.6.3 Convection 96 8.6.4 Practical examples of convection 96 8.6.5 Radiation 96 References/Further reading 98 9 Thermal energy and humidity 99 9.1 Introduction 99 9.2 Thermal insulation 100 9.2.1 Experiment: To compare the thermal insulation values of expanded polystyrene, vermiculite, mineral wool, glass fibre and cork 101 9.3 Heat transmission 103 9.3.1 Thermal conductivity 103 9.3.2 Thermal resistivity (r) 103 9.3.3 Thermal resistance (R) 103 9.4 Thermal transmittance 105 9.5 Heat loss from buildings 110 9.6 Temperature drop through materials 113 9.7 Humidity 115 9.7.1 Measurement of relative humidity 115 9.8 Condensation 118 9.8.1 The psychrometric chart 119 9.8.2 Prevention of surface condensation 119 9.8.3 Interstitial condensation 122 9.8.4 Prevention of interstitial condensation 127 References/Further reading 130 10 Forces and structures 1 131 10.1 Introduction 131 10.2 Force 132 10.2.1 Internal and external forces 133 10.3 Bending 133 10.3.1 Deflection 134 10.4 Types of loading 135 10.4.1 Dead load 135 10.4.2 Imposed load 136 10.4.3 Wind load 136 10.4.4 Loading from other effects 136 10.4.5 Point load 136 10.4.6 Uniformly distributed load 136 10.4.7 Triangular load 136 10.5 Stress and strain 140 10.5.1 Stress 140 10.5.2 Strain 140 10.6 Elasticity 141 10.6.1 Experiment 1: Proof of Hooke s law 142 10.6.2 Experiment 2: Proof of Hooke s law 143 10.6.3 Factor of safety 146 References/Further reading 148 11 Forces and structures 2 149 11.1 Moment of a force 149 11.1.1 Sign convention 150 11.2 Laws of equilibrium 154 11.3 Analysis of beams 154 11.3.1 Beam reactions 154 11.3.2 Shear force (S.F.) 159 11.3.3 Bending moment (B.M.) 165 11.4 Triangle of forces 172 11.4.1 Bow s notation 176 11.4.2 Frames and roof trusses 178 References/Further reading 186 12 Fluid mechanics 187 12.1 Introduction 187 12.2 Pressure of fluids at rest 187 12.2.1 Why do the liquids flow? 190 12.2.2 Centre of pressure 191 12.3 The flow of a fluid 193 12.3.1 Flow rate 194 12.3.2 Bernoulli s theorem 195 12.3.3 The venturimeter 198 12.3.4 Flow in pipes: energy loss 200 12.4 Flow in open channels 200 References/Further reading 205 13 Sound 207 13.1 Introduction 207 13.2 Frequency, wavelength and velocity of sound 208 13.2.1 Frequency (f) 208 13.2.2 Wavelength ( ) 208 13.2.3 Velocity (v) 208 13.3 Measurement of sound 210 13.3.1 Threshold values of sound 211 13.3.2 The decibel scale 211 13.4 Addition of sound levels 214 13.4.1 Approximate addition of sound levels 214 13.5 Transmission of sound in buildings 216 13.5.1 Noise 217 13.5.2 Requirements of sound insulation 217 13.5.3 Sound-insulation techniques 218 13.5.4 Noise in a workplace 221 13.5.5 Measurement of sound insulation 222 13.6 Sound absorption 223 13.6.1 Reverberation 224 13.6.2 Reverberation time 225 13.6.3 Types of sound absorbers 228 13.7 Sound level meter 230 References/Further reading 231 14 Light 233 14.1 Introduction 233 14.2 Additive and subtractive colours 234 14.3 Units for measuring light 235 14.3.1 Angular measure 235 14.3.2 Solid angle 236 14.3.3 Luminous intensity (I) 237 14.3.4 Luminous fl ux (F) 237 14.3.5 Illuminance (E) 237 14.3.6 Luminance 238 14.4 Inverse square law of illuminance 238 14.5 Lambert s cosine law of illuminance 240 14.6 Lamps and luminaires 242 14.7 Design of interior lighting 244 14.7.1 Light output ratio 245 14.7.2 Direct ratio 246 14.7.3 Room index 246 14.7.4 Reflection of light 246 14.7.5 Level of illuminance 247 14.7.6 Utilisation factor (UF) 247 14.7.7 Maintenance factor (MF) 247 14.7.8 Lumen design method 252 14.7.9 SHR 252 14.8 Light meter 257 14.9 Daylighting 257 14.9.1 Uniform sky 257 14.9.2 CIE standard overcast sky 257 14.9.3 Daylight factor 258 14.9.4 Components of daylight factor 258 14.9.5 Prediction of daylight factors 260 References/Further reading 262 15 Human comfort 263 15.1 Introduction 263 15.2 Temperature 263 15.2.1 Air temperature 264 15.2.2 Mean radiant temperature 264 15.2.3 Environmental temperature 265 15.2.4 Dry resultant temperature 265 15.2.5 Activity 266 15.2.6 Clothing 266 15.3 Air movement 267 15.4 Humidity 267 15.5 Ventilation 267 15.6 Noise 268 15.7 Lighting 269 References/Further reading 270 16 Construction materials 271 16.1 Bricks 271 16.1.1 Clay bricks 271 16.1.2 Size 271 16.1.3 Classifi cation 272 16.1.4 Manufacture 272 16.1.5 Properties 272 16.1.6 Deterioration of brickwork 274 16.1.7 Environmental implications 276 16.1.8 COSHH 276 16.2 Aerated concrete blocks 276 16.2.1 Manufacture 276 16.2.2 Sizes 277 16.2.3 Properties 277 16.2.4 Environmental implications 278 16.3 Cement 278 16.3.1 Raw materials 278 16.3.2 Manufacture 279 16.3.3 Setting and hardening of cement 279 16.3.4 Constituents of portland cement 280 16.3.5 Types of cement 280 16.3.6 Compressive strength 282 16.3.7 Environmental implications 282 16.3.8 COSHH 283 16.4 Concrete 283 16.4.1 Raw materials 283 16.4.2 Manufacture of concrete 283 16.4.3 Concrete mix 284 16.4.4 Properties of fresh concrete 285 16.4.5 Properties of hardened concrete 286 16.4.6 Deterioration of concrete 287 16.4.7 Environmental implications 289 16.5 Metals 289 16.5.1 Ferrous metals 289 16.5.2 Raw materials 290 16.5.3 Manufacturing process 290 16.5.4 Iron and its alloys 291 16.5.5 Properties of steel 291 16.5.6 Corrosion of iron/steel 293 16.5.7 Environmental implications 293 16.5.8 Non-ferrous metal: aluminium 294 16.5.9 Raw materials 294 16.5.10 Properties 294 16.5.11 Environmental implications 295 16.6 Timber 295 16.6.1 Seasoning 296 16.6.2 Properties 297 16.6.3 Deterioration 298 16.6.4 Preservation 300 16.6.5 Environmental implications 300 16.7 Plastics 300 16.7.1 Raw materials and manufacture 301 16.7.2 Classifi cation 301 16.7.3 Properties and uses 302 References/Further reading 303 17 Assignments 305 17.1 Assignments for Level 2 courses 305 17.1.1 Assignment No. 1 305 17.1.2 Assignment No. 2 305 17.1.3 Assignment No. 3 306 17.2 Assignments for Level 3/4 courses 306 17.2.1 Assignment No. 1 306 17.2.2 Assignment No. 2 308 17.2.3 Assignment No. 3 308 Appendix 1: Formulae for Example 9.2 311 Appendix 2: Solutions for Example 13.10 313 Appendix 3: Answers to Exercises 315 Index 327 A colour plate section can be found between pages 130 and 131 The book s companion website is at www.wiley.com/go/virdiconstructionscience You will fi nd here freely downloadable support material: fully worked solutions to the exercises at the end of chapters model answers for the assignment tasks set in Chapter 17 explanation of settlement and consolidation in structures details on the design of building foundations daylight calculations a task + solution on the design of timber joists PowerPoint slides for lectures on: Hooke s Law; Forces & Their Effects; Temperature & Heat Loss