building materials oxford university press

1

Consulting EngineerMaryland, USA

N. SubramaNiaN

BuildingTesting and SustainabilityMaterials

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PREFACEAncient civilization lived in caves. After fire and tools were discovered, they started to use natural products such as stones, bricks, and wood to build habitats, which provided protection from the nat-ural environment. Bricks have been found in Egypt as early as 14,000 BC. By 200 BC, the Romans successfully used concrete in the majority of their construction (though the present day concrete construction is much different from theirs). In the industrial age (between the mid-1700s and 1840), several manufacturing processes to produce cement (Joseph Aspdin, 1824), concrete, macadam roads (John Loudon McAdam, c. 1815), mass production of steel from molten pig iron by the Bessemer Process (Henry Bessemer, 1856), method of converting pig iron into wrought iron (Henry Cort, 1784), etc., were invented, resulting in the extensive use of concrete and steel. Now, concrete is the most widely used substance on earth, after water. We now use a variety of materials in our buildings and construc-tions ranging from stones, bricks, cement, reinforced concrete, steel, stainless steel, wood and wood products, glass, fibreglass, aluminium, plastics, ceramics, gypsum, paints and varnishes, bitumen, to copper, zinc, and aluminium alloys.

The exploding population growth (3 billion in 1960 to an estimated 7.7 billion in 2019) and the re-sulting urbanization has resulted in greater energy use [according to BP’s Statistical Review of World Energy, world primary energy consumption reached 157 terawatt-hour (TWh) in 2017]; it has to be noted that materials such as cement and steel require large amounts of energy as their production requires them to be heated to temperatures exceeding 1300°C in kilns. This causes emission of huge quantities of greenhouse gases like CO

2 and also large amounts of industrial waste by-products like fly

ash, which are harmful to the environment. In addition, indiscriminant mining of natural resources for the production of building materials has resulted in severe adverse effects on the environment, includ-ing loss of biodiversity, erosion, contamination of surface and ground water, and soil. Several (rocky) mountains are disappearing and river beds and even beaches (which took numerous years to form) are being denuded of sands. As these natural resources are limited, there is a shortage of coarse aggregates and sand in several parts of the world, necessitating the use of alternate materials or recycling of used materials and even the use of industrial wastes like fly ash. Several other materials such as plastics and lead are harmful to the environment or to the heath of human beings and have to be handled carefully. In addition, some materials like paints, varnishes, or wood impregnated with preservative chemicals may off-gas volatile organic compounds (VOC), which may affect the health of people living in air-conditioned interiors.

Almost all materials that are used in the construction have to follow the norms stipulated in the national codes (Bureau of Indian Standards has numerous codes on building materials). In addition, as buildings account for about one-third of worldwide energy consumption and are one of the larg-est contributors to GCG emissions, several countries including India have recently developed Energy Conservation Building Codes. They usually contain mandatory and voluntary provisions on insulation, thermal and solar properties of the building envelope, heating, ventilation and air conditioning, and also hot water supply systems, lighting, and electrical power.

From the above discussions, it is clear that all those engaged in the design and construction of buildings should have a sound knowledge about the manufacture, energy required in the manufac-ture, properties, effect on health, environmental friendliness, recyclability, sustainability, etc., of the materials they are using and also the norms prescribed for these materials. This book has been written

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to fulfill these needs. This text is based on several latest Indian Standard codes on building materials. SI units have been used throughout the book.

About the BookBuilding Materials, Testing, and Sustainability is a comprehensive text book designed to meet the re-quirements of the undergraduate students of civil engineering, based on the recent AICTE syllabus on Materials, Testing & Evaluation. This book will also be useful to students of architecture (who usually specify the materials), students of diploma courses in civil engineering and will serve as an invaluable reference to postgraduate students and practising engineers, as well as researchers.

Each chapter starts with an introduction about the origin and development of the material discussed in that chapter, the manufacture, properties, uses, advantages and disadvantages, and sustainability of that material. After presenting the subject, multiple-choice questions (MCQ) and review questions are provided at the end of each chapter, which will help the students assimilate the topics presented in the chapters. Answers to the MCQ are given at the end of each chapter, so that the students can check their answers. Several interesting case studies are also included as part of every chapter.

Key FeaturesThe following features in the book make it stand out among the other books in this area:

• It covers traditional materials to the most modern materials such as plastics, gypsum, and ceramics. • Each chapter covers a brief history, composition, classification, manufacture, properties, advantages

and disadvantages, use in buildings, environmental effects, sustainability, etc., of the material dis-cussed in that chapter.

• Several Indian codes are available which stipulate norms for these materials. Most of these codes are cited in the book and important extracts are provided. The list of several codes, which are not cited, are also included in the references of each chapter and included in the online resource centre (ORC). In addition, a bibliography is provided in the book which lists the important references, for further study and research.

• Several topics, which are normally not found in other books, such as different types of brick kilns, substitutes for bricks, green cement, industrial by-products that can be used to replace cement, green substitutes for coarse aggregates and sand, green mortars, green and special concrete, mix design of concrete, controlled permeability formwork (CPF), industrial timber products, various reinforcing bars, structural insulated panel (SIP), sustainability of various materials, green building rating systems, bamboo, nano-materials, composite materials and concrete canvas, health effects and precautions to be taken while handling certain materials, etc., are discussed.

• 30 interesting practical case studies are provided. • Students and engineers will find the separate chapter on testing and evaluation of these materials to

be useful. • A rich pedagogy provides the required rigour for students to excel in this subject in the

examinations: Over 750 review questions and 440 multiple-choice questions (with answers) to test the understanding of the students; over 300 illustrative figures and photographs and 200 tables to supplement the text; more than 1440 references, which include relevant Indian and American codes.

• Provides most updated information in this subject covering the state-of-the-art trends and develop-ments.

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Online ResourcesThe following resources are available to support the faculty and students using this text:

For faculty For students • Lecture PPTs • List of references

Using the BookThe text is divided into 25 chapters and completely covers the undergraduate (UG) curriculum of most of the universities. The teacher adopting this book is requested to exercise discretion to select portions of the text to be presented for a particular course. It is suggested that portions of Chapters 2–8, 11–13, 15–18, and 25 may be taught and Chapters 1, 9–10, 14, and 19–24 may be left for self-study.

Although relevant information from some important codes of practice has been included in the text, readers are advised to buy and refer to the latest codes published by the Bureau of Indian Standards, New Delhi. It is recommended that readers should use the book along with the latest codes/publications released by the Bureau of Indian Standards, for better clarity.

Contents and CoverageThe text is divided into 25 chapters. Chapter 1 deals with the general information on physical, mechanical, thermal, and other properties of materials. It also gives some indications on sustainable (healthy and ecological) materials. Introduction to various green building systems is given and a comparison of structural steel, reinforced and pre-stressed concrete, and wood, which are the major materials used in construction, is provided. A discus-sion on Alternative Building Materials and building codes is also included.

Various aspects of stone including durability, deterioration, preservation, selection and uses of stones are discussed in Chapter 2. It also has brief introduction to stone masonry and a comparison of stone and brick masonry.

Bricks, which are usually used for constructing the walls of buildings, are the subject of Chapter 3. In India, the current brick manufacturing is through the use of highly polluting, energy inefficient, and uneconomical kilns. Hence various types of kilns are discussed and the vertical shaft brick kiln/ tunnel kiln is suggested. Qualities of good bricks, properties, characteristics, etc., of bricks are provided. Several substitutes for bricks are also suggested.

Chapter 4 deals with lime, which is a green material, and was used in olden days; this chapter discusses its manufacture, types, classifications, uses, and precautions while handling it. The manufacture, chem-ical composition, properties, and hydration of various types of cement, which is an important ingredient of concrete, are explained in Chapter 5 along with the various pozzolana/green cement replacement materials. Chapter 6 deals with the characteristics and properties of coarse and fine aggregates, which are mainly used in concrete, and include topics on grading of aggregates, alkali–aggregate reaction, and green substitutes for coarse aggregates and sand. Chapter 7 is concerned with mortars and plasters, which are used in building masonry and providing protective coating on walls and ceilings, respectively.

Various aspects of concrete and RCC, which is used extensively in India in buildings, bridges, dams, etc., are covered in Chapter 8. Various special concretes such as ready mixed concrete, high-strength/high-performance concrete, self-compacting concrete (which is the material of the future), structural light weight concrete, foamed concrete, fibre reinforced concrete, ultra-high performance concrete, poly-mer concrete, geoploymer concrete, prestressed concrete, precast concrete, decorative concrete, etc., are discussed in Chapter 9. As concrete contributes to about 5–6% of global emissions of greenhouse gases,

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the methods to reduce these emissions by the use of industrial by-products such as fly ash, GGBS, etc., (which also improve the properties of concrete) are also described in Chapter 9.

Chapter 10 describes gypsum, a fire retardant and sustainable material, requiring low energy in its production, and mostly used in wall panels. The technology developed at IITM, using glass fibre rein-forced gypsum panels, could reduce the cost and time required to build houses.

Wood is the most sustainable and renewable building material having a low level of embodied energy, and wood products can be carbon negative. In order to use it we should maintain sustainable forestry. Chapter 11 explains the classifications, defects, conservation, seasoning and preservation, properties, selection and testing of timber. Several wood products such as layered timber composites, parallel laminates, particle composites, fibre composites, and timber-concrete composites are now available; their use and properties are briefly explained along with cork and linoleum.

Chapter 12 deals with the various forms of iron (pig, wrought, cast) and Chapter 13 describes steel, which is the second most used structural material. Steel could be alloyed with other elements (mainly with carbon) to improve the properties. It has equal strength in tension and compression, but its main drawback is its corrosion. Steel is used in various forms from structural sections to bolts, nuts, and nails. Hot rolled and cold-formed steel sections are available. Rebars used in concrete and prestressed concrete are usually made of high strength steel. Several techniques have been developed to mitigate the corrosion problem including the development of stainless steel and weathering steel. The produc-tion of steel is also energy intensive and requires high temperatures (up to 1650°C), but is considered sustainable due to its 100% recyclability. Chapter 14 is concerned with non-ferrous materials such as aluminium, copper, zinc, lead, etc., and its alloys like brass and bronze. Steel is galvanized using zinc.

Glass, which is obtained from silica sand, lime, soda, and alumina, and mainly used in windows and curtain walls of multi-storey buildings, is discussed in Chapter 15. Common types (sheet, plate, float, and extra clear) and special types of glass (safety, translucent, etched, tinted, reflective/coated, insulated, double-glazed, glass blocks) are described. Clay roofing tiles of various types and ceramic products are discussed in Chapter 16. Chapter 17 discusses plastics, which were invented in the 1800s and have rev-olutionized the construction industry and being used in a variety of applications. This chapter describes its classification, methods of production, properties, and uses. Most of the plastics are not recyclable and are not bio-degradable and hence have to be used with caution.

Details about paints and varnishes are provided in Chapter 18 and asphalt, bitumen, and tar in Chapter 19. Chapters 20–22 deal with thermal and sound insulating materials and waterproof-ing materials, respectively. Miscellaneous and recent materials are discussed in Chapter 23. A brief description of deformation and fracture of materials is provided in Chapter 24. Chapter 25 describes the various tests that are performed on some of the important materials, in order to evaluate them.

Though care has been taken to present error-free material, some errors might have crept in inadvert-ently. I would highly appreciate if these errors are brought to the attention of publishers. Any sugges-tions for improvement are also welcome.

AcknowledgementsI was greatly influenced during the preparation of this book by several books, papers, and websites on building materials, sustainability and testing. Although sufficient effort was taken to acknowledge the source of images, tables, etc., I wish to apologize for the use of any phrase, image, or illustrations used in this book inadvertently without acknowledgement.

I thank the following organizations/publishers for permitting to reproduce material from their publications: Ms Angela R. Matthews of American Concrete Institute (ACI), Ms Rachel Jordan of

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American Institute of Steel Construction (AISC), Mr Toru Kawai, Executive Director of Japan Concrete Institute (JCI), The US Green Building Council, Dr Steven H. Kosmatka, former Vice President, and Guiyun Wang of Portland Cement Association (PCA), USA, Mr Chris Shaw of UK, The Indian Concrete Journal, Mr Craig Donnelly of the Scottish Government, Er Robert Jackson of Fast+Epp, of Vancouver, BC, Canada, Dr Warren South, Director – Research and Technical Services of Cement Concrete & Aggregates, Australia, Ms Rousalina Barkhamatova, Secretary, Industrial Minerals Association Europe (IMA-Europe), Brussels, Belgium, Mr Opinder Saggi of Allied Concrete Ltd and AML Ltd, Auckland, New Zealand, Dr Mohammed Nadeem of Ambuja Cements, Mr Drew Burns, Executive Director of Slag Cement Association, Dr M.C. Nataraja, Professor of JSS Science and Technology University, Mysore, Prof. Devdas Menon of IITM, Er Alok Bhowmick of B&S Engineering Consultants Pvt. Ltd, Mr Samuel Sundar Singh of The Indian Green Building Council (IGBC), and M/s Tata Steel.

I thank the following organizations/persons for gi ving permission to use photographs of testing equipment/buildings/materials: Er Dar Adil of IITD, Mr Mohammed Razal of Bangalore Tile Company, Bangalore, Prof. Manu Santhanam of IITM, Mr Robin Bailey of Humboldt Mfg Co., Elgin, IL, Prof. Jake Hiller of Michigan Technological University, USA, Dr Ajoy Kumar Mullick, former Director General of the National Council for Cement & Building Materials and Consultant, New Delhi, Mr Garry Watkins of Concrete Canvas Ltd, UK, Mr Giorgio Maestroni and Ms Elena Agazzi of Matest S.P.A. Unipersonale, Italy, Ms Sadia Parveen of ELE International, UK, Ms Aarti Bhargava of Aimil Ltd, New Delhi, Mr Jean Pol Grandmont (Flickr), Er Sebastian Kaminski of Arup, UK, Prof. M. Sekar of Anna University, Mr Lori Maloney of JC Steele & Sons, Inc., Mr John Lamond (Controls USA, Inc.) and Ms Paola Bettinelli (Controls S.p.A.) of Controls Group, Milan, Italy, M/s Elsevier (Fig. 5.4), Mr Nemish Sheth, Director of Asona India Pvt. Ltd Mumbai, Ms Sara DeWaay of the University of Oregon Libraries, Ms Alison of Findlay–Evans Waterproofing & Liquid Rubber Melbourne, Australia, Dr Narayan V. Nayak, Advisor, Gammon India Ltd, Dr V.S. Parameswaran, Former Director of SERC, Dr G. Mohan Ganesh of Vellore Institute of Technology, Vellore, Er S.H. Gajendra n, Er E.S. Jayakumar, Superintending Engineer ( Civil), BSNL Civil Wing, Kerala, Er Rahul Leslie , Deputy Director of Kerala PWD, Cochin, and Er M. Karthik.

I thank all those who assisted me in the preparation of this book. First and foremost I thank Dr Col. Nallathambi, Managing Director, Sakthi Civil & Structural Consultancy Pvt. Ltd, Chennai for his help in writing Chapters 20–22. My sincere thanks are due to Prof. B. Vijaya Rangan, Emeritus Professor of Civil Engineering, Curtin University of Technology, Perth, Australia, Prof. Dr P. Suryanarayana, Professor & Former Dean (Retd), Maulana Azad National Institute of Technology, Bhopal, Dr Ch. T. Madhavi, Professor & Head, SRM Institute of Science and Technology, Ramapuram Campus, Dr Abdul Rashid Dar, Professor and former Director, National Institute of Technology Srinagar, J&K, India, and Dr G. Mohan Ganesh, of VIT, for going through the chapters patiently and offering useful comments, and Er Hemal Mistry and Er Dar Adil of IITM for their help in locating the literature. Finally I express my gratitude to Er Kumar Abhishek Singh of New Delhi, Er Vivek Abhyankar of L&T Mumbai, Er Siddique, and Er Ganesh of Nagpur for their encouragement.

I will be failing in my duty if I do not acknowledge the help and wonderful assistance I received from Ms S. Chithra at all the stages of this book-writing project. Lastly, I acknowledge the excellent support and coordination provided by the editorial team of Oxford University Press India.

N. Subramanian

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BRIEF CONTENTSPreface vDetailed Contents xiList of Acronyms xxii

1. Properties of Building Materials 1

2. Building Stones 23

3. Bricks and Brick Substitutes 53

4. Building Lime 92

5. Cement and Cementitious Materials 115

6. Aggregates 145

7. Mortars and Plasters 183

8. Concrete and Reinforced Concrete 208

9. Special Structural Concrete 263

10. Gypsum 301

11. Wood and Wood Products 317

12. Ferrous Metals other than Steel 368

13. Steel 386

14. Non-ferrous Metals and Alloys 440

15. Glass 467

16. Clay and Ceramic Products 489

17. Plastics and Rubbers 511

18. Paints and Varnishes 540

19. Asphalt, Bitumen, and Tar 570

20. Thermal Insulating Materials 590

21. Sound Insulating Materials 614

22. Waterproofing and Damp-proofing Materials 636

23. Miscellaneous Materials 656

24. Deformation and Fracture of Materials 674

25. Testing and Evaluation of Building Materials 688

Bibliography 777Index 782

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DETAILED CONTENTSPreface vBrief Contents xList of Acronyms xxii

1. Properties of Building Materials 1 1.1 Introduction 1 1.2 Functions of a Building 2 1.3 Choosing Materials for Construction 2 1.4 Physical Properties 3 1.5 Mechanical Properties 5 1.6 Thermal Properties 6 1.7 Other Properties 7 1.8 Sustainable Materials 9 1.8.1 Healthy Materials 10 1.8.2 Ecological Materials 10 1.9 Green Building Rating Systems 10 1.9.1 LEED-NC 11 1.10 Embodied Energy and Energy

Efficiency 15 1.11 Comparison of some Major

Building Materials 17 1.12 Alternative Building Materials 19 1.13 Building Codes and By-Laws 20

2. Building Stones 23 2.1 Introduction 23 2.2 Classification of Rocks 24 2.2.1 Igneous Rocks 26 2.2.2 Sedimentary Rocks 26 2.2.3 Metamorphic Rocks 27 2.3 Common Stones used in India 27 2.4 Quarrying, Seasoning, and

Dressing of Stones 29 2.4.1 Quarrying Methods 30 2.4.2 Seasoning of Stones 32 2.4.3 Dressing of Stones 33 2.5 Requirements of Good

Building Stones 33 2.6 Durability of Stones 36 2.7 Deterioration of Stones 37 2.8 Preservation of Stones 39 2.8.1 Precautions During

Construction 39 2.8.2 Preservation of Completed

Stonework 39

2.9 Selection and Applications of Stones 40

2.10 Stone Masonry 43 2.10.1 Rubble Masonry 43 2.10.2 Ashlar Masonry 44 2.10.3 Stone Veneers 45 2.10.4 Advantages and Disadvantages of

Stone Masonry 45 2.11 Stone Masonry vs Brick Masonry 46 2.12 Artificial Stones 47 2.13 Stone Flooring 48

3. Bricks and Brick Substitutes 53 3.1 Introduction 53 3.2 Properties of Brick Clay 54 3.2.1 Types of Clay 55 3.2.2 Composition of Good Brick

Clay 55 3.2.3 Harmful Ingredients in

Brick Clay 56 3.3 Manufacture of Bricks 57 3.4 Different Types of Brick Kilns 62 3.4.1 Classification of Brick

Kilns 62 3.4.2 Clamp Kiln 63 3.4.3 Down-draught Kiln 64 3.4.4 Vertical Shaft Brick Kiln 65 3.4.5 Tunnel Kiln 68 3.5 Classification of Bricks 70 3.6 Qualities of Good Bricks 71 3.7 Architectural Characteristics

of Bricks 71 3.7.1 Shape and Types of Bricks 71 3.7.2 Size and Weight of Bricks 75 3.7.3 Colour and Texture of Bricks 76 3.8 Defects in Burnt Clay Bricks 76 3.9 Advantages and Uses of Bricks 77 3.10 Substitutes for Bricks 78 3.10.1 Fly Ash Bricks 79 3.10.2 Sand-lime Bricks and Calcium

Silicate Bricks 80 3.10.3 Compressed Earth Blocks 81 3.10.4 Concrete Blocks 82 3.10.5 Plastic Blocks 86 3.11 Sustainability and Brick 87

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Detailed Contentsxii

4. Building Lime 92 4.1 Introduction 92 4.2 Constituents of Limestone or

Varieties of Lime 93 4.3 Lime Cycle 93 4.4 Manufacture of Lime 94 4.4.1 Preparation of Raw Materials 95 4.4.2 Calcination of Limestone

in Kilns 95 4.4.3 Method of Storage of Lime 97 4.4.4 Chemical Reaction that occurs

during Manufacturing 97 4.4.5 Estimating the Quantity

of Lime 98 4.4.6 Effect of Impurities in

Limestone 98 4.4.7 Hydrators used

in Lime Production 99 4.5 Different Types of Limes 99 4.5.1 Quicklime or Lime Putty 99 4.5.2 Hydrated or Slaked Lime 100 4.5.3 Equipment used for

Slaking Process 100 4.5.4 Hydraulic Lime or Natural

Hydraulic Lime (NHL) 102 4.6 Cementing Action of Lime 103 4.7 Classification of Lime 103 4.8 Storing of Lime 104 4.9 Precautions to be Taken while

Handling Lime 105 4.10 Uses and Products of Lime in

Construction 105 4.10.1 Lime Putty 106 4.10.2 Lime Mortar and Plaster 106 4.10.3 Limewash 106 4.10.4 FaL-G Technology 108 4.10.5 Hempcrete and Limecrete 109 4.11 Advantages and Disadvantages of

using Lime 109 4.11.1 Advantages of Lime 109 4.11.2 Disadvantages of Lime 110 4.12 Lime vs Cement 111 4.13 Use of Lime as Green Building

Material 111

5. Cement and Cementitious Materials 115 5.1 Introduction 115 5.2 Portland Cement 116 5.2.1 Grades of Cements in India 117 5.3 Manufacture of Portland Cement 117 5.4 Chemical Composition of Raw

Materials of Portland Cement 119

5.5 Chemical Compounds of Cement Clinker 120

5.6 Physical Properties of Portland Cement 122

5.7 Chemical Properties of Portland Cement 123

5.8 Hydration of Cement 124 5.8.1 Heat of Hydration 126 5.8.2 Rate of Hydration 127 5.8.3 Water-Cement Ratio 128 5.9 Green Cement Replacement

Materials (Pozzolana) 128 5.9.1 Surkhi 129 5.9.2 Fly Ash 129 5.9.3 Ground Granulated Blast

Furnace Slag (GGBS) 131 5.9.4 Silica Fume 132 5.9.5 Metakaolin 132 5.9.6 Rice Husk Ash 133 5.10 Types of Cements Produced

in India 133 5.10.1 Portland Pozzolana Cement 133 5.10.2 Portland Slag Cement 134 5.10.3 Blended Cements 135 5.10.4 Special-purpose Cements 136 5.10.5 Portland Limestone Cement 138 5.11 Novel, Resource-efficient

Cements 138 5.11.1 Alkali-activated/Geopolymer

Cement 138 5.11.2 Self-cleaning Cement 139 5.12 Storage and Handling of Cement 140 5.13 Uses of Cement 140

6. Aggregates 145 6.1 Introduction 145 6.2 Classification of Aggregates 145 6.2.1 According to Geological

Origin 146 6.2.2 According to Size 147 6.2.3 According to Shape 148 6.2.4 According to Unit Weight 150 6.3 Characteristics of Coarse

Aggregates 150 6.3.1 Particle Size, Shape, and

Texture 151 6.3.2 Crushing or Impact Strength 152 6.3.3 Relative Density 152 6.3.4 Bulk Density 152 6.3.5 Voids 153 6.3.6 Porosity 153 6.3.7 Moisture Content 153

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Detailed Contents xiii

6.4 Deleterious Substances and Organic Impurities 154

6.5 Soundness of Aggregate 155 6.6 Alkali–Aggregate Reaction 155 6.7 Thermal Properties of

Aggregates 157 6.8 Fineness Modulus and Sieve

Analysis 158 6.9 Maximum Size of Aggregates 162 6.10 Grading of Aggregates 163 6.10.1 Grading Limits 165 6.11 Green Substitutes for Coarse

Aggregates 167 6.11.1 Recycled Aggregates 168 6.11.2 Iron and Steel Slags 169 6.11.3 Sintered Fly Ash Lightweight

Aggregates 170 6.12 Fine Aggregates (Natural Sand) 170 6.12.1 Sources of Sand 171 6.12.2 Classification of Sand 171 6.12.3 Bulking of Sand 172 6.12.4 Uses of Sand 173 6.13 Green Substitutes for Sand 174 6.13.1 Manufactured Sand 175 6.13.2 Copper Slag 176 6.13.3 Granulated Blast Furnace Slag

(GBFS) 177 6.13.4 Foundry Waste Sand 177 6.14 Storing and Handling

of Aggregates 178

7. Mortars and Plasters 183 7.1 Introduction 183 7.2 Characteristics of Good Mortar 184 7.2.1 Ingredients of Mortar 185 7.3 Classification of Mortars 186 7.4 Cement Mortar 187 7.4.1 Preparation 187 7.4.2 Precautions to be Taken 188 7.4.3 Properties 188 7.4.4 Applications 189 7.5 Lime Mortar 189 7.5.1 Preparation 190 7.5.2 Hydraulic Lime Mortars 192 7.5.3 Advantages and

Disadvantages 192 7.5.4 Precautions to Be Taken 193 7.6 Composite (Lime-Cement) Mortar 193 7.7 Surkhi Mortar 194 7.8 Mud Mortar 195 7.8.1 Preparation 195 7.8.2 Limitations 195

7.8.3 Rules for application 196 7.8.4 Precautions to be taken 196 7.9 Special Mortars 196 7.10 Green Mortars 197 7.10.1 Lime Mortar 198 7.10.2 Lime-Pozzolana Mixture 198 7.10.3 Cement-Fly Ash-Sand

Mortar 199 7.10.4 Masonry Cement Mortar 199 7.11 Selection of Mortar 200 7.12 Plasters 201 7.12.1 Cement or Lime Plasters 202 7.12.2 Polymer-based Plaster

Systems 202 7.12.3 Stucco Plasters for Exterior

Walls 203 7.13 Grout 204

8. Concrete and Reinforced Concrete 208 8.1 Introduction 208 8.1.1 Brief History 209 8.1.2 Advantages and Disadvantages

of Concrete 210 8.2 Ingredients of Concrete 212 8.2.1 Water and Water-Cement

Ratio 212 8.2.2 Concrete Chemicals 213 8.3 Classification of Concrete 215 8.4 Mixing the Materials for Concrete 216 8.4.1 Batching Plants 217 8.5 Transporting and Placing

Concrete 218 8.6 Consolidation of Concrete 218 8.6.1 Hand Consolidation 219 8.6.2 Compaction by Vibration 219 8.6.3 Bleeding of Concrete 223 8.6.4 Revibration 225 8.7 Curing of Concrete 225 8.7.1 Internal Curing of Concrete 228 8.7.2 Removal of Forms 229 8.8 Properties of Fresh and Hardened

Concrete 229 8.8.1 Workability 229 8.8.2 Compressive Strength 230 8.8.3 Stress-Strain Characteristics 232 8.8.4 Tensile Strength and Shear

Strength 233 8.8.5 Bearing Strength 234 8.8.6 Modulus of Elasticity and

Poisson’s Ratio 234 8.8.7 Shrinkage and Temperature

Effects 236 8.8.8 Creep of Concrete 237

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8.9 Mix Design of Ordinary Grade Concrete 238

8.10 Reinforced Cement Concrete (RCC) 247

8.10.1 Corrosion Problem of Reinforced Concrete 248

8.10.2 Cover for Steel Reinforcement 249

8.10.3 Controlled Permeability Formwork (CPF) Systems 253

8.10.4 Vacuum Dewatering of Concrete 255

8.11 Durability of Concrete 255 8.12 Defects in Concrete 256 8.13 Formwork 258

9. Special Structural Concrete 263 9.1 Introduction 263 9.2 Ready Mixed Concrete 264 9.3 Green Concrete (with Supplementary

Cementitious Materials) 266 9.3.1 Fly Ash Concrete 267 9.3.2 Silica Fume and RHA

Concrete 271 9.3.3 Slag Cement Concrete 273 9.3.4 Concrete with Recycled

Aggregates 274 9.4 High Strength/High Performance

Concrete 276 9.5 Self-compacting Concrete 279 9.6 Structural Lightweight Concrete 281 9.6.1 Autoclaved Aerated

Concrete 284 9.6.2 Lightweight Foamed

Concrete 288 9.7 Fibre Reinforced Concrete 289 9.7.1 Ultra-high Performance

Concrete 290 9.8 Polymer Concrete 293 9.9 Precast Concrete 295 9.10 Decorative Concrete 295 9.11 Ferrocement 295 9.12 Geopolymer Concrete 296 9.13 Prestressed Concrete 296 9.14 Shotcrete 296 9.15 Other Types of Concrete 297

10. Gypsum 301 10.1 Introduction 301 10.2 Effect of Heat and Moisture 302 10.3 Classification 303 10.4 Plaster of Paris 304

10.5 Gypsum Wall Plasters 304 10.5.1 Characteristics of

Wet-plastered Walls 307 10.6 Gypsum Plaster Boards 307 10.6.1 Types of Gypsum

Boards 308 10.6.2 Characteristics of Drywall

Construction 311 10.7 Non-load Bearing Gypsum Partition

Blocks 313 10.8 Sustainability of Gypsum 314

11. Wood and Wood Products 317 11.1 Introduction 317 11.2 Classification of Trees 318 11.3 Parts of the Stem of a Tree 318 11.4 Classification of Wood/Timber 320 11.4.1 Commercial/Hardness

Classification 320 11.4.2 On the Basis of Grading 320 11.4.3 According to Availability 321 11.4.4 According to Durability 321 11.4.5 Based on Modulus of

Elasticity 322 11.4.6 Based on Treatability 322 11.4.7 Based on Refractoriness to

Air-Seasoning 322 11.5 Defects in Wood/Timber 322 11.5.1 Defects due to Natural

Forces 323 11.5.2 Defects that Develop after

Felling Trees 324 11.6 Rot and Decay of Timber 325 11.6.1 Dry Rot 326 11.6.2 Wet Rot 326 11.6.3 Damage due to Insects 327 11.7 Moisture Content of Timber 329 11.7.1 Shrinkage of Timber 331 11.8 Conversion and Seasoning

of Timber 331 11.8.1 Conversion and Market

Forms of Timber 332 11.8.2 Seasoning of Timber 333 11.8.3 Seasoning Degrade 336 11.9 Preservation of Timber 336 11.9.1 Prophylactic Treatment 338 11.9.2 Precautions to be taken while

Handling Chemically Treated Wood 338

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11.9.3 Thermal or Heat Treatment 339

11.9.4 Wood-Polymer Composites 339

11.9.5 Protective Coating 339 11.10 Storage of Timber 340 11.11 Qualities of Good Timber 340 11.12 Selection of Timber 341 11.13 Fire Proofing of Timber 342 11.14 Structural Properties of Timber 342 11.15 Advantages and Problems

of Timber 344 11.16 Industrial Timber Products 345 11.17 Layered Timber Composites 346 11.17.1 Veneers and Veneer Plywood

( Cross-laminate) 346 11.17.2 Cross-laminated Timber

(CLT) 348 11.17.3 Nail-laminated Timber

(NLT) 349 11.18 Parallel Laminates 349 11.18.1 Glued Laminated Timber

(GLT or Glulam) 349 11.18.2 Laminated Veneer Lumber

(LVL) 350 11.18.3 Block Board, Lamin Board,

and Sandwich Panels 351 11.18.4 Flush Doors 352 11.19 Particle Composites 352 11.19.1 Particle Boards 352 11.19.2 Parallel Strand Lumber

(PSL) 355 11.19.3 Oriented Strand Board

(OSB) 355 11.19.4 Laminated Strand Lumber

(LSL) 355 11.20 Fibre Composites 356 11.20.1 Fibreboards 356 11.20.2 Hardboard 357 11.21 Timber-concrete Composites

(TCC) 358 11.22 Advantages and Drawbacks of Wooden

Composites 358 11.23 Applications of Wood and Wood

Products 359 11.23.1 Tall Buildings in Wood 361 11.24 Cork and Linoleum 361 11.25 Timber: The Ultimate Green Building

Material 362

12. Ferrous Metals other than Steel 368 12.1 Introduction 368 12.2 Pig Iron 369 12.2.1 Production of Pig Iron 369 12.2.2 Properties and Uses of Pig

Iron 371 12.3 Wrought Iron 372 12.3.1 Manufacture 373 12.3.2 Properties 374 12.3.3 Uses of Wrought Iron 374 12.4 Cast Iron 374 12.4.1 Manufacture 375 12.4.2 Classification 377 12.4.3 Grey Cast Iron 378 12.4.4 White Cast iron 379 12.4.5 Malleable Cast Iron 379 12.4.6 Spheroidal Graphite Iron

(Ductile Iron) 380 12.4.7 Alloyed Iron 380 12.4.8 Corrosion Resistance of Cast

Iron 381 12.5 Steel 381 12.6 Environmental Effects of Iron/

Steel Production 382

13. Steel 386 13.1 Introduction 386 13.2 Steel Making 387 13.2.1 Integrated Steel Plants 387 13.2.2 Mini Steel Plants 389 13.2.3 Hot Rolling Process 390 13.3 Production of Steel in India 390 13.4 Metallurgy of Steel 391 13.4.1 Crystalline Structure of

Metals 391 13.4.2 Structure of Steel 392 13.5 Heat Treatment of Steel 394 13.5.1 Annealing 394 13.5.2 Normalizing 394 13.5.3 Quenching and

Tampering 395 13.5.4 Stress Relieving 395 13.5.5 Case Hardening 395 13.6 Alloying Elements in Steel 396 13.6.1 Weldability of Steel 397 13.7 Chemical Composition of Steel 398 13.8 Types of Structural Steel 398 13.9 Mechanical Properties of Steel 399

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13.9.1 Tensile Strength/Yield Strength 400

13.9.2 Characteristic Strength 403 13.9.3 Ductility 404 13.9.4 Low Temperature and

Toughness (Brittle Fracture) 404

13.9.5 Lamellar Tearing 405 13.9.6 High Temperature

Effects 406 13.9.7 Hardness 407 13.9.8 Fatigue Resistance 407 13.10 Residual Stresses 407 13.11 Mechanical Working of Metals 409 13.11.1 Hot Working 409 13.11.2 Cold Working 410 13.12 Structural Steel Products 412 13.12.1 Hot-rolled Steel Sections

(IS 808) 412 13.12.2 Wide Flange Sections

(IS 12778:2004) 413 13.12.3 Welded and Hybrid

Sections 414 13.12.4 Hollow Steel Sections

(HSS) 416 13.12.5 Light-gauge Cold-formed

Steel Sections 417 13.12.6 Steel Wires and Ropes 418 13.12.7 Steel Fasteners 419 13.12.8 Other Products 420 13.13 Reinforcing Steel Bars 421 13.13.1 Hot-rolled Bars 421 13.13.2 Cold Twisted Deformed

(CTD) Bars (Torsteel Bars) 421

13.13.3 Thermo-mechanically Treated (TMT) Bars 422

13.13.4 Welded Wire Fabrics (WWF) 424

13.13.5 Steel for Prestressed Concrete 424

13.13.6 Corrosion of Rebars and Mitigation Methods 425

13.14 Protection of Structural Steel from Corrosion 427

13.14.1 Weathering Steel 429 13.15 Stainless Steel 429 13.5.1 Surface Finish 432 13.16 High-performance Steel 432

13.16.1 High-strength Low-alloy (HSLA) Steel 433

13.17 Storage and Handling of Steel 434 13.18 Advantages and Disadvantages

of Steel 434 13.19 Steel and Sustainability 436

14. Non-ferrous Metals and Alloys 440 14.1 Introduction 440 14.2 Aluminium and its Alloys 440 14.2.1 Manufacture of

Aluminium 440 14.2.2 Properties of

Aluminium 442 14.2.3 Aluminium Alloys 444 14.2.4 Anodizing of

Aluminium 447 14.2.5 Available Forms of

Aluminium 447 14.2.6 Uses of Aluminium 448 14.2.7 Advantages of using

Aluminium 450 14.3 Copper and its Alloys 451 14.3.1 Manufacture of Copper 451 14.3.2 Properties of Copper 453 14.3.3 Uses of Copper 453 14.3.4 Copper Alloys (Brass and

Bronze) 454 14.4 Zinc and its Alloys 456 14.4.1 Zinc Galvanizing 457 14.5 Lead 458 14.6 Chromium 459 14.7 Nickel 459 14.8 Magnesium 461 14.9 Vanadium 461 14.10 Problems with Non-ferrous

Metals 462 14.11 Sustainability of Non-ferrous Materials

463

15. Glass 467 15.1 Introduction 467 15.2 Composition and Classification 468 15.3 Manufacture of Glass 469 15.3.1 Fourcault System of Sheet

Glass Manufacture 469 15.3.2 The Float-glass

Process 470 15.3.3 Rolled Glass Process to make

Plate Glass 470

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15.4 Treatments given to Glass 471 15.5 Properties of Glass 472 15.5.1 Physical Properties 472 15.5.2 Engineering and Mechanical

Properties 472 15.6 Uses of Glass in Buildings 473 15.7 Common Types 474 15.7.1 Sheet Glass 474 15.7.2 Plate Glass 474 15.7.3 Float Glass 475 15.7.4 Extra Clear Glass 475 15.8 Special Types 475 15.8.1 Safety Glass 475 15.8.2 Translucent Glass 477 15.8.3 Etched Glass 477 15.8.4 Tinted Glass 478 15.8.5 Coated/Reflective Glass 478 15.8.6 Insulated Glass/Double-

glazed Window Units 479 15.8.7 Glass Blocks 481 15.8.8 Heat-absorbing and

Glare-reducing Glass 482 15.8.9 Self-cleaning Glass 482 15.8.10 Associated Glazing

Materials 482 15.8.11 Types of Window

Frames 483 15.9 Fibreglass 483 15.10 Plastic Sheets for Glazing 483 15.11 Characteristics and Performance

of Glass 484 15.11.1 Solar Control 484 15.11.2 Wind Loading 484 15.11.3 Sound Insulation 485 15.12 Advantages and Disadvantages 485

16. Clay and Ceramic Products 489 16.1 Introduction 489 16.2 Clay Tiles 489 16.3 Clay Roofing Tiles 490 16.3.1 Flat Plain Tiles 490 16.3.2 Pan Tiles 491 16.3.3 Mangalore Pattern Roofing

Tiles 492 16.3.4 Clay Half-Round Country Tiles

(Spanish Tiles) 494 16.3.5 Allahabad Tiles (Italian

Tiles) 495 16.3.6 Ridge and Ceiling Tiles 495

16.3.7 Solar Roof Tiles 497 16.4 Clay Flooring Tiles 497 16.4.1 Clay vs Concrete Roof

Tiles 498 16.5 Ceramics 498 16.5.1 Manufacturing of Ceramic

Products 499 16.5.2 Properties of Ceramics 501 16.5.3 Ceramic Tiles 501 16.5.4 Vitrified Tiles 502 16.5.5 Fixing of Floor Tiles 503 16.6 Porcelain 504 16.6.1 Porcelain Tiles 504 16.7 Choosing Tiles 505 16.8 Terracotta 506 16.9 Earthenware 507 16.10 Stoneware Pipes and Fittings 507 16.11 Ceramic Sanitary Appliances 507 16.12 Burnt Clay Jallies 508 16.13 Environmental Effects of Ceramics 508

17. Plastics and Rubbers 511 17.1 Introduction 511 17.2 Brief History of Plastics

and Polymers 512 17.3 Composition of Plastics 512 17.4 Classification of Plastics 513 17.4.1 Thermoplastics 513 17.4.2 Thermosetting Plastics 513 17.5 Polymerization 513 17.6 Fabrication of Plastic Products 514 17.6.1 Additives/Moulding

Compounds 515 17.6.2 Solvents 515 17.6.3 Fabrication Methods 515 17.7 Properties of Some Plastics in

Common Use 518 17.8 Advantages and Disadvantages of

Plastics 518 17.9 Common Plastics and their Use 519 17.10 Use of Plastics In Buildings 522 17.10.1 PVC Pipes in Buildings 522 17.10.2 Polyethylene Water

Tanks 524 17.10.3 Doors and Windows 524 17.10.4 Polycarbonate or PVC

Roofing Sheets 524 17.10.5 Vinyl Flooring Sheets/Tiles/

Planks 525

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17.10.6 Plastic Insulation 525 17.10.7 Structural Insulated

Panel 526 17.10.8 Use of Plastic Fabrics in

Tensile Structures 527 17.10.9 Geosynthetic Materials 529 17.11 Bioplastics 529 17.12 Fibre Reinforced Plastics 530 17.13 Thermocol/Geofoam 531 17.14 Environmental Effects of Plastics 532 17.15 Rubber 534 17.15.1 Types of Rubber 534 17.15.2 Vulcanization of

Rubber 535 17.15.3 Properties of Rubber 535 17.15.4 Uses of Rubber in

Buildings 536

18. Paints and Varnishes 540 18.1 Introduction 540 18.2 Components of Paints 540 18.3 Manufacture of Paints 543 18.3.1 Packaging of Paints 543 18.4 Classification and Types of Paints 544 18.4.1 Water-based Latex

Paints 544 18.4.2 Oil-based Alkyd Paints 544 18.4.3 Application Methods 546 18.4.4 Characteristics of Good

Quality Paint 546 18.5 Considerations in Choosing Paints 546 18.5.1 Pigment Volume

Concentration 548 18.6 Paint Primers 548 18.7 Cement Paints 549 18.7.1 Procedure for Applying

Cement Paint 550 18.7.2 Advantages and

Disadvantages of Cement Paint 550

18.8 Distempers 551 18.8.1 Soft Distempers 551 18.8.2 Oil-bound Distemper 552 18.9 Plastic Emulsion Paints 552 18.9.1 Latex (Acrylic) Emulsion

Paint 552 18.9.2 Vinyl Emulsion Paint 553 18.10 Solvent or Oil-based Paints 553 18.10.1 Enamel Paints 553 18.10.2 Synthetic Enamel Paints 554

18.11 Exterior Paints 554 18.12 Whitewash and Colour Wash 554 18.13 Painting on Different Substrates 555 18.14 Varnishes 557 18.14.1 Ingredients of Varnish 557 18.14.2 Types of Varnishes 558 18.14.3 Application and

Recoating 559 18.15 Industrial Paints 560 18.15.1 Innovations in Industrial

Paint Industry 561 18.16 Covering Capacity of Paints 562 18.17 Defects in Painting 564 18.18 Harmful Effects of Paints 566

19. Asphalt, Bitumen, and Tar 570 19.1 Introduction 570 19.2 Asphalt 570 19.2.1 Types of Asphalt 571 19.2.2 Uses of Asphalt 571 19.2.3 Forms of Asphalt-Paving

Materials 571 19.2.4 Mixture Formulations 572 19.3 Bitumen 575 19.3.1 Types of Bitumen 575 19.3.2 Specifications of Paving

Bitumen 578 19.3.3 Tar Paper and Bitumen

Felts 579 19.3.4 Commercial Roofing

Systems 580 19.3.5 Health, Safety, and

Environmental Aspects of Bitumen 583

19.3.6 Other Bituminous Products 584 19.4 Tar/Pitch 584 19.5 General Properties

of Bituminous Products 585 19.6 Sustainability of Bituminous

Materials 586

20. Thermal Insulating Materials 590 20.1 Introduction 590 20.1.1 General Principles of

Thermal Insulation 591 20.1.2 Choice of Insulating

Materials 591 20.2 Importance of Thermal Insulation

in Buildings 591 20.3 Heat Transfer Fundamentals 592

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20.3.1 Conduction 593 20.3.2 Convection 593 20.3.3 Radiation 593 20.4 Thermal Properties of Insulating

Materials 594 20.5 Criteria for Selection of Insulation

Materials 599 20.5.1 Thermal Bridging 600 20.5.2 Convection and Air

Leakage 601 20.6 Common Insulation Materials 602 20.6.1 Inorganic Materials 602 20.6.2 Organic Materials 604 20.7 Plastic Insulation Products 606 20.7.1 Rigid Foam Boards 606 20.7.2 Sprayed In-place Plastic

Foams 607 20.8 Vapour Barriers 609 20.9 Low-E™ Reflective Insulation 610 20.10 Other Products 610 20.11 Fenestration 610 20.12 Insulation and Ventilation 611

21. Sound Insulating Materials 614 21.1 Introduction 614 21.1.1 Brief History 615 21.2 Fundamentals of Acoustics 615 21.2.1 Sound and Noise 615 21.2.2 Speed of Sound 616 21.2.3 Frequency (Pitch) 616 21.2.4 Wavelength 617 21.2.5 Amplitude (Loudness) 617 21.2.6 Sound Pressure Level 618 21.2.7 Airborne and Structure-borne

Sound 619 21.2.8 Transmission Loss 621 21.3 Maximum Acceptable Noise Levels 621 21.4 Principles of Soundproofing 621 21.5 Sound Transmission Class and

Sound Reduction Index 624 21.6 Sound-absorbing Materials 624 21.7 Techniques used in Noise

Reduction/Mitigation 628 21.7.1 Planning of Buildings 628 21.7.2 Sound Insulation

of Walls 628 21.7.3 Sound Insulation

of Windows 630

21.7.4 Sound Insulation of Doors 631

21.7.5 Sound Insulation of Floors and Ceilings 631

21.8 Barriers and Noise Reduction at Source 633

22. Waterproofing and Damp-proofing Materials 636

22.1 Introduction 636 22.2 Causes and Effects of Dampness

in Building 636 22.2.1 Requirements of

Waterproofing Systems 637

22.3 Waterproofing Systems and their Applications 638

22.3.1 Bitumen Primer (IS 3384:1986) 638

22.4 Sheet Membranes 638 22.4.1 Bituminous Materials and

Membranes 639 22.4.2 Thermoplastic

Membranes 642 22.4.3 Elastomeric

Membranes 642 22.4.4 Liquid Applied

Membranes 643 22.5 Waterproofing Coatings 645 22.5.1 Bitumen-based Waterproof

Coating 646 22.5.2 Bitumen-based Polymer

Coating 646 22.5.3 Elastomeric Coating 646 22.5.4 Impregnating Polymer

Coatings 647 22.5.5 Epoxy Coating 647 22.5.6 Testing to Evaluate

Waterproof Coatings 648 22.6 Cementitious Waterproofing 648 22.6.1 Integral Waterproofing 648 22.6.2 Crystalline Admixtures 649 22.6.3 Repellent Type

Admixtures 649 22.6.4 Polymeric Modifiers 649 22.6.5 Redispersible Polymer

Powders 650 22.6.6 Water-soluble Polymers 650

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22.7 Bentonite Membrane Systems 650 22.8 Brickbat Coba with Lime 651 22.9 Damp-proofing of Walls and

Basements 651

23. Miscellaneous Materials 656 23.1 Introduction 656 23.2 Adhesives 656 23.2.1 Adhesives used in Timber

Constructions 657 23.2.2 Adhesives for Fixing Ceramic

Tiles and Mosaics 658 23.2.3 Adhesives for Joining

Concrete 658 23.3 Caulks and Sealants 658 23.4 Bamboo 660 23.5 Composite Materials 663 23.5.1 Concrete Canvas 665 23.6 Asbestos Cement Products 666 23.7 Nanomaterials 667 23.7.1 Graphene 669 23.8 Smart Materials 669 23.8.1 Shape-Memory Alloys 670 23.8.2 3D Printing of

Materials 670

24. Deformation and Fracture of Materials 674

24.1 Introduction 674 24.2 Types of Material Failures 674 24.2.1 Elastic and Plastic

Deformation 674 24.2.2 Tension Tests 676 24.2.3 Bending Test 678 24.2.4 Torsion Test 679 24.2.5 Quasi-brittle Fracture 680 24.3 Creep Deformation 680 24.3.1 Creep Testing 681 24.4 Fatigue under Cyclic Loading 682 24.5 Background to Fracture

Mechanics 683 24.5.1 Fracture Toughness Testing

– Different Materials 685 24.5.2 Structural Integrity

Assessment Procedure and Fracture Mechanics 686

25. Testing and Evaluation of Building Materials 688

25.1 Introduction 688 25.2 Sampling of Specimen 689 25.3 Tests Conducted on Stones 689 25.3.1 Simple Field Tests 690 25.3.2 Laboratory Tests 691 25.4 Tests for Burnt Clay Bricks 692 25.4.1 Compressive Strength 692 25.4.2 Water Absorption 692 25.4.3 Potential to

Efflorescence 693 25.4.4 Warpage 693 25.4.5 Dimensional Tolerance 693 25.4.6 Hardness, Soundness, and

Structure 694 25.5 Tests for Concrete Blocks 694 25.6 Tests for Building Limes 694 25.6.1 Field Tests 695 25.6.2 Laboratory Tests 696 25.7 Sampling and Testing of Cement 697 25.7.1 Methods of Sampling 698 25.7.2 Test for Fineness 698 25.7.3 Tests for Soundness 701 25.7.4 Test for Consistency 704 25.7.5 Test for Initial and

Final Setting using Vicat Apparatus 705

25.7.6 Test for Compressive Strength 706

25.7.7 Test for Tensile Strength 707 25.7.8 Test for Heat of

Hydration 707 25.7.9 Specific Gravity Test 710 25.7.10 Test Certificate from

Cement Manufacturer 711 25.8 Field Tests on Cement 711 25.9 Chemical Tests on Cement 712 25.9.1 Loss on Ignition 712 25.9.2 Silica 713 25.9.3 Sulphuric Anhydride 713 25.9.4 Insoluble Residue 714 25.9.5 X-Ray Fluorescence

Spectrometer Test 714 25.9.6 Atomic Absorption

Spectrophotometer Method 714

25.9.7 Calorimetric Analysis 715

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25.10 Tests for Aggregates 715 25.10.1 Flakiness and Elongation

Index 715 25.10.2 Limits of Deleterious

Materials 716 25.10.3 Specific Gravity, Density,

Voids, Absorption, and Bulking 718

25.10.4 Mechanical Properties: Aggregate Crushing Value, Impact Value, and Abrasion Value 719

25.10.5 Soundness of Aggregate 722 25.10.6 Mortar-making Properties of

Fine Aggregates 723 25.10.7 Alkali Aggregate

Reactivity 724 25.10.8 Petrographic

Examination 725 25.11 Tests for Mortars 725 25.11.1 Compression Strength 725 25.11.2 Consistency 726 25.11.3 Water Retention Test 726 25.11.4 Tensile Strength 728 25.11.5 Test for Adhesion 729 25.11.6 Test for Brickwork in

Compression 730 25.12 Tests on Fresh Concrete 731 25.12.1 Slump Test 731 25.12.2 Compacting

Factor Test 732 25.12.3 Vee-Bee Consistometer

Test 733 25.12.4 Flow Table Test 734 25.12.5 Kelly Ball Test 736 25.12.6 Other Tests on Freshly Mixed

Concrete 737 25.13 Tests on Hardened Concrete 737 25.13.1 Compression Tests (on

Cylinder/Cube or Core Samples) 737

25.13.2 Flexure Test (Equivalent Cube Method) 738

25.13.3 Split Tensile Strength Test 740

25.13.4 Testing for Elastic Modulus 740

25.14 Non-destructive Testing 742 25.14.1 Rebound Hammer Test 743 25.14.2 Ultrasonic Pulse Velocity

Test 745 25.14.3 Impact-echo Test 747 25.14.4 Maturity Method 748 25.14.5 Permeability Test 751 25.15 Partial Destructive Tests 753 25.15.1 Penetration Resistance

Method (Windsor Probe) 753

25.15.2 The Pullout Test 754 25.16 Sampling and Acceptance Criteria of

Concrete 755 25.17 Tests on Self-Compacting Concrete 757 25.18 Testing of Gypsum Products 759 25.19 Testing of Timber and Timber Products

759 25.19.1 Determination of Moisture

Content 759 25.20 Tests on Metals/Steel 760 25.20.1 Tension Test 760 25.20.2 The Charpy Impact test 763 25.20.3 Tests to Determine

Hardness 764 25.21 Testing for Quality of Glass 765 25.22 Testing of Clay Tiles 765 25.22.1 Water Absorption Test 765 25.22.2 Permeability Test 766 25.22.3 Test for Flexural

strength 766 25.22.4 Test for Breaking

Strength 766 25.22.5 Test for Impact

Resistance 767 25.22.6 Tests for Ceramic Tiles 767 25.23 Testing of Bitumen and Bitumen

Emulsions 768 25.23.1 Viscosity Test 768 25.23.2 Penetration Test 769 25.23.3 Softening Point Test 770 25.23.4 Ductility Test 770 25.24 Testing of Polymers 771 25.25 Tests on Composites 772

Bibliography 777 Index 782

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CHAPTER 1PROPERTIES OF BUILDING MATERIALS1.1 IntroductionIn the early societies, human beings lived in caves and almost certainly rested in the shade of trees. Gradually, they learnt to use naturally occurring materials such as stone, timber, mud, and biomass (e.g., leaves, grasses, and natural fibres) to construct houses, which was then followed by brick mak-ing, rope making, and glass and metal work (see Table 1.1). From these early beginnings, the modern materials–manufacturing industries developed.

The principal modern building materials are bricks, cement, concrete (e.g., mass, reinforced, and pre-stressed), timber, structural steel (in rolled and fabricated sections), aluminium, glass, paints, plastics, and ceramic products. All these materials have particular advantages in certain applications and hence the construction of a building may include various materials; for example, a commercial multi-storey

Table 1.1 Historical developments in building materials

Material PeriodMud, stones, and thatch 400,000 BC

Sun-dried bricks 7500 BC

Timber 5000 BC

Fired bricks 2000 BC (First appeared in the Middle East)

Lime 3000 BC

Glass 2500 BC (The Egyptians provided the first examples with silica and calcium.)

Iron 1350 BC

Lime–pozzolana cement 300 BC–AD 476 (Romans and Greeks)

Aluminium In 1808, it was discovered by English chemist Sir Humphrey Davy. In addition, the smelting process was discovered by Charles Martin Hall of the USA in 1886.

Portland cement Invented by Joseph Aspdin in 1824

Natural rubber A method of processing invented by Charles Goodyear in 1839

Steel In 1855, Sir Henry Bessemer invents the Bessemer process for the mass production of steel

Plastics In 1862, by Alexander Parkes at the 1862 Great International Exhibition in London

Stainless steel Invented by Henry Brearly in 1913

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Building Materials, Testing, and Sustainability2

building may have concrete/steel frame, infilled, and partition walls made of bricks or concrete blocks, wooden doors, and double-glazed windows of aluminium. The architect or design engineer has to think about the various alternatives and suggest a suitable material, which will satisfy economic, aesthetic, functional, and ecological/sustainability requirements.

Since construction is the largest consumer of natural materials, India was one of the first few coun-tries in the world to add a specific provision on environment protection in its Constitution, through the 42nd Amendment, during 1976. The Environment (Protection) Act, 1986 was introduced as an umbrella legislation that provides a holistic framework for the protection and improvement to the environment.

1.2 Functions of a BuildingThe major requirement of any building is to shelter its occupants from the environmental conditions and offer a pleasant, comfortable, and healthy indoor environment. Thus, a well-designed building will pro-vide good weather resistance (adequate resistance to rain and wind penetration), ample lighting, proper ventilation, adequate thermal insulation (to prevent heat loss to the environment in cool areas and heat gain in hot areas), low noise levels (to prevent airborne sound and impact sound from outside and pre-vent the passage of sound from one inner space to another inner space), have adequate strength and stability, privacy, security, and fire resistance (for the occupants to exit safely in the case of major fires), proper ingress and egress, good appearance, durability, and have reasonable cost. These requirements can be achieved by the proper selection of building materials and products. Proper site location, shape, orientation, and vegetation around the building may also help in obtaining better lighting and thermal performance (Reid, 1984).

1.3 Choosing Materials for ConstructionBuilding materials may be categorized based on the source of availability as natural and manufactured. They may also be classified as traditional and modern. The traditional building materials are generally the naturally occurring substances such as earth (e.g., clay, sand), stone and rocks, lime, and wood logs. Whereas, modern building materials include many artificial or manufactured synthetic and com-posite products such as bricks, lightweight concrete blocks, concrete, metals, glass, ceramics, plastics, and petroleum-based paints. The manufacture of building materials is an established industry, and the use of these materials is generally segmented into specific specialty trades such as concrete, masonry, carpentry, plumbing, roofing, electrical, mechanical, insulation, and HVAC (heating, ventilation, and air conditioning). In the countries like the USA, in order to work in these trades, one has to get certified by passing the Law and Business and the Trade Examinations.

For a material to be considered suitable for construction, it should have some essential engineering properties. These properties are broadly classified as follows:

1. Physical properties 2. Mechanical properties 3. Thermal properties 4. Chemical properties

5. Optical properties 6. Acoustical properties 7. Physiochemical properties 8. Metallurgical properties

These properties of building materials are responsible for its quality and capacity and will be useful while deciding the use of the material in different applications. Physical and mechanical properties, such as strength, porosity, etc., are generally considered while selecting a material for a particular use. Chemical properties are considered when the material is used in aggressive environments. Some of these properties are discussed in Sections 1.4–1.7. Before using the materials, they should be tested and eval-uated to ascertain whether the properties assumed in the design are actually available. For this purpose,



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Properties of Building Materials 3

samples are taken randomly (the number of samples tested is based on statistical analysis) and tested. The test methods, required equipment, and selection criteria are discussed in Chapter 25.

1.4 Physical PropertiesThe physical properties generally include the shape, size, density/bulk density, specific gravity, and porosity of the material.

Density (r) Density of a homogeneous material is defined as the mass per unit volume and expressed in kg/m3. Density is also called the unit weight of substance.

r = m

V (1.1)

where m = mass (kg) and V = volume (m3).

Bulk density (rb) This is defined as the mass per unit volume of material in its natural state (including

pores and voids), and expressed in kg/m3. It is calculated as:

rbb

m

V= (1.2)

where m = mass of specimen (kg) and Vb = volume of specimen in its natural state (m3).

For most of the materials, bulk density will be less than their densities; however, for liquids and materials like glass and dense stone materials, density and bulk density will not differ much. Bulk density represents the degree of compactness of material. Bulk density of a material depends upon the packing of particles, particle shape and size, moisture content, and grading. For example, in coarse aggregates, a higher bulk density indicates fewer voids that are to be filled by sand and cement in concrete.

Properties like strength and heat conductivity are greatly affected by their bulk density. Density and bulk density of some building materials are compared in Table 1.2.

Table 1.2 Comparison of density and bulk density of some building materials

Material Density (kg/m3) Bulk density (kg/m3)Brick 1920–2400 1600–1800

Granite 2600–2900 2500–2700

Wood (teak) 1500–1600 630–720

Steel 7750–8050 7850

Concrete 2400 2080–2400

Density index (r0) This is the ratio of bulk density of a material to its density and is expressed as:

rrr0 = =Bulk density

densityb (1.3)

It indicates the degree to which the volume of a material is filled with solid matter. For natural building materials, r

0 will be less than 1.0 because natural materials are not absolutely dense.

Specific weight (γ) This is also called unit weigh. This is the weight per unit volume of material in kN/m3, and is expressed as:

γ = rg (1.4)



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where, r = density of the material (kg/m3) and g = acceleration due to gravity (m/s2).Unit weight is used to determine the dead load of a structure in structural design. The unit weight of

water is 9.81 kN/m3 at 4°C.

Specific gravity or relative density (Gs) This is the ratio of the density of a substance to the density

of a reference substance, and is a dimensionless quantity. The reference substance is usually specified as water at 4°C. At this temperature, the density of water will be the highest at 981 kg/m3 (approximately taken as 1000 kg/m3). Hence, the specific gravity may be expressed as:

Gg

gss

w

s

w

s

w

= = =gg

rr

rr

(1.5)

True or absolute specific gravity (Ga) When both the permeable and impermeable voids are excluded

to determine the true volume of solids, the specific gravity is called true or absolute specific gravity and can be expressed as:

Ga

s a

w

=( )r

r (1.6)

The absolute specific gravity is not much used in practical applications.

Porosity (n) This is a measure of the void or empty spaces in a material, and is expressed as a ratio of the volume of voids (V

v) to the total volume (V), between 0 and 1, or as a percentage between 0 and 100%.

nV

Vv= (1.7)

Porous materials absorb more moisture. Porosity influences many properties like thermal conductivity, strength, bulk density, and durability. Porosity reduces the resistance to freezing, thawing, and abrasion. Rocks usually have porosity of less than 20%. Dense materials, which have low porosity, have to be used when high mechanical strength is required, whereas walls of buildings are commonly built with materials like bricks, which have considerable porosity.

Void ratio (e) This is defined as the ratio of volume of voids (Vv) to the volume of solids (V

s) in the

material.

eV

Vv

s

= (1.8)

The following relationship exists between void ratio and the porosity.

ne

e=

+1 (1.9)

Durability This is the ability of a material to perform its required function over a lengthy period under normal conditions of use without excessive expenditure on maintenance or repair.

It has to be noted that the strength and durability are two separate aspects: neither guarantees the other. Durability may be affected by a number of parameters. For example, the durability of reinforced concrete is affected by the following (Subramanian, 2013):

1. Environment 2. Temperature or humidity gradients 3. Abrasion and chemical attack

4. Permeability of concrete to the ingress of water, oxygen, carbon dioxide, chloride, sulphate and other deleterious substances



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5. Alkali-aggregate reaction (chemical attack within the concrete)

6. Chemical decomposition of hydrated cement 7. Corrosion of reinforcement 8. Concrete cover to the embedded steel

9. The quality and type of constituent materials 10. Cement content and water/cement ratio 11. Degree of compaction and curing of concrete 12. Shape and size of member 13. The presence of cracks

1.5 Mechanical PropertiesThe important mechanical properties of building materials are strength (compressive, tensile, bending, and impact), elasticity, plasticity, ductility, hardness, toughness, malleability, brittleness, fatigue, impact strength, abrasion resistance, creep resistance, and stiffness/flexibility.

Strength This is the ability of a material to resist stresses caused by the external forces (i.e., tension, compression, bending, torsion, and impact), without failure or fracture. It is of importance to note that materials such as stones and concrete have high compressive strength but low tensile, bending, and impact strengths (about 1/5 to 1/50th of compressive strength).

Ultimate strength This is the minimum guaranteed ultimate tensile strength at which a metal would fail, is obtained from a tensile test on a standard specimen, as described in Section 25.20.1 of Chapter 25. The stress–strain curve obtained from this test for various materials is shown in Fig. 1.1.

Compressive strength Compressive strength of concrete is found by testing standard cylinders (150 mm diameter and 300 mm long) or cubes (150 mm size) in compression testing machines, usually on the 28th day of casting them—cylinders have lower resistance than cubes of the same cross-sectional area. Properties such as modulus of elasticity, tensile strength, shear strength, and bond strength are usually expressed in terms of the compressive strength (see Subramanian, 2013, for more details).

Bending strength Tests of building strength on concrete are performed on small beams supported at their ends and subjected to one or two concentrated loads, which are gradually increased until failure takes place.

Hardness This is a measure of the resistance of the material to indentations and scratching. Several methods are available to determine the hardness of steel and other metals. In all these methods, an ‘ indenter’ is forced on the surface of the specimen. On removal, the size of indentation is measured using a microscope. Based on the size of the indentation, the hardness of the specimen is determined.

Elasticity This is the ability of a material to regain its original shape and size after removal of the external load. Ideally, elastic materials obey the Hooke’s law, which states that, within elastic limits, stress is directly proportional to strain. The ratio of unit stress to unit deformation is termed as the modulus of elasticity. A large value of it represents a material with very small deformation.

Plasticity This is the ability of a material to change its shape under load without cracking and retain its shape after the load is removed. Some of the examples of plastic materials are steel, copper, and hot bitumen.

Ductility This is the ability of a material (such as a metal or reinforced concrete) to undergo plastic deformation without fracture and is required for materials to resist earthquake loads. The lack of ductil-ity is often termed as brittleness. Cast iron, stone, and brick and plain concrete are comparatively brittle materials. Malleability is a similar property, and is the ability of material to deform under pressure (compressive stress), without rupture. If malleable, a material may be flattened by hammering or rolling. Copper is the most malleable building material.



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Creep This is defined as the deformation of structure under sustained load. More ma-terials will creep or flow to some extent and eventually fail under a sustained stress less than the short-time ultimate strength. For example, when load is applied on a con-crete specimen, it shows an instantaneous deformation followed by a slow increase of deformation over a period of time. Creep and long-time strength, at atmospheric temperatures, must sometimes be taken into account while designing the members of nonferrous metals and while selecting allowable stresses for wood, plastics, and concrete.

Stiffness This is a measure of the resist-ance offered by a member to deformation (k = F/d), and has a unit of Newton per me-ter (N/m). Stiff materials have high modulus of elasticity, hence, will result in small deformations for a given load. Stiffness is the reverse of flexibility.

Fatigue strength This is the highest stress that a material can withstand for a given number of cycles without breaking. A material has a tendency to fail at a lesser stress level when subjected to repeated load-ing, such as those occurring in steel bridges and cranes. Welding details also affect the fatigue strength.

Impact strength This is the capacity of the material to withstand a suddenly applied load, and expressed in terms of energy. It is often measured with the Izod impact strength test or the Charpy impact test, both of which measure the impact energy required to fracture a sample. It thus indicates the toughness of the material, which is the ability of a material to absorb energy when impacted. Stainless steels and titanium alloys are tough, whereas glass and ceramics are very fragile (opposite of tough). Hardness and toughness have an inverse relationship. For a particular solid, the toughness decreases when hardness increases.

1.6 Thermal PropertiesThe important thermal properties are thermal conductivity, thermal capacity, and fire resistance.

Thermal conductivity This is also called heat conductivity. This is the ability of a material to conduct heat, and is measured in Watts per metre-Kelvin [W/(m·K)]. It is influenced by the nature of material, its structure, porosity, character of pores, moisture content, and mean temperature at which heat exchange takes place. Higher the thermal conductivity, faster will be the heat transfer—it is usually measured by the U-value. Materials with large size pores have high heat conductivity because the air inside the pores enhances heat transfer. Moist materials have higher heat conductivity than dry materials. The lower the U-value of a material, the better will be its ability to resist heat conduction. This property is impor-tant while selecting insulating materials for walls of heated buildings, which should have negligible thermal conductivity. The reciprocal of thermal conductivity is called thermal resistivity. Designated as R (R-value), thermal resistance indicates how effective any material is as an insulator. A higher R-value indicates a better insulating performance. It has to be noted that U = 1/R and R = 1/U.

High strength steel

Ultimate tensile strength Mild steel

TimberCast iron200

400

600

800

1000

00 5 10 15

Strain (%)20 25 30

Stre

ss (M

Pa)

Upper yieldstrength

Unloading behaviour

Aluminium alloy

Ultimate tensile strength

Fig. 1.1 Typical tensile stress–strain curves for some structural materials



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Thermal capacity This may be defined as the ability of a material to store heat per unit volume, and is measured by the product of density and specific heat, with units of Joule per Kelvin (J/K). When a material shows greater thermal capacity, it shows that it can store more heat in a given volume for every degree of increase in temperature. Specific heat is a measure of the amount of heat required to raise the temperature of given mass of material by 1° [measured in J/(kg.K)]. It takes less energy input to raise the temperature of a low specific heat material than that of a high specific heat material. For example, it requires one calorie of heat energy to increase the temperature of water by 1°C. As water has a high heat capacity, it is sometimes used as thermal mass in buildings. Generally, materials with higher thermal capacity can reduce heat flow from the outside to the inside of buildings by storing the heat within the material. Thus, by using a material of adequate thermal capacity, the heat (produced by the Sun) entering a wall during the daytime could be stored within the wall itself for several hours, and conveniently made to flow out during the cool night hours. Table 1.3 shows the typical thermal properties of some building materials.

Table 1.3 Thermal properties of some building materials

Material Modulus of elasticity, E (GPa)

Poisson’s ratio

Coefficient of thermal expansion, α (×10−6/°C)

Thermal conductivity, λa(W/mK)

Specific heat capacity, ca (J/kg · K)

Aluminium alloys 72 0.33 23.5 56–205 900

Concrete (M30) 27.4 0.15–0.25 11 0.8–1.40 840–880

Copper 118 0.33 17.6 385 386

Glass 70 0.24 9.0 0.8–1.0 840

Iron (grey cast) 90 0.26 12.1 79.5 448

Structural steel 200–207 0.30 11–12 54 425

Stainless steel 193 0.30 16 14.6 450

Fire resistance This is the ability of a material to resist the action of high temperature without any appreciable deformation and loss of strength. While a fire-resistant material is one that is designed to resist burning and withstand heat, fire-retardant materials are designed to burn slowly. Some exam-ples of fire-retardant materials are: fire-retardant treated wood, brick, concrete, mineral wool, gypsum boards, and intumescent paint. Steel suffers considerable deformation and loss of strength under the action of high temperature. Refractoriness denotes the ability of a material to withstand the prolonged action of high temperature of about 1580°C without melting or losing shape.

1.7 Other PropertiesChemical properties include corrosion resistance, chemical composition, acidity, or alkalinity. Optical properties include the colour, light reflection, and light transmission. Acoustical properties comprise sound absorption, transmission, and reflection. Physiochemical properties include hygroscopicity and water absorption. Useful in construction, metallurgical properties are metal fusibility, weldability, hardening, and tempering. Some of these properties are briefly described here.

Chemical resistance This is the capacity of any material to resist the deteriorating action of substance such as harmful acids, alkalis, seawater, and gases. For example, natural stones such as limestone, marble, and dolomite are affected even by weak acids, wood has low resistance to acids and alkalis, and bitumen disintegrates due to alkaline liquids.



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Hygroscopicity It is the property of a material to absorb water vapour from air, resulting in volume change (shrinkage or swelling). It is influenced by air temperature and relative humidity, and types, number and size of pores. Wood, concrete, brick, plaster, and several engineering polymers are hygroscopic, including nylon, polycarbonate, cellulose, and poly (methyl methacrylate). Hydrophobic materials are the opposites of hygroscopic materials and repel water; their typical examples include glass, metals, and plastics.

Water absorption This denotes the ability of the material to absorb and retain water. It is expressed as percentage in weight or of the volume of dry material:

WM M

Mw =-

¥1 100 (1.10a)

WM M

Vv =-

¥1 100 (1.10b)

where M1 = mass of saturated material (g), M = mass of dry material (g), and V = volume of material

including the pores (mm3). Water absorption by volume is always less than 100%, whereas that by the weight of porous material may exceed 100%.

The properties of building materials can change considerably when saturated. The water resistance of a material is expressed by the coefficient of softening, which is the ratio of compressive strength in water-saturated condition to that in dry condition. For example, the coefficient of softening for clay is zero, as it soaks readily in water. However, for materials like glass and metals, which are not affected by water, it is taken as one. In locations exposed to moisture (like roofing or foundations), materials with the coefficient of softening less than 0.8 should not be used.

Corrosion resistance Formation of rust (iron oxide) in metals, when they are subjected to atmos-phere, is called corrosion, and is a recurring problem in steel structures and steel reinforcements. To mit-igate corrosion in steel structures, several methods are applied such as treatment of the environment to render it non-corrosive, coating/painting systems (surface preparation, such as sand blasting, plays an important role in the durability), galvanizing, thermal (metal) spraying, cathodic protection, and use of corrosion-resistant structural steels (e.g., weathering steel and stainless steel). For reinforcements in concrete, cathodic protection, corrosion-inhibiting admixtures, or the use of thermo-mechanically treated corrosion-resistant steel bars (TMT-CRS bars), fusion-bonded epoxy-coated rebars, galvanized rebars, stainless steel rebars, fibre-reinforced polymer bars, and basalt bars may be used.

Metallurgical, acoustical, and optical properties are discussed in detail in the relevant chapters. Properties of some materials used in building construction are given in Table 1.4.

Table 1.4 Properties of some materials used in building construction

Material Density, kg/m3

Stiffness (E), GPa

Poisson’s ratio

Strength1, MPa

Fracture toughness, MN/m3/2

Clay bricks 1480–2400 14–18 – 5–110 (compression) 0.6

Timber2 170–980 (dry) 3–21 0.25–0.49 10–80 (tension)15–90 (compression)

7–13

Structural steel 7850 195–205 0.3 235–960 50–100

Cast iron 6900–7800 170 0.26 220–1000 20–50

High strength steel 7850 205 0.3 500–1900 50–125

Aluminium alloys 2700 70 0.33 80–505 25–35

(Contd)



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Material Density, kg/m3

Stiffness (E), GPa

Poisson’s ratio

Strength1, MPa

Fracture toughness, MN/m3/2

Concrete (M20–M100) 1800–2500 22–50 0.15–0.25 2–12 (tension)20–100 (compression)

0.8–1.2

Glass 2500 70 0.24 40–703 0.8

Rubber 830–910 0.1–1 0.5 15–30 –

Polyethylene (high-density)

960 1.1 0.4–0.45 20–30 2.5

Glass fibre composite 1400–2000 6–50 – 40–12504 7–23

Carbon fibre composite 1500–1600 70–200 – 600–20004 6–80

Epoxy resin 1100–1400 2.6–3 – 30–100 0.5–1

1. In tension unless stated, yield or proof strength for metals, ultimate strength for other materials2. Based on tests on small specimens, loaded parallel to grain3. Modulus of rupture4. In the longitudinal direction

1.8 Sustainable MaterialsThe definition of sustainability, suggested by the then Prime Minister of Norway, Gro Bruntland, in 1987, is meeting the needs of the present without compromising the ability of future generations to meet their needs. Sustainability is thus is a realization that today’s population is merely borrowing resources and environmental conditions from future generations. The greatest threats to the sustainable develop-ment on earth are as follows:

1. Population growth and urbanization 2. Energy use and global warming 3. Excessive waste generation and the subsequent pollution of soil, air, and water 4. Transportation in cities 5. Limited supply of resources

Many of them are interrelated and discussed in the work of Subramanian (2016).The materials we use for construction affect the environment. Their production and transportation

deplete natural resources, consume considerable energy, and pollute the environment. Several building materials, and the energy needed to produce them, are becoming scarce. If the present trends continue, some of the common raw materials and energy sources (like oil and natural gas) will be exhausted with-in about the next century. As per www.msci.org, the grades of mined copper and iron ore are declining and the natural reserves of lead, molybdenum, chromium, nickel, copper, zinc, tin, and radium are depleting. There is an urgent need to use alternate materials—for example, using M-sand in the place of natural sand—to preserve natural resources.

A reclassification of all building materials and products based on sustainability, and to meet cri-teria pertaining to personal health and health of environment, is necessary. Traditional materials like clay, lime, and stone are still abound, and timber (especially softwoods) can be replenished by prop-erly managed forestation. In addition, these materials can be easily reused or recycled; they produce little or no pollution and are reabsorbed into the natural cycles of environment, when they are dis-carded. Recycling materials like steel and aluminium also preserves the natural resources and saves considerable energy.

Table 1.4 (Contd)



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1.8.1 Healthy MaterialsIn order to satisfy the criteria of being healthy to human beings, Pearson (1998) has suggested the following:

1. The materials should be clean and should not contain pollutants or toxins, emit no biologically harmful vapours, dust, particles or be odours either during manufacture or usage. They should also be resistant to bacteria, viruses, moulds, and other harmful microorganisms.

2. They should not be radioactive and must not emit any harmful levels of radiation. 3. They should not be electromagnetic and should not allow the conduction or built-up of static

electricity or emit harmful electric fields of any type. 4. They should have good sound-reduction properties and should not themselves produce any noise.

1.8.2 Ecological MaterialsFor materials to be environment friendly, they should satisfy the following criteria (Pearson, 1998):

1. They should be renewable and abundant, and coming from diverse natural sources. Their production should have a low impact on the environment.

2. They should be non-polluting and should not emit harmful vapours, particles, or toxins into the environment, either during manufacture or usage.

3. They should be energy efficient, and use low energy in production, transport and should generally be available locally (see also Section 1.8).

4. They should be durable and easy to maintain and repair—additionally, it is better if they are tried and tested over several generations, as in the case of natural materials.

5. They should produce less waste during production and be capable of being reused and recycled, so that the vast amount of energy spent on processing raw materials could be saved.

Many countries now have a system of labelling environment-friendly products. In the USA, since 1989, a non-profit organi-zation called Green Seal identifies prod-ucts and services that have less impact on our health and environment and awards a ‘Green Seal’ as shown in Fig. 1.2 (www .greenseal.org). Similar 28 international eco-labelling programmes exist, including

Germany’s Blue Angel, the European Union’s Ecolabel, and the Nordic Swan, and all are members of the Global Eco- labelling Network (GEN).

1.9 Green Building Rating SystemsTo promote the design and construction practices that reduce the negative environmental impacts of buildings and improve occupant health and well-being, the US Green Building Council (USGBC), a Washington D.C.-based non-profit coalition of building industry leaders, developed the LEED® green building rating system in 1993. In the USA and in a number of other countries around the world, LEED® certification is the recognized standard for measuring building sustainability. Similar assess-ment systems are available in other countries also. Some of these are

1. the British green building rating system developed by Building Research Establishment (BRE) in 1992 called the Building Research Establishment Environmental Assessment Method (BREEAM),

2. Griha in India ([email protected]),

Fig 1.2 Green Seal and EU Ecolabel



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3. the comprehensive Assessment System for Building Environmental Efficiency (CASBEE) of Japan, 4. Green Star of Australia, and 5. Green Globes, which is a web-based, interactive learning tool developed from BREEAM to the

needs of US commercial buildings.

All these systems are designed to encourage the construction of green buildings, which will minimize the disruption of local ecosystems; ensure the efficient use of water, energy, and other natural resources; and ensure a healthy indoor environment. However, they differ in terminology, structure, assessment of performance, points assigned to different performance criteria, and documentation required for the certification. These systems, while voluntary in nature, continue to gain recognition. It is interesting to note that adoption of these systems also results in economic incentives, as owners and renters are increasingly demanding facilities with high green building ratings.

1.9.1 LEED-NC From 1994 to 2009, LEED® grew from one standard for new construction to a comprehensive system of six interrelated standards covering all aspects of the development and construction process: LEED-NC, for New Construction; LEED-EB, for Existing Buildings; LEED-CI, for Commercial Interiors; LEED-H, for Homes; LEED-CS, for Core and Shell projects; and LEED-ND for Neighbourhood Development (Kibert, 2005). LEED-NC, which was originally developed for office buildings but is now being used for all types of buildings except single family homes, is briefly discussed here.

LEED-NC 2009 is structured with eight prerequisites and a maximum of 110 points. These points are divided into the following seven major categories:

1. Energy and atmosphere (35 maximum points) 2. Indoor environmental quality (15 points) 3. Sustainable sites (26 points) 4. Materials and resources (14 points)

5. Water efficiency (10 points) 6. Innovation and design process (6 points) 7. Regional priority (4 points)

A building is LEED® certified if it obtains at least 40–49 points. Silver, gold, and platinum levels are awarded for 50–59, 60–79, and greater than 80 points, respectively (see Table 1.5). Note that LEED is continuously evolving and improving. The recent update to the rating system LEED-NC 4.0 was launched in 2014. LEED-NC 4.0 has the following six main credit categories (Subramanian, 2017):

1. Location & Transportation (LT) 2. Sustainable Sites (SS) 3. Water Efficiency (WE) 4. Energy & Atmosphere (EA)

5. Materials & Resources (MR) 6. Indoor Environmental Quality (EQ) 7. Innovation and Design Process 8. Regional Priority

Table 1.5 Overview of LEED-V4 categories and credits

Integrative Process: 1 Possible PointLocation and Transportation: 16 Possible Points Required

Credit 1 Sensitive Land Protection 1

Credit 2 High Priority Site 2

Credit 3 Surrounding Density and Diverse Uses 5

Credit 4 Access to Quality Transit 5

Credit 5 Bicycle Facilities 1

Credit 6 Reduced Parking Footprint 1

Credit 7 Green Vehicles 1

(Contd)



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Sustainable Sites: 10 Possible PointsPrerequisite 1 Construction Activity: Pollution Prevention Required

Credit 1 Site Assessment 1

Credit 2 Site Development - Protect or Restore Habitat 2

Credit 3 Open Space 1

Credit 4 Rainwater Management 3

Credit 5 Heat Island Reduction 2

Credit 6 Light Pollution Reduction 1

Water Efficiency: 11 Possible PointsPrerequisite 1 Outdoor Water Use Reduction Required

Prerequisite 2 Indoor Water Use Reduction Required

Prerequisite 3 Building-Level Water Metering Required

Credit 1 Outdoor Water Use Reduction 2

Credit 2 Indoor Water Use Reduction 6

Credit 3 Cooling Tower Water Use 2

Credit 4 Water Metering 1

Energy and Atmosphere: 33 Possible PointsPrerequisite 1 Fundamental Commissioning and Verification Required

Prerequisite 2 Minimum Energy Performance Required

Prerequisite 3 Building-level Energy Metering Required

Prerequisite 4 Fundamental Refrigerant Management Required

Credit 1 Enhanced Commissioning 6

Credit 2 Optimize Energy Performance 18

Credit 3 Advanced Energy Metering 1

Credit 4 Demand Response 2

Credit 5 Renewable Energy Production 3

Credit 6 Enhanced Refrigerant Management 1

Credit 6 Green Power and Carbon Offsets 2

Materials and Resources: 13 Possible PointsPrerequisite 1 Storage & Collection of Recyclables Required

Prerequisite 2 Construction & Demolition Waste Management Planning Required

Credit 1 Building Life-Cycle Impact Reduction 5

Credit 2 Building Product Disclosure & Optimization - Environmental Product Declarations 2

Credit 3 Building Product Disclosure and Optimization - Sourcing of Raw Materials 2

Credit 4 Building Product Disclosure & Optimization - Material Ingredients 2

Credit 5 Construction & Demolition Waste Management 2

Indoor Environmental Quality: 15 Possible PointsPrerequisite 1 Minimum IAQ Performance Required

Prerequisite 2 Environmental Tobacco Smoke (ETS) Control Required

Table 1.5 (Contd)

(Contd)



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Credit 1 Enhanced Indoor Air Quality Strategies 2

Credit 2 Low-emitting Materials 3

Credit 3 Construction Indoor Air Quality Management Plan 1

Credit 4 Indoor Air Quality Assessment 2

Credit 5 Thermal Comfort 1

Credit 6 Interior Lighting 2

Credit 7 Daylight 3

Credit 8 Quality Views 1

Credit 9 Acoustic Performance 1

Innovation and Design Process: 6 Possible PointsCredit 1 Innovation in Design 5

Credit 2 LEED® Accredited Professional 1

Regional Priority: 4 Possible PointsCredit 1 Regional Priority 1–4

Project Total: 100 base points; 6 possible Innovation in Design and 4 Regional Priority points

Certified: 40–49 Points; Silver: 50–59 Points; Gold: 60–79 Points; Platinum: > 80 Points

(Source: www.usgbc.org)

Figure 1.3 shows the views of a LEED Platinum certified building in Rockville, MD, USA.

Fig. 1.3 Views of the LEED Platinum certified building in Rockville, MD, USA

A part of the Confederation of Indian Industry (CII), the Indian Green Building Council’s (IGBC) Green Building rating systems were launched in 2003. CII–Sohrabji Godrej Green Business Centre building in Hyderabad was the first to receive the prestigious Platinum rated green building rating in India (see Fig. 1.4). Since then, the rating systems have been successfully applied to more than 4025 buildings, with a foot-print of 4.50 billion square feet. It is given under the following 16 different categories (https://igbc.in):

1. IGBC Green New Buildings 2. IGBC Existing Buildings 3. IGBC Green Homes 4. IGBC Green Residential Societies 5. IGBC Green Healthcare

6. IGBC Green Schools 7. IGBC Green Factory Buildings 8. IGBC Green Data Centres 9. IGBC Green Campus 10. IGBC Green Villages

Table 1.5 (Contd)



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11. IGBC Green Townships 12. IGBC Green Cities 13. IGBC Green SEZ 14. IGBC Green Landscapes

15. IGBC Green Mass Rapid Transit System

16. IGBC Green Existing Mass Rapid Transit System

The task of selecting building materials and products, for a high-performance green building, is the most difficult and challenging task for any design team. Several tools are available for this process and one best tool is the life-cycle assessment (LCA). LCA provides information about the resources, emis-sions, and other impacts resulting from the life cycle of material use. Hence, one must consider the impact of the material from extraction to disposal. One such LCA programme is Building for Environmental and Economic Sustainability software (BEES-NIST). Ideally, the material cycle should be a closed looped and waste free. Thus, the following rules apply while selecting the materials for green construction:

Fig. 1.4 Platinum-rated CII–Sohrabji Godrej Green Business Centre, Hyderabad (Source: CII–IGBC)

1. They should consume least energy to manufacture. 2. They should not involve long-distance transportation (for the raw materials as well as finished

product). 3. The natural resources and raw materials do not affect the environment. 4. They must be easy to recycle and safe to dispose in landfills. 5. Materials should be harmless in production and use. 6. Materials dissipated from recycling must be harmless. 7. They should have long life and durability. 8. Buildings must be de-constructible. 9. Building components must be easy to disassemble.

It may be difficult to identify a material that obeys all the aforementioned rules. Especially, the last rule of disassembly has not been considered in traditional building materials, except prefabricated steel structures. Disassembly also discourages the use of composite materials. It has been shown that by using concrete, one can earn 37–62 LEED® points (see Table 1.6).



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Table 1.6 Summary of possible points to increase LEED ratings of buildings

Category Total number of points Points earned using concreteSustainable sites 26 12

Water efficiency 10 10

Energy and atmosphere 35 1–19

Materials and resources 14 9

Indoor environmental quality 15 2

Innovation credits 6 2–6

Regional priority 4 1–4

Total 110 37–62

(Source: Adapted from RMC-Guide, 2010)

Green buildings adopt various strategies for water management: using low flow or ultra-low flow plumbing fixtures, electronic controls and fixtures, substitution of alternative water sources (rain-water, reclaimed water, and grey water) for potable water, rainwater harvesting, xeriscaping, and use of other technologies and approaches that result in the reduction of potable water consumption (Kibert, 2005).

1.10 Embodied Energy and Energy EfficiencyEnergy from fossil fuels is becoming scarce and the amount used in the production and transportation is high. As mentioned earlier, the best materials are those which are energy efficient (using low energy in production, transport, and use), need minimum processing and are available locally. Embodied energy refers to the total energy consumed in the acquisition and processing of materials, including manufac-turing, transportation, and final installation. Products with greater embodied energy usually have higher environmental impact due to the greenhouse gas emissions associated with their energy consumption. However, a true indicator of environmental impact will be obtained, only when the embodied energy is divided by the number of times the product is used or recycled. Thus, aluminium may have low embod-ied energy per time in use, as it is very durable. Similarly, recycled aluminium and steel have less than 10–20% of embodied energy, compared to original steel or aluminium made from ores.

Typical embodied energy of some common building materials is shown in Table 1.7. From this, it is seen that the embodied energy of locally grown and reclaimed timber is low (Haseltine, 1975). Clay used as adobe or unbaked brick is another example of material requiring low energy. In contrast, synthetic and processed products such as plastics, aluminium, steel, glass, and oven-fired bricks and clay tiles, have higher embodied energy (Pearson, 1998). In addition, the materials used should be good energy conserv-ers with high insulation value that should retain heat in winter and keep the building cool in summer.

Table 1.7 Embodied energy of common building materials (http://www.yourhome.gov.au)

Material Embodied energy (MJ/kg)

Very high energyAluminium 227.0

Carpet (synthetic) 148.0

Polystyrene insulation 117.0

Synthetic rubber 110.0

(Contd)



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Material Embodied energy (MJ/kg)

Very high energyLinoleum 116.0

Stainless steel 100+

Plastics (general) 90.0

PVC (polyvinyl chloride) 80.0

Copper 70–100

Acrylic paint 61.5

Zinc 51.0

High energySteel 32.0

Galvanized steel 38.0

Hardboard 24.2

Glass 12.7

Glue-laminated timber 11.0

Plywood 10.4

Cement 5.6

Steel (recycled) 8.9

Aluminium (recycled) 8.1

Particleboard 8.0

Medium energyAutoclaved aerated concrete (AAC) 3.6

Kiln dried sawn softwood 3.4

Lime 3-5

Gypsum plaster 2.9

Clay bricks and tiles 2.5

Lumber 2.5

Kiln dried sawn hardwood 2.0

Precast steam-cured concrete 2.0

Concrete (30 MPa) 1.3

Concrete blocks 1.5

Low energyStabilized earth 0.7

Fly ash, rice husk ash (RHA), volcanic ash <0.5

Sand, aggregate 0.1

These figures should be used with caution because:1. The actual embodied energy of a material manufactured and used in one location may be very different from the same

material transported by road to another location.2. Though materials like stainless steel have high embodied energy value, they are recycled many times, reducing their

life cycle impact.

Table 1.7 (Contd)



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As discussed in Section 1.8, it is not enough to consider the energy requirement of material dur-ing the production stage; a life-cycle assessment approach is necessary to determine its environmental impact. Thus, all stages in the life of a product should be analysed, that is, raw material acquisition, manufacture, transportation, installation, use, recycling, and waste management. There is also a Life-cycle Cost Analysis (LCCA), which deals with the cost impact of a product or material, but does not deal with the environmental impact. Both have important roles to play in sustainability assessment of a material/product.

1.11 Comparison of some Major Building MaterialsThough the various building materials are covered individually in the subsequent chapters, the four major building materials, which are used extensively, are briefly discussed here.

Masonry Masonry may be defined as the work done by masons using individual units, which are often laid in and bound together by mortar; the term masonry can also refer to the units themselves. The common materials of masonry construction are brick, stone, concrete block, glass block, and cob (made of soil, water, straw, and sometimes with lime).

Some important features include:

1. Different types of bricks and concrete blocks exist (see Chapter 3). The process of manufacturing of bricks from clay involves preparation of clay, moulding, and then drying and burning of bricks in kilns, at temperature of about 1100°C, to give them their final hardness and appearance.

2. The vertical shaft brick kiln (VSBK) technology, which consumes less fuel and energy and emits lower suspended particulate matter (SPM), as compared with Bull’s Trench Kiln (BTK), is suitable for medium sized kilns. VSBK technology was introduced during 1996; at present, there are more than 40 operational VSBKs in India (www.teriin.org).

3. Masonry is mainly used for load bearing walls and walls taking in-plane or transverse loads. It is durable, fire resistant, and aesthetically pleasing. It can be used for buildings with moderate heights, that is, up to 20 storeys. (Unfortunately, the bricks produced in India do not have uniform quality and the bricks produced in south India have low strength. Hence, buildings with load-bearing brick masonry are built only up to three to four floors).

Reinforced and prestressed concrete Concrete is a composite material made of two or more sizes of aggregates (generally with gravel and sand), with a binding medium of Portland cement and water. After mixing, it is placed into moulds (called formwork) with proper compaction, and after proper curing, the cement hydrates and eventually hardens into a stone-like material. The following are some of its features:

1. As concrete is weak in tension, it is usually strengthened with steel bars (known as reinforcement or rebars). This strengthened concrete is called as reinforced concrete or RCC.

2. Currently, concrete is the predominant building material in India and several other countries. Reinforced concrete framed or shear wall construction, if properly poured and cured, is very dura-ble and fire resistant.

3. Since reinforced concrete can be cast to any required shape, it is used for a variety of constructions including tall buildings and floors and foundation of all types of buildings.

4. Substitution of cement by several wastes such as fly ash, ground-granulated blast furnace slag, silica fume, reactive rice-husk ash, etc., can lead to significant reductions in the amount of cement needed to make concrete, hence reduces emissions of CO

2 and consumption of energy and raw materials,

and results in reduced landfill/disposal burdens.



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5. Recent advancements such as self-compacting concrete (SCC), though having more binder content, reduce manpower, as SCC is easier to place even in congested structural members, has reduced noise level, and is environment friendly.

Prestressed concrete is a concrete in which high strength reinforcing steel bars are stretched and anchored to compress it, thus increasing its resistance to stress. It is used for floor construction of large span structures and in buildings, bridges, and towers.

Some of the shortcomings are as follows:

1. In India, though concrete is used extensively in all types of construction, except by a small number of big companies, quality control is not exercised during mixing of concrete.

2. Moreover, the curing of concrete is mostly ignored or not done properly for the code prescribed duration.

3. In addition, the steel reinforcements (especially the smaller diameter rods) available in the market are produced by re-rollers and do not possess the required ductility and strength.

4. Since concrete can be mixed and poured to any required shape, it is misused by several small con-tractors, who do not give much importance to design or detailing.

The aforementioned factors have led to the deterioration of several concrete structures all over the country and resulted in the failure of several concrete structures in the recent earthquakes. Since prestressed concrete is used in major constructions, as well as used by major contracting companies, the quality of prestressed concrete in India is up to the standards.

Structural steel Most metals used for construction purposes are alloys. For example, structural steel is a primary alloy of iron and carbon (0.10–0.25%). The properties of steel vary widely, depending on its alloying elements. Some of its features are as follows:

1. Steel is made using the basic oxygen steel making (BOS) process or the electric arc method. 2. Raw materials such as iron ore, scrap steel, coke, limestone, and dolomite are charged in a blast

furnace, and heated up to 1600°C, and oxygen of greater than 99.5% purity is blown into the mix. 3. The liquid steel is solidified into large blocks called ingots and then rolled into semi-finished prod-

ucts and then into plates, structural shapes, bars, etc. 4. The main advantages of steel are strength, speed of erection, prefabrication, and demountability. 5. They are used in load-bearing frames in buildings, and as members in trusses, bridges, and space

frames. Steel, however, requires fire and corrosion protection. 6. Steel is also used in conjunction with concrete in composite constructions and in combined frame

and shear-wall constructions. 7. In many cases, the fabrication of steel members is done in the workshop and the members are then

transported to the site and assembled. 8. Tolerances specified for steel fabrication and erections are small compared to reinforced concrete

structures. 9. Different steel sections are joined by welding or bolting. Welding or tightening of high strength

friction grip bolts requires proper training. 10. Due to these factors, steel structures are often handled by trained persons and assembled with

proper care, resulting in structures with better quality. 11. Compared with concrete, steel offers much better compressive and tensile strength, and enables

lighter constructions. Unlike masonry or reinforced concrete, steel can be easily recycled.

Wood This imparts natural, human warmth that steel and concrete lack. Due to this, wood has long been used for housing (up to three floors) and for historical structures in western countries such as the



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USA, the UK, Germany, France, and Japan where there is cold climate. However, with the development of wood composites—thin, pressed sheets—combined with joints and steel frames have changed the scene. Glued laminated wood has been used in a number of large span structures. Prominent wood com-posite structures are Tacoma Dome and North Michigan University stadium in the United States and Odate Jukai Dome in Japan. All these domes have diameters in the range of 160–180 m. Since wood is a natural product, it is environment friendly, though the resins used in glued laminated wood many contain harmful chemicals. However, not all woods can be used for constructions and quality wood is in short supply in India and hence wood is used in India only for doors and windows. (Nowadays, even they are replaced with aluminium, steel, ferrocement, or plastic doors and windows.)

Important structural properties of steel, concrete, and wood are compared in Table 1.8.

Table 1.8 Important properties of steel, concrete, and wood

Item Mild steel Concrete*M20 grade

Wood

Unit mass, kg/m3 7850 (100) 2400 (31)# 290–900 (4–11)

Maximum stress in MPa CompressionTensionShear

250 (100)250 (100)144 (100)

20 (8)3.13 (1)2.8 (1.9)

5.2–23+ (2–9)2.5–13.8 (1–5)0.6–2.6 (0.4–1.8)

Young’s modulus, MPa 2 × 105 (100) 22,360 (11) 4600–18,000 (2–9)

Coefficient of linear expansion × 10–6/oC 12 10 to 14 4.5

Poisson’s ratio 0.3 0.20 0.20

* Characteristic compressive strength of 150 mm cubes at 28 days+ Parallel to grain# Relative value when compared to steel

1.12 Alternative Building MaterialsA number of industrial, agricultural, and mining wastes are used in the production of alternative build-ing materials (Venkatarama Reddy, 2004). The industrial wastes include: fly ash, phosphogypsum, blast furnace slag, silica fume, alumina red mud, slate and marble waste, glass powder, paper-mill pulp, sludge, and discarded tires. Fly ash is used in the production of Portland-pozzolana cement, lime-fly ash bricks, fly ash-lime-gypsum (Fal-G) concrete, fly ash-lime cellular concrete, and sintered fly ash lightweight aggregate. However, the response by the Indian building community to the use of fly ash is poor, as only 5% of generated fly ash is used in India. It has to be noted that not all the available fly ash is suitable for use in concrete and other products.

Calcium silicate bricks are manufactured from a mixture of sand and/or siliceous waste and a small portion of lime, which is mechanically pressed and autoclaved. These bricks can also solve the problem of waste disposal.

The agricultural wastes that could be used in building products such as roofing units, thermal insu-lating materials, and walling boards are bagasse, jute stalks, groundnut hulls, hemp, flax, reed, natural wool, expanded cork, and straw bales. Rice husk ash, saw dust, cork granules, and coconut kernel are used as substitutes in concrete.

In addition, several substitutes for teak, rosewood, and white cedar, such as secondary species of timber, poly-vinyl chloride (PVC), mild steel and galvanized steel, aluminium, precast concrete, fer-rocement, particle boards, fibre boards, fibre glass, and glass reinforced gypsum composite boards, have been tried. The use of some of these waste products and other substitutes as building materials are discussed in the respective chapters (3, 5–7, 9, and 11).



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1.13 Building Codes and By-LawsA building code contains a set of rules that knowledgeable people recommend for others to follow. It is not a law, but can be adopted into law. National building codes contain administrative regula-tions, development control rules, and general building requirements; fire safety requirements, stipula-tion regarding materials, structural design and construction, building and plumbing services, landscape development, guidelines for sustainability, asset and facility management, and other aspects of build-ings to ensure safety and health for people living in or around buildings (see SP 7-2016, SP 21:2005, SP 41-1987, IS 3362:1977, IS 3792:1978, and IS 6060:1971). They are mandatory in nature and serve to protect buildings against fire, earthquake, noise, structural failures, and other hazards (IS 1641:1988, IS 1950:1962, and IS 2526:1963). Building by-laws usually contain provisions for parking, peripheral open spaces including set-backs, disaster management, and fire safety. They may also contain green building and sustainability provisions, rainwater harvesting, wastewater reuse, and recycle and instal-lation of solar roof-top photovoltaic (PV) norms. Recent by-laws also have guidelines for mitigating electromagnetic radiations (Model Building Bye-Laws, 2016).

In addition, the Energy Conservation Building Code (ECBC) was launched by the Ministry of Power, Government of India in May 2007, as a first step towards promoting energy efficiency in the building sector (ECBC, 2006). The ECBC provides design norms for:

1. Building envelope, including thermal performance requirements for walls, roofs, and windows; 2. Lighting system, including day lighting, and lamps and luminary performance requirements; 3. HVAC system, including energy performance of chillers and air distribution systems; 4. Electrical system; and 5. Water heating and pumping systems, including requirements for solar hot-water systems.

SUMMARY

• The major requirement of any building is to shelter its occupants from the environment and offer a pleasant, comfort-able, and healthy indoor environment.

• Building materials are categorized based on the source of availability as natural (e.g., clay, sand, stone, lime, and wood logs) and manufactured (e.g., concrete, metals, glass, ceramics, and plastics).

• The different properties which are of concern are physical, mechanical, thermal, chemical, optical, acoustical, phys-iochemical, and metallurgical.

• The physical properties include the shape, size, density/bulk density, specific gravity, and porosity of the material. • The important mechanical properties are strength, elasticity, plasticity, ductility, hardness, toughness, malleability,

brittleness, fatigue, impact strength, abrasion resistance, creep resistance, and stiffness/flexibility.• Production and transportation of building materials deplete natural resources, consume considerable energy, and pol-

lute the environment. Several materials are also becoming scarce. • In order to have sustainable development, it is important to preserve these materials, by reducing their use (by using

alternative materials), recycling them after use, or reusing them. In addition, the materials used should be environment friendly and not affect the health of the occupants. A number of industrial, agricultural, and mining wastes are now used to provide alternative building materials.

• Several rating systems have been developed, such as LEED, BREEAM, Green Globes, and CASBEE. For a building to be LEED® certified, it should obtain at least 40–49 points.

• Embodied energy is the total energy consumed in the mining, manufacturing, transportation, and final installation. Products with greater embodied energy have higher environmental impact.

• A building code, like the NBC of India, contains a set of rules that should be followed to have better functioning.



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EXERCISES

Multiple-choice Questions 1. Density of concrete is about

(a) 2000 kg/m3

(b) 2400 kg/m3

(c) 3200 kg/m3

(d) 7000 kg/m3

2. The modulus of elasticity of steel is about(a) 150 GPa(b) 200 GPa

(c) 220 GPa(d) 240 GPa

3. Match the following:(a) BREEAM (i) The USA(b) LEED (ii) India(c) CASBEE (iii) Australia(d) Green Star (iv) Japan(e) IGBC (v) The UK

4. As per LEED-NC, the combination of energy and atmosphere has the following possible points:(a) 26(b) 10

(c) 35(d) 5

5. As per LEED-NC, sustainable sites has the following possible points:(a) 26(b) 10

(c) 35(d) 5

6. To get a Gold rating in LEED-NC, one has to obtain the following points: (a) 40–49(b) 50–59

(c) 60–79(d) 80–100

7. To get a Silver rating in LEED-NC, one has to obtain the following points: (a) 40–49(b) 50–59

(c) 60–79(d) 80–100

8. Which of the following materials has the maximum value of embodied energy?(a) Steel(b) Copper

(c) Aluminium(d) Zinc

9. Which of the following materials has the lowest val-ue of embodied energy?(a) Recycled steel(b) Concrete(c) Recycled aluminium(d) Cement

Review Questions

1. What are the functions of a building? 2. How are building materials classified? 3. How are the properties of building materials classified? 4. List and define the different physical properties of building materials. 5. Define the following:

(a) Density(b) Bulk density

(c) Density index(d) Specific weight

(e) Porosity(f) Void ratio

6. List the mechanical properties of building materials. 7. What are the thermal properties of materials? 8. What are the chemical, optical, acoustical, physiochemical, and metallurgical properties of materials? 9. What are the factors influencing the choice of a building material? 10. Write short notes on the following:

(a) Ductility(b) Thermal conductivity(c) Selection of building materials

(d) Fire-resistant and fire-retarding materials(e) Corrosion resistance(f) Durability

11. Define sustainability. Why is it important to consider sustainability while selecting a building material? 12. When is a product or material considered sustainable? Illustrate with an example. 13. What are healthy materials? 14. When are materials considered as ecological materials? 15. List any three green-labelling systems. 16. Name any three green building rating systems 17. Describe the LEED-NC rating system briefly. 18. What is embodied energy? Is it the true indicator of environmental impact?



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19. Briefly describe four important building materials. 20. What are the alternative or substitute building materials. Name five such materials and describe two of them briefly. 21. Why is it important to have standards for building materials?

ANSWERS

Multiple-choice Questions

1. (b) 2. (b) 3. (a)–(v), (b)–(i), (c)–(iv), (d)–(iii), (e)–(ii) 4. (c) 5. (a) 6. (c) 7. (b) 8. (c) 9. (b)



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