1.PHYSICAL PROPERTIES OF BUILDING MATERIALS Mohammad Naser Rozy 3rd year Department of Civil Engineering NIT Rourkela

2. CONCRETE Ingredient cement, water, small stones Strength cheap, fireproof & weatherproof, molds any shape, strong in compression Weaknesses cracks with temperature changes, weak in tension Applications early arch bridges & domes 3. REINFORCED CONCRETE Type fine-grained concrete with high-strength steel Ingredient steel bars hidden in concrete Strength low-cost, fireproof & weatherproof, molds any shape, strong in compression & tension Weaknesses can crack as it cools & hardens Applications bridges, dams, domes, buildings 4. BRICK Type ordinary brick Ingredient burned clay Strength cheap, strong in compression Weaknesses heavy, weak in tension Applications walls of early skyscrapers and tunnels, domes 5. CAST IRON Type cast iron Ingredient iron with lots of carbon Strength molds to any shape, strong in compression Weaknesses weaker than steel in tension, breaks without warning Applications arch bridges, cannons, domes 6. STEEL Type high-strength steel Ingredient iron with a touch of carbon Strength one of the strongest materials used in construction, strong in compression & tension Weaknesses rusts, loses strength in extremely high temperature Applications cables in suspension bridges, buildings 7. ALUMINUM Type aluminum alloy Ingredients aluminum w/ magnesium & copper Strength lightweight, doesnt rust, strong in compression & tension Weaknesses expensive Applications airplane wings, boats, skyscrapers skin 8. WOOD Strength cheap, lightweight, moderately strong in compression & tension Weaknesses rots, swells and burn easily Applications bridges, houses, 2 or 3-story bldgs 9. PLASTIC Type high-strength plastic fabric Ingredients long chain of molecules Strength flexible, lightweight, long lasting, strong in compression & tension Weaknesses expensive Applications tent structures, 10. Introduction to ConcreteProf. P. K. Bhuyan Department of Civil Engineering NIT Rourkela 11. Concrete As A Material Concrete, literally, forms the basis of our modern life: Roadways/transportation systems Infrastructure (bridges, dams, buildings) Harbor protection (breakwalls) Water distribution (pipes & conduit) 12. Concrete has deep roots in history: Wall at Palestrina, Italy, 1st Century BC 13. Roman Aqueduct & Pantheon 14. Grand Coulee Dam 15. Concrete The word concrete originates from the Latin verb concretus, which means to grow together. 16. Concrete is a mixture of portland cement, water, aggregates, and in some cases, admixtures. The cement and water form a paste that hardens and bonds the aggregates together. Concrete is often looked upon as man made rock. 17. REASONS WHY CONCRETE IS THE MOST WIDELY USED MATERIAL: Concrete is one of the cheapest and most readily available materials Concrete can be formed into a variety of shapes and sizes Concrete possesses excellent resistance to water 18. Advantage of Concrete We have the ability to cast desired shapes Arches, piers, columns, shells Properties can be tailored according to need (strength, durability, etc.) Ability to resist high temperatures Will maintain structural integrity far longer than structural steel Does not require protective coatings Can be an architectural & structural member at the same time 19. Concrete Structural Frame City of Arts and Sciences, Valencia, Spain 20. Properties of Quality Concrete Workability (ease of placement; resistance to segregation; homogenous mass) Consistency (ability to flow) Durability Strength Chloride Penetration Resistance Abrasion Resistance 21. Workability Workability is the property that determines the ease with which freshly mixed concrete can be placed and finished without segregation. Workability is difficult to measure but redi-mix companies usually have experience in determining the proper mix. Therefore, it is important to accurately describe what the concrete is to be used for, and how it will be placed. 22. Durability If acceptable materials are used, the properties of concrete, such as durability, freeze/thaw resistance, wear resistance, and strength depend on the cement mixture. A mixture with a sufficiently low ratio of water to cement plus entrained air, if specified, is the most desirable. These properties--and thus the desired concrete quality--can only be fully achieved through proper placement and finishing, followed by prompt and effective curing. 23. The Nature of Concrete It is a composite material Aggregates are 65% - 80% of the volume Fine aggregate: sand Coarse aggregate: stone Cement: General term & applies to any binder WaterPortland cement fly ash ground slag silica fume 24. Concrete Microstructure 25. The Purpose Of The Aggregates Large aggregates: provide density (fill space: cheap filler) provide strength (hard material) Fine aggregates: fill small voids between large aggregates (reduce volume changes) Increases strength of the cement binder 26. The Cement Matrix Cement: produces a crystalline structure binds aggregates together Water Uses for cement: Mortar = cement + sand + water Plaster = cement + lime + sand + water Grout = cement + sand + considerable amount of water Paste = cement + water 27. Water needed for two purposes: chemical reaction with cement workability only 1/3 of the water is needed for chemical reaction extra water remains in pores and holes results in porosity Good for preventing plastic shrinkage cracking and workability Bad for permeability, strength, durability. 28. Portland Cement Portland cement was named for the Isle of Portland, a peninsula in the English Channel where it was first produced in the 1800's. Since that time, a number of developments and improvements have been made in the production process and cement properties. 29. What is Portland Cement? Raw limestone, clay & gypsum minerals are ground into powder & heated in kiln (1600 C) Minerals interact at that temperature to form calcium silicates (clinker) Available in five types, each with varying performance characteristics and uses 30. Portland Cement Manufacturing Process 31. Clinker 32. Hydration Portland cement becomes cementitious when mixed with water This reaction is referred to as hydration. During hydration, a crystalline structure grows to form bonds Hydration begins as soon as water meets cement Rate of hydration increases with increased cement fineness 33. In Fact. Concrete does not gain strength by drying out Concrete must have continuous free access to water to achieve its ultimate strength!! 34. Admixtures: 35. Admixtures Admixtures are ingredients other than portland cement, water, and aggregates. Admixtures are added to the concrete mixture immediately before or during mixing. 36. Admixtures chemical set retarders set accelerators water reducing air entraining mineral fly ash silica fume slags 37. Admixtures: Coloring Agent are pigments or dyes mixed into topping to render/alter color evenly to concrete surface Surface Sealing Agents liquid waxes sprayed over the surface that is easily removed after curing. Prevents evaporation of water into a new concrete allowing hydration and seal the pores of concrete surface after it has hardened Dispersal Agents- prevents bleeding of concrete from concrete. 38. Admixtures: Bonding Agent either metallic aggregate or synthetic latex to improve the bond between old and new concrete. Gas Forming Agent develops the potential strength of a concrete Non-Skid Surfaces - use abrasive material in topping to produced un-slippery surface for pavement construction Hardener chemical/fine metallic aggregate improve the density of concrete surface subject to impact and wear. 39. Admixtures: Retarding admixtures delays or extend the setting time of concrete especially during hot weather condition (hydration accelerates curing) allowing more time to place, consolidate and finish the concrete. 40. Admixtures: Accelerating admixtures Speeds up the setting of concrete to reduce the whole curing period or for early removal of forms. such as calcium chloride, are used to increase the rate of hardening--usually during cold weather. 41. Admixtures: Water Reducers (Super-Plasticizers) Water can be reduced Increases viscosity Results in higher strength and more durable concrete due to reduced water 42. Air Entrainment Admixtures All concrete contains entrapped air Large bubbles Large voids are undesirable for durability & permeability Entrained air Bubbles are microscopic in size & distributed through out concrete Increases durability by providing escape route for freezing water as it expandsWhen Do We Use Air Entrained Concrete? Concrete to be placed in exterior locations requires air entraining (water/freeze/thaw) 43. Entrapped Air Voids 44. Entrained Air 45. Water Cement Ratio Water cement ratio controls the strength, durability and water tightness of hardened concrete. Based on Abrams Law (D.A. Abrams, 1919) the compressive strength of concrete is inversely proportional to the ratio of water to cement Too much water will weaken concrete after curing. Little water is dense but causes difficulty in placement and workability of concrete. 46. Water Cement Ratio The Average water-cement ratio is 30 liters per 50 kg. of cement bag. Excessive water causes bleeding and laitance. Bleeding (emergence of excess mixing water on the surface of newly placed concrete caused by settlement of solids within the mass) Laitance (milky deposit containing cement and fine aggregate on the surface of new concrete combined with bleeding, overworking of mix or improper finishing). 47. Control of Concrete Mixes: Concrete is normally specified according to the compressive strength it develops depending on the type of cement used. If ordinary Portland (7 - 28 days) or high early strength (3 7 days) after placementTwo methods of testing concretes compressive strength: 1. Slump test 2. Compressive Cylinder Test 48. Control of Concrete Mixes: 1. Slump test to measure the consistency of freshly mixed concrete. Where a concrete is placed at a slump cone ( 300 mm high with a respective top diameter and bottom is 100 mm and 200 mm) and tamped in a prescribed manner then lifted to determine the decrease in height expressed by vertical settling in cm/mm. 49. Slump Test Inverted cone fill it up with three layers of equal volume rod each layer 25 times scrape off the surface100300200 50. Slump Test slump cone rodconcrete 51. Slump test Ruler Slump 52. Placing Conditions Blinding Concrete; Shallow Sections; Pavements using pavers Mass Concrete; Lightly reinforced sections in Slabs, Beams, Walls, Columns; Floors; Hand placed Pavements; Canal lining; Strip FootingsHeavily reinforced sections in Slabs, Beams, Walls, Columns; Slip form work; Pumped Concrete. Trench fill; In-Situ PilingDegree of WorkabilitySlump (mm)Very LowSee 7.1.1Low25-75Medium50-100High100-15052 53. Factors affecting slump water cement ratio w/c = weight of water / weight of cement constant cement content increase water content increase slump NO GOOD 54. Factors affecting slump Paste ContentLow paste content Harsh mixHigh paste content Rich mix 55. ball bearing effect-start starting height 56. ball bearing effect-end slump 57. Factors affecting slump Aggregates Grading: larger the particle size, the higher the slump for a given paste content 58. effect of aggregate size11 1 Consider a single aggregate the size of 1x1x1 59. Compute the surface area as you break up the particles block surface area = 1*1*6= 6block surface area = 0.5*0.5*6=1.5volume = 1 cubic in surface area = 6 square inches volume = 1 cubic in surface area = 1.5*8= 12 square inches 60. Break it up further 61. Compute the surface area surface area = 0.25*0.25*6*8*8=240.5 in0.25 in 62. Larger particles, less surface area, thicker coating, easy sliding of particles 63. Smaller particles, more surface area, thinner coating, interlocking of particles 64. Effect of aggregate size size# of particlesvolumesurface area1"11 cubic inch6 square inches.5"81 cubic inch12 square inches0.25641 cubic inch24 square inches0.1255121 cubic inch48 square inches 65. Angularity and surface texture of aggregatesangular and rough aggregatesmooth aggregate river gravel 66. Bleeding 67. Water accumulation on surface Examine the concrete surface 68. Temperaturefresh concrete aggregatespaste 69. Interaction between bleeding and evaporationEvaporation surface water Bleed waterBleed water = evaporation 70. Bleeding and its control Creates problems: poor pumpability delays in finishing high w/c at the top poor bond between two layerscauses lack of fines too much water contentRemedies more fines adjust grading entrained air reduce water content 71. Causes of Plastic Shrinkage Cracking water evaporates faster than it can reach the top surface drying while plastic cracking 72. Too much evaporation leads to surface crackingEvaporation no surface water dryingBleed water < Evaporation 73. Plastic Shrinkage Cracking-Remedies Control the wind velocity reduce the concretes temperature use ice as mixing water increase the humidity at the surface fogging cover w/polyethylene curing compound Fiber reinforcement 74. Free Shrinkage, causes volume change, but no stressesbefore shrinkageAfter Shrinkage 75. Restrained Shrinkage- creates stresses, which may cause cracking 76. Restrained shrinkage cracking Parallel cracking perpendicular to the direction of shrinkage 77. Curing The time needed for the chemical reaction of portland cement with water. concrete after 14 days of curing has completed only 40% of its potential. 70 % at 28 days. 78. Curing tips ample water do not let it dry dry concrete = dead concrete, all reactions stop can not revitalize concrete after it dries keep temperature at a moderate level concrete with flyash requires longer curing 79. Temperature effects on curing The higher the temperature the faster the curing best temperature is room temperature strongest concrete is made at temperature around 5 C.(not practical) If concrete freezes during the first 24 hrs., it may never be able to attain its original properties. 80. Temperature effects on curing real high temperatures above 50 C can cause serious damage since cement may set too fast. accelerated curing procedures produce strong concrete, but durability might suffer. 81. Two general methods of curing can be used: Keep water on the concrete during the curing period. These include ponding or immersion, spraying or fogging, and saturated wet coverings. Such methods provide some cooling through evaporation, which is beneficial in hot weather. 82. Prevent the loss of the mixing water from concrete by sealing the surface. Can be done by: covering the concrete with impervious paper or plastic sheets, applying membrane-forming curing compounds. 83. Testing of concrete Concrete testing can broadly classified in to two major divisions. Green (Fresh) concrete Tests. Workability tests 1. 2. 3. 4. 5. 6. 7. 8. 9.Slump test Compacting factor test ASTM flow test Remoulding test Vebe Test Flow test Ball penetration test Nassers K-test Two point tests 84. Testing of concrete Hardened concrete tests. Strength in compression Cube test (British Standard1881 : Part 111 :1983) Cylinder test (BS 1881 : Part 110 :1983) (ASTM C 192-90a Flexural strength test Tensile test 85. Compression Tests Three types of compression test specimens are used: cubes, cylinders, and prisms. Cubes are used in Great Britain, Germany and many other countries in Europe. Cylinders are the standard specimens in the Unites States, France, Canada, Australia and Newzeland. In Scandinavia tests are made on both cubes and cylinders. The tendency nowadays, especially in research is to use cylinders in preference to cubes. 86. Strength Development and Strength Measurement Aggregates glued together by cement paste to form concrete Cement hydration is a chemical reaction which requires water Strength gain reflects degree of hydration Strength gain depends on Type of cement Temperature history temperature and time Curing Admixtures 87. Factors Affecting Compressive Strength at 28 days Aggregate content Cement type and fineness Water/cement ratio Degree of compaction Extent of curing Temperature 88. Strength Measurement 100mm or 150mm cubes at 7 and 28 days 300mm x 150mm cylinders at 7 and 28 days (note ratio 2:1 and circular in plan) Other tests direct tension, bending and cores Non-destructive testing 89. Cube Making: Cube making: Prime objectives to achieve full compaction avoid loss of moisture keep at proper temperature when in curing tank Use proper tools. Advantage of cube shape is ease of making accurate sides. 90. Cube Making 91. Specifications Cube Curing and Cube Testing Cube Reports and Cube Failures 92. Cube Curing and Cube Testing Cube Curing: De-mould (take the mould out) when stability of cube allows. Prevent loss of moisture before placing in curing tank. Loss in strength due to initial drying out is unrecoverable. No provision for in-situ cubes. Give temperature matched curing. 93. Cube curing 94. Cube Testing After curing process, cubes were tested by compressive strength machine as shown in the figure to measure the compressive load at which cubes will fail . 95. COMPRESSIVE STRENGTH TESTING MACHINE FOR CONCRETE 96. Compressive strength testing of Concrete cubes 97. Criteria for cube failures A strength (the characteristic 28-day strength) is specified based on design the concrete Grade In compression test, two tested cubes at 28 days = one result Provided difference between individual results is within 15% of average Individual cube result: every individual result must be greater than the characteristic -3MPa 98. Concrete Cube Test Result Variability Variability 28 day cube results have a mean strength and a standard deviation For an expected 5% defective level, the target mean strength is the specified characteristic strength plus 1.64 times the standard deviation Ensure actual mean is greater than target mean strength 99. Failure modes - Normal 100. Failure modes - Abnormal 101. Cylinder Test A quality control test based on 728 days curing period to determine the compressive strength of a concrete specimen. The standard cylinder is 150 mm diameter, 300 mm long and is cast in a mould generally made of steel or cast iron. The cylinder specimens are made are compacted either in three layers using a 16 mm diameter rod or in two layers by means of a vibrator. Details of procedure are prescribed in ASTM Standard C192-76. 102. Cylinder Compressive Tests After top surface of the cyliner has been finished by means of trowel, the cube is stored undistributed for 24 hours at a temperature of 18 to 22 C and relative humidity of not less than 90 percent. At the end of this period the mould is stripped and the cylinder is further cured in a water at 19 to 21 C . The test is generally performed at 28 days but it also perform additional test at 3 and 7 days. In compression test, the cylinder is placed with the faces in contact with the platens of the testing machine, i.e. the position of the cube when tested is at right angles to that as-cast. The load on the cylinder should be applied at a constant rate of stress equal to 0.0250 KN/sq. meter/ sec 103. Dr. Mohamed Abdallah El-Reedy Email:elreedyna@gmail.com 104. Consolidation of Concrete: The process of eliminating voids other than entrained air within newly placed concrete and ensuring close contact of the concrete with form surfaces and embedded steel reinforcement. Through : vibration, spading and rodding Excessive vibration causes segregation (separation of coarse aggregate from mortar causing excessive horizontal movement making a free fall mix) Excessive vibration also causes stratification (separation combined with excessive wetting into horizontal layers where lighter material migrate towards the top) 105. Different Process of Mixing Concrete: Manual flat surface with shovels and buggy Small Power a manual mixing rotating drum Bagger Mixer equipped with diesel engine and pump operated mechanical mixing drum (1 or 2bags) or rotating mixing drum at the back of a truck. 106. Method of Transporting a Concrete: Ready Mixed- concrete mixed at batch plant for delivery by an agitator to construction site. 107. Method of Transporting a Concrete: Shrink Mixed concrete partially mixed at the batch plant then mixed completely in a truck mixed en route to construction site. Transit Mixed concrete dry batch at a batch plant & mixed at the truck mixer en route to construction site. 108. Method of Transporting a Concrete: Gunite or shotcrete for lightweight construction, where concrete mix is pumped through a hose and sprayed at high velocity over reinforcement until desired thickness is reached. 109. Concrete-Applications With proper materials and techniques, concrete can withstand many acids, milk, manure, fertilizers, water, fire, and abrasion. Concrete can be finished to produce surfaces ranging from glass-smooth to coarsely textured, and it can be colored with pigments or painted. 110. Concrete has substantial strength in compression, but is weak in tension. Most structural uses, such as beams, slabs, and tanks, involve reinforced concrete, which depends on concrete's strength in compression and steel's strength in tension. 111. When specifying and ordering concrete, the customer should be prepared to discuss such things as: 1. Amount of concrete required, 2. use of the concrete, 3. type of cement, 112. 4. minimum amount of cement per cubic meter 5. maximum water-cement ratio 6. any special admixtures, 7. amount of air entrainment, 8. desired compressive strength, 9. amount of slump, and 10. any special considerations or restrictions 113. CONSTRUCTION STONESProf. P. K. Bhuyan Department of Civil Engineering NIT Rourkela 114. TOPICS Stone Masonry Stone as a Construction Material Classification of Stone Cutting and Dressing of Stones Construction of Stone Masonry Comparison between Brick and Stone masonry 115. Stone a natural, hard substance formed from minerals and earth material which are present in rocks. Rock the portion of the earths crust having no definite shape and structure 116. To qualify as a construction material, stone should have the following qualities: 117. Strength: Most types of stone have more than adequate compressive strength. The shear strength of stone, however, is usually about 1/10 of its compressive strength 118. Hardness: hardness is important when stone is used for flooring, paving, and stair treads. 119. Hardness: Talc, easily scratched with the thumb-nail: 1 Gypsum, scratched by the thumb-nail: 2 Calcite, not scratched by thumb-nail but easily cut by knife: 3 Fluorite, can be cut by knife with greater difficulty than calcite: 4 Apatite, can be cut only with difficulty by knife: 5 Orthoclase, can be cut w/ knife w/ great difficulty on thin edges: 6 Quartz, not scratched by steel, scratches glass: 7 Topaz: 8 Sapphire: 9 Diamond: 10 120. Durability: Resistance to the weathering effects of rain, wind, heat, and frost action is necessary for exterior stonework 121. Workability: A stones hardness and grain texture must allow it to be quarried, cut and shaped 122. Density: A stones porosity affects its ability to withstand frost action and staining 123. Density: Porosity of Stones 24-hours Water Absorption of Stones by Volume 124. Appearance: Appearance factors include color, grain, and texture 125. Quarrying and Producing Building Stones Produced by blasting or cutting - Irregular-sized stone is produced by blasting the rock, the larger pieces are cut into smaller units for use as an exterior finish, rest is crushed and sorted into various sizes as aggregates - Most of the dimensional stones used in building construction are produced by cutting large blocks in the quarry - Cut with diamond belt saws; rubber air bags inflated in the saw cut to break it away and then the separated rock is lowered onto prepared stone chips cushion - Thereafter it is cut into smaller sizes and transported by front-end loaders to the mill for further processing 126. CLASSIFICATION OF STONES (according to geological origin): Igneous rockSedimentary rockMetamorphic rocks 127. Igneous rock is formed as a result of cooling of the molten rock to solid state - It is nonporous, hard, strong and durable Igneous rock also known as primary, un-stratified or eruptive rocks 128. Granite : Consists mainly of quartz, feldspar, mica, and other colored minerals; colors include black, gray, red, pink, brown, buff, and greenSerpentine: Main ingredient is serpentine; color ranges from olive green to greenish black, is fine grained and denseBasalt : Color ranges from gray to black; used mainly for paving stones and retaining walls 129. Granite Non-porous, hard, strong, durableColor RangeSurface TexturesSourcesPrimary Uses133 130. Polished SurfaceRough Texture134 131. ShapeFlat to Round135 132. TYPES OF BUILDING STONES Serpentine igneous with mineral serpentine. Typically olive green to greenish black but impurities may color the rock. Used only for interiors due to weathering 133. Sedimentary rock is formed by the deposition of sediment by water, wind or glacier, results in sandstone, limestone and shale 134. Sedimentary rocks are also known as aqueous or stratified rocks Sandstone: Sedimentary rock composed of sand sized grains made of silica, iron oxide and clay - Colors include gray, brown, light brown, buff, russet, red, copper, and purple Limestone: Sedimentary rock composed of calcite and dolomite - Three types: oolitic, dolomitic and crystalline Has high compressive strength - Used for building stones and for paneling Shale: Derived from clays and silts; weak along planes and is in thin laminations - High in limestone and color varies from black to red, yellow, and blue 135. TYPES OF BUILDING STONES Sandstone class of rock of cemented silica grains with texture ranging from very fine to very coarse. Colors vary from buff, red and light brown. Porous where as 30% of volume composed of pores 136. TYPES OF BUILDING STONES Limestone sedimentary rock like dolomite, no cleavage lines, low in absorption, smooth, uniform in structure & composition. High compressive & tensile strength Used for: wall & floor surfaces 137. Limestone with Granite141 138. TYPES OF BUILDING STONES Travertine sedimentary rock, pleasing texture with small natural pockets on a cut surface. Used for: interior decorative stone 139. Metamorphic rocks has undergone a change in structure, texture, or composition due to the natural agencies, as heat and pressure, especially when the rock becomes harder and more crystalline, as marble and slate 140. Metamorphic rocks: Examples of Transformation of Rocks 141. Metamorphic Rock MarbleSlate 145 142. TYPES OF BUILDING STONES Marble metamorphic rock, a re crystallized limestone forming into carrara, parian, onyx and vermont. Used for: flooring wall & column facing 143. Marble - Exterior Application147 144. TYPES OF BUILDING STONES Slate Rock metamorphosis of clays and shale's deposited in layers. May be separated into thin, tough sheets called slates . Colors are black, green red, grey, or purple. Used for: flooring window sills stair treads & facing 145. Slate Flooring149 146. Other Metamorphic Rocks Used In Stone Masonry Quartzite: It is a variety of stone composed of mainly granular quartz cemented by silica, color varies from brown, buff, tan, ivory, red through graySchist: Made of silica with smaller amounts of iron oxide and magnesium oxide - Color varies from blue, green, brown, gold, white, gray, and red 147. STONE CONSTRUCTIONLargely used as facing for building material with steel and concrete frames.151 148. Application Categories : 1. 2. 3. 4.Paneling Ashlars Rubblework Trim 149. Paneling thin slabs of stone cut to dimension and thickness to cover back up walls and provide finished exterior Running Bond - a masonry bond formed when all units are laid in stretcher position, with a half-unit overlap 150. Paneling thin slabs of stone cut to dimension and thickness to cover back up walls and provide finished exterior Stack Bond - a masonry bond formed when there is no overlapping of all units and all horizontal & vertical joints are aligned 151. Ashlar Masonry In this type properly dressed stones areused. 1. Ashlar fine or course ashlar masonry 2. Random coursed ashlar masonry 3. Rough tooled ashlar masonry 4. Rock or quarry faced ashlar masonry 5. Chamfered ashlar masonry 6. Block in course masonry 7. Ashlar facing 152. Ashlars work requires the use of cut stone that includes broken ashlars, regularly / irregularly coursed. Coursed Ashlar - Ashlar masonry laid out in courses of equal height; blocks of various sizes may be combined to make up the height of the course 153. Ashlars work requires the use of cut stone that includes broken ashlars, regularly / irregularly coursed. Random Ashlar - Ashlar masonry laid without regular courses but with an overall effect of horizontal orientation 154. Rubble Masonry In this type undressed or roughly dressedstones are used1. Un-coarsed Rubble Masonry 2. Random Rubble Masonry 3. Coursed Rubble Masonry 4. Dry Rubble Masonry 155. Rubble - consists of rough fragments of broken stone that have at least one good face for exposure in a wall. 156. Rubblework random & no attempt to produced an orderly course either horizontal or vertical.. Small spaces are filled with smaller stones. Coursed Rubble - Fieldstone or roughly dressed stone, with or without mortar, assembled to give a effect of courses 157. Rubblework random & no attempt to produced an orderly course either horizontal or vertical.. Small spaces are filled with smaller stones. Fieldstone - Stone found on the ground (i.e., not quarried) that is a suitable size and shape for use as drywall or rubble masonry 158. Dimension stone - is quarried and squared stone 2 or more in length and width and of specified thickness, used commonly for wall panels, cornices, copings, lintels and flooring. 159. Trim stones cut for specific purposes like: Corbel Cornice Drip Stone Throating Coping Frieze Spalls 160. Corbel It is a piece of stone projected outside of a wall to provide support to a structural member of the Roof or Floor. DIAGRAM Cornice Its a large course of stone masonry provided at the ceiling level of roof, projected outside of wall. Drip Stone A projected stone with toothing at undersurface. It is provided to through the rain water off the wall. 161. Throating The process of cutting groves in Soffits of sills Drip stones Coping String course etc. Its purpose is to avoid the entry of rain water. Coping It is a special course provided at the top of a wall to avoid entry of rain water in wall. Frieze The stone course provided below the cornice is called frieze 162. Stone Finish Rusticated - A term describing stone masonry with a recessed cut margin, so a channel is formed when the blocks are aligned 163. Sand Finish - A stone finish that is granular and moderately smooth, varying with the characteristics of the specific stone 164. Sawn Face - A term describing stone exhibiting the marks left by the saw used to cut it 165. Rock Face - A stone finish with emphasized face-plane shifts and rough corners, exaggerating the natural look of the stone 166. Split Face - A stone finish exhibiting the natural quarry texture resulting from splitting the stone 167. Flagstone - refers to flat stone slabs used for flooring and horizontal surfacing. 168. Stone Pavers Cobble stone - A stone used in paving. It may be rectangular, or naturally rounded 169. Durex Blocks - Roughly cubed, usually granite blocks used for paving 170. Lifting Appliances for Stone Masonry Pin LewisChain Lewis LewisChain DogsThree Legged 171. Stone vs Brick Similarities: Both stacked Mortar JointsDifferences: Shape: Brick molded - Stone Cut and Carved Physical Properties: Brick made/controlled Stone provided by nature 176 172. Brick & Brick MasonryDr. P. K. Bhuyan NIT Rourkela 173. Definitions Masonry It is used for the work of a mason. Mason is a person who built structures with constructionmaterials.Masonry Units It is an artificially prepared regular shape block used in themasonry works. Like . Brick in brick masonry Stone block in stone masonry Concrete block in Block masonry 174. History of Bricks: Bricks are one of the oldest types of building blocks. They are an ideal building material because they are relativelycheap to make, very durable, and require little maintenance. A brick is a block of ceramic material used in masonry construction, usually laid using various kinds of mortar. Bricks dated 10,000 years old were found in the Middle East. Examples of the civilizations who used mud brick are the ancient Egyptians and the Indus Valley Civilization, where it was used exclusively. In particular, it is evident from the ruins of Buhen, Mohenjo-Daro and Harappa. The first sun-dried bricks were made in Mesopotamia (what is now Iraq), in the ancient city of Ur in about 4000 BC 175. Advantages of bricks : * Brick will not burn, buckle or melt * Brick will not rot * Brick will not rust and corrode * Brick will not dent (depress). * Brick will not fade from the Sun's UV Rays. * Brick will not be damaged by high winds, rain or hail. Brick will not require constant maintenance. * Brick will not limit your personal expression. * Brick will not limit your design options. 176. General Characteristics of Bricks Brick is made of clay or shale formed, dried and fired intoa durable ceramic product. There are three ways to form the shape and size of a brick: extruded (stiff mud), molded (soft mud) and drypressed. The majority of brick are made by the extrusion method. Brick achieves its color through the minerals in the fired clay or through coatings that are applied before or after the firing process. This provides a durable color that never fades or diminishes. Brick shrink during the manufacturing process as vitrification occurs. Brick will vary in size due to the manufacturing process. 177. The method used to form a brick has a major impact onits texture.Sand-finished surfaces are typical with molded brick. A variety of textures can be achieved with extruded brick.manufacturing facilities near clay sources to reducetransportation, by recycling of process waste, by reclaiming land where mining has occurred, and by taking measures to reduce plant emissions. Most brick are used within 500 km of a brick manufacturing facility. 178. Raw material for clay: Clay is one of the most abundant natural mineralmaterials on earth. For brick manufacturing, clay must possess some specific properties and characteristics. Such clays must have plasticity, which permits them to be shaped or molded when mixed with water; they must have sufficient wet and air-dried strength to maintain their shape after forming. Also, when subjected to appropriate temperatures, the clay particles must fuse together. 179. Types of Clay: Clays occur in three principal forms, all of which havesimilar chemical compositions but different physical characteristics.Surface Clays. Surface clays may be the upthrusts of olderdeposits or of more recent sedimentary formations. As the name implies, they are found near the surface of the earth. Shales. Shales are clays that have been subjected to high pressures until they have nearly hardened into slate. Fire Clays. Fire clays are usually mined at deeper levels than other clays and have refractory qualities. Surface and fire clays have a different physical structure from shales but are similar in chemical composition. 180. All three types of clay are composed of silica and aluminawith varying amounts of metallic oxides. Metallic oxides act as fluxes promoting fusion of the particles at lower temperatures. Metallic oxides (particularly those of iron, magnesium and calcium) influence the color of the fired brick. The manufacturer minimizes variations in chemical composition and physical properties by mixing clays from different sources and different locations in the pit. Chemical composition varies within the pit, and the differences are compensated for by varying manufacturing processes. As a result, brick from the same manufacturer will have slightly different properties in subsequent production runs. Further, brick from different manufacturers that have the same appearance may differ in other properties. 181. Raw Material 182. Bricks Manufacture - 4 stages Material preparation Manufacturing drying FiringPreparation: material(clay) washed and grinding (fineness) Sample of grinding machine for claySample of crushing machine191 183. Brick Manufacturing : Clay isgrinded with 15% of water. The clay is then pushed through the mould base to take the shape. After that, Clay is cut to get a standard size and shape of brick using wire. Sometimes, bricks are produced using big mould in which clay will be pressed using hydraulic machine or without hydraulic press.192 184. Molded or Handmade solid units pressed into fiberglass, woodor steel molds used to be by hand, now machines sand or water coated molds to release bricks usually rougher surface and edges 185. After bricks in form,identification or perforation to the bricks. Drying : Wet unit bricks are then dried by keeping them in space or in a room with controlled temperature to make sure that bricks will be complete dry. Brick was compile before bring to the kiln194 186. Firing : Dry bricks, arethen compiled in kiln for firing process with 600oC as initial temperature. This is to burn the carbon and sulfur that have remained. After that, temperature is increased to 900oC to start the vetrification process. Normally, vitrification process occurrs at around 800oC. Bricks become hard/strong after vitrification process.195 187. BricksBricks manufacturing process flow 188. MATERIAL PREPARATION 189. Manufacturing 190. Manufacturing 191. Setting 192. Firing Process 193. Packaging 194. Important Components Of Brick Making 195. Important Components Of Brick Making 2.The Raw Materials 196. This wood sheet is used as the stand for bricks, because when the bricks are ready - they are wet, so we cant touch them and thats why we are using this wood stand. 197. MIX THE MATERIALSThey are mixing the materials: chopped stone, cement,white sand and water. 198. START THE WORKFirst, arrange the wood sheet in the machine, below the two holes.Secondly, pull the wood handle and move it round so you can see the two holes 199. Then fill the material on the two holes, and manage it equally. 200. Then pull up the handle and move it around like this.Afterwards, get back to the old position and push the handle harder in down way. 201. Then pull it up... get the shape! 202. Take the bricks out of the machine. 203. Arrange the bricks in a line. 204. Style of the bricks arrangement when they are wet. 205. Remove the wood stand and arrange it in different styles.. 206. Next morning, the water should be applied to the brick and they become more harder.Transport facilities of the material.. 207. Different kinds of bricks. 208. PROPERTIES OF BRICKS The most important properties of brick are1) durability, 2) color, 3) texture, 4) size variation, 5) compressive strength and 6) absorption. Durability: The durability of brick depends upon achieving incipientfusion and partial vitrification during firing. Because compressive strength and absorption values are also related to the firing temperatures, these properties, together with saturation coefficient, are currently taken as predictors of durability in brick specifications. However, because of differences in raw materials and manufacturing methods, a single set of values of compressive strength and absorption will not reliably indicate the degree of firing. 209. Texture: Coatings and Glazes : Many brick have smooth or sand-finished textures produced by the dies or molds used in forming. A smooth texture, results from pressure exerted by the steel die as the clay passes through it in the extrusion process. Most extruded brick have the die skin removed and the surface further treated to produce other textures using devices that cut, scratch, roll, brush. Brick may be tumbled before or after firing to achieve an antique appearance. 210. Color: The color of fired clay depends upon its chemical composition,the firing temperatures and the method of firing control. Of all the oxides commonly found in clays, iron probably has the greatest effect on color. Regardless of its natural color, clay containing iron in practically any form will exhibit a shade of red when exposed to an oxidizing fire because of the formation of ferrous oxide. When fired in a reducing atmosphere, the same clay will assume a dark (or black) hue. Creating a reducing atmosphere in the kiln is known as flashing or reduction firing. Given the same raw material and manufacturing method, darker colors are associated with higher firing temperatures, lower absorption values and higher compressive strength values. However, for products made from different raw materials, there is no direct relationship between strength and color or absorption and color. 211. Size Variation Because clays shrink during both drying and firing,allowances are made in the forming process to achieve the desired size of the finished brick. Both drying shrinkage and firing shrinkage vary for different clays, usually falling within the following ranges: Drying shrinkage: 2 to 4 percent Firing shrinkage: 2.5 to 4 percent Firing shrinkage increases with higher temperatures, whichproduce darker shades. When a wide range of colors is desired, some variation between the sizes of the dark and light units is inevitable. To obtain products of uniform size, manufacturers control factors contributing to shrinkage. Because of normal variations in raw materials and temperature variations within kilns, absolute uniformity is impossible. Consequently, specifications for brick allow size variations. 212. Compressive Strength and Absorption Both compressive strength and absorption are affectedby properties of the clay, method of manufacture and degree of firing. For a given clay and method of manufacture, higher compressive strength values and lower absorption values are associated with higher firing temperatures. Although absorption and compressive strength can be controlled by manufacturing and firing methods, these properties depend largely upon the properties of the raw materials. 213. Tests on bricks: Clay Masonry Units -ASTM C 67, Standard Test Methodsfor Sampling and Testing Brick and Structural Clay Tile Procedures for the sampling and testing of brick andstructural clay tile. Tests include modulus of rupture, compressive strength, absorption, saturation coefficient, effect of freezing and thawing, efflorescence, initial rate of absorption and determination of weight, size, length change, and void area. 214. Brick British SpecificationRecommends LENGTH (L) Minimum Length = 8-5/8 Maximum Length = 8-7/8 WIDTH (W) Minimum Width = 4-1/8 Maximum Width = 4-1/4 DEPTH (D) Minimum Depth = 1-15/16 Maximum Depth = 2-15/16 L D W 215. Brick Positions: Stretcher Header Soldier Shiner Rowlock Sailor 216. Definitions Frog Arrises The edges formed by theintersection of plane surfaces of a brick are called arrises. Frog The depression provided in theface of a brick during its manufacturing is called the frog. Courseeach horizontal layer of bricks laid in mortar is called course.CoursesArises 217. Definitions QuoinsPerpends The external corners of a wallare called Quoins. And the bricks forming quoins are called quoin bricks. E.g quoin header or quoin stretcher.Perpends The imaginary vertical lineswhich includes vertical joints are called Perpends.Quoin Header Quoin Stretcher 218. Definitions Header Brick laid with its width in elevation is called header. Ina course in which all bricks are header is called heading or header course.Stretcher Brick laid with its length in elevation is called stretcher.In a course in which all bricks are stretcher is called stretcher or stretching course. 219. Definitions Closure Closure bricks are prepared by cutting standardbrick across length or in different ways to fulfill the requirements of bond in straight walls, corners, junctions or crosses is called closures. They are of four types Queen closure King closure Bevelled closure Mitered closure Brick bats Brick bats are prepared by cutting standard brickacross width. They are of four types Three quarter bat Half or square bat Quarter bat Bevelled bat 220. Definitions Facing The external face of wall is called facing.Backing The unexposed or internal face of wall is called backing.Hearting The interior portion between facing and backing iscalled hearting. 221. Definitions RevealsIt is the verticle sides of door or window opening fromoutside is called reveals.JambsIt is the verticle sides of door or window opening frominside is called jambs.SoffitThe under surface of a lintel is called Soffit. Its thehorizontal surface.SillThe horizontal surface at the bottom side of a door orwindow opening is called sill. 222. Definitions Column The isolated vertical load bearing member whose cross sectionaldimensions are much lesser then its length is called column.Pillar The isolated vertical non load bearing member used forornamental purpose or as memorial is called pillar.Pier The isolated vertical load bearing members used as anintermediate support of a series of arches is called pier.Pilaster The thickened vertical load bearing member strengthening a wallis called pilaster.Stanchion The vertical load bearing member constructed of rolled steelsection is called stanchion. 223. Definitions Mortar The mixture of binding material and fine aggregateforming a workable paste is called mortar.Grout or slurry The thin paste of cement is called grout or slurry. It isused to fill the joints.Lintel A small horizontal member to span up small opening iscalled lintel.Copping It is provided at the top of a wall to avoid dampness. 224. Classification of Brick Masonry According to type of Mortar Pucca Masonry Pucca & Kutcha MasonryAccording to types of bricks First class brick Masonry Second class brick Masonry Third class brick Masonry Kutcha Masonry 225. Mortar Functions Provides for full bearing Seals between masonry units Adheres / bonds masonry units Aesthetics20% of wall area Affects the color and texture of masonry wall Mortar specified in testing standard ASTM C-270 226. Mortar Ingredients Portland Cement Hydrated Lime Sand Water Admixtures (optional) 227. Bond in brick masonry It is the arrangement of bricks in each layer to avoid the continuity ofvertical joints in any two adjacent courses. NECESSITY OF BOND Bond in brickwork is provided for the following reasons To break the continuity of vertical joints in consecutive courses. To ensure longitudinal and lateral strength of the masonry work. To distribute the load uniformly over the structural mass. To ensure the quality of work. To ensure systematic work To provide good esthetics To economize the work. REQUIREMENTS OF a GOOD BOND IN BRICK WORK Bricks should be uniform in size. Mortar thickness should be less than 10mm Vertical joints in alternate courses should be in a single plumb line. Header should be exactly in the middle of stretcher in two consecutivecourses. Brick bats should be avoided. 228. Types of bonds Following are the different types of bonds used in brick masonry work. BONDS IN MASONRY WALLS Header bond Stretcher bond English bond Flemish bond Facing bond Dutch bondBONDS IN MASONRY COLUMNS English bond Flemish bond 229. Wall Junctions The places where the walls of same or different widths meets orcrosses each other are called wall junctions. TYPES OF WALL JUNCTIONS Two types Straight junctions Squint junctions Straight junctions The junctions formed when two walls crossing each other at rightangle. Corner junctions Tee junctions Cross junctions Squint quoins The corner formed when two walls are meeting at some angle. Obtuse quoins Acute quoins 230. Masons tools in Bick masonry Trowel Brick hammer Lines and pins Spirit level and water level Straight edge Plumb bob Mason;s square or guniya Tape (steel) 231. General Principles and precautions in Brick MasonryEnglish bond should be used if not specified. Bricks used should be well burnt and should be uniform insize, shape and colour. For facing work selected bricks should be used. Curing of bricks should be done for at least 2 hours. Bricks should be laid with frogs pointing upward or as specified by the Engineer In charge. Mortar used in brick masonry should be of good quality. In walls greater than 9 or 0.225 m width hearting joints should be filled properly. Brick bats are avoided. 232. Reinforced brick Masonry The brick masonry done by embedding reinforcementin rich cement mortar is called Reinforced brick masonry.Reinforcement used may be in the form of Steel bars Hoop iron Wire mesh or XPM (expanded metal with specified LWM and SWM) 233. Constructions of Brick Masonry It is the art of laying bricks in a proper bond withspecified mortar to form a structure. It involves the following activities Selection of bricks Stacking of bricks Soaking of bricks Preparation of mortar (ASTM Specifications C 270, "Mortar for Unit Masonry)Laying of bricks 234. Defects and Maintenance of Brick Masonry DEFECTS Due to Substandard materials Due to corrosion of metals Due to effect of sulphates Due to frost action Due to efflorescence MAINTENANCE Cleaning brick masonry Removing efflorescence Re-conditioning the brick masonry Repainting the brick masonry 235. More Bonds 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.Header bond Stretcher bond English bond Flemish bond Raking bond English Cross bond Hoop Iron Bond Facing bond Dutch bond Monk bond Brick on edge bond Silverlocks bond 236. Header Bond 3/4 3/4First course or Odd coursesSecond course or Even courses 237. Course: Continuous layer Wythe: Continuous vertical section 238. Basic Brickwork Terminology Head Joint Bed JointCourse - horizontal layer of brick 239. Basic Brickwork Terminology Header - Bonds two wythes together Wythe: vertical layer 1 unit thickRowlock laid on face, end visibleStretcher - long dimension horizontal & face parallel to the wallSoldier - Laid on its end, face parallel 240. CorbelShelf or ledge formed by projecting successive courses of masonry out from the face of a wall 241. Quions Stone blocks used to form strong corners. 242. English Bond 243. 2 courses of English bond 244. Flemish Bond 245. Flemish Bond 246. Lintel and load distribution 247. Brick Pilaster 248. Corner Junctions (English Bond & Flemish Bond) 249. Tee Junctions (English Bond & Flemish Bond) 250. Cross Junction & Squint Junctions 251. Squint Quoins(English Bond)* 252. Brick Work Brickarrangement in brick work266 253. Brick work Brickarrangement in brick work267 254. Brick WorkBrickarrangement in brick work268 255. Brick Work Brickarrangement in brick work269 256. Brick Work Brick laying Material that was used in mortar (mix of cement or lime with sand or both Ratio; binder : sand = 1:3 Thickness or mortar normally in range 6.5mm 9mm270 257. Brick Work Plastering These have been done after brick lying finishing. The purpose is to get a smooth surface and uniformity in color. The wall should scratch to get a rough surface that will easy when plastering work Materials that was used : lime, cement Portland, gypsum Plastering work should be in two layers, which one base layer and finishing layer. Base layer ; cement :Lime : sand = 1:2:8-9 @ 1:1: 5-6 @ cement : sand = 1:3 @ gysum : sand = 1:1-3 @ gypsum : lime : sand = 1:3:7-9 Finishing layer; lime : gypsum = 1: 0.25 - 0.5271 258. Walk wayDecorative of brick work272 259. Advantages of brick273 260. The End278 261. Considerations in Choosing Brick process Molding Color Size Grade Type 262. However, most brick is.EXTRUDED pushed through a dye & then cut by wire hollow core formed into a column and cut to size with wires usually smoother surface and finer edgeskinda like square toothpaste 263. Brick Masonry - Sizes and Shapes No standard size Normal coursing - 3 bricks h8 (including mortar joints so it aligns with 8 block (CMU) Larger sizes mostly for economy Custom Shapes & Colors ($$$$$) = 264. Sizes: MODULAR STANDARD875/8 THREE-INCH OVERSIZE ROMAN NORMAN SIX-INCH JUMBO JUMBO 265. Bitumen & Desirable PropertiesBy Dr. P. K. Bhuyan NIT Rourkela 266. Overview Pavement materials Soil (sub-grade, embankment) Aggregates (coarse, fine) Binders (Bitumen, cement) 284 267. Bitumen Bitumen is a petroleum product obtained by the distillation of petroleum crude Bitumen is a hydrocarbon material of either natural or hydrogenousorigin,foundingaseous,liquid,semisolid or solid form Highway construction: hydrocarbon material which are cementious in character285 268. Bitumen 1. Natural product (lake asphalt, rock asphalt) 2. Fractional distillation of petroleum a. Asphalt cement (Penetration grade) b. Oxidised asphalt (softening point grade) c. Liquid asphalt3. Tar: destructive distillation of coal286 269. Liquid Bitumen Cutback: the viscosity of bitumen reduced by volatile diluents (kerosene, diesel): slow, medium, rapid curing Emulsion: bitumen is suspended in finely divided condition in an aqueous medium (water) and stabilized with an emulsifier: slow, medium, rapid setting287 270. 1. Normal Bitumen Production The portion of bituminous material present in petroleum may widely differ depending on the sourceAlmost all the crude petroleum's contain considerable amounts of water along with crude oilHence the petroleum should be dehydrated before the distillation288 271. Petroleum distillation Flow Chart289 272. Petroleum distillation290 273. Types of Distillation Processes Fractional distillation In the fractional distillation the various volatile constituents are separated at successively higher temperatures without substantial chemical change The fractions obtained yield gasoline, naphtha, kerosene and lubricating oil and the residue would be petroleum bitumen Destructive distillation The material undergoes chemical changes under the application of extreme heat and pressure 291 274. Types of Distillation Processes Steam distillation 1. Steam distillation is employed to produce steam refined petroleum bitumen without causing chemical change 2. When the residue is distilled to a definite consistency without further treatment it is called as Straight-run Bitumen 292 275. Desirable Properties of Bitumen It should be fluid enough at the time of mixing to coat the aggregate evenly by a thin film It should have low temperature susceptibility It should show uniform viscosity characteristics Bitumen should have good amount of volatiles in it, and it should not lose them excessively when subjected to higher temperature293 276. Desirable Properties of Bitumen The bitumen should be ductile and not brittle The bitumen should be capable of being heated to the temperature at which it can be easily mixed without any fire hazards The bitumen should have good affinity to the aggregate and should not be stripped off in the continued presence off water294 277. 2. Cutback Bitumen Bitumen, the viscosity of which has been reduced by a volatile dilutent Thus to increase fluidity at lower temperatures bitumen is blended with a volatile solvent After the use of cutback, the volatiles get evaporated and binding property gets developed For use in some constructions like, surface dressings, some type of bitumen macadam and soil-bitumen stabilization, it can be mixed at low temperatures 295 278. Continue. The viscosity of cutback and the rate at which it hardens on the road depend on the characteristics and quantity of both bitumen and volatile oil used as the dilutentTypes: classification based on rate of curing or hardening after application 1. Rapid Curing (RC) 2. Medium Curing (MC) 3. Slow Curing (SC) 296 279. Viscosity of Cutbacks Viscosity in seconds in tar viscometerType and grade of Cutback4mm orifice 25oCRC-0, MC-0 & SC-010mm orifice 40oC25 to 75RC-1, MC-1 & SC-110mm orifice 25oC50 to 100RC-2, MC-2 & SC-210 to 20RC-3, MC-3 & SC-325 to 75RC-4, MC-4 & SC-414 to 45RC-5, MC-5 & SC-560 to 100 297 280. Continue. Lower grade cutbacks like RC-0, RC-1 etc. would contain higher proportion of solvent RC-0 & MC-0: 45% solvent, 55% bitumen RC-5 & MC-5: 15% solvent, 85% bitumen298 281. Continue. Rapid Curing Cutbacks are bitumen's, fluxed or cutback with a petroleum distillate such as naphtha or gasoline which will rapidly evaporate after use Medium Curing Cutbacks are bitumen fluxed to greater fluidity by blending with an intermediate-boiling-point solvent like kerosene or light diesel oil Slow Curing Cutbacks are obtained either by blending bitumen with high-boiling-point gas oil, or by controlling the rate of flow and temperature of the crude during the refining299 282. 3. Bituminous Emulsion A liquid product in which substantial amount of bitumen is suspended in a finely divided condition in an aqueous medium and stabilized by means of one or more suitable materials. Two phase system, one liquid being dispersed as fine globules in the other Bitumen is broken up into fine globules and kept suspended in water Small proportion of an emulsifier is used to facilitate the formation of dispersion and to keep the globules of dispersed binder in suspension 300 283. Continue. Bitumen content of emulsion ranges from 40 to 60% and the remaining portion is water Emulsifiers usually adopted are soaps, surface active agents and colloidal powders (1.5 to 1%) Penetration values of bitumen grades that are emulsified for road construction are generally between 190-320 Manufactured emulsions stored in air tight drums Used mainly in maintenance and patch works and also in wet weather conditions 301 284. Continue. Bituminous Emulsion 1.Residue on sieving: not more than 0.25% by wt. of emulsion consists of particles greater than 0.15mm diameter2.Stability of mixing: To test if emulsion breaks down and coats the coarse aggregates with bitumen too early before mixing is complete3.Stability of mixing: To assess the stability of emulsions when the aggregate contains large proportions of fines with cement 302 285. Continue. 4.Water Cement: To know the percentage of water in the emulsion which depends on the type of the emulsion5.Sedimentation: Some sedimentation may occur when a drum of emulsion is left standing before use6. Viscosity: Should be Low enough to be sprayed through jets or to coat aggregates in simple mixing303 286. Continue. Breaking of Emulsion When applied on road, breaks down and the binder starts binding the aggregates, though the full binding power develops slowly as and when the water evaporates. First sign of breakdown is change in color of film from chocolate brown to black Rapid-set grades: Emulsion which break rapidly on coming in contact with aggregates Medium-set grades: Which do not break spontaneously on coming in contact with aggregates but break during mixing or by fine mineral dust Slow-set grades: When special emulsifying agents are used to make emulsion relatively stable 304 287. Quality Control Tests Bitumen (Normal) 1. Penetration 2. Ductility 3. Softening point 4. Specific gravity 5. Loss on heating 6. Flash & Fire point 7. Viscosity 8. Solubility Modified Bitumen (PMB, CRMB etc) 1. Elastic Recovery 2. Separation Difference 3. Tests on TFOT residue 305 288. Continue. Cutback Bitumen 1.Viscosity test using specified orifice2. 3. 4. 5.Penetration test Ductility test Solubility test Flash point test306 289. Flexible Pavements307 290. BITUMINOUS PAVEMENT CONSTRUCTION Bituminous construction are classified into four categories Interface Treatments Thin Bituminous Surfacing Bituminous Surface Courses Bituminous Binder Courses 308 291. INTERFACE TREATMENTS Prime Coat Tack Coat Crack Prevention Courses309 292. PURPOSE OF PRIMING To plug the capillary voidsTo coat and bond loose materials on the surfaceTo harden or toughen the surfaceTo promote adhesion between granular and the bituminous layer 310 293. TACK COAT Purpose of Tack Coat: To ensure a bond between the new construction and the old surfaceUse of Cutback: It should be restricted for sites at subzero temperatures or for emergency applications 311 294. WRONG PRACTICE OF TACK COAT312 295. MECHANICAL SPRAYER FOR TACK COAT313 296. INSUFFICIENT TACK COAT314 297. CRACKED SURFACEMap/Alligator CrackingTransverse Cracking315 298. BITUMINOUS SURFACE DRESSING (BSD) BSD is provided over an existing bituminous or granular surface to serve as thin wearing coat. This may be one coat or two coats. The main functions of BSD are: To serve as a thin wearing course of pavement To prevent infiltration of surface water To provide dust free pavement surface316 299. FAILURE OF SURFACE DRESSING317 300. MODERN SURFACE DRESSING SPRAYER318 301. SEAL COAT A. Liquid Seal Coat: comprising of a layer of binder followed by a cover of stone chipping B.Premixed Seal Coat: a thin application of fine aggregates premixed with bituminous binder319 302. BITUMINOUS SURFACE COURSES320 303. BITUMINOUS CONCRETE (BC) BC is a Dense Graded Bituminous Mix used as Wearing Course for Heavily Trafficked Roads 321 304. BITUMINOUS CONCRETE (BC) BC Mix consists of Coarse Aggregates, Fine Aggregates, Filler and Binder blended as per Marshall Mix Design322 305. BITUMINOUS CONCRETE (BC) Quality control operations involved are: Design of mix in laboratory, and control of mixing, laying and rolling temperatures Density, Marshall Stability, Flow, Air Voids, Bitumen Content, radiation of aggregates are controlledRiding quality is a control 323 306. Freshly Laid BC layerBC Layer after Traffic 324 Movement 307. SEMI DENSE BITUMINOUS CONCRETE (SDBC) Wearing course on roads carrying moderate traffic, generally less than 10 msa Lesser binder content when compared to BC 325 308. SDBC LAYER326 309. COMPACTION OF BITUMINOUS MIXES Lack of adequate compaction in field leads to reduce pavement life Inadequate compaction of hot mix leads to early oxidation, ravelling, cracking and disintegration before its life expectancy is achieved327 310. COMPACTION OF MIXEScontd Lack of attention to the air voids requirement of compacted dense graded bituminous mixes is the most common cause of poor pavement performance Laboratory compaction produces more density, hence 95-98% of laboratory density or 92% of theoretical density is preferred in the field 328 311. MASTIC ASPHALT Mastic Asphalt is a mixture of Bitumen, Filler and Fine Aggregates in suitable proportions designed to yield a void less compact massIt is heated to 200CIt solidifies into a dense mass on cooling to normal temperatureNo compacting effort required 329 312. SEGREGATION IN MIX Segregation due to Single Drop330 313. SEGREGATION IN BM MIX331 314. PROPER LOADING332 315. GOOD PAVEMENT SURFACE333 316. DENSE BITUMINOUS MACADAM (DBM) DBM is Closely GradedDBM is used as a Binder Course for pavements subjected to heavy trafficHydrated Lime or Cement shall be used as filler, if the mix fails to meet the water sensitivityrequirement 334 317. Wet Mix Macadam Laying and compacting clean, crushed, graded aggregate and granular material, premixed with water, to a dense mass on prepared sub-grade or existing pavement Thickness of single compacted Wet Mix Macadam layer shall not be less than 75 mm Coarse aggregate shall be crushed stone If crushed gravel is used, not less than 90% by Wt of gravel pieces retained on 4.75 mm sieve shall have at least two fractured faces If water absorption value of coarse aggregate is greater than 2%, the soundness test shall be carried out as per IS:2386(Part-5)335 318. TIMBER AS A BUILDING MATERIALDr. P. K. Bhuyan NIT Rourkela 319. INTRODUCTION WHY TIMBER AS A BUILDING MATERIAL? ENVIRONMENTALY SUPERIOR BUILDING MATERIAL 320. CLASSIFICATION OF TIMBER GROWTH OF TREES DURABILITY STRENGTH REFRACTIVENESSCLASSIFICATION ACCORDING TO IS 399 - ZONES - USES - AVAILABILITY - COMPARATIVE STRENGTH CLASS A, CLASS B, CLASS C 321. Defects in Timber Defect, in this case, means anything that effects the structural integrity or appearance of timber. 322. Things that attack timber 323. STAGES IN DEFECTS DEFECTS IN TREE DURING ITS GROWTH DEFECTS IN TREE AFTER FELLING DEFECTS IN TREE DURING SEASONING DECAY AND DISEASES IN TREE IS SPECIFICATION 1) PROHIBITED DEFECTS 2) PERMISSIBLE DEFECTS 324. DEFECTS AND DECAY IN TIMBER CENTRE HEART/HEART SHAKES BOW TWISTED GRAIN KNOTS WANE SLOPE OF GRAIN FOXINESS CUPPING 325. Defects in timber Timber is a natural material that is prone to defects. One of these is the tendency to split if it is put under stress from rapid drying or de-lamination of the growth rings. These defects are all known as Shakes Click your mouse once to continue 326. ShakesClick your mouse once to continue 327. HEART SHAKES 328. What other defects occur in timber? Blue stainsapheartpith juvenile Click your mouse once to continue 329. BOW 330. TWISTED GRAIN 331. KNOTS 332. WANE 333. SLOPE OF GRAIN 334. CUPPING DEFECTS 335. What other defects occur in timber?Insect attackClick your mouse once to continue 336. What other defects occur in timber? ShrinkageClick your mouse once to continue 337. Timber Seasoning 338. SEASONINGRemoval of moisture from timber so as to be in equilibrium with moisture in surrounding atmospheric conditions, where timber is likely to be used, is called as seasoning. 339. Timber Seasoning When timber is first felled it is known as green timber and has a very high moisture content approx 50% Before it can be used it must be dried If this process is not controlled properly defects can occur that can ruin good timber Aim of seasoning is to dry out the wood to a suitable moisture content of 22% or less 340. Reasons for Seasoning Seasoning is the controlled process of reducing the moisture content (MC) of the timber so that it is suitable for the environment and intended use. Wood will dry naturally so seasoning helps us to control the process and keep the timber more stable and more useful. Prevents splitting Prevents a lot of fungal and insect attacks It is less likely to distort or warp later After seasoning timber is easier to work with, because it is lighter, harder and stronger. 341. Influence of Relative Humidity Relative Humidity: the amount of moisture (water vapour) in the air at a given temperature, compared with the maximum amount of moisture the air could hold at the same temperature Wood will continue to shrink or grow (HYDROSCOPIC) to reach equilibrium moisture content. This means that it acclimatises to its surrounding environment. For example if a piece of timber with a moisture content of 12% is placed in a room with a moisture content of 20% the moisture level in the timber will rise until it reaches 20%. 342. OBJECTIVES OF SEASONING Seasoning improves following properties: Strength Durability Working qualities including polishing, painting, and gluing Resistance to attack of insects, fungus Proper seasoning reduces tendency to split, shrink and warp. Seasoning reduces weight of timber and is easy to handle. Timber becomes fit to receive preservative treatment 343. PREPARING TIMBER FOR SEASONING Girdling Coating with thick layers of moisture proof substance such as coal tar, bituminous paint, paraffin wax. Water seasoning 344. METHODS OF SEASONING SEASONING OF TIMBER Air Seasoning Kiln seasoning Other methods of seasoning- Chemical Seasoning 345. Air Seasoning 346. Air Seasoning With this process the timber is roughly sawn to size and stacked using spacers called stickers, with the timber stacked in the open air. Vertical spacing achieved by using timber battens (25mm) of the same species. The piling sticks should be spaced close enough to prevent bowing (600 to 900 mm centres) This allows the free movement of air. The stack should be protected from the direct influence of the elements. The ends of the beams must be painted to prevent splitting. 347. Air Seasoning Advantages No expensive equipment needed Small labour cost once stack is made Environmentally friendly- uses little energyDisadvantages Slow drying rate Large area of space required for a lot of timber Only dries the timber to approximately 20% M.C. so leaving it open to some insect and fungal attacks while it is only suitable for outdoor joinery 348. Kiln Seasoning There are two main types of kiln used in artificial seasoning Compartmental Kilns Progressive Kilns. Both methods rely on the controlled environment to dry out the timber and require the following factors: Forced air circulation by using large fans, blowers, etc. Heat of some form provided by piped steam. Humidity control provided by steam jets. The amount and duration of air, heat and humidity again depends on species, size, quantity, etc. In general, the atmosphere in the kiln at first will be cool and moist. The temperature is gradually increased and the humidity reduced until the required moisture content is achieved. 349. Compartmental Kilns This kiln is a single enclose container or building, etc. The timber is stacked same manner as air seasoning Whole stack is seasoned using a programme of settings(temperature and humidity) until the whole stack is reduced to the MC required. 350. Progressive KilnsA progressive kiln has the stack on trolleys that progressively travel through a sequence of chambers. Each chamber has varying atmospheres that change the MC of the timber stack as it travels through. Advantages of this system- has a continuous flow of seasoned timber coming off line 351. Kiln Seasoning Advantages Quicker due to higher temperatures, ventilation and air circulation Achieve a lower moisture content Defects associated with drying can be controlled Allows more precise rates of drying for various timber species and thickness of boardsDisadvantages Is expensive Requires supervision by a skilled operator Uses a lot of energy 352. Finding the MC A moisture meter is most commonly used to establish the MC of a particular batch of timber. These meters are usually attached to two probes which send an electrical signal through the wood. Water is a conductor of electricity and therefore the more water present the higher the conductivity and this can be read from the display.Another method of establishing the MC is to remove random samples from the stack. Each of the samples are placed on a micro scales and their weight recorded. The samples are then placed in an oven or microwave until the moisture has evaporated. The samples are then weighted again and their dry weight recorded. The %MC is obtained by the formulae Wet weight dry weight X 100 = %MC dry 353. Finding the MC Find the percentage moisture content of the following sample of wood given the following information; Wet weight = 224g Dry weight = 200g Wet weight dry weight X 100 = %MC dry weight 224 200 X 100 = %MC 200 24 X 100 = %MC 200 0.12 X 100 = %MC 354. Moisture Content 355. Seasoning and ShrinkageSeasoning will cause dramatic changes such as increase in strength but also distortion and shrinkage.The greatest amount of shrinkage takes place tangentially along the grain with little loss over the radial direction and along the length of the board. Because of these varying shrinkage rates, tangential boards tend to cup because of the geometry of the annual rings. Some rings are much longer than the others close to the heart. Therefore there will be more shrinkage at these parts than the others. 356. Seasoning Defects: Shakes Shakes are separation of the fibres along the grain developed in the standing tree, in felling or in seasoning. They are caused by the development of high internal stresses probably caused by the maturity of the tree. The shake is the result of stress relief and in the first place results in a single longitudinal crack from the heart and through the diameter of the tree. As the stress increases a second relief crack takes form and is shown as a double heart shake. Further cracks are known as star shakes and show the familiar pattern shown. 357. USES OF TIMBER AS A BUILDING MATERIAL BEAMS TRUSSES RAFTERS JOISTS IN FLOORS DOORS FRAME AND SHUTTERS WINDOWS FRAME AND SHUTTERS STAIR CASES POLES PILES COLUMNS 358. WOOD PRODUCTS OF TIMBER Veneers Plywood Particle board Fiber boards Batten boards : Block boards and laminated boards 359. BAMBOO AND CANE AS AN ALTERNATIVE SOURCE OFTIMBER BAMBOO AS PLYWOOD BAMBOO AS VEENERS BAMBOO AS PARTICLE BOARDS BAMBOO AS BATTENS BOARDS BAMBOO AS POST etc. 360. BAMBOO AN ENDOGENOUS TREE 361. BAMBOO A BUILDING MATERIAL 362. BAMBOO AS FLOORING MATERIAL 363. TIMBER STRUCTURES 364. TIMBER FLOOR, CEILING,WALL AND FURNITURES. 365. TIMBER AS A STRUCTURAL MEMBER 366. CONCLUSIONFOREST UTILIZATION THE GENERATION OF BY PRODUCTS DISPOSAL OF WASTE RESOURCE DEPLETION GLOBAL WARMING SYNTHESIS OF COMPOUNDS RESPONSIBLE FOR ACID RAIN 367. FERROUS METAL AND NON-FERROUS METALDr. P. K. Bhuyan NIT Rourkela 368. FERROUS METAL A metal containing iron as a primary material - Iron - Cast Iron - Steel - Stainless Steel - Wrought Iron 369. NON-FERROUS METAL A metal containing little or no iron - Aluminum - Bronze - Brass - Copper - Lead 370. IRON Iron is a metal extracted mainly from the iron ore hematite. It oxidizes readily in air and water to form Fe2O3 and is rarely found as a free element. Iron is believed to be the sixth most abundant element in the universe 371. SMELTING TECHNIQUE 372. Pig iron is the intermediate product of smelting iron ore with coke and resinCast into pigs in preparation for conversion into cast iron, wrought iron or steelPig iron has a very high carbon content, typically 3.5 - 4.5%, which makes it very brittle and not useful directly as a material except for limited applications 373. FERROUS METALS CAST IRON A hard, brittle, nonmalleable iron-based alloy containing 2%-4.5% carbon and 0.5%-3% silicon 374. FERROUS METALS CAST IRON APPLICATION: - Piping & Fittings - Ornamental Ironwork - Hardware - Base Metal for Porcelain Enameled Plumbing Fixtures - Floor & Wall Brackets for Railings - Circular Stairs - Manhole Cover - Gratings 375. FERROUS METALS WROUGHT IRON A tough, malleable, readily soft iron that is easily forged & welded. Fatigue & corrosion resistant Commercially pure iron, containing only approximately 0.2% carbon A fibrous material due to the slag inclusions, that gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure 376. FERROUS METALS WROUGHT IRON Literally means worked iron APPLICATION: - Piping & Fittings for Plumbing, Heating & Air-conditioning - Ornamental Ironwork 377. FERROUS METALS GALVANIZED IRON (G.I.) Iron coated with zinc to prevent rust. The process is achieved thru hot-dip galvanizing 378. FERROUS METALS GALVANIZED IRON APPLICATION: - Metal Decking - Roofing & Accessories - Ceiling Framing - Wall Framing - Piping 379. FERROUS METALS STEEL Alloys of iron and carbon Carbon content is no more than 2% Alloy elements is composed of phosphorous, sulfur, oxygen, nitrogen, manganese, silicon, aluminum, copper, nickel, etc. Can be wrought, rolled, cast, and welded, but not extruded 380. FERROUS METALS ALLOY ELEMENTS & ITS PURPOSE/S: 1. Aluminum for surface hardening 2. Chromium for corrosion resistance 3. Copper for resistance to atmospheric corrosion 4. Manganese in small amounts for hardening; in larger amounts for wear resistance 5. Molybdenum, combined with other alloying metals such as chromium & nickel, to increase corrosion resistance and to raise tensile strength without reducing ductility. 381. ALLOY ELEMENTS & ITS PURPOSE/S: 6. Nickel to increase tensile strength without reducing ductility; in high concentrations, to improve corrosion resistance 7. Silicon to strengthen low alloy steels and improve oxidation resistance; in larger amounts to provide hard, brittle castings resistant to corrosive chemicals 8. Sulfur for free machining, especially in mild steels 9. Titanium to prevent intergranular corrosion of stainless steels 10. Tungsten, vanadium, and cobalt for hardness and abrasion resistance 382. FERROUS METALS Types of Steel: Carbon Steel Alloy Steel - Stainless Steel - HSLA Steel (high-strength low-alloy) - Weathering Steel 383. FERROUS METALS Carbon Steel Unalloyed steel in which the residual element as carbon, manganese, phosphorus, sulfur and silicon are controlled. Any increase in carbon content increase the strength and hardness but reduces its ductility and weldability. 384. FERROUS METALS Carbon Steel APPLICATION: - Structural Steel - Concrete Reinforcement - Decking and Panels - Roofing & Accessories - Windows & Doors - Hardware 385. FERROUS METALS Carbon Steel APPLICATION: - Structural Steel I-beam W-shape S-shape Channels Angles Plates Pipes & Tubing 386. FERROUS METALS Stainless Steel An alloy steel containing a minimum of 12% chromium & additional nickel, manganese, and molybdenum alloy elements Resistance to heat, oxidation & corrosion Does not stain, corrode or rust as ordinary steel, but not stain-proof 387. FERROUS METALS Stainless Steel APPLICATION: - Exterior Wall Finishes - Interior Wall Finishes - Railings - Signage - Doors & Windows - Hardware 388. FERROUS METALS HSLA (High-Strength Low-Alloy) Steel A group of low-carbon steels containing less than 2% alloys in a chemical composition specifically developed for increase strength, ductility, & resistance to corrosion Much stronger & tougher than ordinary carbon steel 389. FERROUS METALS HSLA Steel APPLICATION: - Reinforcement for Pre-stressed Concrete - High-strength Bolts - Special Structural Steel - Cables for Elevators 390. FERROUS METALS Weathering Steel A high-strength, low-alloy steel that forms an oxide coating when exposed to rain or moisture in the atmosphere Best-known under the trademark COR-TEN steel 391. FERROUS METALS Weathering SteelAngel of the North (20x54m), Gateshead, United Kingdom 392. FERROUS METALS Tools Steel refers to a variety of carbon and alloy steels that are particularly suited to be made into tools Distinctively hard, resistance to abrasion and deformation, and has ability to hold a cutting edge 393. NNON-FERROUS METALS Aluminum Soft, non magnetic, ductile and malleable silvery white metal with thermal and electrical conductivity.Aluminium is the most abundant metal in the Earth's crust, and the third most abundant element therein, after oxygen and silicon.Used as structural framing like the high strength aluminum alloys and secondary building elements such as windows, doors, roofing, flashing, trim and hard wares. 394. Copper Ductile, malleable and bright reddish brown color with high thermal and electrical conductivity. Posses a patina weather reactive surface layer of insoluble green salt which retards corrosion and used to alloy bronze and brass to increase strength and corrosion resistance.Used as electrical wiring, piping and roofing material. Care must be taken in fastening, attaching or supported only by selected brass fittings. 395. Brass Brass is any alloy of copper and zinc. It has a muted yellow color, somewhat similar to gold. It is relatively resistant to tarnishing, and is often used as decoration and for coins. In antiquity, polished brass was often used as a mirror.Lead Lead is a soft, malleable poor metal, also considered to be one of the heavy metals. Lead has a bluish white color when freshly cut, but tarnishes to a dull grayish color when it is exposed to air and is a shiny chrome silver when melted into a liquid. . 396. Lead pipe in Roman baths 397. Tungsten carbide, or tungsten semicarbide, is a chemical compound containing tungsten and carbon, similar to titanium carbide. Tungsten carbide is often simply called carbide. 398. METAL JOINERY Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a relatively low melting point. (below 840deg F) Annealing In the cases of copper, steel, and brass this process is performed by substantially heating the material (until glowing) for a while and allowing it to cool slowly. The metal is softened and prepared for further work such as shaping, or forming. 399. Brazing is a joining process whereby a filler metal or alloy is heated to melting temperature above 450C (842F), or, by the traditional definition that has been used in the United States, above 800F (425C) and distributed between two or more close-fitting parts by capillary action.Soldering is distinguished from brazing by use of a lower melting-temperature filler metal; it is distinguished from welding by the base metals not being melted during the joining process. 400. Welding is a fabrication process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld puddle) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. 401. A rivet is a mechanical fastener. Before it is installed it consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail.Blind rivets (also known as pop rivets) The rivet assembly is inserted into a hole drilled through the parts to be joined and a specially designed tool used to draw the mandrel into the rivet. 402. PROTECTING METALS Alclad is a trademark of Alcoa used as a generic term to describe corrosion resistant Aluminum sheet formed from high-purity aluminum surface layers metallurgically bonded to high strength Aluminum Alloy core material. These sheets commonly used by the aircraft industry Sherardising is a method of galvanizing also called vapor galvanizing. A layer of zinc is applied to the metal target object by heating the object in an airtight container with zinc powder. The temperature that the container reaches does not exceed the melting point of zinc. Another method of sherardisation is to expose the intended objects to vapor from molten zinc using a reducing gas to prevent oxidation. 403. Geo-syntheticsDr. P. K. Bhuyan NIT Rourkela 404. What is geo-synthetic? A geo-synthetic has been defined by the American Society for Testing and Materials (ASTM) Committee on Geosynthetics as A planar product manufactured from polymeric material used with soil, rock, earth, or other geotechnical engineering related material as an integral part of a manmade project, structure, or system. 405. WOVEN GEOTEXTILE Uniform and regular interweaving of threads in two directions. Regular Visible Construction Pattern. Function: Soil Separation, Reinforcement, Load distribution, Filtration, Drainage Have high tensile strength and relatively low strain. 406. NON WOVEN GEOTEXTILE Formed by heat bonding, resin bonding or needle punching. No visible thread pattern. Function: Soil separation, stabilization, load distribution, but not used for reinforcement. They have high strain and stretch considerably under load. 407. Geo synthetics are classified as follows: 1. Geotextiles 2. Geogrids 3. Geonets 4. Geomembranes 5. Geosynthetic clay liners 6. Geocells/geo web members 7. Geofoam 8. Geocomposites 408. Geotextiles Geotextiles are defined as any permeable textile used with foundation soil, rock, earth, or any other geotechnical engineering-related material as an integral part of human-made project, structure, or system.CHARACTERISTICS Porous and allow flow of water through it. Most used geosynthetics. They may be either woven or non woven Available in rolls of 5-6m wide and 50-150m long. Composed of polymers like polypropylene, high density polyethylene, polyster. Function: Separation, Reinforcement, Filtration, Drainage. 409. GEOGRIDS They have open grid like configuration i.e. they have large aperture between individual ribs. They have Low strain and stretch about 2% under load. Strength is more that other common geotextiles. Function: Used exclusively for reinforcement 410. GEONETS (Geospacers) Formed by continuous parallel sets of polymeric ribs at preset angles to one another. Their design function is completely within the in-plane drainage area where they are used to convey all types of liquids. Though they are used for the drainage function but they have high tensile strength. Generally used along with one or two geotextile matter one at the top and other at the bottom to prevent soil intrusion . 411. GEOMEMBRANES Materials are relatively thin impervious sheets . Generally made from butyl rubber. Geomembrane are used more often than geotextiles. 412. GEOSYNTHETIC CLAY LINERS This is the mixed position of polymeric materials and natural soil. Factory fabricated and bentonite clay is sandwitched between 2 geotextile. Structural integrity is obtained by needle punching. Function: Containment, As Hydraulic barrier. 413. GEO CELLS/GEO WEB MEMBERS Similar to geotextiles or geogrids but have depth. Formed by High Density Polyethylene sheets. When opened form honey comb like structure and that contain soil,gravel. Allow water through it. USE: In slopes with soft sub-grade erosion control in channels 414. GEO FOAM: Large but extremely light materials with gas filled cells. Made from expanded poly styrene and extruded poly styrene by polymeric expansion process. Function: separation, lightweight fill, compressible inclusions, thermal insulation, 415. GEOCOMPOSITES This is a factory fabricated unit with two or more geosynthetic components. This is prepared to extract all the major properties of the geosynthetics into a single unit with minimum cost. Along with geosynthetic materials sometimes some non geosynthetic materials are also used. The various types of Geocomposites are :Geotextile-Geonet Composites Geotextile Geomembrane Composiets Geotextile Geogrid Composiets Geomembrane Geogrid Composite Geotextile-Polymer Core Composite 416. Advantages of Geo-synthetics Cheaper in poduct cost, transport and installation. Can be designed (predictability) Can be installed quickly with flexibility to construct during short period. Consistent over a wide range of soils Space Savings Material Quality Control - More homogeneous than soil and aggregates. Better Construction Quality Control at site Easy Material Deployment Less Environmentally Sensitive Improved performance and extended life Increased safety factor Compatible with field conditions Increased service life of flexible pavement section by a factor of 2.5 to 3.0 for weak subgrades (CBR 2%) and by 2.0 to 3.3 for moderate subgrades (CBR 4.2 to 4.5%) Increase in allowable load bearing capacity by 40 to 50% for subgrade CBR>3 and well over 50% for subgrade CBR